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| author | Dmitry Safonov <dima@arista.com> | 2018-10-12 16:42:52 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-11-01 14:59:25 +0300 |
| commit | a846446b1914d1e3d996d657754f43fde89bab51 (patch) | |
| tree | c1cd5bdd8d5c2f627a8ade867681df57850efaec /include | |
| parent | c6ee7a548e2c291398b4f32c1f741c66b9f98e1c (diff) | |
| download | linux-a846446b1914d1e3d996d657754f43fde89bab51.tar.xz | |
x86/compat: Adjust in_compat_syscall() to generic code under !COMPAT
The result of in_compat_syscall() can be pictured as:
x86 platform:
---------------------------------------------------
| Arch\syscall | 64-bit | ia32 | x32 |
|-------------------------------------------------|
| x86_64 | false | true | true |
|-------------------------------------------------|
| i686 | | <true> | |
---------------------------------------------------
Other platforms:
-------------------------------------------
| Arch\syscall | 64-bit | compat |
|-----------------------------------------|
| 64-bit | false | true |
|-----------------------------------------|
| 32-bit(?) | | <false> |
-------------------------------------------
As seen, the result of in_compat_syscall() on generic 32-bit platform
differs from i686.
There is no reason for in_compat_syscall() == true on native i686. It also
easy to misread code if the result on native 32-bit platform differs
between arches.
Because of that non arch-specific code has many places with:
if (IS_ENABLED(CONFIG_COMPAT) && in_compat_syscall())
in different variations.
It looks-like the only non-x86 code which uses in_compat_syscall() not
under CONFIG_COMPAT guard is in amd/amdkfd. But according to the commit
a18069c132cb ("amdkfd: Disable support for 32-bit user processes"), it
actually should be disabled on native i686.
Rename in_compat_syscall() to in_32bit_syscall() for x86-specific code
and make in_compat_syscall() false under !CONFIG_COMPAT.
A follow on patch will clean up generic users which were forced to check
IS_ENABLED(CONFIG_COMPAT) with in_compat_syscall().
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-efi@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: https://lkml.kernel.org/r/20181012134253.23266-2-dima@arista.com
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/compat.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/compat.h b/include/linux/compat.h index d30e4dbd4be2..f1ef24c68fcc 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -1029,9 +1029,9 @@ int kcompat_sys_fstatfs64(unsigned int fd, compat_size_t sz, #else /* !CONFIG_COMPAT */ #define is_compat_task() (0) -#ifndef in_compat_syscall +/* Ensure no one redefines in_compat_syscall() under !CONFIG_COMPAT */ +#define in_compat_syscall in_compat_syscall static inline bool in_compat_syscall(void) { return false; } -#endif #endif /* CONFIG_COMPAT */ |