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| author | Roland McGrath <roland@redhat.com> | 2008-01-30 13:30:43 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:30:43 +0100 |
| commit | 36197c92a20c142fc2a068e0366053d770fa0096 (patch) | |
| tree | 796f377cadc86bb9cad36090698f6bbaec0ca0f1 /arch/x86 | |
| parent | 0aa97fb22624f18e5925d702ab0364d3838cfd91 (diff) | |
| download | linux-36197c92a20c142fc2a068e0366053d770fa0096.tar.gz linux-36197c92a20c142fc2a068e0366053d770fa0096.tar.bz2 linux-36197c92a20c142fc2a068e0366053d770fa0096.zip | |
x86 vDSO: ia32 sysenter_return
This changes the 64-bit kernel's support for the 32-bit sysenter
instruction to use stored fields rather than constants for the
user-mode return address, as the 32-bit kernel does. This adds a
sysenter_return field to struct thread_info, as 32-bit has. There
is no observable effect from this yet. It makes the assembly code
independent of the 32-bit vDSO mapping address, paving the way for
making the vDSO address vary as it does on the 32-bit kernel.
[ akpm@linux-foundation.org: build fix on !CONFIG_IA32_EMULATION ]
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/ia32/ia32entry.S | 7 | ||||
| -rw-r--r-- | arch/x86/ia32/syscall32.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/asm-offsets_64.c | 3 |
3 files changed, 10 insertions, 4 deletions
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index df588f0f76e1..2499a324feaa 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -12,7 +12,6 @@ #include <asm/ia32_unistd.h> #include <asm/thread_info.h> #include <asm/segment.h> -#include <asm/vsyscall32.h> #include <asm/irqflags.h> #include <linux/linkage.h> @@ -104,7 +103,7 @@ ENTRY(ia32_sysenter_target) pushfq CFI_ADJUST_CFA_OFFSET 8 /*CFI_REL_OFFSET rflags,0*/ - movl $VSYSCALL32_SYSEXIT, %r10d + movl 8*3-THREAD_SIZE+threadinfo_sysenter_return(%rsp), %r10d CFI_REGISTER rip,r10 pushq $__USER32_CS CFI_ADJUST_CFA_OFFSET 8 @@ -142,6 +141,8 @@ sysenter_do_call: andl $~TS_COMPAT,threadinfo_status(%r10) /* clear IF, that popfq doesn't enable interrupts early */ andl $~0x200,EFLAGS-R11(%rsp) + movl RIP-R11(%rsp),%edx /* User %eip */ + CFI_REGISTER rip,rdx RESTORE_ARGS 1,24,1,1,1,1 popfq CFI_ADJUST_CFA_OFFSET -8 @@ -149,8 +150,6 @@ sysenter_do_call: popq %rcx /* User %esp */ CFI_ADJUST_CFA_OFFSET -8 CFI_REGISTER rsp,rcx - movl $VSYSCALL32_SYSEXIT,%edx /* User %eip */ - CFI_REGISTER rip,rdx TRACE_IRQS_ON swapgs sti /* sti only takes effect after the next instruction */ diff --git a/arch/x86/ia32/syscall32.c b/arch/x86/ia32/syscall32.c index d751d96c2ef2..98ff99f5b59a 100644 --- a/arch/x86/ia32/syscall32.c +++ b/arch/x86/ia32/syscall32.c @@ -46,6 +46,10 @@ int syscall32_setup_pages(struct linux_binprm *bprm, int exstack) VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC| VM_ALWAYSDUMP, syscall32_pages); + if (ret == 0) { + current->mm->context.vdso = (void __user *)VSYSCALL32_BASE; + current_thread_info()->sysenter_return = VSYSCALL32_SYSEXIT; + } up_write(&mm->mmap_sem); return ret; } diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c index 40f41752c1df..c27c646214f4 100644 --- a/arch/x86/kernel/asm-offsets_64.c +++ b/arch/x86/kernel/asm-offsets_64.c @@ -46,6 +46,9 @@ int main(void) ENTRY(addr_limit); ENTRY(preempt_count); ENTRY(status); +#ifdef CONFIG_IA32_EMULATION + ENTRY(sysenter_return); +#endif BLANK(); #undef ENTRY #define ENTRY(entry) DEFINE(pda_ ## entry, offsetof(struct x8664_pda, entry)) |