From: "Eric W. Biederman" ebiederm@xmission.com
stable inclusion from stable-v5.10.121 commit f8ef79687b2e156841b5758cc96e63796fd53542 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 4a3d2717d140401df7501a95e454180831a0c5af upstream.
xtensa is the last user of the PT_SINGLESTEP flag. Changing tsk->ptrace in user_enable_single_step and user_disable_single_step without locking could potentiallly cause problems.
So use a thread info flag instead of a flag in tsk->ptrace. Use TIF_SINGLESTEP that xtensa already had defined but unused.
Remove the definitions of PT_SINGLESTEP and PT_BLOCKSTEP as they have no more users.
Cc: stable@vger.kernel.org Acked-by: Max Filippov jcmvbkbc@gmail.com Tested-by: Kees Cook keescook@chromium.org Reviewed-by: Oleg Nesterov oleg@redhat.com Link: https://lkml.kernel.org/r/20220505182645.497868-4-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" ebiederm@xmission.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- arch/xtensa/kernel/ptrace.c | 4 ++-- arch/xtensa/kernel/signal.c | 4 ++-- include/linux/ptrace.h | 6 ------ 3 files changed, 4 insertions(+), 10 deletions(-)
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c index bb3f4797d212..db6cdea471d8 100644 --- a/arch/xtensa/kernel/ptrace.c +++ b/arch/xtensa/kernel/ptrace.c @@ -226,12 +226,12 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task)
void user_enable_single_step(struct task_struct *child) { - child->ptrace |= PT_SINGLESTEP; + set_tsk_thread_flag(child, TIF_SINGLESTEP); }
void user_disable_single_step(struct task_struct *child) { - child->ptrace &= ~PT_SINGLESTEP; + clear_tsk_thread_flag(child, TIF_SINGLESTEP); }
/* diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c index 1fb1047f905c..1cb230fafdf2 100644 --- a/arch/xtensa/kernel/signal.c +++ b/arch/xtensa/kernel/signal.c @@ -465,7 +465,7 @@ static void do_signal(struct pt_regs *regs) /* Set up the stack frame */ ret = setup_frame(&ksig, sigmask_to_save(), regs); signal_setup_done(ret, &ksig, 0); - if (current->ptrace & PT_SINGLESTEP) + if (test_thread_flag(TIF_SINGLESTEP)) task_pt_regs(current)->icountlevel = 1;
return; @@ -491,7 +491,7 @@ static void do_signal(struct pt_regs *regs) /* If there's no signal to deliver, we just restore the saved mask. */ restore_saved_sigmask();
- if (current->ptrace & PT_SINGLESTEP) + if (test_thread_flag(TIF_SINGLESTEP)) task_pt_regs(current)->icountlevel = 1; return; } diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 468bb073c993..ae7dbdfa3d83 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -46,12 +46,6 @@ extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, #define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT) #define PT_SUSPEND_SECCOMP (PTRACE_O_SUSPEND_SECCOMP << PT_OPT_FLAG_SHIFT)
-/* single stepping state bits (used on ARM and PA-RISC) */ -#define PT_SINGLESTEP_BIT 31 -#define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) -#define PT_BLOCKSTEP_BIT 30 -#define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) - extern long arch_ptrace(struct task_struct *child, long request, unsigned long addr, unsigned long data); extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);