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authorEric W. Biederman <ebiederm@xmission.com>2022-04-26 16:45:37 -0500
committerEric W. Biederman <ebiederm@xmission.com>2022-05-11 14:33:44 -0500
commit4a3d2717d140401df7501a95e454180831a0c5af (patch)
tree7baae80c9ca9792e5dac16a17e1339b6e0a55991
parentc200e4bb44e80b343c09841e7caaaca0aac5e5fa (diff)
downloadlwn-4a3d2717d140401df7501a95e454180831a0c5af.tar.gz
lwn-4a3d2717d140401df7501a95e454180831a0c5af.zip
ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP
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>
-rw-r--r--arch/xtensa/kernel/ptrace.c4
-rw-r--r--arch/xtensa/kernel/signal.c4
-rw-r--r--include/linux/ptrace.h6
3 files changed, 4 insertions, 10 deletions
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
index 323c678a691f..b952e67cc0cc 100644
--- a/arch/xtensa/kernel/ptrace.c
+++ b/arch/xtensa/kernel/ptrace.c
@@ -225,12 +225,12 @@ 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 6f68649e86ba..ac50ec46c8f1 100644
--- a/arch/xtensa/kernel/signal.c
+++ b/arch/xtensa/kernel/signal.c
@@ -473,7 +473,7 @@ 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;
@@ -499,7 +499,7 @@ 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 4c06f9f8ef3f..c952c5ba8fab 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);