[gcc r14-7012] asan: Do not call asan_function_start () without the current function [PR113251]

[Ilya Leoshkevich]

https://gcc.gnu.org/g:ba4cfef0a45dd50e16ca7bee158bc630fa646ee7

commit r14-7012-gba4cfef0a45dd50e16ca7bee158bc630fa646ee7
Author: Ilya Leoshkevich <iii@linux.ibm.com>
Date:   Mon Jan 8 10:11:59 2024 +0100

    asan: Do not call asan_function_start () without the current function [PR113251]
    
    Using ASAN on i686-linux with -fPIC causes an ICE, because when
    pc_thunks are generated, there is no current function anymore, but
    asan_function_start () expects one.
    
    Fix by not calling asan_function_start () without one.
    
    A narrower fix would be to temporarily disable ASAN around pc_thunk
    generation.  However, the issue looks generic enough, and may affect
    less often tested configurations, so go for a broader fix.
    
    Fixes: e66dc37b299c ("asan: Align .LASANPC on function boundary")
    Suggested-by: Jakub Jelinek <jakub@redhat.com>
    Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
    
    gcc/ChangeLog:
    
            PR sanitizer/113251
            * varasm.cc (assemble_function_label_raw): Do not call
            asan_function_start () without the current function.

Diff:
---
 gcc/varasm.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/gcc/varasm.cc b/gcc/varasm.cc
index 25c1e05628d..1a869ae458a 100644
--- a/gcc/varasm.cc
+++ b/gcc/varasm.cc
@@ -1845,7 +1845,9 @@ assemble_function_label_raw (FILE *file, const char *name)
   ASM_OUTPUT_LABEL (file, name);
   if ((flag_sanitize & SANITIZE_ADDRESS)
       /* Notify ASAN only about the first function label.  */
-      && (in_cold_section_p == first_function_block_is_cold))
+      && (in_cold_section_p == first_function_block_is_cold)
+      /* Do not notify ASAN when called from, e.g., code_end ().  */
+      && cfun)
     asan_function_start ();
 }