summaryrefslogtreecommitdiff
path: root/include/linux/compat.h
diff options
context:
space:
mode:
authorDmitry Safonov <dima@arista.com>2018-10-12 14:42:52 +0100
committerThomas Gleixner <tglx@linutronix.de>2018-11-01 12:59:25 +0100
commita846446b1914d1e3d996d657754f43fde89bab51 (patch)
treec1cd5bdd8d5c2f627a8ade867681df57850efaec /include/linux/compat.h
parentc6ee7a548e2c291398b4f32c1f741c66b9f98e1c (diff)
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/linux/compat.h')
-rw-r--r--include/linux/compat.h4
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 */