From: "Eric W. Biederman" ebiederm@xmission.com
stable inclusion from stable-v5.10.121 commit 6580673b17e0d302a78b31c7b1b4c7155d0a6011 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 c200e4bb44e80b343c09841e7caaaca0aac5e5fa upstream.
User mode linux is the last user of the PT_DTRACE flag. Using the flag to indicate single stepping is a little confusing and worse changing tsk->ptrace without locking could potentionally cause problems.
So use a thread info flag with a better name instead of flag in tsk->ptrace.
Remove the definition PT_DTRACE as uml is the last user.
Cc: stable@vger.kernel.org Acked-by: Johannes Berg johannes@sipsolutions.net Tested-by: Kees Cook keescook@chromium.org Reviewed-by: Oleg Nesterov oleg@redhat.com Link: https://lkml.kernel.org/r/20220505182645.497868-3-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/um/include/asm/thread_info.h | 2 ++ arch/um/kernel/exec.c | 2 +- arch/um/kernel/process.c | 2 +- arch/um/kernel/ptrace.c | 8 ++++---- arch/um/kernel/signal.c | 4 ++-- include/linux/ptrace.h | 1 - 6 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/arch/um/include/asm/thread_info.h b/arch/um/include/asm/thread_info.h index 4c19ce4c49f1..66ab6a07330b 100644 --- a/arch/um/include/asm/thread_info.h +++ b/arch/um/include/asm/thread_info.h @@ -63,6 +63,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_RESTORE_SIGMASK 7 #define TIF_NOTIFY_RESUME 8 #define TIF_SECCOMP 9 /* secure computing */ +#define TIF_SINGLESTEP 10 /* single stepping userspace */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) @@ -70,5 +71,6 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_MEMDIE (1 << TIF_MEMDIE) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) #define _TIF_SECCOMP (1 << TIF_SECCOMP) +#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
#endif diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c index e8fd5d540b05..7f7a74c82abb 100644 --- a/arch/um/kernel/exec.c +++ b/arch/um/kernel/exec.c @@ -44,7 +44,7 @@ void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp) { PT_REGS_IP(regs) = eip; PT_REGS_SP(regs) = esp; - current->ptrace &= ~PT_DTRACE; + clear_thread_flag(TIF_SINGLESTEP); #ifdef SUBARCH_EXECVE1 SUBARCH_EXECVE1(regs->regs); #endif diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 9505a7e87396..8eb8b736abc1 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -341,7 +341,7 @@ int singlestepping(void * t) { struct task_struct *task = t ? t : current;
- if (!(task->ptrace & PT_DTRACE)) + if (!test_thread_flag(TIF_SINGLESTEP)) return 0;
if (task->thread.singlestep_syscall) diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c index b425f47bddbb..d37802ced563 100644 --- a/arch/um/kernel/ptrace.c +++ b/arch/um/kernel/ptrace.c @@ -12,7 +12,7 @@
void user_enable_single_step(struct task_struct *child) { - child->ptrace |= PT_DTRACE; + set_tsk_thread_flag(child, TIF_SINGLESTEP); child->thread.singlestep_syscall = 0;
#ifdef SUBARCH_SET_SINGLESTEPPING @@ -22,7 +22,7 @@ void user_enable_single_step(struct task_struct *child)
void user_disable_single_step(struct task_struct *child) { - child->ptrace &= ~PT_DTRACE; + clear_tsk_thread_flag(child, TIF_SINGLESTEP); child->thread.singlestep_syscall = 0;
#ifdef SUBARCH_SET_SINGLESTEPPING @@ -121,7 +121,7 @@ static void send_sigtrap(struct uml_pt_regs *regs, int error_code) }
/* - * XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and + * XXX Check TIF_SINGLESTEP for singlestepping check and * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check */ int syscall_trace_enter(struct pt_regs *regs) @@ -145,7 +145,7 @@ void syscall_trace_leave(struct pt_regs *regs) audit_syscall_exit(regs);
/* Fake a debug trap */ - if (ptraced & PT_DTRACE) + if (test_thread_flag(TIF_SINGLESTEP)) send_sigtrap(®s->regs, 0);
if (!test_thread_flag(TIF_SYSCALL_TRACE)) diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c index 88cd9b5c1b74..ae4658f576ab 100644 --- a/arch/um/kernel/signal.c +++ b/arch/um/kernel/signal.c @@ -53,7 +53,7 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) unsigned long sp; int err;
- if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED)) + if (test_thread_flag(TIF_SINGLESTEP) && (current->ptrace & PT_PTRACED)) singlestep = 1;
/* Did we come from a system call? */ @@ -128,7 +128,7 @@ void do_signal(struct pt_regs *regs) * on the host. The tracing thread will check this flag and * PTRACE_SYSCALL if necessary. */ - if (current->ptrace & PT_DTRACE) + if (test_thread_flag(TIF_SINGLESTEP)) current->thread.singlestep_syscall = is_syscall(PT_REGS_IP(¤t->thread.regs));
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 2a9df80ea887..468bb073c993 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -30,7 +30,6 @@ extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
#define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ #define PT_PTRACED 0x00000001 -#define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
#define PT_OPT_FLAG_SHIFT 3 /* PT_TRACE_* event enable flags */