From: Prasanna Meda ptrace_setsiginfo/ptrace_getsiginfo need to do locked access to last_siginfo. ptrace_notify()/ptrace_stop() sets the current->last_siginfo and sleeps on schedule(). It can be waked up by kill signal from signal_wake_up before debugger wakes it up. On return from schedule(), the current->last_siginfo is reset. Signed-off-by: Prasanna Meda Signed-off-by: Andrew Morton --- 25-akpm/kernel/ptrace.c | 29 ++++++++++++++++++++++------- 1 files changed, 22 insertions(+), 7 deletions(-) diff -puN kernel/ptrace.c~ptrace-locked-accesss-to-ptrace-last_siginfo kernel/ptrace.c --- 25/kernel/ptrace.c~ptrace-locked-accesss-to-ptrace-last_siginfo 2004-11-21 15:52:10.490855832 -0800 +++ 25-akpm/kernel/ptrace.c 2004-11-21 15:52:10.494855224 -0800 @@ -319,18 +319,33 @@ static int ptrace_setoptions(struct task static int ptrace_getsiginfo(struct task_struct *child, siginfo_t __user * data) { - if (child->last_siginfo == NULL) - return -EINVAL; - return copy_siginfo_to_user(data, child->last_siginfo); + siginfo_t lastinfo; + + spin_lock_irq(&child->sighand->siglock); + if (likely(child->last_siginfo != NULL)) { + memcpy(&lastinfo, child->last_siginfo, sizeof (siginfo_t)); + spin_unlock_irq(&child->sighand->siglock); + return copy_siginfo_to_user(data, &lastinfo); + } + spin_unlock_irq(&child->sighand->siglock); + return -EINVAL; } static int ptrace_setsiginfo(struct task_struct *child, siginfo_t __user * data) { - if (child->last_siginfo == NULL) - return -EINVAL; - if (copy_from_user(child->last_siginfo, data, sizeof (siginfo_t)) != 0) + siginfo_t newinfo; + + if (copy_from_user(&newinfo, data, sizeof (siginfo_t)) != 0) return -EFAULT; - return 0; + + spin_lock_irq(&child->sighand->siglock); + if (likely(child->last_siginfo != NULL)) { + memcpy(child->last_siginfo, &newinfo, sizeof (siginfo_t)); + spin_unlock_irq(&child->sighand->siglock); + return 0; + } + spin_unlock_irq(&child->sighand->siglock); + return -EINVAL; } int ptrace_request(struct task_struct *child, long request, _