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| author | Ingo Molnar <mingo@elte.hu> | 2009-02-13 09:45:09 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-02-13 09:45:09 +0100 |
| commit | ab639f3593f0b5e4439d549831442c18c3baf989 (patch) | |
| tree | 118743e94e5dc86c835dbc1f1d3bf1612f4ae740 /arch/x86 | |
| parent | f8a6b2b9cee298a9663cbe38ce1eb5240987cb62 (diff) | |
| parent | 58105ef1857112a186696c9b8957020090226a28 (diff) | |
| download | linux-stable-ab639f3593f0b5e4439d549831442c18c3baf989.tar.gz linux-stable-ab639f3593f0b5e4439d549831442c18c3baf989.tar.bz2 linux-stable-ab639f3593f0b5e4439d549831442c18c3baf989.zip | |
Merge branch 'core/percpu' into x86/core
Diffstat (limited to 'arch/x86')
38 files changed, 888 insertions, 569 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 148c112c9ca4..1042d69b267d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -194,6 +194,10 @@ config X86_TRAMPOLINE depends on SMP || (64BIT && ACPI_SLEEP) default y +config X86_32_LAZY_GS + def_bool y + depends on X86_32 && !CC_STACKPROTECTOR + config KTIME_SCALAR def_bool X86_32 source "init/Kconfig" @@ -1339,7 +1343,6 @@ config CC_STACKPROTECTOR_ALL config CC_STACKPROTECTOR bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" - depends on X86_64 select CC_STACKPROTECTOR_ALL ---help--- This option turns on the -fstack-protector GCC feature. This diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 99550c407990..1836191839ee 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -70,14 +70,17 @@ else # this works around some issues with generating unwind tables in older gccs # newer gccs do it by default KBUILD_CFLAGS += -maccumulate-outgoing-args +endif - stackp := $(CONFIG_SHELL) $(srctree)/scripts/gcc-x86_64-has-stack-protector.sh - stackp-$(CONFIG_CC_STACKPROTECTOR) := $(shell $(stackp) \ - "$(CC)" "-fstack-protector -DGCC_HAS_SP" ) - stackp-$(CONFIG_CC_STACKPROTECTOR_ALL) += $(shell $(stackp) \ - "$(CC)" -fstack-protector-all ) - - KBUILD_CFLAGS += $(stackp-y) +ifdef CONFIG_CC_STACKPROTECTOR + cc_has_sp := $(srctree)/scripts/gcc-x86_$(BITS)-has-stack-protector.sh + ifeq ($(shell $(CONFIG_SHELL) $(cc_has_sp) $(CC)),y) + stackp-y := -fstack-protector + stackp-$(CONFIG_CC_STACKPROTECTOR_ALL) += -fstack-protector-all + KBUILD_CFLAGS += $(stackp-y) + else + $(warning stack protector enabled but no compiler support) + endif endif # Stackpointer is addressed different for 32 bit and 64 bit x86 diff --git a/arch/x86/include/asm/a.out-core.h b/arch/x86/include/asm/a.out-core.h index 3c601f8224be..bb70e397aa84 100644 --- a/arch/x86/include/asm/a.out-core.h +++ b/arch/x86/include/asm/a.out-core.h @@ -55,7 +55,7 @@ static inline void aout_dump_thread(struct pt_regs *regs, struct user *dump) dump->regs.ds = (u16)regs->ds; dump->regs.es = (u16)regs->es; dump->regs.fs = (u16)regs->fs; - savesegment(gs, dump->regs.gs); + dump->regs.gs = get_user_gs(regs); dump->regs.orig_ax = regs->orig_ax; dump->regs.ip = regs->ip; dump->regs.cs = (u16)regs->cs; diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index f51a3ddde01a..83c1bc8d2e8a 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -112,7 +112,7 @@ extern unsigned int vdso_enabled; * now struct_user_regs, they are different) */ -#define ELF_CORE_COPY_REGS(pr_reg, regs) \ +#define ELF_CORE_COPY_REGS_COMMON(pr_reg, regs) \ do { \ pr_reg[0] = regs->bx; \ pr_reg[1] = regs->cx; \ @@ -124,7 +124,6 @@ do { \ pr_reg[7] = regs->ds & 0xffff; \ pr_reg[8] = regs->es & 0xffff; \ pr_reg[9] = regs->fs & 0xffff; \ - savesegment(gs, pr_reg[10]); \ pr_reg[11] = regs->orig_ax; \ pr_reg[12] = regs->ip; \ pr_reg[13] = regs->cs & 0xffff; \ @@ -133,6 +132,18 @@ do { \ pr_reg[16] = regs->ss & 0xffff; \ } while (0); +#define ELF_CORE_COPY_REGS(pr_reg, regs) \ +do { \ + ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\ + pr_reg[10] = get_user_gs(regs); \ +} while (0); + +#define ELF_CORE_COPY_KERNEL_REGS(pr_reg, regs) \ +do { \ + ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\ + savesegment(gs, pr_reg[10]); \ +} while (0); + #define ELF_PLATFORM (utsname()->machine) #define set_personality_64bit() do { } while (0) diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index 52948df9cd1d..f923203dc39a 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -79,7 +79,7 @@ do { \ #ifdef CONFIG_X86_32 #define deactivate_mm(tsk, mm) \ do { \ - loadsegment(gs, 0); \ + lazy_load_gs(0); \ } while (0) #else #define deactivate_mm(tsk, mm) \ diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index 0b64af4f13ac..aee103b26d01 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -34,6 +34,12 @@ #define PER_CPU_VAR(var) per_cpu__##var #endif /* SMP */ +#ifdef CONFIG_X86_64_SMP +#define INIT_PER_CPU_VAR(var) init_per_cpu__##var +#else +#define INIT_PER_CPU_VAR(var) per_cpu__##var +#endif + #else /* ...!ASSEMBLY */ #include <linux/stringify.h> @@ -45,6 +51,22 @@ #define __percpu_arg(x) "%" #x #endif +/* + * Initialized pointers to per-cpu variables needed for the boot + * processor need to use these macros to get the proper address + * offset from __per_cpu_load on SMP. + * + * There also must be an entry in vmlinux_64.lds.S + */ +#define DECLARE_INIT_PER_CPU(var) \ + extern typeof(per_cpu_var(var)) init_per_cpu_var(var) + +#ifdef CONFIG_X86_64_SMP +#define init_per_cpu_var(var) init_per_cpu__##var +#else +#define init_per_cpu_var(var) per_cpu_var(var) +#endif + /* For arch-specific code, we can use direct single-insn ops (they * don't give an lvalue though). */ extern void __bad_percpu_size(void); diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index a6643f68fbb1..a0133838b67c 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -393,8 +393,14 @@ union irq_stack_union { }; DECLARE_PER_CPU(union irq_stack_union, irq_stack_union); +DECLARE_INIT_PER_CPU(irq_stack_union); + DECLARE_PER_CPU(char *, irq_stack_ptr); +#else /* X86_64 */ +#ifdef CONFIG_CC_STACKPROTECTOR +DECLARE_PER_CPU(unsigned long, stack_canary); #endif +#endif /* X86_64 */ extern void print_cpu_info(struct cpuinfo_x86 *); extern unsigned int xstate_size; diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index 6d34d954c228..e304b66abeea 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -28,7 +28,7 @@ struct pt_regs { int xds; int xes; int xfs; - /* int gs; */ + int xgs; long orig_eax; long eip; int xcs; @@ -50,7 +50,7 @@ struct pt_regs { unsigned long ds; unsigned long es; unsigned long fs; - /* int gs; */ + unsigned long gs; unsigned long orig_ax; unsigned long ip; unsigned long cs; diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index 1dc1b51ac623..14e0ed86a6f9 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -61,7 +61,7 @@ * * 26 - ESPFIX small SS * 27 - per-cpu [ offset to per-cpu data area ] - * 28 - unused + * 28 - stack_canary-20 [ for stack protector ] * 29 - unused * 30 - unused * 31 - TSS for double fault handler @@ -95,6 +95,13 @@ #define __KERNEL_PERCPU 0 #endif +#define GDT_ENTRY_STACK_CANARY (GDT_ENTRY_KERNEL_BASE + 16) +#ifdef CONFIG_CC_STACKPROTECTOR +#define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY * 8) +#else +#define __KERNEL_STACK_CANARY 0 +#endif + #define GDT_ENTRY_DOUBLEFAULT_TSS 31 /* diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h index 36a700acaf2b..c2d742c6e15f 100644 --- a/arch/x86/include/asm/stackprotector.h +++ b/arch/x86/include/asm/stackprotector.h @@ -1,8 +1,54 @@ +/* + * GCC stack protector support. + * + * Stack protector works by putting predefined pattern at the start of + * the stack frame and verifying that it hasn't been overwritten when + * returning from the function. The pattern is called stack canary + * and unfortunately gcc requires it to be at a fixed offset from %gs. + * On x86_64, the offset is 40 bytes and on x86_32 20 bytes. x86_64 + * and x86_32 use segment registers differently and thus handles this + * requirement differently. + * + * On x86_64, %gs is shared by percpu area and stack canary. All + * percpu symbols are zero based and %gs points to the base of percpu + * area. The first occupant of the percpu area is always + * irq_stack_union which contains stack_canary at offset 40. Userland + * %gs is always saved and restored on kernel entry and exit using + * swapgs, so stack protector doesn't add any complexity there. + * + * On x86_32, it's slightly more complicated. As in x86_64, %gs is + * used for userland TLS. Unfortunately, some processors are much + * slower at loading segment registers with different value when + * entering and leaving the kernel, so the kernel uses %fs for percpu + * area and manages %gs lazily so that %gs is switched only when + * necessary, usually during task switch. + * + * As gcc requires the stack canary at %gs:20, %gs can't be managed + * lazily if stack protector is enabled, so the kernel saves and + * restores userland %gs on kernel entry and exit. This behavior is + * controlled by CONFIG_X86_32_LAZY_GS and accessors are defined in + * system.h to hide the details. + */ + #ifndef _ASM_STACKPROTECTOR_H #define _ASM_STACKPROTECTOR_H 1 +#ifdef CONFIG_CC_STACKPROTECTOR + #include <asm/tsc.h> #include <asm/processor.h> +#include <asm/percpu.h> +#include <asm/system.h> +#include <asm/desc.h> +#include <linux/random.h> + +/* + * 24 byte read-only segment initializer for stack canary. Linker + * can't handle the address bit shifting. Address will be set in + * head_32 for boot CPU and setup_per_cpu_areas() for others. + */ +#define GDT_STACK_CANARY_INIT \ + [GDT_ENTRY_STACK_CANARY] = { { { 0x00000018, 0x00409000 } } }, /* * Initialize the stackprotector canary value. @@ -15,12 +61,9 @@ static __always_inline void boot_init_stack_canary(void) u64 canary; u64 tsc; - /* - * Build time only check to make sure the stack_canary is at - * offset 40 in the pda; this is a gcc ABI requirement - */ +#ifdef CONFIG_X86_64 BUILD_BUG_ON(offsetof(union