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| author | Christoph Hellwig <hch@lst.de> | 2020-09-17 09:41:58 +0200 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2020-09-17 13:00:46 -0400 |
| commit | 527c412519eb63ed354790f4291c3728815d11a6 (patch) | |
| tree | d0fee0cb3bc9bd021f293e3fc8ba46d63f237b32 | |
| parent | cc7886d25bcaffe7f4412d774365d85b462366f8 (diff) | |
| download | linux-stable-527c412519eb63ed354790f4291c3728815d11a6.tar.gz linux-stable-527c412519eb63ed354790f4291c3728815d11a6.tar.bz2 linux-stable-527c412519eb63ed354790f4291c3728815d11a6.zip | |
compat: add a compat_need_64bit_alignment_fixup() helper
Add a helper to check if the calling syscall needs a fixup for
non-natural 64-bit type alignment in the compat ABI. This will only
return true for i386 syscalls on x86_64.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | arch/x86/include/asm/compat.h | 1 | ||||
| -rw-r--r-- | include/linux/compat.h | 9 |
2 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index bf547701f41f..0e327a01f50f 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -209,6 +209,7 @@ static inline bool in_compat_syscall(void) return in_32bit_syscall(); } #define in_compat_syscall in_compat_syscall /* override the generic impl */ +#define compat_need_64bit_alignment_fixup in_ia32_syscall #endif struct compat_siginfo; diff --git a/include/linux/compat.h b/include/linux/compat.h index d38c4d7e83bd..f0026a344482 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -933,6 +933,15 @@ static inline bool in_compat_syscall(void) { return false; } #endif /* CONFIG_COMPAT */ /* + * Some legacy ABIs like the i386 one use less than natural alignment for 64-bit + * types, and will need special compat treatment for that. Most architectures + * don't need that special handling even for compat syscalls. + */ +#ifndef compat_need_64bit_alignment_fixup +#define compat_need_64bit_alignment_fixup() false +#endif + +/* * A pointer passed in from user mode. This should not * be used for syscall parameters, just declare them * as pointers because the syscall entry code will have |