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| author | Andy Lutomirski <luto@kernel.org> | 2019-07-15 19:08:48 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-11-26 22:00:12 +0100 |
| commit | 8e05f1b4f27d07a0f93e7c6fd28525a5d082b85c (patch) | |
| tree | 0bcf277c56d26e3f4b2f0d033847892fdd1496d3 /arch/x86/kernel/ptrace.c | |
| parent | x86/traps: die() instead of panicking on a double fault (diff) | |
| download | linux-8e05f1b4f27d07a0f93e7c6fd28525a5d082b85c.tar.xz linux-8e05f1b4f27d07a0f93e7c6fd28525a5d082b85c.zip | |
x86/ptrace: Remove set_segment_reg() implementations for current
seg_segment_reg() should be unreachable with task == current.
Rather than confusingly trying to make it work, just explicitly
disable this case.
(regset->get is used for current in the coredump code, but the ->set
interface is only used for ptrace, and you can't ptrace yourself.)
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/ptrace.c')
| -rw-r--r-- | arch/x86/kernel/ptrace.c | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 066e5b01a7e0..3b3b16932589 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -182,6 +182,9 @@ static u16 get_segment_reg(struct task_struct *task, unsigned long offset) static int set_segment_reg(struct task_struct *task, unsigned long offset, u16 value) { + if (WARN_ON_ONCE(task == current)) + return -EIO; + /* * The value argument was already truncated to 16 bits. */ @@ -209,10 +212,7 @@ static int set_segment_reg(struct task_struct *task, break; case offsetof(struct user_regs_struct, gs): - if (task == current) - set_user_gs(task_pt_regs(task), value); - else - task_user_gs(task) = value; + task_user_gs(task) = value; } return 0; @@ -272,6 +272,9 @@ static u16 get_segment_reg(struct task_struct *task, unsigned long offset) static int set_segment_reg(struct task_struct *task, unsigned long offset, u16 value) { + if (WARN_ON_ONCE(task == current)) + return -EIO; + /* * The value argument was already truncated to 16 bits. */ @@ -281,23 +284,15 @@ static int set_segment_reg(struct task_struct *task, switch (offset) { case offsetof(struct user_regs_struct,fs): task->thread.fsindex = value; - if (task == current) - loadsegment(fs, task->thread.fsindex); break; case offsetof(struct user_regs_struct,gs): task->thread.gsindex = value; - if (task == current) - load_gs_index(task->thread.gsindex); break; case offsetof(struct user_regs_struct,ds): task->thread.ds = value; - if (task == current) - loadsegment(ds, task->thread.ds); break; case offsetof(struct user_regs_struct,es): task->thread.es = value; - if (task == current) - loadsegment(es, task->thread.es); break; /* |