irq_stack_union, stack_canary) != 40); - +#endif /* * We both use the random pool and the current TSC as a source * of randomness. The TSC only matters for very early init, @@ -32,7 +75,50 @@ static __always_inline void boot_init_stack_canary(void) canary += tsc + (tsc << 32UL); current->stack_canary = canary; +#ifdef CONFIG_X86_64 percpu_write(irq_stack_union.stack_canary, canary); +#else + percpu_write(stack_canary, canary); +#endif } +static inline void setup_stack_canary_segment(int cpu) +{ +#ifdef CONFIG_X86_32 + unsigned long canary = (unsigned long)&per_cpu(stack_canary, cpu) - 20; + struct desc_struct *gdt_table = get_cpu_gdt_table(cpu); + struct desc_struct desc; + + desc = gdt_table[GDT_ENTRY_STACK_CANARY]; + desc.base0 = canary & 0xffff; + desc.base1 = (canary >> 16) & 0xff; + desc.base2 = (canary >> 24) & 0xff; + write_gdt_entry(gdt_table, GDT_ENTRY_STACK_CANARY, &desc, DESCTYPE_S); +#endif +} + +static inline void load_stack_canary_segment(void) +{ +#ifdef CONFIG_X86_32 + asm("mov %0, %%gs" : : "r" (__KERNEL_STACK_CANARY) : "memory"); +#endif +} + +#else /* CC_STACKPROTECTOR */ + +#define GDT_STACK_CANARY_INIT + +/* dummy boot_init_stack_canary() is defined in linux/stackprotector.h */ + +static inline void setup_stack_canary_segment(int cpu) +{ } + +static inline void load_stack_canary_segment(void) +{ +#ifdef CONFIG_X86_32 + asm volatile ("mov %0, %%gs" : : "r" (0)); #endif +} + +#endif /* CC_STACKPROTECTOR */ +#endif /* _ASM_STACKPROTECTOR_H */ diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h index c0b0bda754ee..68b1be10cfad 100644 --- a/arch/x86/include/asm/syscalls.h +++ b/arch/x86/include/asm/syscalls.h @@ -29,21 +29,21 @@ asmlinkage int sys_get_thread_area(struct user_desc __user *); /* X86_32 only */ #ifdef CONFIG_X86_32 /* kernel/process_32.c */ -asmlinkage int sys_fork(struct pt_regs); -asmlinkage int sys_clone(struct pt_regs); -asmlinkage int sys_vfork(struct pt_regs); -asmlinkage int sys_execve(struct pt_regs); +int sys_fork(struct pt_regs *); +int sys_clone(struct pt_regs *); +int sys_vfork(struct pt_regs *); +int sys_execve(struct pt_regs *); /* kernel/signal_32.c */ asmlinkage int sys_sigsuspend(int, int, old_sigset_t); asmlinkage int sys_sigaction(int, const struct old_sigaction __user *, struct old_sigaction __user *); -asmlinkage int sys_sigaltstack(unsigned long); -asmlinkage unsigned long sys_sigreturn(unsigned long); -asmlinkage int sys_rt_sigreturn(unsigned long); +int sys_sigaltstack(struct pt_regs *); +unsigned long sys_sigreturn(struct pt_regs *); +long sys_rt_sigreturn(struct pt_regs *); /* kernel/ioport.c */ -asmlinkage long sys_iopl(unsigned long); +long sys_iopl(struct pt_regs *); /* kernel/sys_i386_32.c */ asmlinkage long sys_mmap2(unsigned long, unsigned long, unsigned long, @@ -59,8 +59,8 @@ struct oldold_utsname; asmlinkage int sys_olduname(struct oldold_utsname __user *); /* kernel/vm86_32.c */ -asmlinkage int sys_vm86old(struct pt_regs); -asmlinkage int sys_vm86(struct pt_regs); +int sys_vm86old(struct pt_regs *); +int sys_vm86(struct pt_regs *); #else /* CONFIG_X86_32 */ diff --git a/arch/x86/include/asm/system.h b/arch/x86/include/asm/system.h index c22383743f36..c00bfdbdd456 100644 --- a/arch/x86/include/asm/system.h +++ b/arch/x86/include/asm/system.h @@ -23,6 +23,20 @@ struct task_struct *__switch_to(struct task_struct *prev, #ifdef CONFIG_X86_32 +#ifdef CONFIG_CC_STACKPROTECTOR +#define __switch_canary \ + "movl %P[task_canary](%[next]), %%ebx\n\t" \ + "movl %%ebx, "__percpu_arg([stack_canary])"\n\t" +#define __switch_canary_oparam \ + , [stack_canary] "=m" (per_cpu_var(stack_canary)) +#define __switch_canary_iparam \ + , [task_canary] "i" (offsetof(struct task_struct, stack_canary)) +#else /* CC_STACKPROTECTOR */ +#define __switch_canary +#define __switch_canary_oparam +#define __switch_canary_iparam +#endif /* CC_STACKPROTECTOR */ + /* * Saving eflags is important. It switches not only IOPL between tasks, * it also protects other tasks from NT leaking through sysenter etc. @@ -44,6 +58,7 @@ do { \ "movl %[next_sp],%%esp\n\t" /* restore ESP */ \ "movl $1f,%[prev_ip]\n\t" /* save EIP */ \ "pushl %[next_ip]\n\t" /* restore EIP */ \ + __switch_canary \ "jmp __switch_to\n" /* regparm call */ \ "1:\t" \ "popl %%ebp\n\t" /* restore EBP */ \ @@ -58,6 +73,8 @@ do { \ "=b" (ebx), "=c" (ecx), "=d" (edx), \ "=S" (esi), "=D" (edi) \ \ + __switch_canary_oparam \ + \ /* input parameters: */ \ : [next_sp] "m" (next->thread.sp), \ [next_ip] "m" (next->thread.ip), \ @@ -66,6 +83,8 @@ do { \ [prev] "a" (prev), \ [next] "d" (next) \ \ + __switch_canary_iparam \ + \ : /* reloaded segment registers */ \ "memory"); \ } while (0) @@ -182,6 +201,25 @@ extern void native_load_gs_index(unsigned); #define savesegment(seg, value) \ asm("mov %%" #seg ",%0":"=r" (value) : : "memory") +/* + * x86_32 user gs accessors. + */ +#ifdef CONFIG_X86_32 +#ifdef CONFIG_X86_32_LAZY_GS +#define get_user_gs(regs) (u16)({unsigned long v; savesegment(gs, v); v;}) +#define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v)) +#define task_user_gs(tsk) ((tsk)->thread.gs) +#define lazy_save_gs(v) savesegment(gs, (v)) +#define lazy_load_gs(v) loadsegment(gs, (v)) +#else /* X86_32_LAZY_GS */ +#define get_user_gs(regs) (u16)((regs)->gs) +#define set_user_gs(regs, v) do { (regs)->gs = (v); } while (0) +#define task_user_gs(tsk) (task_pt_regs(tsk)->gs) +#define lazy_save_gs(v) do { } while (0) +#define lazy_load_gs(v) do { } while (0) +#endif /* X86_32_LAZY_GS */ +#endif /* X86_32 */ + static inline unsigned long get_limit(unsigned long segment) { unsigned long __limit; diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index cf3bb053da0b..0d5342515b86 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -41,7 +41,7 @@ dotraplinkage void do_int3(struct pt_regs *, long); dotraplinkage void do_overflow(struct pt_regs *, long); dotraplinkage void do_bounds(struct pt_regs *, long); dotraplinkage void do_invalid_op(struct pt_regs *, long); -dotraplinkage void do_device_not_available(struct pt_regs); +dotraplinkage void do_device_not_available(struct pt_regs *, long); dotraplinkage void do_coprocessor_segment_overrun(struct pt_regs *, long); dotraplinkage void do_invalid_TSS(struct pt_regs *, long); dotraplinkage void do_segment_not_present(struct pt_regs *, long); diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 0ec6de4bcb0b..b685ece89d5c 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -186,7 +186,7 @@ extern int __get_user_bad(void); #ifdef CONFIG_X86_32 -#define __put_user_asm_u64(x, addr, err) \ +#define __put_user_asm_u64(x, addr, err, errret) \ asm volatile("1: movl %%eax,0(%2)\n" \ "2: movl %%edx,4(%2)\n" \ "3:\n" \ @@ -197,7 +197,7 @@ extern int __get_user_bad(void); _ASM_EXTABLE(1b, 4b) \ _ASM_EXTABLE(2b, 4b) \ : "=r" (err) \ - : "A" (x), "r" (addr), "i" (-EFAULT), "0" (err)) + : "A" (x), "r" (addr), "i" (errret), "0" (err)) #define __put_user_asm_ex_u64(x, addr) \ asm volatile("1: movl %%eax,0(%1)\n" \ @@ -211,8 +211,8 @@ extern int __get_user_bad(void); asm volatile("call __put_user_8" : "=a" (__ret_pu) \ : "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx") #else -#define __put_user_asm_u64(x, ptr, retval) \ - __put_user_asm(x, ptr, retval, "q", "", "Zr", -EFAULT) +#define __put_user_asm_u64(x, ptr, retval, errret) \ + __put_user_asm(x, ptr, retval, "q", "", "Zr", errret) #define __put_user_asm_ex_u64(x, addr) \ __put_user_asm_ex(x, addr, "q", "", "Zr") #define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu) @@ -289,7 +289,8 @@ do { \ __put_user_asm(x, ptr, retval, "l", "k", "ir", errret); \ break; \ case 8: \ - __put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval); \ + __put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval, \ + errret); \ break; \ default: \ __put_user_bad(); \ @@ -525,8 +526,6 @@ struct __large_struct { unsigned long buf[100]; }; */ #define get_user_try uaccess_try #define get_user_catch(err) uaccess_catch(err) -#define put_user_try uaccess_try -#define put_user_catch(err) uaccess_catch(err) #define get_user_ex(x, ptr) do { \ unsigned long __gue_val; \ @@ -534,9 +533,29 @@ struct __large_struct { unsigned long buf[100]; }; (x) = (__force __typeof__(*(ptr)))__gue_val; \ } while (0) +#ifdef CONFIG_X86_WP_WORKS_OK + +#define put_user_try uaccess_try +#define put_user_catch(err) uaccess_catch(err) + #define put_user_ex(x, ptr) \ __put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) +#else /* !CONFIG_X86_WP_WORKS_OK */ + +#define put_user_try do { \ + int __uaccess_err = 0; + +#define put_user_catch(err) \ + (err) |= __uaccess_err; \ +} while (0) + +#define put_user_ex(x, ptr) do { \ + __uaccess_err |= __put_user(x, ptr); \ +} while (0) + +#endif /* CONFIG_X86_WP_WORKS_OK */ + /* * movsl can be slow when source and dest are not both 8-byte aligned */ diff --git a/arch/x86/include/asm/uv/uv.h b/arch/x86/include/asm/uv/uv.h index 8ac1d7e312f3..8242bf965812 100644 --- a/arch/x86/include/asm/uv/uv.h +++ b/arch/x86/include/asm/uv/uv.h @@ -3,6 +3,9 @@ enum uv_system_type {UV_NONE, UV_LEGACY_APIC, UV_X2APIC, UV_NON_UNIQUE_APIC}; +struct cpumask; +struct mm_struct; + #ifdef CONFIG_X86_UV extern enum uv_system_type get_uv_system_type(void); diff --git a/arch/x86/kernel/asm-offsets_32.c b/arch/x86/kernel/asm-offsets_32.c index ee4df08feee6..fbf2f33e3080 100644 --- a/arch/x86/kernel/asm-offsets_32.c +++ b/arch/x86/kernel/asm-offsets_32.c @@ -75,6 +75,7 @@ void foo(void) OFFSET(PT_DS, pt_regs, ds); OFFSET(PT_ES, pt_regs, es); OFFSET(PT_FS, pt_regs, fs); + OFFSET(PT_GS, pt_regs, gs); OFFSET(PT_ORIG_EAX, pt_regs, orig_ax); OFFSET(PT_EIP, pt_regs, ip); OFFSET(PT_CS, pt_regs, cs); diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index cbcdb796d47f..e8f4a386bd9d 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -39,6 +39,7 @@ #include <asm/sections.h> #include <asm/setup.h> #include <asm/hypervisor.h> +#include <asm/stackprotector.h> #include "cpu.h" @@ -122,6 +123,7 @@ DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = { [GDT_ENTRY_ESPFIX_SS] = { { { 0x00000000, 0x00c09200 } } }, [GDT_ENTRY_PERCPU] = { { { 0x0000ffff, 0x00cf9200 } } }, + GDT_STACK_CANARY_INIT #endif } }; EXPORT_PER_CPU_SYMBOL_GPL(gdt_page); @@ -304,6 +306,7 @@ void load_percpu_segment(int cpu) loadsegment(gs, 0); wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu)); #endif + load_stack_canary_segment(); } /* Current gdt points %fs at the "master" per-cpu area: after this, @@ -938,12 +941,8 @@ struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table }; DEFINE_PER_CPU_FIRST(union irq_stack_union, irq_stack_union) __aligned(PAGE_SIZE); -#ifdef CONFIG_SMP -DEFINE_PER_CPU(char *, irq_stack_ptr); /* will be set during per cpu init */ -#else DEFINE_PER_CPU(char *, irq_stack_ptr) = - per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64; -#endif + init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64; DEFINE_PER_CPU(unsigned long, kernel_stack) = (unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE; @@ -986,16 +985,21 @@ unsigned long kernel_eflags; */ DEFINE_PER_CPU(struct orig_ist, orig_ist); -#else +#else /* x86_64 */ -/* Make sure %fs is initialized properly in idle threads */ +#ifdef CONFIG_CC_STACKPROTECTOR +DEFINE_PER_CPU(unsigned long, stack_canary); +#endif + +/* Make sure %fs and %gs are initialized properly in idle threads */ struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs) { memset(regs, 0, sizeof(struct pt_regs)); regs->fs = __KERNEL_PERCPU; + regs->gs = __KERNEL_STACK_CANARY; return regs; } -#endif +#endif /* x86_64 */ /* * cpu_init() initializes state that is per-CPU. Some data is already @@ -1157,9 +1161,6 @@ void __cpuinit cpu_init(void) __set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss); #endif - /* Clear %gs. */ - asm volatile ("mov %0, %%gs" : : "r" (0)); - /* Clear all 6 debug registers: */ set_debugreg(0, 0); set_debugreg(0, 1); diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 65efd42454be..e99206831459 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -30,12 +30,13 @@ * 1C(%esp) - %ds * 20(%esp) - %es * 24(%esp) - %fs - * 28(%esp) - orig_eax - * 2C(%esp) - %eip - * 30(%esp) - %cs - * 34(%esp) - %eflags - * 38(%esp) - %oldesp - * 3C(%esp) - %oldss + * 28(%esp) - %gs saved iff !CONFIG_X86_32_LAZY_GS + * 2C(%esp) - orig_eax + * 30(%esp) - %eip + * 34(%esp) - %cs + * 38(%esp) - %eflags + * 3C(%esp) - %oldesp + * 40(%esp) - %oldss * * "current" is in register %ebx during any slow entries. */ @@ -101,121 +102,221 @@ #define resume_userspace_sig resume_userspace #endif -#define SAVE_ALL \ - cld; \ - pushl %fs; \ - CFI_ADJUST_CFA_OFFSET 4;\ - /*CFI_REL_OFFSET fs, 0;*/\ - pushl %es; \ - CFI_ADJUST_CFA_OFFSET 4;\ - /*CFI_REL_OFFSET es, 0;*/\ - pushl %ds; \ - CFI_ADJUST_CFA_OFFSET 4;\ - /*CFI_REL_OFFSET ds, 0;*/\ - pushl %eax; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET eax, 0;\ - pushl %ebp; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET ebp, 0;\ - pushl %edi; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET edi, 0;\ - pushl %esi; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET esi, 0;\ - pushl %edx; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET edx, 0;\ - pushl %ecx; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET ecx, 0;\ - pushl %ebx; \ - CFI_ADJUST_CFA_OFFSET 4;\ - CFI_REL_OFFSET ebx, 0;\ - movl $(__USER_DS), %edx; \ - movl %edx, %ds; \ - movl %edx, %es; \ - movl $(__KERNEL_PERCPU), %edx; \ +/* + * User gs save/restore + * + * %gs is used for userland TLS and kernel only uses it for stack + * canary which is required to be at %gs:20 by gcc. Read the comment + * at the top of stackprotector.h for more info. + * + * Local labels 98 and 99 are used. + */ +#ifdef CONFIG_X86_32_LAZY_GS + + /* unfortunately push/pop can't be no-op */ +.macro PUSH_GS + pushl $0 + CFI_ADJUST_CFA_OFFSET 4 +.endm +.macro POP_GS pop=0 + addl $(4 + \pop), %esp + CFI_ADJUST_CFA_OFFSET -(4 + \pop) +.endm +.macro POP_GS_EX +.endm + + /* all the rest are no-op */ +.macro PTGS_TO_GS +.endm +.macro PTGS_TO_GS_EX +.endm +.macro GS_TO_REG reg +.endm +.macro REG_TO_PTGS reg +.endm +.macro SET_KERNEL_GS reg +.endm + +#else /* CONFIG_X86_32_LAZY_GS */ + +.macro PUSH_GS + pushl %gs + CFI_ADJUST_CFA_OFFSET 4 + /*CFI_REL_OFFSET gs, 0*/ +.endm + +.macro POP_GS pop=0 +98: popl %gs + CFI_ADJUST_CFA_OFFSET -4 + /*CFI_RESTORE gs*/ + .if \pop <> 0 + add $\pop, %esp + CFI_ADJUST_CFA_OFFSET -\pop + .endif +.endm +.macro POP_GS_EX +.pushsection .fixup, "ax" +99: movl $0, (%esp) + jmp 98b +.section __ex_table, "a" + .align 4 + .long 98b, 99b +.popsection +.endm + +.macro PTGS_TO_GS +98: mov PT_GS(%esp), %gs +.endm +.macro PTGS_TO_GS_EX +.pushsection .fixup, "ax" +99: movl $0, PT_GS(%esp) + jmp 98b +.section __ex_table, "a" + .align 4 + .long 98b, 99b +.popsection +.endm + +.macro GS_TO_REG reg + movl %gs, \reg + /*CFI_REGISTER gs, \reg*/ +.endm +.macro REG_TO_PTGS reg + movl \reg, PT_GS(%esp) + /*CFI_REL_OFFSET gs, PT_GS*/ +.endm +.macro SET_KERNEL_GS reg + movl $(__KERNEL_STACK_CANARY), \reg + movl \reg, %gs +.endm + +#endif /* CONFIG_X86_32_LAZY_GS */ + +.macro SAVE_ALL + cld + PUSH_GS + pushl %fs + CFI_ADJUST_CFA_OFFSET 4 + /*CFI_REL_OFFSET fs, 0;*/ + pushl %es + CFI_ADJUST_CFA_OFFSET 4 + /*CFI_REL_OFFSET es, 0;*/ + pushl %ds + CFI_ADJUST_CFA_OFFSET 4 + /*CFI_REL_OFFSET ds, 0;*/ + pushl %eax + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET eax, 0 + pushl %ebp + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET ebp, 0 + pushl %edi + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET edi, 0 + pushl %esi + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET esi, 0 + pushl %edx + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET edx, 0 + pushl %ecx + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET ecx, 0 + pushl %ebx + CFI_ADJUST_CFA_OFFSET 4 + CFI_REL_OFFSET ebx, 0 + movl $(__USER_DS), %edx + movl %edx, %ds + movl %edx, %es + movl $(__KERNEL_PERCPU), %edx movl %edx, %fs + SET_KERNEL_GS %edx +.endm -#define RESTORE_INT_REGS \ - popl %ebx; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE ebx;\ - popl %ecx; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE ecx;\ - popl %edx; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE edx;\ - popl %esi; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE esi;\ - popl %edi; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE edi;\ - popl %ebp; \ - CFI_ADJUST_CFA_OFFSET -4;\ - CFI_RESTORE ebp;\ - popl %eax; \ - CFI_ADJUST_CFA_OFFSET -4;\ +.macro RESTORE_INT_REGS + popl %ebx + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE ebx + popl %ecx + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE ecx + popl %edx + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE edx + popl %esi + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE esi + popl %edi + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE edi + popl %ebp + CFI_ADJUST_CFA_OFFSET -4 + CFI_RESTORE ebp + popl %eax + CFI_ADJUST_CFA_OFFSET -4 CFI_RESTORE eax +.endm -#define RESTORE_REGS \ - RESTORE_INT_REGS; \ -1: popl %ds; \ - CFI_ADJUST_CFA_OFFSET -4;\ - /*CFI_RESTORE ds;*/\ -2: popl %es; \ - CFI_ADJUST_CFA_OFFSET -4;\ - /*CFI_RESTORE es;*/\ -3: popl %fs; \ - CFI_ADJUST_CFA_OFFSET -4;\ - /*CFI_RESTORE fs;*/\ -.pushsection .fixup,"ax"; \ -4: movl $0,(%esp); \ - jmp 1b; \ -5: movl $0,(%esp); \ - jmp 2b; \ -6: movl $0,(%esp); \ - jmp 3b; \ -.section __ex_table,"a";\ - .align 4; \ - .long 1b,4b; \ - .long 2b,5b; \ - .long 3b,6b; \ +.macro RESTORE_REGS pop=0 + RESTORE_INT_REGS +1: popl %ds + CFI_ADJUST_CFA_OFFSET -4 + /*CFI_RESTORE ds;*/ +2: popl %es + CFI_ADJUST_CFA_OFFSET -4 + /*CFI_RESTORE es;*/ +3: popl %fs + CFI_ADJUST_CFA_OFFSET -4 + /*CFI_RESTORE fs;*/ + POP_GS \pop +.pushsection .fixup, "ax" +4: movl $0, (%esp) + jmp 1b +5: movl $0, (%esp) + jmp 2b +6: movl $0, (%esp) + jmp 3b +.section __ex_table, "a" + .align 4 + .long 1b, 4b + .long 2b, 5b + .long 3b, 6b .popsection + POP_GS_EX +.endm -#define RING0_INT_FRAME \ - CFI_STARTPROC simple;\ - CFI_SIGNAL_FRAME;\ - CFI_DEF_CFA esp, 3*4;\ - /*CFI_OFFSET cs, -2*4;*/\ +.macro RING0_INT_FRAME + CFI_STARTPROC simple + CFI_SIGNAL_FRAME + CFI_DEF_CFA esp, 3*4 + /*CFI_OFFSET cs, -2*4;*/ CFI_OFFSET eip, -3*4 +.endm -#define RING0_EC_FRAME \ - CFI_STARTPROC simple;\ - CFI_SIGNAL_FRAME;\ - CFI_DEF_CFA esp, 4*4;\ - /*CFI_OFFSET cs, -2*4;*/\ +.macro RING0_EC_FRAME + CFI_STARTPROC simple + CFI_SIGNAL_FRAME + CFI_DEF_CFA esp, 4*4 + /*CFI_OFFSET cs, -2*4;*/ CFI_OFFSET eip, -3*4 +.endm -#define RING0_PTREGS_FRAME \ - CFI_STARTPROC simple;\ - CFI_SIGNAL_FRAME;\ - CFI_DEF_CFA esp, PT_OLDESP-PT_EBX;\ - /*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/\ - CFI_OFFSET eip, PT_EIP-PT_OLDESP;\ - /*CFI_OFFSET es, PT_ES-PT_OLDESP;*/\ - /*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/\ - CFI_OFFSET eax, PT_EAX-PT_OLDESP;\ - CFI_OFFSET ebp, PT_EBP-PT_OLDESP;\ - CFI_OFFSET edi, PT_EDI-PT_OLDESP;\ - CFI_OFFSET esi, PT_ESI-PT_OLDESP;\ - CFI_OFFSET edx, PT_EDX-PT_OLDESP;\ - CFI_OFFSET ecx, PT_ECX-PT_OLDESP;\ +.macro RING0_PTREGS_FRAME + CFI_STARTPROC simple + CFI_SIGNAL_FRAME + CFI_DEF_CFA esp, PT_OLDESP-PT_EBX + /*CFI_OFFSET cs, PT_CS-PT_OLDESP;*/ + CFI_OFFSET eip, PT_EIP-PT_OLDESP + /*CFI_OFFSET es, PT_ES-PT_OLDESP;*/ + /*CFI_OFFSET ds, PT_DS-PT_OLDESP;*/ + CFI_OFFSET eax, PT_EAX-PT_OLDESP + CFI_OFFSET ebp, PT_EBP-PT_OLDESP + CFI_OFFSET edi, PT_EDI-PT_OLDESP + CFI_OFFSET esi, PT_ESI-PT_OLDESP + CFI_OFFSET edx, PT_EDX-PT_OLDESP + CFI_OFFSET ecx, PT_ECX-PT_OLDESP CFI_OFFSET ebx, PT_EBX-PT_OLDESP +.endm ENTRY(ret_from_fork) CFI_STARTPROC @@ -362,6 +463,7 @@ sysenter_exit: xorl %ebp,%ebp TRACE_IRQS_ON 1: mov PT_FS(%esp), %fs + PTGS_TO_GS ENABLE_INTERRUPTS_SYSEXIT #ifdef CONFIG_AUDITSYSCALL @@ -410,6 +512,7 @@ sysexit_audit: .align 4 .long 1b,2b .popsection + PTGS_TO_GS_EX ENDPROC(ia32_sysenter_target) # system call handler stub @@ -452,8 +555,7 @@ restore_all: restore_nocheck: TRACE_IRQS_IRET restore_nocheck_notrace: - RESTORE_REGS - addl $4, %esp # skip orig_eax/error_code + RESTORE_REGS 4 # skip orig_eax/error_code CFI_ADJUST_CFA_OFFSET -4 irq_return: INTERRUPT_RETURN @@ -595,28 +697,50 @@ syscall_badsys: END(syscall_badsys) CFI_ENDPROC -#define FIXUP_ESPFIX_STACK \ - /* since we are on a wrong stack, we cant make it a C code :( */ \ - PER_CPU(gdt_page, %ebx); \ - GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah); \ - addl %esp, %eax; \ - pushl $__KERNEL_DS; \ - CFI_ADJUST_CFA_OFFSET 4; \ - pushl %eax; \ - CFI_ADJUST_CFA_OFFSET 4; \ - lss (%esp), %esp; \ - CFI_ADJUST_CFA_OFFSET -8; -#define UNWIND_ESPFIX_STACK \ - movl %ss, %eax; \ - /* see if on espfix stack */ \ - cmpw $__ESPFIX_SS, %ax; \ - jne 27f; \ - movl $__KERNEL_DS, %eax; \ - movl %eax, %ds; \ - movl %eax, %es; \ - /* switch to normal stack */ \ - FIXUP_ESPFIX_STACK; \ -27:; +/* + * System calls that need a pt_regs pointer. + */ +#define PTREGSCALL(name) \ + ALIGN; \ +ptregs_##name: \ + leal 4(%esp),%eax; \ + jmp sys_##name; + +PTREGSCALL(iopl) +PTREGSCALL(fork) +PTREGSCALL(clone) +PTREGSCALL(vfork) +PTREGSCALL(execve) +PTREGSCALL(sigaltstack) +PTREGSCALL(sigreturn) +PTREGSCALL(rt_sigreturn) +PTREGSCALL(vm86) +PTREGSCALL(vm86old) + +.macro FIXUP_ESPFIX_STACK + /* since we are on a wrong stack, we cant make it a C code :( */ + PER_CPU(gdt_page, %ebx) + GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah) + addl %esp, %eax + pushl $__KERNEL_DS + CFI_ADJUST_CFA_OFFSET 4 + pushl %eax + CFI_ADJUST_CFA_OFFSET 4 + lss (%esp), %esp + CFI_ADJUST_CFA_OFFSET -8 +.endm +.macro UNWIND_ESPFIX_STACK + movl %ss, %eax + /* see if on espfix stack */ + cmpw $__ESPFIX_SS, %ax + jne 27f + movl $__KERNEL_DS, %eax + movl %eax, %ds + movl %eax, %es + /* switch to normal stack */ + FIXUP_ESPFIX_STACK +27: +.endm /* * Build the entry stubs and pointer table with some assembler magic. @@ -1070,7 +1194,10 @@ ENTRY(page_fault) CFI_ADJUST_CFA_OFFSET 4 ALIGN error_code: - /* the function address is in %fs's slot on the stack */ + /* the function address is in %gs's slot on the stack */ + pushl %fs + CFI_ADJUST_CFA_OFFSET 4 + /*CFI_REL_OFFSET fs, 0*/ pushl %es CFI_ADJUST_CFA_OFFSET 4 /*CFI_REL_OFFSET es, 0*/ @@ -1099,20 +1226,15 @@ error_code: CFI_ADJUST_CFA_OFFSET 4 CFI_REL_OFFSET ebx, 0 cld - pushl %fs - CFI_ADJUST_CFA_OFFSET 4 - /*CFI_REL_OFFSET fs, 0*/ movl $(__KERNEL_PERCPU), %ecx movl %ecx, %fs UNWIND_ESPFIX_STACK - popl %ecx - CFI_ADJUST_CFA_OFFSET -4 - /*CFI_REGISTER es, ecx*/ - movl PT_FS(%esp), %edi # get the function address + GS_TO_REG %ecx + movl PT_GS(%esp), %edi # get the function address movl PT_ORIG_EAX(%esp), %edx # get the error code movl $-1, PT_ORIG_EAX(%esp) # no syscall to restart - mov %ecx, PT_FS(%esp) - /*CFI_REL_OFFSET fs, ES*/ + REG_TO_PTGS %ecx + SET_KERNEL_GS %ecx movl $(__USER_DS), %ecx movl %ecx, %ds movl %ecx, %es @@ -1136,26 +1258,27 @@ END(page_fault) * by hand onto the new stack - while updating the return eip past * the instruction that would have done it for sysenter. */ -#define FIX_STACK(offset, ok, label) \ - cmpw $__KERNEL_CS,4(%esp); \ - jne ok; \ -label: \ - movl TSS_sysenter_sp0+offset(%esp),%esp; \ - CFI_DEF_CFA esp, 0; \ - CFI_UNDEFINED eip; \ - pushfl; \ - CFI_ADJUST_CFA_OFFSET 4; \ - pushl $__KERNEL_CS; \ - CFI_ADJUST_CFA_OFFSET 4; \ - pushl $sysenter_past_esp; \ - CFI_ADJUST_CFA_OFFSET 4; \ +.macro FIX_STACK offset ok label + cmpw $__KERNEL_CS, 4(%esp) + jne \ok +\label: + movl TSS_sysenter_sp0 + \offset(%esp), %esp + CFI_DEF_CFA esp, 0 + CFI_UNDEFINED eip + pushfl + CFI_ADJUST_CFA_OFFSET 4 + pushl $__KERNEL_CS + CFI_ADJUST_CFA_OFFSET 4 + pushl $sysenter_past_esp + CFI_ADJUST_CFA_OFFSET 4 CFI_REL_OFFSET eip, 0 +.endm ENTRY(debug) RING0_INT_FRAME cmpl $ia32_sysenter_target,(%esp) jne debug_stack_correct - FIX_STACK(12, debug_stack_correct, debug_esp_fix_insn) + FIX_STACK 12, debug_stack_correct, debug_esp_fix_insn debug_stack_correct: pushl $-1 # mark this as an int CFI_ADJUST_CFA_OFFSET 4 @@ -1213,7 +1336,7 @@ nmi_stack_correct: nmi_stack_fixup: RING0_INT_FRAME - FIX_STACK(12,nmi_stack_correct, 1) + FIX_STACK 12, nmi_stack_correct, 1 jmp nmi_stack_correct nmi_debug_stack_check: @@ -1224,7 +1347,7 @@ nmi_debug_stack_check: jb nmi_stack_correct cmpl $debug_esp_fix_insn,(%esp) ja nmi_stack_correct - FIX_STACK(24,nmi_stack_correct, 1) + FIX_STACK 24, nmi_stack_correct, 1 jmp nmi_stack_correct nmi_espfix_stack: diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 722464c520cf..2a0aad7718d5 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -19,6 +19,7 @@ #include <asm/asm-offsets.h> #include <asm/setup.h> #include <asm/processor-flags.h> +#include <asm/percpu.h> /* Physical address */ #define pa(X) ((X) - __PAGE_OFFSET) @@ -437,8 +438,26 @@ is386: movl $2,%ecx # set MP movl $(__KERNEL_PERCPU), %eax movl %eax,%fs # set this cpu's percpu - xorl %eax,%eax # Clear GS and LDT +#ifdef CONFIG_CC_STACKPROTECTOR + /* + * The linker can't handle this by relocation. Manually set + * base address in stack canary segment descriptor. + */ + cmpb $0,ready + jne 1f + movl $per_cpu__gdt_page,%eax + movl $per_cpu__stack_canary,%ecx + subl $20, %ecx + movw %cx, 8 * GDT_ENTRY_STACK_CANARY + 2(%eax) + shrl $16, %ecx + movb %cl, 8 * GDT_ENTRY_STACK_CANARY + 4(%eax) + movb %ch, 8 * GDT_ENTRY_STACK_CANARY + 7(%eax) +1: +#endif + movl $(__KERNEL_STACK_CANARY),%eax movl %eax,%gs + + xorl %eax,%eax # Clear LDT lldt %ax cld # gcc2 wants the direction flag cleared at all times diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index a0a2b5ca9b7d..2e648e3a5ea4 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -205,19 +205,6 @@ ENTRY(secondary_startup_64) pushq $0 popfq -#ifdef CONFIG_SMP - /* - * Fix up static pointers that need __per_cpu_load added. The assembler - * is unable to do this directly. This is only needed for the boot cpu. - * These values are set up with the correct base addresses by C code for - * secondary cpus. - */ - movq initial_gs(%rip), %rax - cmpl $0, per_cpu__cpu_number(%rax) - jne 1f - addq %rax, early_gdt_descr_base(%rip) -1: -#endif /* * We must switch to a new descriptor in kernel space for the GDT * because soon the kernel won't have access anymore to the userspace @@ -275,11 +262,7 @@ ENTRY(secondary_startup_64) ENTRY(initial_code) .quad x86_64_start_kernel ENTRY(initial_gs) -#ifdef CONFIG_SMP - .quad __per_cpu_load -#else - .quad PER_CPU_VAR(irq_stack_union) -#endif + .quad INIT_PER_CPU_VAR(irq_stack_union) __FINITDATA ENTRY(stack_start) @@ -425,7 +408,7 @@ NEXT_PAGE(level2_spare_pgt) early_gdt_descr: .word GDT_ENTRIES*8-1 early_gdt_descr_base: - .quad per_cpu__gdt_page + .quad INIT_PER_CPU_VAR(gdt_page) ENTRY(phys_base) /* This must match the first entry in level2_kernel_pgt */ diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c index b12208f4dfee..e41980a373ab 100644 --- a/arch/x86/kernel/ioport.c +++ b/arch/x86/kernel/ioport.c @@ -131,9 +131,8 @@ static int do_iopl(unsigned int level, struct pt_regs *regs) } #ifdef CONFIG_X86_32 -asmlinkage long sys_iopl(unsigned long regsp) +long sys_iopl(struct pt_regs *regs) { - struct pt_regs *regs = (struct pt_regs *)®sp; unsigned int level = regs->bx; struct thread_struct *t = ¤t->thread; int rc; diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 1a1ae8edc40c..fec79ad85dc6 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -11,6 +11,7 @@ #include <stdarg.h> +#include <linux/stackprotector.h> #include <linux/cpu.h> #include <linux/errno.h> #include <linux/sched.h> @@ -91,6 +92,15 @@ void cpu_idle(void) { int cpu = smp_processor_id(); + /* + * If we're the non-boot CPU, nothing set the stack canary up + * for us. CPU0 already has it initialized but no harm in + * doing it again. This is a good place for updating it, as + * we wont ever return from this function (so the invalid + * canaries already on the stack wont ever trigger). + */ + boot_init_stack_canary(); + current_thread_info()->status |= TS_POLLING; /* endless idle loop with no priority at all */ @@ -131,7 +141,7 @@ void __show_regs(struct pt_regs *regs, int all) if (user_mode_vm(regs)) { sp = regs->sp; ss = regs->ss & 0xffff; - savesegment(gs, gs); + gs = get_user_gs(regs); } else { sp = (unsigned long) (®s->sp); savesegment(ss, ss); @@ -212,6 +222,7 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) regs.ds = __USER_DS; regs.es = __USER_DS; regs.fs = __KERNEL_PERCPU; + regs.gs = __KERNEL_STACK_CANARY; regs.orig_ax = -1; regs.ip = (unsigned long) kernel_thread_helper; regs.cs = __KERNEL_CS | get_kernel_rpl(); @@ -304,7 +315,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, p->thread.ip = (unsigned long) ret_from_fork; - savesegment(gs, p->thread.gs); + task_user_gs(p) = get_user_gs(regs); tsk = current; if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) { @@ -342,7 +353,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, void start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) { - __asm__("movl %0, %%gs" : : "r"(0)); + set_user_gs(regs, 0); regs->fs = 0; set_fs(USER_DS); regs->ds = __USER_DS; @@ -539,7 +550,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) * used %fs or %gs (it does not today), or if the kernel is * running inside of a hypervisor layer. */ - savesegment(gs, prev->gs); + lazy_save_gs(prev->gs); /* * Load the per-thread Thread-Local Storage descriptor. @@ -585,31 +596,31 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) * Restore %gs if needed (which is common) */ if (prev->gs | next->gs) - loadsegment(gs, next->gs); + lazy_load_gs(next->gs); percpu_write(current_task, next_p); return prev_p; } -asmlinkage int sys_fork(struct pt_regs regs) +int sys_fork(struct pt_regs *regs) { - return do_fork(SIGCHLD, regs.sp, ®s, 0, NULL, NULL); + return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL); } -asmlinkage int sys_clone(struct pt_regs regs) +int sys_clone(struct pt_regs *regs) { unsigned long clone_flags; unsigned long newsp; int __user *parent_tidptr, *child_tidptr; - clone_flags = regs.bx; - newsp = regs.cx; - parent_tidptr = (int __user *)regs.dx; - child_tidptr = (int __user *)regs.di; + clone_flags = regs->bx; + newsp = regs->cx; + parent_tidptr = (int __user *)regs->dx; + child_tidptr = (int __user *)regs->di; if (!newsp) - newsp = regs.sp; - return do_fork(clone_flags, newsp, ®s, 0, parent_tidptr, child_tidptr); + newsp = regs->sp; + return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr); } /* @@ -622,27 +633,27 @@ asmlinkage int sys_clone(struct pt_regs regs) * do not have enough call-clobbered registers to hold all * the information you need. */ -asmlinkage int sys_vfork(struct pt_regs regs) +int sys_vfork(struct pt_regs *regs) { - return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.sp, ®s, 0, NULL, NULL); + return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0, NULL, NULL); } /* * sys_execve() executes a new program. */ -asmlinkage int sys_execve(struct pt_regs regs) +int sys_execve(struct pt_regs *regs) { int error; char *filename; - filename = getname((char __user *) regs.bx); + filename = getname((char __user *) regs->bx); error = PTR_ERR(filename); if (IS_ERR(filename)) goto out; error = do_execve(filename, - (char __user * __user *) regs.cx, - (char __user * __user *) regs.dx, - ®s); + (char __user * __user *) regs->cx, + (char __user * __user *) regs->dx, + regs); if (error == 0) { /* Make sure we don't return using sysenter.. */ set_thread_flag(TIF_IRET); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 8eb169e45584..836ef6575f01 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -120,12 +120,11 @@ void cpu_idle(void) current_thread_info()->status |= TS_POLLING; /* - * If we're the non-boot CPU, nothing set the PDA stack - * canary up for us - and if we are the boot CPU we have - * a 0 stack canary. This is a good place for updating - * it, as we wont ever return from this function (so the - * invalid canaries already on the stack wont ever - * trigger): + * If we're the non-boot CPU, nothing set the stack canary up + * for us. CPU0 already has it initialized but no harm in + * doing it again. This is a good place for updating it, as + * we wont ever return from this function (so the invalid + * canaries already on the stack wont ever trigger). */ boot_init_stack_canary(); diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 0a5df5f82fb9..7ec39ab37a2d 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -75,10 +75,7 @@ static inline bool invalid_selector(u16 value) static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno) { BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0); - regno >>= 2; - if (regno > FS) - --regno; - return ®s->bx + regno; + return ®s->bx + (regno >> 2); } static u16 get_segment_reg(struct task_struct *task, unsigned long offset) @@ -90,9 +87,10 @@ static u16 get_segment_reg(struct task_struct *task, unsigned long offset) if (offset != offsetof(struct user_regs_struct, gs)) retval = *pt_regs_access(task_pt_regs(task), offset); else { - retval = task->thread.gs; if (task == current) - savesegment(gs, retval); + retval = get_user_gs(task_pt_regs(task)); + else + retval = task_user_gs(task); } return retval; } @@ -126,13 +124,10 @@ static int set_segment_reg(struct task_struct *task, break; case offsetof(struct user_regs_struct, gs): - task->thread.gs = value; if (task == current) - /* - * The user-mode %gs is not affected by - * kernel entry, so we must update the CPU. - */ - loadsegment(gs, value); + set_user_gs(task_pt_regs(task), value); + else + task_user_gs(task) = value; } return 0; diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index ef91747bbed5..d992e6cff730 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -16,6 +16,7 @@ #include <asm/proto.h> #include <asm/cpumask.h> #include <asm/cpu.h> +#include <asm/stackprotector.h> #ifdef CONFIG_DEBUG_PER_CPU_MAPS # define DBG(x...) printk(KERN_DEBUG x) @@ -95,6 +96,7 @@ void __init setup_per_cpu_areas(void) per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu); per_cpu(cpu_number, cpu) = cpu; setup_percpu_segment(cpu); + setup_stack_canary_segment(cpu); /* * Copy data used in early init routines from the * initial arrays to the per cpu data areas. These diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 7fc78b019815..7cdcd16885ed 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -50,27 +50,23 @@ # define FIX_EFLAGS __FIX_EFLAGS #endif -#define COPY(x) { \ - get_user_ex(regs->x, &sc->x); \ -} +#define COPY(x) do { \ + get_user_ex(regs->x, &sc->x); \ +} while (0) -#define COPY_SEG(seg) { \ - unsigned short tmp; \ - get_user_ex(tmp, &sc->seg); \ - regs->seg = tmp; \ -} +#define GET_SEG(seg) ({ \ + unsigned short tmp; \ + get_user_ex(tmp, &sc->seg); \ + tmp; \ +}) -#define COPY_SEG_CPL3(seg) { \ - unsigned short tmp; \ - get_user_ex(tmp, &sc->seg); \ - regs->seg = tmp | 3; \ -} +#define COPY_SEG(seg) do { \ + regs->seg = GET_SEG(seg); \ +} while (0) -#define GET_SEG(seg) { \ - unsigned short tmp; \ - get_user_ex(tmp, &sc->seg); \ - loadsegment(seg, tmp); \ -} +#define COPY_SEG_CPL3(seg) do { \ + regs->seg = GET_SEG(seg) | 3; \ +} while (0) static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, @@ -86,7 +82,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, get_user_try { #ifdef CONFIG_X86_32 - GET_SEG(gs); + set_user_gs(regs, GET_SEG(gs)); COPY_SEG(fs); COPY_SEG(es); COPY_SEG(ds); @@ -138,12 +134,7 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, put_user_try { #ifdef CONFIG_X86_32 - { - unsigned int tmp; - - savesegment(gs, tmp); - put_user_ex(tmp, (unsigned int __user *)&sc->gs); - } + put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs); put_user_ex(regs->fs, (unsigned int __user *)&sc->fs); put_user_ex(regs->es, (unsigned int __user *)&sc->es); put_user_ex(regs->ds, (unsigned int __user *)&sc->ds); @@ -558,14 +549,9 @@ sys_sigaction(int sig, const struct old_sigaction __user *act, #endif /* CONFIG_X86_32 */ #ifdef CONFIG_X86_32 -asmlinkage int sys_sigaltstack(unsigned long bx) +int sys_sigaltstack(struct pt_regs *regs) { - /* - * This is needed to make gcc realize it doesn't own the - * "struct pt_regs" - */ - struct pt_regs *regs = (struct pt_regs *)&bx; - const stack_t __user *uss = (const stack_t __user *)bx; + const stack_t __user *uss = (const stack_t __user *)regs->bx; stack_t __user *uoss = (stack_t __user *)regs->cx; return do_sigaltstack(uss, uoss, regs->sp); @@ -583,14 +569,12 @@ sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, * Do a signal return; undo the signal stack. */ #ifdef CONFIG_X86_32 -asmlinkage unsigned long sys_sigreturn(unsigned long __unused) +unsigned long sys_sigreturn(struct pt_regs *regs) { struct sigframe __user *frame; - struct pt_regs *regs; unsigned long ax; sigset_t set; - regs = (struct pt_regs *) &__unused; frame = (struct sigframe __user *)(regs->sp - 8); if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) @@ -617,7 +601,7 @@ badframe: } #endif /* CONFIG_X86_32 */ -static long do_rt_sigreturn(struct pt_regs *regs) +long sys_rt_sigreturn(struct pt_regs *regs) { struct rt_sigframe __user *frame; unsigned long ax; @@ -648,25 +632,6 @@ badframe: return 0; } -#ifdef CONFIG_X86_32 -/* - * Note: do not pass in pt_regs directly as with tail-call optimization - * GCC will incorrectly stomp on the caller's frame and corrupt user-space - * register state: - */ -asmlinkage int sys_rt_sigreturn(unsigned long __unused) -{ - struct pt_regs *regs = (struct pt_regs *)&__unused; - - return do_rt_sigreturn(regs); -} -#else /* !CONFIG_X86_32 */ -asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) -{ - return do_rt_sigreturn(regs); -} -#endif /* CONFIG_X86_32 */ - /* * OK, we're invoking a handler: */ diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/syscall_table_32.S index e2e86a08f31d..3bdb64829b82 100644 --- a/arch/x86/kernel/syscall_table_32.S +++ b/arch/x86/kernel/syscall_table_32.S @@ -1,7 +1,7 @@ ENTRY(sys_call_table) .long sys_restart_syscall /* 0 - old "setup()" system call, used for restarting */ .long sys_exit - .long sys_fork + .long ptregs_fork .long sys_read .long sys_write .long sys_open /* 5 */ @@ -10,7 +10,7 @@ ENTRY(sys_call_table) .long sys_creat .long sys_link .long sys_unlink /* 10 */ - .long sys_execve + .long ptregs_execve .long sys_chdir .long sys_time .long sys_mknod @@ -109,17 +109,17 @@ ENTRY(sys_call_table) .long sys_newlstat .long sys_newfstat .long sys_uname - .long sys_iopl /* 110 */ + .long ptregs_iopl /* 110 */ .long sys_vhangup .long sys_ni_syscall /* old "idle" system call */ - .long sys_vm86old + .long ptregs_vm86old .long sys_wait4 .long sys_swapoff /* 115 */ .long sys_sysinfo .long sys_ipc .long sys_fsync - .long sys_sigreturn - .long sys_clone /* 120 */ + .long ptregs_sigreturn + .long ptregs_clone /* 120 */ .long sys_setdomainname .long sys_newuname .long sys_modify_ldt @@ -165,14 +165,14 @@ ENTRY(sys_call_table) .long sys_mremap .long sys_setresuid16 .long sys_getresuid16 /* 165 */ - .long sys_vm86 + .long ptregs_vm86 .long sys_ni_syscall /* Old sys_query_module */ .long sys_poll .long sys_nfsservctl .long sys_setresgid16 /* 170 */ .long sys_getresgid16 .long sys_prctl - .long sys_rt_sigreturn + .long ptregs_rt_sigreturn .long sys_rt_sigaction .long sys_rt_sigprocmask /* 175 */ .long sys_rt_sigpending @@ -185,11 +185,11 @@ ENTRY(sys_call_table) .long sys_getcwd .long sys_capget .long sys_capset /* 185 */ - .long sys_sigaltstack + .long ptregs_sigaltstack .long sys_sendfile .long sys_ni_syscall /* reserved for streams1 */ .long sys_ni_syscall /* reserved for