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-rw-r--r--arch/arm/kernel/ptrace.c13
-rw-r--r--arch/arm64/kernel/ptrace.c8
-rw-r--r--arch/mips/kernel/ptrace.c9
-rw-r--r--arch/parisc/kernel/ptrace.c9
-rw-r--r--arch/powerpc/kernel/ptrace.c46
-rw-r--r--arch/s390/kernel/ptrace.c21
-rw-r--r--arch/tile/kernel/ptrace.c11
-rw-r--r--arch/um/kernel/skas/syscall.c9
-rw-r--r--arch/x86/entry/common.c106
-rw-r--r--arch/x86/entry/vsyscall/vsyscall_64.c2
-rw-r--r--arch/x86/include/asm/ptrace.h6
11 files changed, 84 insertions, 156 deletions
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 4d9375814b53..ce131ed5939d 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -932,18 +932,19 @@ asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno)
 {
 	current_thread_info()->syscall = scno;
 
-	/* Do the secure computing check first; failures should be fast. */
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
+
+	/* Do seccomp after ptrace; syscall may have changed. */
 #ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
-	if (secure_computing() == -1)
+	if (secure_computing(NULL) == -1)
 		return -1;
 #else
 	/* XXX: remove this once OABI gets fixed */
-	secure_computing_strict(scno);
+	secure_computing_strict(current_thread_info()->syscall);
 #endif
 
-	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
-
+	/* Tracer or seccomp may have changed syscall. */
 	scno = current_thread_info()->syscall;
 
 	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 030c1d5aa46d..e0c81da60f76 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -1347,13 +1347,13 @@ static void tracehook_report_syscall(struct pt_regs *regs,
 
 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 {
-	/* Do the secure computing check first; failures should be fast. */
-	if (secure_computing() == -1)
-		return -1;
-
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
 
+	/* Do the secure computing after ptrace; failures should be fast. */
+	if (secure_computing(NULL) == -1)
+		return -1;
+
 	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 		trace_sys_enter(regs, regs->syscallno);
 
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 0dcf69194473..6103b24d1bfc 100644
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -888,17 +888,16 @@ long arch_ptrace(struct task_struct *child, long request,
  */
 asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
 {
-	long ret = 0;
 	user_exit();
 
 	current_thread_info()->syscall = syscall;
 
-	if (secure_computing() == -1)
-		return -1;
-
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 	    tracehook_report_syscall_entry(regs))
-		ret = -1;
+		return -1;
+
+	if (secure_computing(NULL) == -1)
+		return -1;
 
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 		trace_sys_enter(regs, regs->regs[2]);
diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c
index b5458b37fc5b..e02d7b4d2b69 100644
--- a/arch/parisc/kernel/ptrace.c
+++ b/arch/parisc/kernel/ptrace.c
@@ -311,10 +311,6 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 
 long do_syscall_trace_enter(struct pt_regs *regs)
 {
-	/* Do the secure computing check first. */
-	if (secure_computing() == -1)
-		return -1;
-
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 	    tracehook_report_syscall_entry(regs)) {
 		/*
@@ -325,6 +321,11 @@ long do_syscall_trace_enter(struct pt_regs *regs)
 		regs->gr[20] = -1UL;
 		goto out;
 	}
+
+	/* Do the secure computing check after ptrace. */
+	if (secure_computing(NULL) == -1)
+		return -1;
+
 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 		trace_sys_enter(regs, regs->gr[20]);
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 060b140f03c6..134bee9ac664 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -1783,12 +1783,12 @@ static int do_seccomp(struct pt_regs *regs)
 	 * have already loaded -ENOSYS into r3, or seccomp has put
 	 * something else in r3 (via SECCOMP_RET_ERRNO/TRACE).
 	 */
-	if (__secure_computing())
+	if (__secure_computing(NULL))
 		return -1;
 
 	/*
 	 * The syscall was allowed by seccomp, restore the register
-	 * state to what ptrace and audit expect.
+	 * state to what audit expects.
 	 * Note that we use orig_gpr3, which means a seccomp tracer can
 	 * modify the first syscall parameter (in orig_gpr3) and also
 	 * allow the syscall to proceed.
@@ -1822,22 +1822,25 @@ static inline int do_seccomp(struct pt_regs *regs) { return 0; }
  */
 long do_syscall_trace_enter(struct pt_regs *regs)
 {
-	bool abort = false;
-
 	user_exit();
 
+	/*
+	 * The tracer may decide to abort the syscall, if so tracehook
+	 * will return !0. Note that the tracer may also just change
+	 * regs->gpr[0] to an invalid syscall number, that is handled
+	 * below on the exit path.
+	 */
+	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+	    tracehook_report_syscall_entry(regs))
+		goto skip;
+
+	/* Run seccomp after ptrace; allow it to set gpr[3]. */
 	if (do_seccomp(regs))
 		return -1;
 
