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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2017-09-18 21:43:37 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-09-28 09:39:04 +0200 |
| commit | 2704fbb672d0d9a19414907fda7949283dcef6a1 (patch) | |
| tree | ace300ec47e25c9884e8c8d2391c3a20cc43b3a2 /arch/x86/kernel | |
| parent | abbe1cac6214d81d2f4e149aba64a8760703144e (diff) | |
| download | linux-stable-2704fbb672d0d9a19414907fda7949283dcef6a1.tar.gz linux-stable-2704fbb672d0d9a19414907fda7949283dcef6a1.tar.bz2 linux-stable-2704fbb672d0d9a19414907fda7949283dcef6a1.zip | |
x86/head: Add unwind hint annotations
Jiri Slaby reported an ORC issue when unwinding from an idle task. The
stack was:
ffffffff811083c2 do_idle+0x142/0x1e0
ffffffff8110861d cpu_startup_entry+0x5d/0x60
ffffffff82715f58 start_kernel+0x3ff/0x407
ffffffff827153e8 x86_64_start_kernel+0x14e/0x15d
ffffffff810001bf secondary_startup_64+0x9f/0xa0
The ORC unwinder errored out at secondary_startup_64 because the head
code isn't annotated yet so there wasn't a corresponding ORC entry.
Fix that and any other head-related unwinding issues by adding unwind
hints to the head code.
Reported-by: Jiri Slaby <jslaby@suse.cz>
Tested-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/78ef000a2f68f545d6eef44ee912edceaad82ccf.1505764066.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/head_64.S | 14 |
2 files changed, 12 insertions, 3 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index fd0a7895b63f..d8e2b700d1db 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -26,7 +26,6 @@ KASAN_SANITIZE_dumpstack.o := n KASAN_SANITIZE_dumpstack_$(BITS).o := n KASAN_SANITIZE_stacktrace.o := n -OBJECT_FILES_NON_STANDARD_head_$(BITS).o := y OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o := y OBJECT_FILES_NON_STANDARD_ftrace_$(BITS).o := y OBJECT_FILES_NON_STANDARD_test_nx.o := y diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index edacd579d504..42e32c2e51bb 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -49,6 +49,7 @@ L3_START_KERNEL = pud_index(__START_KERNEL_map) .code64 .globl startup_64 startup_64: + UNWIND_HINT_EMPTY /* * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0, * and someone has loaded an identity mapped page table @@ -88,6 +89,7 @@ startup_64: addq $(early_top_pgt - __START_KERNEL_map), %rax jmp 1f ENTRY(secondary_startup_64) + UNWIND_HINT_EMPTY /* * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0, * and someone has loaded a mapped page table. @@ -132,6 +134,7 @@ ENTRY(secondary_startup_64) movq $1f, %rax jmp *%rax 1: + UNWIND_HINT_EMPTY /* Check if nx is implemented */ movl $0x80000001, %eax @@ -246,6 +249,7 @@ END(secondary_startup_64) */ ENTRY(start_cpu0) movq initial_stack(%rip), %rsp + UNWIND_HINT_EMPTY jmp .Ljump_to_C_code ENDPROC(start_cpu0) #endif @@ -270,13 +274,18 @@ ENTRY(early_idt_handler_array) i = 0 .rept NUM_EXCEPTION_VECTORS .ifeq (EXCEPTION_ERRCODE_MASK >> i) & 1 - pushq $0 # Dummy error code, to make stack frame uniform + UNWIND_HINT_IRET_REGS + pushq $0 # Dummy error code, to make stack frame uniform + .else + UNWIND_HINT_IRET_REGS offset=8 .endif pushq $i # 72(%rsp) Vector number jmp early_idt_handler_common + UNWIND_HINT_IRET_REGS i = i + 1 .fill early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE - ., 1, 0xcc .endr + UNWIND_HINT_IRET_REGS offset=16 END(early_idt_handler_array) early_idt_handler_common: @@ -305,6 +314,7 @@ early_idt_handler_common: pushq %r13 /* pt_regs->r13 */ pushq %r14 /* pt_regs->r14 */ pushq %r15 /* pt_regs->r15 */ + UNWIND_HINT_REGS cmpq $14,%rsi /* Page fault? */ jnz 10f @@ -427,7 +437,7 @@ ENTRY(phys_base) EXPORT_SYMBOL(phys_base) #include "../../x86/xen/xen-head.S" - + __PAGE_ALIGNED_BSS NEXT_PAGE(empty_zero_page) .skip PAGE_SIZE |