streams2 */ - .long sys_vfork /* 190 */ + .long ptregs_vfork /* 190 */ .long sys_getrlimit .long sys_mmap2 .long sys_truncate64 diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 0d032d2d8a18..bde57f0f1616 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -905,19 +905,20 @@ void math_emulate(struct math_emu_info *info) } #endif /* CONFIG_MATH_EMULATION */ -dotraplinkage void __kprobes do_device_not_available(struct pt_regs regs) +dotraplinkage void __kprobes +do_device_not_available(struct pt_regs *regs, long error_code) { #ifdef CONFIG_X86_32 if (read_cr0() & X86_CR0_EM) { struct math_emu_info info = { }; - conditional_sti(®s); + conditional_sti(regs); - info.regs = ®s; + info.regs = regs; math_emulate(&info); } else { math_state_restore(); /* interrupts still off */ - conditional_sti(®s); + conditional_sti(regs); } #else math_state_restore(); diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c index 4eeb5cf9720d..d7ac84e7fc1c 100644 --- a/arch/x86/kernel/vm86_32.c +++ b/arch/x86/kernel/vm86_32.c @@ -158,7 +158,7 @@ struct pt_regs *save_v86_state(struct kernel_vm86_regs *regs) ret = KVM86->regs32; ret->fs = current->thread.saved_fs; - loadsegment(gs, current->thread.saved_gs); + set_user_gs(ret, current->thread.saved_gs); return ret; } @@ -197,9 +197,9 @@ out: static int do_vm86_irq_handling(int subfunction, int irqnumber); static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk); -asmlinkage int sys_vm86old(struct pt_regs regs) +int sys_vm86old(struct pt_regs *regs) { - struct vm86_struct __user *v86 = (struct vm86_struct __user *)regs.bx; + struct vm86_struct __user *v86 = (struct vm86_struct __user *)regs->bx; struct kernel_vm86_struct info; /* declare this _on top_, * this avoids wasting of stack space. * This remains on the stack until we @@ -218,7 +218,7 @@ asmlinkage int sys_vm86old(struct pt_regs regs) if (tmp) goto out; memset(&info.vm86plus, 0, (int)&info.regs32 - (int)&info.vm86plus); - info.regs32 = ®s; + info.regs32 = regs; tsk->thread.vm86_info = v86; do_sys_vm86(&info, tsk); ret = 0; /* we never return here */ @@ -227,7 +227,7 @@ out: } -asmlinkage int sys_vm86(struct pt_regs regs) +int sys_vm86(struct pt_regs *regs) { struct kernel_vm86_struct info; /* declare this _on top_, * this avoids wasting of stack space. @@ -239,12 +239,12 @@ asmlinkage int sys_vm86(struct pt_regs regs) struct vm86plus_struct __user *v86; tsk = current; - switch (regs.bx) { + switch (regs->bx) { case VM86_REQUEST_IRQ: case VM86_FREE_IRQ: case VM86_GET_IRQ_BITS: case VM86_GET_AND_RESET_IRQ: - ret = do_vm86_irq_handling(regs.bx, (int)regs.cx); + ret = do_vm86_irq_handling(regs->bx, (int)regs->cx); goto out; case VM86_PLUS_INSTALL_CHECK: /* @@ -261,14 +261,14 @@ asmlinkage int sys_vm86(struct pt_regs regs) ret = -EPERM; if (tsk->thread.saved_sp0) goto out; - v86 = (struct vm86plus_struct __user *)regs.cx; + v86 = (struct vm86plus_struct __user *)regs->cx; tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs, offsetof(struct kernel_vm86_struct, regs32) - sizeof(info.regs)); ret = -EFAULT; if (tmp) goto out; - info.regs32 = ®s; + info.regs32 = regs; info.vm86plus.is_vm86pus = 1; tsk->thread.vm86_info = (struct vm86_struct __user *)v86; do_sys_vm86(&info, tsk); @@ -323,7 +323,7 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk info->regs32->ax = 0; tsk->thread.saved_sp0 = tsk->thread.sp0; tsk->thread.saved_fs = info->regs32->fs; - savesegment(gs, tsk->thread.saved_gs); + tsk->thread.saved_gs = get_user_gs(info->regs32); tss = &per_cpu(init_tss, get_cpu()); tsk->thread.sp0 = (unsigned long) &info->VM86_TSS_ESP0; diff --git a/arch/x86/kernel/vmlinux_64.lds.S b/arch/x86/kernel/vmlinux_64.lds.S index 07f62d287ff0..087a7f2c639b 100644 --- a/arch/x86/kernel/vmlinux_64.lds.S +++ b/arch/x86/kernel/vmlinux_64.lds.S @@ -257,6 +257,14 @@ SECTIONS DWARF_DEBUG } + /* + * Per-cpu symbols which need to be offset from __per_cpu_load + * for the boot processor. + */ +#define INIT_PER_CPU(x) init_per_cpu__##x = per_cpu__##x + __per_cpu_load +INIT_PER_CPU(gdt_page); +INIT_PER_CPU(irq_stack_union); + /* * Build-time check on the image size: */ diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index 19e33b6cd593..da2e314f61b5 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -283,7 +283,7 @@ static void lguest_load_tls(struct thread_struct *t, unsigned int cpu) /* There's one problem which normal hardware doesn't have: the Host * can't handle us removing entries we're currently using. So we clear * the GS register here: if it's needed it'll be reloaded anyway. */ - loadsegment(gs, 0); + lazy_load_gs(0); lazy_hcall(LHCALL_LOAD_TLS, __pa(&t->tls_array), cpu, 0); } diff --git a/arch/x86/math-emu/get_address.c b/arch/x86/math-emu/get_address.c index 420b3b6e3915..6ef5e99380f9 100644 --- a/arch/x86/math-emu/get_address.c +++ b/arch/x86/math-emu/get_address.c @@ -150,11 +150,9 @@ static long pm_address(u_char FPU_modrm, u_char segment, #endif /* PARANOID */ switch (segment) { - /* gs isn't used by the kernel, so it still has its - user-space value. */ case PREFIX_GS_ - 1: - /* N.B. - movl %seg, mem is a 2 byte write regardless of prefix */ - savesegment(gs, addr->selector); + /* user gs handling can be lazy, use special accessors */ + addr->selector = get_user_gs(FPU_info->regs); break; default: addr->selector = PM_REG_(segment); diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c index 08d140fbc31b..deb1c1ab7868 100644 --- a/arch/x86/mm/numa_64.c +++ b/arch/x86/mm/numa_64.c @@ -702,7 +702,7 @@ void __cpuinit numa_set_node(int cpu, int node) } #ifdef CONFIG_DEBUG_PER_CPU_MAPS - if (cpu >= nr_cpu_ids || !per_cpu_offset(cpu)) { + if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) { printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu); dump_stack(); return; @@ -790,7 +790,7 @@ int early_cpu_to_node(int cpu) if (early_per_cpu_ptr(x86_cpu_to_node_map)) return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu]; - if (!per_cpu_offset(cpu)) { + if (!cpu_possible(cpu)) { printk(KERN_WARNING "early_cpu_to_node(%d): no per_cpu area!\n", cpu); dump_stack(); diff --git a/arch/x86/vdso/Makefile b/arch/x86/vdso/Makefile index 4d6ef0a336d6..16a9020c8f11 100644 --- a/arch/x86/vdso/Makefile +++ b/arch/x86/vdso/Makefile @@ -38,7 +38,7 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE $(call if_changed,objcopy) CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \ - $(filter -g%,$(KBUILD_CFLAGS)) + $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) $(vobjs): KBUILD_CFLAGS += $(CFL) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 37230342c2c4..95ff6a0e942a 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -323,13 +323,14 @@ static void load_TLS_descriptor(struct thread_struct *t, static void xen_load_tls(struct thread_struct *t, unsigned int cpu) { /* - * XXX sleazy hack: If we're being called in a lazy-cpu zone, - * it means we're in a context switch, and %gs has just been - * saved. This means we can zero it out to prevent faults on - * exit from the hypervisor if the next process has no %gs. - * Either way, it has been saved, and the new value will get - * loaded properly. This will go away as soon as Xen has been - * modified to not save/restore %gs for normal hypercalls. + * XXX sleazy hack: If we're being called in a lazy-cpu zone + * and lazy gs handling is enabled, it means we're in a + * context switch, and %gs has just been saved. This means we + * can zero it out to prevent faults on exit from the + * hypervisor if the next process has no %gs. Either way, it + * has been saved, and the new value will get loaded properly. + * This will go away as soon as Xen has been modified to not + * save/restore %gs for normal hypercalls. * * On x86_64, this hack is not used for %gs, because gs points * to KERNEL_GS_BASE (and uses it for PDA references), so we @@ -341,7 +342,7 @@ static void xen_load_tls(struct thread_struct *t, unsigned int cpu) */ if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) { #ifdef CONFIG_X86_32 - loadsegment(gs, 0); + lazy_load_gs(0); #else loadsegment(fs, 0); #endif diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S index 4c6f96799131..79d7362ad6d1 100644 --- a/arch/x86/xen/xen-asm.S +++ b/arch/x86/xen/xen-asm.S @@ -1,14 +1,14 @@ /* - Asm versions of Xen pv-ops, suitable for either direct use or inlining. - The inline versions are the same as the direct-use versions, with the - pre- and post-amble chopped off. - - This code is encoded for size rather than absolute efficiency, - with a view to being able to inline as much as possible. - - We only bother with direct forms (ie, vcpu in percpu data) of - the operations here; the indirect forms are better handled in - C, since they're generally too large to inline anyway. + * Asm versions of Xen pv-ops, suitable for either direct use or + * inlining. The inline versions are the same as the direct-use + * versions, with the pre- and post-amble chopped off. + * + * This code is encoded for size rather than absolute efficiency, with + * a view to being able to inline as much as possible. + * + * We only bother with direct forms (ie, vcpu in percpu data) of the + * operations here; the indirect forms are better handled in C, since + * they're generally too large to inline anyway. */ #include <asm/asm-offsets.h> @@ -18,17 +18,19 @@ #include "xen-asm.h" /* - Enable events. This clears the event mask and tests the pending - event status with one and operation. If there are pending - events, then enter the hypervisor to get them handled. + * Enable events. This clears the event mask and tests the pending + * event status with one and operation. If there are pending events, + * then enter the hypervisor to get them handled. */ ENTRY(xen_irq_enable_direct) /* Unmask events */ movb $0, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask - /* Preempt here