61 lines
2.1 KiB
Diff
61 lines
2.1 KiB
Diff
|
Index: sysdeps/x86_64/elf/initfini.c
|
||
|
|
===================================================================
|
||
|
|
--- sysdeps/x86_64/elf/initfini.c.orig 2004-08-16 06:50:55.000000000 +0200
|
||
|
|
+++ sysdeps/x86_64/elf/initfini.c 2010-04-16 16:41:11.000000000 +0200
|
||
|
|
@@ -44,6 +44,25 @@
|
||
|
|
* crtn.s puts the corresponding function epilogues
|
||
|
|
in the .init and .fini sections. */
|
||
|
|
|
||
|
|
+/* The unwind annotation for _fini is peculiar for good reasons:
|
||
|
|
+ (a) We need a real function that isn't constructed separately
|
||
|
|
+ (i.e. one which has a .size directive) in order to attach unwind
|
||
|
|
+ info to it. Hence _fini is a wrapper around _real_fini, the
|
||
|
|
+ former being a normal function, the latter being the first
|
||
|
|
+ instruction of the traditional _fini.
|
||
|
|
+ (b) We must not fiddle with the stack pointer in _real_fini,
|
||
|
|
+ as we wouldn't be able to describe the effects in unwind info
|
||
|
|
+ (c) some versions of GCC have no correct unwind info for
|
||
|
|
+ __do_global_dtors_aux, meaning they can't properly restore %rbp
|
||
|
|
+ (unwinding through it is possible but later up when we next
|
||
|
|
+ need %rbp we can't access it anymore)
|
||
|
|
+ Therefore we save/restore it in _fini for uses later up the call chain.
|
||
|
|
+ But we don't make the CFA use that register (that would lead to
|
||
|
|
+ the above problem)
|
||
|
|
+ (d) We want an 16-aligned stack pointer at _real_fini. Because of (a)
|
||
|
|
+ we can't align it in _real_fini, hence we do it in the caller by
|
||
|
|
+ subtracting 8, making in 8mod16 which the call then make 0mod16
|
||
|
|
+ again. */
|
||
|
|
__asm__ ("\n\
|
||
|
|
#include \"defs.h\"\n\
|
||
|
|
\n\
|
||
|
|
@@ -88,16 +107,28 @@ _init:\n\
|
||
|
|
.globl _fini\n\
|
||
|
|
.type _fini,@function\n\
|
||
|
|
_fini:\n\
|
||
|
|
+ .cfi_startproc\n\
|
||
|
|
+ push %rbp\n\
|
||
|
|
+ .cfi_def_cfa_offset 16\n\
|
||
|
|
+ .cfi_offset 6,-16\n\
|
||
|
|
subq $8, %rsp\n\
|
||
|
|
+ .cfi_def_cfa_offset 24\n\
|
||
|
|
+ call _real_fini\n\
|
||
|
|
+ addq $8, %rsp\n\
|
||
|
|
+ .cfi_def_cfa_offset 16\n\
|
||
|
|
+ pop %rbp\n\
|
||
|
|
+ ret\n\
|
||
|
|
+ .cfi_endproc\n\
|
||
|
|
ALIGN\n\
|
||
|
|
END_FINI\n\
|
||
|
|
+.size _fini, .-_fini\n\
|
||
|
|
+_real_fini:\n\
|
||
|
|
\n\
|
||
|
|
/*@_fini_PROLOG_ENDS*/\n\
|
||
|
|
call i_am_not_a_leaf@PLT\n\
|
||
|
|
\n\
|
||
|
|
/*@_fini_EPILOG_BEGINS*/\n\
|
||
|
|
.section .fini\n\
|
||
|
|
- addq $8, %rsp\n\
|
||
|
|
ret\n\
|
||
|
|
END_FINI\n\
|
||
|
|
\n\
|