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| author | jah <jah@FreeBSD.org> | 2020-09-12 07:04:00 +0000 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2020-10-26 14:18:46 +0100 |
| commit | 303c61925d9256be02dcbda8f1e5e0d4adf8b3b9 (patch) | |
| tree | 4e5780399f69d8c5c4b57530a0573363d5ef895e | |
| parent | 47efca5ac3da9aacc3a4216a1725ed2d62dd27b1 (diff) | |
| download | cygnal-303c61925d9256be02dcbda8f1e5e0d4adf8b3b9.tar.gz cygnal-303c61925d9256be02dcbda8f1e5e0d4adf8b3b9.tar.bz2 cygnal-303c61925d9256be02dcbda8f1e5e0d4adf8b3b9.zip | |
amd64: prevent KCSan false positives on LAPIC mapping
For configurations without x2APIC support (guests, older hardware), the global
LAPIC MMIO mapping will trigger false-positive KCSan reports as it will appear
that multiple CPUs are concurrently reading and writing the same address.
This isn't actually true, as the underlying physical access will be performed
on the local CPU's APIC. Additionally, because LAPIC access can happen during
event timer configuration, the resulting KCSan printf can produce a panic due
to attempted recursion on event timer resources.
Add a __nosanitizethread preprocessor define to prevent the compiler from
inserting TSan hooks, and apply it to the x86 LAPIC accessors.
PR: 249149
Reported by: gbe
Reviewed by: andrew, kib
Tested by: gbe
Differential Revision: https://reviews.freebsd.org/D26354
| -rw-r--r-- | newlib/libc/include/sys/cdefs.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h index 1be994ffd..da7290921 100644 --- a/newlib/libc/include/sys/cdefs.h +++ b/newlib/libc/include/sys/cdefs.h @@ -716,8 +716,10 @@ */ #if __has_attribute(no_sanitize) && defined(__clang__) #define __nosanitizeaddress __attribute__((no_sanitize("address"))) +#define __nosanitizethread __attribute__((no_sanitize("thread"))) #else #define __nosanitizeaddress +#define __nosanitizethread #endif /* Guard variables and structure members by lock. */ |