doesn't matter because that will deal with - any pending interrupts. The pending check may end up being - run on the wrong CPU, but that doesn't hurt. */ + /* + * Preempt here doesn't matter because that will deal with any + * pending interrupts. The pending check may end up being run + * on the wrong CPU, but that doesn't hurt. + */ /* Test for pending */ testb $0xff, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_pending @@ -43,8 +45,8 @@ ENDPATCH(xen_irq_enable_direct) /* - Disabling events is simply a matter of making the event mask - non-zero. + * Disabling events is simply a matter of making the event mask + * non-zero. */ ENTRY(xen_irq_disable_direct) movb $1, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask @@ -54,18 +56,18 @@ ENDPATCH(xen_irq_disable_direct) RELOC(xen_irq_disable_direct, 0) /* - (xen_)save_fl is used to get the current interrupt enable status. - Callers expect the status to be in X86_EFLAGS_IF, and other bits - may be set in the return value. We take advantage of this by - making sure that X86_EFLAGS_IF has the right value (and other bits - in that byte are 0), but other bits in the return value are - undefined. We need to toggle the state of the bit, because - Xen and x86 use opposite senses (mask vs enable). + * (xen_)save_fl is used to get the current interrupt enable status. + * Callers expect the status to be in X86_EFLAGS_IF, and other bits + * may be set in the return value. We take advantage of this by + * making sure that X86_EFLAGS_IF has the right value (and other bits + * in that byte are 0), but other bits in the return value are + * undefined. We need to toggle the state of the bit, because Xen and + * x86 use opposite senses (mask vs enable). */ ENTRY(xen_save_fl_direct) testb $0xff, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask setz %ah - addb %ah,%ah + addb %ah, %ah ENDPATCH(xen_save_fl_direct) ret ENDPROC(xen_save_fl_direct) @@ -73,12 +75,11 @@ ENDPATCH(xen_save_fl_direct) /* - In principle the caller should be passing us a value return - from xen_save_fl_direct, but for robustness sake we test only - the X86_EFLAGS_IF flag rather than the whole byte. After - setting the interrupt mask state, it checks for unmasked - pending events and enters the hypervisor to get them delivered - if so. + * In principle the caller should be passing us a value return from + * xen_save_fl_direct, but for robustness sake we test only the + * X86_EFLAGS_IF flag rather than the whole byte. After setting the + * interrupt mask state, it checks for unmasked pending events and + * enters the hypervisor to get them delivered if so. */ ENTRY(xen_restore_fl_direct) #ifdef CONFIG_X86_64 @@ -87,9 +88,11 @@ ENTRY(xen_restore_fl_direct) testb $X86_EFLAGS_IF>>8, %ah #endif setz PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask - /* Preempt here doesn't matter because that will deal with - any pending interrupts. The pending check may end up being - run on the wrong CPU, but that doesn't hurt. */ + /* + * Preempt here doesn't matter because that will deal with any + * pending interrupts. The pending check may end up being run + * on the wrong CPU, but that doesn't hurt. + */ /* check for unmasked and pending */ cmpw $0x0001, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_pending @@ -103,8 +106,8 @@ ENDPATCH(xen_restore_fl_direct) /* - Force an event check by making a hypercall, - but preserve regs before making the call. + * Force an event check by making a hypercall, but preserve regs + * before making the call. */ check_events: #ifdef CONFIG_X86_32 @@ -137,4 +140,3 @@ check_events: pop %rax #endif ret - diff --git a/arch/x86/xen/xen-asm_32.S b/arch/x86/xen/xen-asm_32.S index 082d173caaf3..88e15deb8b82 100644 --- a/arch/x86/xen/xen-asm_32.S +++ b/arch/x86/xen/xen-asm_32.S @@ -1,17 +1,16 @@ /* - Asm versions of Xen pv-ops, suitable for either direct use or inlining. - The inline versions are the same as the direct-use versions, with the - pre- and post-amble chopped off. - - This code is encoded for size rather than absolute efficiency, - with a view to being able to inline as much as possible. - - We only bother with direct forms (ie, vcpu in pda) of the operations - here; the indirect forms are better handled in C, since they're - generally too large to inline anyway. + * Asm versions of Xen pv-ops, suitable for either direct use or + * inlining. The inline versions are the same as the direct-use + * versions, with the pre- and post-amble chopped off. + * + * This code is encoded for size rather than absolute efficiency, with + * a view to being able to inline as much as possible. + * + * We only bother with direct forms (ie, vcpu in pda) of the + * operations here; the indirect forms are better handled in C, since + * they're generally too large to inline anyway. */ -//#include <asm/asm-offsets.h> #include <asm/thread_info.h> #include <asm/processor-flags.h> #include <asm/segment.h> @@ -21,8 +20,8 @@ #include "xen-asm.h" /* - Force an event check by making a hypercall, - but preserve regs before making the call. + * Force an event check by making a hypercall, but preserve regs + * before making the call. */ check_events: push %eax @@ -35,10 +34,10 @@ check_events: ret /* - We can't use sysexit directly, because we're not running in ring0. - But we can easily fake it up using iret. Assuming xen_sysexit - is jumped to with a standard stack frame, we can just strip it - back to a standard iret frame and use iret. + * We can't use sysexit directly, because we're not running in ring0. + * But we can easily fake it up using iret. Assuming xen_sysexit is + * jumped to with a standard stack frame, we can just strip it back to + * a standard iret frame and use iret. */ ENTRY(xen_sysexit) movl PT_EAX(%esp), %eax /* Shouldn't be necessary? */ @@ -49,33 +48,31 @@ ENTRY(xen_sysexit) ENDPROC(xen_sysexit) /* - This is run where a normal iret would be run, with the same stack setup: - 8: eflags - 4: cs - esp-> 0: eip - - This attempts to make sure that any pending events are dealt - with on return to usermode, but there is a small window in - which an event can happen just before entering usermode. If - the nested interrupt ends up setting one of the TIF_WORK_MASK - pending work flags, they will not be tested again before - returning to usermode. This means that a process can end up - with pending work, which will be unprocessed until the process - enters and leaves the kernel again, which could be an - unbounded amount of time. This means that a pending signal or - reschedule event could be indefinitely delayed. - - The fix is to notice a nested interrupt in the critical - window, and if one occurs, then fold the nested interrupt into - the current interrupt stack frame, and re-process it - iteratively rather than recursively. This means that it will - exit via the normal path, and all pending work will be dealt - with appropriately. - - Because the nested interrupt handler needs to deal with the - current stack state in whatever form its in, we keep things - simple by only using a single register which is pushed/popped - on the stack. + * This is run where a normal iret would be run, with the same stack setup: + * 8: eflags + * 4: cs + * esp-> 0: eip + * + * This attempts to make sure that any pending events are dealt with + * on return to usermode, but there is a small window in which an + * event can happen just before entering usermode. If the nested + * interrupt ends up setting one of the TIF_WORK_MASK pending work + * flags, they will not be tested again before returning to + * usermode. This means that a process can end up with pending work, + * which will be unprocessed until the process enters and leaves the + * kernel again, which could be an unbounded amount of time. This + * means that a pending signal or reschedule event could be + * indefinitely delayed. + * + * The fix is to notice a nested interrupt in the critical window, and + * if one occurs, then fold the nested interrupt into the current + * interrupt stack frame, and re-process it iteratively rather than + * recursively. This means that it will exit via the normal path, and + * all pending work will be dealt with appropriately. + * + * Because the nested interrupt handler needs to deal with the current + * stack state in whatever form its in, we keep things simple by only + * using a single register which is pushed/popped on the stack. */ ENTRY(xen_iret) /* test eflags for special cases */ @@ -85,13 +82,15 @@ ENTRY(xen_iret) push %eax ESP_OFFSET=4 # bytes pushed onto stack - /* Store vcpu_info pointer for easy access. Do it this - way to avoid having to reload %fs */ + /* + * Store vcpu_info pointer for easy access. Do it this way to + * avoid having to reload %fs + */ #ifdef CONFIG_SMP GET_THREAD_INFO(%eax) - movl TI_cpu(%eax),%eax - movl __per_cpu_offset(,%eax,4),%eax - mov per_cpu__xen_vcpu(%eax),%eax + movl TI_cpu(%eax), %eax + movl __per_cpu_offset(,%eax,4), %eax + mov per_cpu__xen_vcpu(%eax), %eax #else movl per_cpu__xen_vcpu, %eax #endif @@ -99,37 +98,46 @@ ENTRY(xen_iret) /* check IF state we're restoring */ testb $X86_EFLAGS_IF>>8, 8+1+ESP_OFFSET(%esp) - /* Maybe enable events. Once this happens we could get a - recursive event, so the critical region starts immediately - afterwards. However, if that happens we don't end up - resuming the code, so we don't have to be worried about - being preempted to another CPU. */ + /* + * Maybe enable events. Once this happens we could get a + * recursive event, so the critical region starts immediately + * afterwards. However, if that happens we don't end up + * resuming the code, so we don't have to be worried about + * being preempted to another CPU. + */ setz XEN_vcpu_info_mask(%eax) xen_iret_start_crit: /* check for unmasked and pending */ cmpw $0x0001, XEN_vcpu_info_pending(%eax) - /* If