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| author | Dmitry Safonov <dima@arista.com> | 2018-10-12 15:42:52 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-11-01 12:59:25 +0100 |
| commit | a846446b1914d1e3d996d657754f43fde89bab51 (patch) | |
| tree | c1cd5bdd8d5c2f627a8ade867681df57850efaec /arch/x86/include/asm/compat.h | |
| parent | x86/numa_emulation: Fix uniform-split numa emulation (diff) | |
| download | linux-a846446b1914d1e3d996d657754f43fde89bab51.tar.xz linux-a846446b1914d1e3d996d657754f43fde89bab51.zip | |
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 'arch/x86/include/asm/compat.h')
| -rw-r--r-- | arch/x86/include/asm/compat.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h index fab4df16a3c4..22c4dfe65992 100644 --- a/arch/x86/include/asm/compat.h +++ b/arch/x86/include/asm/compat.h @@ -217,11 +217,18 @@ static inline bool in_x32_syscall(void) return false; } -static inline bool in_compat_syscall(void) +static inline bool in_32bit_syscall(void) { return in_ia32_syscall() || in_x32_syscall(); } + +#ifdef CONFIG_COMPAT +static inline bool in_compat_syscall(void) +{ + return in_32bit_syscall(); +} #define in_compat_syscall in_compat_syscall /* override the generic impl */ +#endif struct compat_siginfo; int __copy_siginfo_to_user32(struct compat_siginfo __user *to, |