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authorDmitry Safonov <dima@arista.com>2018-10-12 16:42:52 +0300
committerThomas Gleixner <tglx@linutronix.de>2018-11-01 14:59:25 +0300
commita846446b1914d1e3d996d657754f43fde89bab51 (patch)
treec1cd5bdd8d5c2f627a8ade867681df57850efaec /arch/x86/mm/mmap.c
parentc6ee7a548e2c291398b4f32c1f741c66b9f98e1c (diff)
downloadlinux-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 'arch/x86/mm/mmap.c')
-rw-r--r--arch/x86/mm/mmap.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index 1e95d57760cf..db3165714521 100644
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -166,7 +166,7 @@ unsigned long get_mmap_base(int is_legacy)
struct mm_struct *mm = current->mm;
#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES
- if (in_compat_syscall()) {
+ if (in_32bit_syscall()) {
return is_legacy ? mm->mmap_compat_legacy_base
: mm->mmap_compat_base;
}