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authorPaul Pluzhnikov <ppluzhnikov@google.com>2016-03-03 09:53:49 -0800
committerPaul Pluzhnikov <ppluzhnikov@google.com>2016-03-03 09:53:49 -0800
commit5cdc3d9db02773ff9904642254edb4c0fb67c9ee (patch)
tree22515d04fb99d7cafa44153c38f13df1fd67c085 /sysdeps
parent87a07a437656aede6f303688b55ae1834962bee2 (diff)
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2016-03-03 Paul Pluzhnikov <ppluzhnikov@google.com>
[BZ #19490] * sysdeps/x86_64/_mcount.S (_mcount): Add unwind descriptor. (__fentry__): Likewise
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/x86_64/_mcount.S55
1 files changed, 42 insertions, 13 deletions
diff --git a/sysdeps/x86_64/_mcount.S b/sysdeps/x86_64/_mcount.S
index ba13643464..a506d21dcd 100644
--- a/sysdeps/x86_64/_mcount.S
+++ b/sysdeps/x86_64/_mcount.S
@@ -24,19 +24,24 @@
#include <sysdep.h>
- .globl C_SYMBOL_NAME(_mcount)
- .type C_SYMBOL_NAME(_mcount), @function
- .align ALIGNARG(4)
-C_LABEL(_mcount)
+ENTRY(_mcount)
/* Allocate space for 7 registers. */
subq $56,%rsp
+ cfi_adjust_cfa_offset (56)
movq %rax,(%rsp)
+ cfi_rel_offset (rax, 0)
movq %rcx,8(%rsp)
+ cfi_rel_offset (rcx, 8)
movq %rdx,16(%rsp)
+ cfi_rel_offset (rdx, 16)
movq %rsi,24(%rsp)
+ cfi_rel_offset (rsi, 24)
movq %rdi,32(%rsp)
+ cfi_rel_offset (rdi, 32)
movq %r8,40(%rsp)
+ cfi_rel_offset (r8, 40)
movq %r9,48(%rsp)
+ cfi_rel_offset (r9, 48)
/* Setup parameter for __mcount_internal. */
/* selfpc is the return address on the stack. */
@@ -47,33 +52,50 @@ C_LABEL(_mcount)
/* Pop the saved registers. Please note that `mcount' has no
return value. */
movq 48(%rsp),%r9
+ cfi_restore (r9)
movq 40(%rsp),%r8
+ cfi_restore (r8)
movq 32(%rsp),%rdi
+ cfi_restore (rdi)
movq 24(%rsp),%rsi
+ cfi_restore (rsi)
movq 16(%rsp),%rdx
+ cfi_restore (rdx)
movq 8(%rsp),%rcx
+ cfi_restore (rcx)
movq (%rsp),%rax
+ cfi_restore (rax)
addq $56,%rsp
+ cfi_adjust_cfa_offset (-56)
ret
-
- ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(_mcount))
+END(_mcount)
#undef mcount
weak_alias (_mcount, mcount)
- .globl C_SYMBOL_NAME(__fentry__)
- .type C_SYMBOL_NAME(__fentry__), @function
- .align ALIGNARG(4)
-C_LABEL(__fentry__)
- /* Allocate space for 7 registers. */
+/* __fentry__ is different from _mcount in that it is called before
+ function prolog. This means (among other things) that it has non-standard
+ stack alignment on entry: (%RSP & 0xF) == 0. */
+
+ENTRY(__fentry__)
+ /* Allocate space for 7 registers
+ (+8 bytes for proper stack alignment). */
subq $64,%rsp
+ cfi_adjust_cfa_offset (64)
movq %rax,(%rsp)
+ cfi_rel_offset (rax, 0)
movq %rcx,8(%rsp)
+ cfi_rel_offset (rcx, 8)
movq %rdx,16(%rsp)
+ cfi_rel_offset (rdx, 16)
movq %rsi,24(%rsp)
+ cfi_rel_offset (rsi, 24)
movq %rdi,32(%rsp)
+ cfi_rel_offset (rdi, 32)
movq %r8,40(%rsp)
+ cfi_rel_offset (r8, 40)
movq %r9,48(%rsp)
+ cfi_rel_offset (r9, 48)
/* Setup parameter for __mcount_internal. */
/* selfpc is the return address on the stack. */
@@ -84,13 +106,20 @@ C_LABEL(__fentry__)
/* Pop the saved registers. Please note that `__fentry__' has no
return value. */
movq 48(%rsp),%r9
+ cfi_restore (r9)
movq 40(%rsp),%r8
+ cfi_restore (r8)
movq 32(%rsp),%rdi
+ cfi_restore (rdi)
movq 24(%rsp),%rsi
+ cfi_restore (rsi)
movq 16(%rsp),%rdx
+ cfi_restore (rdx)
movq 8(%rsp),%rcx
+ cfi_restore (rcx)
movq (%rsp),%rax
+ cfi_restore (rax)
addq $64,%rsp
+ cfi_adjust_cfa_offset (-64)
ret
-
- ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(__fentry__))
+END(__fentry__)