[Bug sanitizer/113284] [14 regression] many failures in asan after r14-6946-ge66dc37b299cac

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113284

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Ilya Leoshkevich from comment #4)
> Thanks, I can repro this on cfarm203 now.  Apparently I missed
> 
> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
> index 94fbf46f2b6..fd9bb807957 100644
> --- a/gcc/config/rs6000/rs6000.cc
> +++ b/gcc/config/rs6000/rs6000.cc
> @@ -21334,7 +21334,7 @@ rs6000_elf_declare_function_name (FILE *file, const
> char *name, tree decl)
>    if (TARGET_64BIT && DEFAULT_ABI != ABI_ELFv2)
>      {
>        fputs ("\t.section\t\".opd\",\"aw\"\n\t.align 3\n", file);
> -      ASM_OUTPUT_LABEL (file, name);
> +      ASM_OUTPUT_FUNCTION_LABEL (file, name, decl);

Is that correct?
The function label is emitted in the .opd section on powerpc big endian,
but I think we want the .LASAN label to be in the text section instead,
e.g. after the rs6000_output_function_entry (file, name); label emitted a few
lines later.

>        fputs (DOUBLE_INT_ASM_OP, file);
>        rs6000_output_function_entry (file, name);
>        fputs (",.TOC.@tocbase,0\n\t.previous\n", file);
> 
> in commit c659dd8bfb55 ("Implement ASM_DECLARE_FUNCTION_NAME using
> ASM_OUTPUT_FUNCTION_LABEL").  I will start a full regtest and send a patch
> shortly.

Before your changes, we used to emit something like
        .section        ".opd","aw"
        .align 3
foo:
        .quad   .L.foo,.TOC.@tocbase,0
        .previous
        .type   foo, @function
.L.foo:
.LASANPC0:
.LFB0:
        .cfi_startproc
The above patch would emit the .LASANPC0: label after foo:, which is clearly
incorrect,
it really should go where it was emitted before.
Completely untested:
--- gcc/config/rs6000/rs6000.cc.jj      2024-01-05 15:22:21.915684074 +0100
+++ gcc/config/rs6000/rs6000.cc 2024-01-09 12:03:09.295509894 +0100
@@ -21357,6 +21357,10 @@ rs6000_elf_declare_function_name (FILE *
       ASM_DECLARE_RESULT (file, DECL_RESULT (decl));
       rs6000_output_function_entry (file, name);
       fputs (":\n", file);
+      if ((flag_sanitize & SANITIZE_ADDRESS)
+          && (in_cold_section_p == first_function_block_is_cold)
+          && cfun)
+       asan_function_start ();
       return;
     }