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| author | Andy Lutomirski <luto@kernel.org> | 2020-06-26 20:24:28 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-07-01 16:27:20 +0300 |
| commit | 8e259031c67a5ea0666428edb64c89e8c6ebd18e (patch) | |
| tree | 379d458f8bf0e85e1bcbaeda683eca889fb97a17 /tools/testing/selftests/x86/fsgsbase.c | |
| parent | 979c2c4247cafd8a91628a7306b6871efbd12fdb (diff) | |
| download | linux-8e259031c67a5ea0666428edb64c89e8c6ebd18e.tar.xz | |
selftests/x86/fsgsbase: Add a missing memory constraint
The manual call to set_thread_area() via int $0x80 was missing any
indication that the descriptor was a pointer, causing gcc to
occasionally generate wrong code. Add the missing constraint.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/432968af67259ca92d68b774a731aff468eae610.1593192140.git.luto@kernel.org
Diffstat (limited to 'tools/testing/selftests/x86/fsgsbase.c')
| -rw-r--r-- | tools/testing/selftests/x86/fsgsbase.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/testing/selftests/x86/fsgsbase.c b/tools/testing/selftests/x86/fsgsbase.c index f47495d2f070..998319553523 100644 --- a/tools/testing/selftests/x86/fsgsbase.c +++ b/tools/testing/selftests/x86/fsgsbase.c @@ -285,7 +285,8 @@ static unsigned short load_gs(void) /* 32-bit set_thread_area */ long ret; asm volatile ("int $0x80" - : "=a" (ret) : "a" (243), "b" (low_desc) + : "=a" (ret), "+m" (*low_desc) + : "a" (243), "b" (low_desc) : "r8", "r9", "r10", "r11"); memcpy(&desc, low_desc, sizeof(desc)); munmap(low_desc, sizeof(desc)); |