liblzma: Fix false Valgrind error report with GCC.

With GCC and a certain combination of flags, Valgrind will falsely
trigger an invalid write. This appears to be due to the omission of
instructions to properly save, set up, and restore the frame pointer.

The IFUNC resolver is a leaf function since it only calls a function
that is inlined. So sometimes GCC omits the frame pointer instructions
in the resolver unless this optimization is explictly disabled.

This fixes https://bugzilla.redhat.com/show_bug.cgi?id=2267598.

1 files changed, 3 insertions, 6 deletions

diff --git a/src/liblzma/check/crc32_fast.c b/src/liblzma/check/crc32_fast.c
index 079051f1..719d696c 100644
--- a/src/liblzma/check/crc32_fast.c
+++ b/src/liblzma/check/crc32_fast.c
@@ -135,15 +135,12 @@ typedef uint32_t (*crc32_func_type)(
 // This resolver is shared between all three dispatch methods. It serves as
 // the ifunc resolver if ifunc is supported, otherwise it is called as a
 // regular function by the constructor or first call resolution methods.
-// The __no_profile_instrument_function__ attribute support is checked when
-// determining if ifunc can be used, so it is safe to use here.
-#ifdef CRC_USE_IFUNC
-__attribute__((__no_profile_instrument_function__))
-#endif
+// The funcion attributes are needed for safe IFUNC resolver usage with GCC.
+lzma_resolver_attributes
 static crc32_func_type
 crc32_resolve(void)
 {
-	return is_arch_extension_supported()
+	return  is_arch_extension_supported()
 			? &crc32_arch_optimized : &crc32_generic;
 }