glibc/elf/tst-dl_find_object-mod4.c

char mod4_data;

void
mod4_function (void (*f) (void))
{
  /* Make sure this is not a tail call and unwind information is
     therefore needed.  */
  f ();
  f ();
}
elf: Add _dl_find_object function It can be used to speed up the libgcc unwinder, and the internal _dl_find_dso_for_object function (which is used for caller identification in dlopen and related functions, and in dladdr). _dl_find_object is in the internal namespace due to bug 28503. If libgcc switches to _dl_find_object, this namespace issue will be fixed. It is located in libc for two reasons: it is necessary to forward the call to the static libc after static dlopen, and there is a link ordering issue with -static-libgcc and libgcc_eh.a because libc.so is not a linker script that includes ld.so in the glibc build tree (so that GCC's internal -lc after libgcc_eh.a does not pick up ld.so). It is necessary to do the i386 customization in the sysdeps/x86/bits/dl_find_object.h header shared with x86-64 because otherwise, multilib installations are broken. The implementation uses software transactional memory, as suggested by Torvald Riegel. Two copies of the supporting data structures are used, also achieving full async-signal-safety. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> 2021-12-29 05:52:56 +08:00			`char mod4_data;`

			`void`
			`mod4_function (void (*f) (void))`
			`{`
			`/* Make sure this is not a tail call and unwind information is`
			`therefore needed. */`
			`f ();`
			`f ();`
			`}`