From: Florian Weimer <fweimer@redhat.com>
Date: Tue, 6 Jun 2023 09:01:07 +0000 (+0200)
Subject: libgcc: Fix eh_frame fast path in find_fde_tail
X-Git-Tag: basepoints/gcc-15~8525
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=49310a993308492348119f4033e4db0bda4fe46a;p=thirdparty%2Fgcc.git

libgcc: Fix eh_frame fast path in find_fde_tail

The eh_frame value is only used by linear_search_fdes, not the binary
search directly in find_fde_tail, so the bug is not immediately
apparent with most programs.

Fixes commit e724b0480bfa5ec04f39be8c7290330b495c59de ("libgcc:
Special-case BFD ld unwind table encodings in find_fde_tail").

libgcc/

	PR libgcc/109712
	* unwind-dw2-fde-dip.c (find_fde_tail): Correct fast path for
	parsing eh_frame.
---

diff --git a/libgcc/unwind-dw2-fde-dip.c b/libgcc/unwind-dw2-fde-dip.c
index 6223f5f18a23..4e0b880513f3 100644
--- a/libgcc/unwind-dw2-fde-dip.c
+++ b/libgcc/unwind-dw2-fde-dip.c
@@ -403,8 +403,8 @@ find_fde_tail (_Unwind_Ptr pc,
 	 BFD ld generates.  */
       signed value __attribute__ ((mode (SI)));
       memcpy (&value, p, sizeof (value));
+      eh_frame = p + value;
       p += sizeof (value);
-      dbase = value;		/* No adjustment because pcrel has base 0.  */
     }
   else
     p = read_encoded_value_with_base (hdr->eh_frame_ptr_enc,