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authorAndy Lutomirski <luto@kernel.org>2016-05-10 09:18:46 -0700
committerIngo Molnar <mingo@kernel.org>2016-05-20 09:10:03 +0200
commitd696ca016d579d43fc043f28ba656d9305fba651 (patch)
tree8ad4ce52e4aaa359b08784126b66f6ea2190b834 /arch/x86/kernel/ptrace.c
parent06cd3d8c14bdd06f49f1c6a06acf219749c5598e (diff)
downloadlinux-d696ca016d579d43fc043f28ba656d9305fba651.tar.bz2
x86/fsgsbase/64: Use TASK_SIZE_MAX for FSBASE/GSBASE upper limits
The GSBASE upper limit exists to prevent user code from confusing the paranoid idtentry path. The FSBASE upper limit is just for consistency. There's no need to enforce a smaller limit for 32-bit tasks. Just use TASK_SIZE_MAX. This simplifies the logic and will save a few bytes of code. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/5357f2fe0f103eabf005773b70722451eab09a89.1462897104.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/ptrace.c')
-rw-r--r--arch/x86/kernel/ptrace.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index e60ef918f53d..600edd225e81 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -392,7 +392,7 @@ static int putreg(struct task_struct *child,
#ifdef CONFIG_X86_64
case offsetof(struct user_regs_struct,fs_base):
- if (value >= TASK_SIZE_OF(child))
+ if (value >= TASK_SIZE_MAX)
return -EIO;
/*
* When changing the segment base, use do_arch_prctl
@@ -406,7 +406,7 @@ static int putreg(struct task_struct *child,
/*
* Exactly the same here as the %fs handling above.
*/
- if (value >= TASK_SIZE_OF(child))
+ if (value >= TASK_SIZE_MAX)
return -EIO;
if (child->thread.gsbase != value)
return do_arch_prctl(child, ARCH_SET_GS, value);