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authorChristoph Hellwig <hch@lst.de>2020-09-17 10:41:58 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2020-09-17 20:00:46 +0300
commit527c412519eb63ed354790f4291c3728815d11a6 (patch)
treed0fee0cb3bc9bd021f293e3fc8ba46d63f237b32 /include/linux/compat.h
parentcc7886d25bcaffe7f4412d774365d85b462366f8 (diff)
downloadlinux-527c412519eb63ed354790f4291c3728815d11a6.tar.xz
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>
Diffstat (limited to 'include/linux/compat.h')
-rw-r--r--include/linux/compat.h9
1 files changed, 9 insertions, 0 deletions
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