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| author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-20 00:10:27 -0300 |
|---|---|---|
| committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-20 00:10:27 -0300 |
| commit | d0b2f91bede3bd5e3d24dd6803e56eee959c1797 (patch) | |
| tree | 7fee4ab0509879c373c4f2cbd5b8a5be5b4041ee /arch/x86/kernel/ptrace.c | |
| parent | e914f8eb445e8f74b00303c19c2ffceaedd16a05 (diff) | |
Linux-libre 4.8.2-gnupck-4.8.2-gnu
Diffstat (limited to 'arch/x86/kernel/ptrace.c')
| -rw-r--r-- | arch/x86/kernel/ptrace.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 600edd225..a1606eadd 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -173,8 +173,8 @@ unsigned long kernel_stack_pointer(struct pt_regs *regs) return sp; prev_esp = (u32 *)(context); - if (prev_esp) - return (unsigned long)prev_esp; + if (*prev_esp) + return (unsigned long)*prev_esp; return (unsigned long)regs; } @@ -923,15 +923,18 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 value) case offsetof(struct user32, regs.orig_eax): /* - * A 32-bit debugger setting orig_eax means to restore - * the state of the task restarting a 32-bit syscall. - * Make sure we interpret the -ERESTART* codes correctly - * in case the task is not actually still sitting at the - * exit from a 32-bit syscall with TS_COMPAT still set. + * Warning: bizarre corner case fixup here. A 32-bit + * debugger setting orig_eax to -1 wants to disable + * syscall restart. Make sure that the syscall + * restart code sign-extends orig_ax. Also make sure + * we interpret the -ERESTART* codes correctly if + * loaded into regs->ax in case the task is not + * actually still sitting at the exit from a 32-bit + * syscall with TS_COMPAT still set. */ regs->orig_ax = value; if (syscall_get_nr(child, regs) >= 0) - task_thread_info(child)->status |= TS_COMPAT; + task_thread_info(child)->status |= TS_I386_REGS_POKED; break; case offsetof(struct user32, regs.eflags): |