-	if (test_thread_flag(TIF_SYSCALL_TRACE)) {
-		/*
-		 * The tracer may decide to abort the syscall, if so tracehook
-		 * will return !0. Note that the tracer may also just change
-		 * regs->gpr[0] to an invalid syscall number, that is handled
-		 * below on the exit path.
-		 */
-		abort = tracehook_report_syscall_entry(regs) != 0;
-	}
+	/* Avoid trace and audit when syscall is invalid. */
+	if (regs->gpr[0] >= NR_syscalls)
+		goto skip;
 
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 		trace_sys_enter(regs, regs->gpr[0]);
@@ -1854,17 +1857,16 @@ long do_syscall_trace_enter(struct pt_regs *regs)
 				    regs->gpr[5] & 0xffffffff,
 				    regs->gpr[6] & 0xffffffff);
 
-	if (abort || regs->gpr[0] >= NR_syscalls) {
-		/*
-		 * If we are aborting explicitly, or if the syscall number is
-		 * now invalid, set the return value to -ENOSYS.
-		 */
-		regs->gpr[3] = -ENOSYS;
-		return -1;
-	}
-
 	/* Return the possibly modified but valid syscall number */
 	return regs->gpr[0];
+
+skip:
+	/*
+	 * If we are aborting explicitly, or if the syscall number is
+	 * now invalid, set the return value to -ENOSYS.
+	 */
+	regs->gpr[3] = -ENOSYS;
+	return -1;
 }
 
 void do_syscall_trace_leave(struct pt_regs *regs)
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 49b1c13bf6c9..cea17010448f 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -821,15 +821,6 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 
 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 {
-	long ret = 0;
-
-	/* Do the secure computing check first. */
-	if (secure_computing()) {
-		/* seccomp failures shouldn't expose any additional code. */
-		ret = -1;
-		goto out;
-	}
-
 	/*
 	 * The sysc_tracesys code in entry.S stored the system
 	 * call number to gprs[2].
@@ -843,7 +834,13 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 		 * the system call and the system call restart handling.
 		 */
 		clear_pt_regs_flag(regs, PIF_SYSCALL);
-		ret = -1;
+		return -1;
+	}
+
+	/* Do the secure computing check after ptrace. */
+	if (secure_computing(NULL)) {
+		/* seccomp failures shouldn't expose any additional code. */
+		return -1;
 	}
 
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
@@ -852,8 +849,8 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 	audit_syscall_entry(regs->gprs[2], regs->orig_gpr2,
 			    regs->gprs[3], regs->gprs[4],
 			    regs->gprs[5]);
-out:
-	return ret ?: regs->gprs[2];
+
+	return regs->gprs[2];
 }
 
 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c
index 54e7b723db99..d89b7011667c 100644
--- a/arch/tile/kernel/ptrace.c
+++ b/arch/tile/kernel/ptrace.c
@@ -255,14 +255,15 @@ int do_syscall_trace_enter(struct pt_regs *regs)
 {
 	u32 work = ACCESS_ONCE(current_thread_info()->flags);
 
-	if (secure_computing() == -1)
+	if ((work & _TIF_SYSCALL_TRACE) &&
+	    tracehook_report_syscall_entry(regs)) {
+		regs->regs[TREG_SYSCALL_NR] = -1;
 		return -1;
-
-	if (work & _TIF_SYSCALL_TRACE) {
-		if (tracehook_report_syscall_entry(regs))
-			regs->regs[TREG_SYSCALL_NR] = -1;
 	}
 
+	if (secure_computing(NULL) == -1)
+		return -1;
+
 	if (work & _TIF_SYSCALL_TRACEPOINT)
 		trace_sys_enter(regs, regs->regs[TREG_SYSCALL_NR]);
 
diff --git a/arch/um/kernel/skas/syscall.c b/arch/um/kernel/skas/syscall.c
index 48b0dcbd87be..ef4b8f949b51 100644
--- a/arch/um/kernel/skas/syscall.c
+++ b/arch/um/kernel/skas/syscall.c
@@ -20,12 +20,12 @@ void handle_syscall(struct uml_pt_regs *r)
 	UPT_SYSCALL_NR(r) = PT_SYSCALL_NR(r->gp);
 	PT_REGS_SET_SYSCALL_RETURN(regs, -ENOSYS);
 
-	/* Do the secure computing check first; failures should be fast. */
-	if (secure_computing() == -1)
+	if (syscall_trace_enter(regs))
 		return;
 
-	if (syscall_trace_enter(regs))
-		goto out;
+	/* Do the seccomp check after ptrace; failures should be fast. */
+	if (secure_computing(NULL) == -1)
+		return;
 
