Commit-ID: d696ca016d579d43fc043f28ba656d9305fba651 Gitweb: http://git.kernel.org/tip/d696ca016d579d43fc043f28ba656d9305fba651 Author: Andy Lutomirski <[email protected]> AuthorDate: Tue, 10 May 2016 09:18:46 -0700 Committer: Ingo Molnar <[email protected]> CommitDate: Fri, 20 May 2016 09:10:03 +0200
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 <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/5357f2fe0f103eabf005773b70722451eab09a89.1462897104.git.l...@kernel.org Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/kernel/process_64.c | 4 ++-- arch/x86/kernel/ptrace.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 6b16c36..6e789ca 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -532,7 +532,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) switch (code) { case ARCH_SET_GS: - if (addr >= TASK_SIZE_OF(task)) + if (addr >= TASK_SIZE_MAX) return -EPERM; cpu = get_cpu(); task->thread.gsindex = 0; @@ -546,7 +546,7 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) case ARCH_SET_FS: /* Not strictly needed for fs, but do it for symmetry with gs */ - if (addr >= TASK_SIZE_OF(task)) + if (addr >= TASK_SIZE_MAX) return -EPERM; cpu = get_cpu(); task->thread.fsindex = 0; diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index e60ef91..600edd2 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);
