diff options
Diffstat (limited to 'mysys/my_context.c')
| -rw-r--r-- | mysys/my_context.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/mysys/my_context.c b/mysys/my_context.c index d2374391a39..9d56b13ecb5 100644 --- a/mysys/my_context.c +++ b/mysys/my_context.c @@ -437,6 +437,8 @@ my_context_destroy(struct my_context *c) int my_context_spawn(struct my_context *c, void (*f)(void *), void *d) { + void (*tmp_f)(void *)= f; + void *tmp_d= d; int ret; DBUG_SWAP_CODE_STATE(&c->dbug_state); @@ -454,6 +456,15 @@ my_context_spawn(struct my_context *c, void (*f)(void *), void *d) ( "movl %%esp, (%[save])\n\t" "movl %[stack], %%esp\n\t" +#if __GNUC__ >= 4 && __GNUC_MINOR__ >= 4 + /* + This emits a DWARF DW_CFA_undefined directive to make the return address + undefined. This indicates that this is the top of the stack frame, and + helps tools that use DWARF stack unwinding to obtain stack traces. + (I use numeric constant to avoid a dependency on libdwarf includes). + */ + ".cfi_escape 0x07, 8\n\t" +#endif /* Push the parameter on the stack. */ "pushl %[d]\n\t" "movl %%ebp, 4(%[save])\n\t" @@ -483,13 +494,13 @@ my_context_spawn(struct my_context *c, void (*f)(void *), void *d) "3:\n\t" "movl $1, %[ret]\n" "4:\n" - : [ret] "=a" (ret) + : [ret] "=a" (ret), + [f] "+c" (tmp_f), + [d] "+d" (tmp_d) : [stack] "a" (c->stack_top), /* Need this in callee-save register to preserve across function call. */ - [save] "D" (&c->save[0]), - [f] "m" (f), - [d] "m" (d) - : "ecx", "edx", "memory", "cc" + [save] "D" (&c->save[0]) + : "memory", "cc" ); DBUG_SWAP_CODE_STATE(&c->dbug_state); |