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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2021-02-13 17:49:08 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2021-02-13 17:49:08 -0500 |
| commit | c3dc311ffd6417b15a467c6ea53e642577e9f00e (patch) | |
| tree | f11166f5d7af9fd12f730317370dfc7f5e95a613 /src/include | |
| parent | 0347470b31c139aa4f1d366fbdb85f32b7f82ad0 (diff) | |
pg_attribute_no_sanitize_alignment() macro
Modern gcc and clang compilers offer alignment sanitizers, which help to detect
pointer misalignment. However, our codebase already contains x86-specific
crc32 computation code, which uses unalignment access. Thankfully, those
compilers also support the attribute, which disables alignment sanitizers at
the function level. This commit adds pg_attribute_no_sanitize_alignment(),
which wraps this attribute, and applies it to pg_comp_crc32c_sse42() function.
Back-patch of commits 993bdb9f9 and ad2ad698a, to enable doing
alignment testing in all supported branches.
Discussion: https://postgr.es/m/CAPpHfdsne3%3DT%3DfMNU45PtxdhSL_J2PjLTeS8rwKnJzUR4YNd4w%40mail.gmail.com
Discussion: https://postgr.es/m/475514.1612745257%40sss.pgh.pa.us
Author: Alexander Korotkov, revised by Tom Lane
Reviewed-by: Tom Lane
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/c.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/src/include/c.h b/src/include/c.h index 0fcd6b193c7..f8754d2ed71 100644 --- a/src/include/c.h +++ b/src/include/c.h @@ -113,6 +113,18 @@ #endif /* + * Place this macro before functions that should be allowed to make misaligned + * accesses. Think twice before using it on non-x86-specific code! + * Testing can be done with "-fsanitize=alignment -fsanitize-trap=alignment" + * on clang, or "-fsanitize=alignment -fno-sanitize-recover=alignment" on gcc. + */ +#if __clang_major__ >= 7 || __GNUC__ >= 8 +#define pg_attribute_no_sanitize_alignment() __attribute__((no_sanitize("alignment"))) +#else +#define pg_attribute_no_sanitize_alignment() +#endif + +/* * Append PG_USED_FOR_ASSERTS_ONLY to definitions of variables that are only * used in assert-enabled builds, to avoid compiler warnings about unused * variables in assert-disabled builds. |