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| author | Paul Pluzhnikov <ppluzhnikov@google.com> | 2016-03-03 09:53:49 -0800 |
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| committer | Paul Pluzhnikov <ppluzhnikov@google.com> | 2016-03-03 09:53:49 -0800 |
| commit | 5cdc3d9db02773ff9904642254edb4c0fb67c9ee (patch) | |
| tree | 22515d04fb99d7cafa44153c38f13df1fd67c085 /sysdeps/x86_64/_mcount.S | |
| parent | 87a07a437656aede6f303688b55ae1834962bee2 (diff) | |
| download | glibc-5cdc3d9db02773ff9904642254edb4c0fb67c9ee.tar.gz glibc-5cdc3d9db02773ff9904642254edb4c0fb67c9ee.tar.xz glibc-5cdc3d9db02773ff9904642254edb4c0fb67c9ee.zip | |
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/x86_64/_mcount.S')
| -rw-r--r-- | sysdeps/x86_64/_mcount.S | 55 |
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__) |