there's something pending, mask events again so we - can jump back into xen_hypervisor_callback */ + /* + * If there's something pending, mask events again so we can + * jump back into xen_hypervisor_callback + */ sete XEN_vcpu_info_mask(%eax) popl %eax - /* From this point on the registers are restored and the stack - updated, so we don't need to worry about it if we're preempted */ + /* + * From this point on the registers are restored and the stack + * updated, so we don't need to worry about it if we're + * preempted + */ iret_restore_end: - /* Jump to hypervisor_callback after fixing up the stack. - Events are masked, so jumping out of the critical - region is OK. */ + /* + * Jump to hypervisor_callback after fixing up the stack. + * Events are masked, so jumping out of the critical region is + * OK. + */ je xen_hypervisor_callback 1: iret xen_iret_end_crit: -.section __ex_table,"a" +.section __ex_table, "a" .align 4 - .long 1b,iret_exc + .long 1b, iret_exc .previous hyper_iret: @@ -139,55 +147,55 @@ hyper_iret: .globl xen_iret_start_crit, xen_iret_end_crit /* - This is called by xen_hypervisor_callback in entry.S when it sees - that the EIP at the time of interrupt was between xen_iret_start_crit - and xen_iret_end_crit. We're passed the EIP in %eax so we can do - a more refined determination of what to do. - - The stack format at this point is: - ---------------- - ss : (ss/esp may be present if we came from usermode) - esp : - eflags } outer exception info - cs } - eip } - ---------------- <- edi (copy dest) - eax : outer eax if it hasn't been restored - ---------------- - eflags } nested exception info - cs } (no ss/esp because we're nested - eip } from the same ring) - orig_eax }<- esi (copy src) - - - - - - - - - - fs } - es } - ds } SAVE_ALL state - eax } - : : - ebx }<- esp - ---------------- - - In order to deliver the nested exception properly, we need to shift - everything from the return addr up to the error code so it - sits just under the outer exception info. This means that when we - handle the exception, we do it in the context of the outer exception - rather than starting a new one. - - The only caveat is that if the outer eax hasn't been - restored yet (ie, it's still on stack), we need to insert - its value into the SAVE_ALL state before going on, since - it's usermode state which we eventually need to restore. + * This is called by xen_hypervisor_callback in entry.S when it sees + * that the EIP at the time of interrupt was between + * xen_iret_start_crit and xen_iret_end_crit. We're passed the EIP in + * %eax so we can do a more refined determination of what to do. + * + * The stack format at this point is: + * ---------------- + * ss : (ss/esp may be present if we came from usermode) + * esp : + * eflags } outer exception info + * cs } + * eip } + * ---------------- <- edi (copy dest) + * eax : outer eax if it hasn't been restored + * ---------------- + * eflags } nested exception info + * cs } (no ss/esp because we're nested + * eip } from the same ring) + * orig_eax }<- esi (copy src) + * - - - - - - - - + * fs } + * es } + * ds } SAVE_ALL state + * eax } + * : : + * ebx }<- esp + * ---------------- + * + * In order to deliver the nested exception properly, we need to shift + * everything from the return addr up to the error code so it sits + * just under the outer exception info. This means that when we + * handle the exception, we do it in the context of the outer + * exception rather than starting a new one. + * + * The only caveat is that if the outer eax hasn't been restored yet + * (ie, it's still on stack), we need to insert its value into the + * SAVE_ALL state before going on, since it's usermode state which we + * eventually need to restore. */ ENTRY(xen_iret_crit_fixup) /* - Paranoia: Make sure we're really coming from kernel space. - One could imagine a case where userspace jumps into the - critical range address, but just before the CPU delivers a GP, - it decides to deliver an interrupt instead. Unlikely? - Definitely. Easy to avoid? Yes. The Intel documents - explicitly say that the reported EIP for a bad jump is the - jump instruction itself, not the destination, but some virtual - environments get this wrong. + * Paranoia: Make sure we're really coming from kernel space. + * One could imagine a case where userspace jumps into the + * critical range address, but just before the CPU delivers a + * GP, it decides to deliver an interrupt instead. Unlikely? + * Definitely. Easy to avoid? Yes. The Intel documents + * explicitly say that the reported EIP for a bad jump is the + * jump instruction itself, not the destination, but some + * virtual environments get this wrong. */ movl PT_CS(%esp), %ecx andl $SEGMENT_RPL_MASK, %ecx @@ -197,15 +205,17 @@ ENTRY(xen_iret_crit_fixup) lea PT_ORIG_EAX(%esp), %esi lea PT_EFLAGS(%esp), %edi - /* If eip is before iret_restore_end then stack - hasn't been restored yet. */ + /* + * If eip is before iret_restore_end then stack + * hasn't been restored yet. + */ cmp $iret_restore_end, %eax jae 1f - movl 0+4(%edi),%eax /* copy EAX (just above top of frame) */ + movl 0+4(%edi), %eax /* copy EAX (just above top of frame) */ movl %eax, PT_EAX(%esp) - lea ESP_OFFSET(%edi),%edi /* move dest up over saved regs */ + lea ESP_OFFSET(%edi), %edi /* move dest up over saved regs */ /* set up the copy */ 1: std @@ -213,6 +223,6 @@ ENTRY(xen_iret_crit_fixup) rep movsl cld - lea 4(%edi),%esp /* point esp to new frame */ + lea 4(%edi), %esp /* point esp to new frame */ 2: jmp xen_do_upcall diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S index d205a283efe0..02f496a8dbaa 100644 --- a/arch/x86/xen/xen-asm_64.S +++ b/arch/x86/xen/xen-asm_64.S @@ -1,14 +1,14 @@ /* - Asm versions of Xen pv-ops, suitable for either direct use or inlining. - The inline versions are the same as the direct-use versions, with the - pre- and post-amble chopped off. - - This code is encoded for size rather than absolute efficiency, - with a view to being able to inline as much as possible. - - We only bother with direct forms (ie, vcpu in pda) of the operations - here; the indirect forms are better handled in C, since they're - generally too large to inline anyway. + * Asm versions of Xen pv-ops, suitable for either direct use or + * inlining. The inline versions are the same as the direct-use + * versions, with the pre- and post-amble chopped off. + * + * This code is encoded for size rather than absolute efficiency, with + * a view to being able to inline as much as possible. + * + * We only bother with direct forms (ie, vcpu in pda) of the + * operations here; the indirect forms are better handled in C, since + * they're generally too large to inline anyway. */ #include <asm/errno.h> @@ -21,25 +21,25 @@ #include "xen-asm.h" ENTRY(xen_adjust_exception_frame) - mov 8+0(%rsp),%rcx - mov 8+8(%rsp),%r11 + mov 8+0(%rsp), %rcx + mov 8+8(%rsp), %r11 ret $16 hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32 /* - Xen64 iret frame: - - ss - rsp - rflags - cs - rip <-- standard iret frame - - flags - - rcx } - r11 }<-- pushed by hypercall page -rsp -> rax } + * Xen64 iret frame: + * + * ss + * rsp + * rflags + * cs + * rip <-- standard iret frame + * + * flags + * + * rcx } + * r11 }<-- pushed by hypercall page + * rsp->rax } */ ENTRY(xen_iret) pushq $0 @@ -48,8 +48,8 @@ ENDPATCH(xen_iret) RELOC(xen_iret, 1b+1) /* - sysexit is not used for 64-bit processes, so it's - only ever used to return to 32-bit compat userspace. + * sysexit is not used for 64-bit processes, so it's only ever used to + * return to 32-bit compat userspace. */ ENTRY(xen_sysexit) pushq $__USER32_DS @@ -64,10 +64,12 @@ ENDPATCH(xen_sysexit) RELOC(xen_sysexit, 1b+1) ENTRY(xen_sysret64) - /* We're already on the usermode stack at this point, but still - with the kernel gs, so we can easily switch back */ + /* + * We're already on the usermode stack at this point, but + * still with the kernel gs, so we can easily switch back + */ movq %rsp, PER_CPU_VAR(old_rsp) - movq PER_CPU_VAR(kernel_stack),%rsp + movq PER_CPU_VAR(kernel_stack), %rsp pushq $__USER_DS pushq PER_CPU_VAR(old_rsp) @@ -81,8 +83,10 @@ ENDPATCH(xen_sysret64) RELOC(xen_sysret64, 1b+1) ENTRY(xen_sysret32) - /* We're already on the usermode stack at this point, but still - with the kernel gs, so we can easily switch back */ + /* + * We're already on the usermode stack at this point, but + * still with the kernel gs, so we can easily switch back + */ movq %rsp, PER_CPU_VAR(old_rsp) movq PER_CPU_VAR(kernel_stack), %rsp @@ -98,28 +102,27 @@ ENDPATCH(xen_sysret32) RELOC(xen_sysret32, 1b+1) /* - Xen handles syscall callbacks much like ordinary exceptions, - which means we have: - - kernel gs - - kernel rsp - - an iret-like stack frame on the stack (including rcx and r11): - ss - rsp - rflags - cs - rip - r11 - rsp-> rcx - - In all the entrypoints, we undo all that to make it look - like a CPU-generated syscall/sysenter and jump to the normal - entrypoint. + * Xen handles syscall callbacks much like ordinary exceptions, which + * means we have: + * - kernel gs + * - kernel rsp + * - an iret-like stack frame on the stack (including rcx and r11): + * ss + * rsp + * rflags + * cs + * rip + * r11 + * rsp->rcx + * + * In all the entrypoints, we undo all that to make it look like a + * CPU-generated syscall/sysenter and jump to the normal entrypoint. */ .macro undo_xen_syscall - mov 0*8(%rsp),%rcx - mov 1*8(%rsp),%r11 - mov 5*8(%rsp),%rsp + mov 0*8(%rsp), %rcx + mov 1*8(%rsp), %r11 + mov 5*8(%rsp), %rsp .endm /* Normal 64-bit system call target */ @@ -146,7 +149,7 @@ ENDPROC(xen_sysenter_target) ENTRY(xen_syscall32_target) ENTRY(xen_sysenter_target) - lea 16(%rsp), %rsp /* strip %rcx,%r11 */ + lea 16(%rsp), %rsp /* strip %rcx, %r11 */ mov $-ENOSYS, %rax pushq $VGCF_in_syscall jmp hypercall_iret |