 	/* Update the syscall number after orig_ax has potentially been updated
 	 * with ptrace.
@@ -37,6 +37,5 @@ void handle_syscall(struct uml_pt_regs *r)
 		PT_REGS_SET_SYSCALL_RETURN(regs,
 				EXECUTE_SYSCALL(syscall, regs));
 
-out:
 	syscall_trace_leave(regs);
 }
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 9e1e27d31c6d..a1e71d431fed 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -64,22 +64,16 @@ static void do_audit_syscall_entry(struct pt_regs *regs, u32 arch)
 }
 
 /*
- * We can return 0 to resume the syscall or anything else to go to phase
- * 2.  If we resume the syscall, we need to put something appropriate in
- * regs->orig_ax.
- *
- * NB: We don't have full pt_regs here, but regs->orig_ax and regs->ax
- * are fully functional.
- *
- * For phase 2's benefit, our return value is:
- * 0:			resume the syscall
- * 1:			go to phase 2; no seccomp phase 2 needed
- * anything else:	go to phase 2; pass return value to seccomp
+ * Returns the syscall nr to run (which should match regs->orig_ax) or -1
+ * to skip the syscall.
  */
-unsigned long syscall_trace_enter_phase1(struct pt_regs *regs, u32 arch)
+static long syscall_trace_enter(struct pt_regs *regs)
 {
+	u32 arch = in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
+
 	struct thread_info *ti = pt_regs_to_thread_info(regs);
 	unsigned long ret = 0;
+	bool emulated = false;
 	u32 work;
 
 	if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
@@ -87,11 +81,19 @@ unsigned long syscall_trace_enter_phase1(struct pt_regs *regs, u32 arch)
 
 	work = ACCESS_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY;
 
+	if (unlikely(work & _TIF_SYSCALL_EMU))
+		emulated = true;
+
+	if ((emulated || (work & _TIF_SYSCALL_TRACE)) &&
+	    tracehook_report_syscall_entry(regs))
+		return -1L;
+
+	if (emulated)
+		return -1L;
+
 #ifdef CONFIG_SECCOMP
 	/*
-	 * Do seccomp first -- it should minimize exposure of other
-	 * code, and keeping seccomp fast is probably more valuable
-	 * than the rest of this.
+	 * Do seccomp after ptrace, to catch any tracer changes.
 	 */
 	if (work & _TIF_SECCOMP) {
 		struct seccomp_data sd;
@@ -118,69 +120,12 @@ unsigned long syscall_trace_enter_phase1(struct pt_regs *regs, u32 arch)
 			sd.args[5] = regs->bp;
 		}
 
-		BUILD_BUG_ON(SECCOMP_PHASE1_OK != 0);
-		BUILD_BUG_ON(SECCOMP_PHASE1_SKIP != 1);
-
-		ret = seccomp_phase1(&sd);
-		if (ret == SECCOMP_PHASE1_SKIP) {
-			regs->orig_ax = -1;
-			ret = 0;
-		} else if (ret != SECCOMP_PHASE1_OK) {
-			return ret;  /* Go directly to phase 2 */
-		}
-
-		work &= ~_TIF_SECCOMP;
-	}
-#endif
-
-	/* Do our best to finish without phase 2. */
-	if (work == 0)
-		return ret;  /* seccomp and/or nohz only (ret == 0 here) */
-
-#ifdef CONFIG_AUDITSYSCALL
-	if (work == _TIF_SYSCALL_AUDIT) {
-		/*
-		 * If there is no more work to be done except auditing,
-		 * then audit in phase 1.  Phase 2 always audits, so, if
-		 * we audit here, then we can't go on to phase 2.
-		 */
-		do_audit_syscall_entry(regs, arch);
-		return 0;
+		ret = __secure_computing(&sd);
+		if (ret == -1)
+			return ret;
 	}
 #endif
 
-	return 1;  /* Something is enabled that we can't handle in phase 1 */
-}
-
-/* Returns the syscall nr to run (which should match regs->orig_ax). */
-long syscall_trace_enter_phase2(struct pt_regs *regs, u32 arch,
-				unsigned long phase1_result)
-{
-	struct thread_info *ti = pt_regs_to_thread_info(regs);
-	long ret = 0;
-	u32 work = ACCESS_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY;
-
-	if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
-		BUG_ON(regs != task_pt_regs(current));
-
-#ifdef CONFIG_SECCOMP
-	/*
-	 * Call seccomp_phase2 before running the other hooks so that
-	 * they can see any changes made by a seccomp tracer.
-	 */
-	if (phase1_result > 1 && seccomp_phase2(phase1_result)) {
-		/* seccomp failures shouldn't expose any additional code. */
-		return -1;
-	}
-#endif
-
-	if (unlikely(work & _TIF_SYSCALL_EMU))
-		ret = -1L;
-
-	if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
-	    tracehook_report_syscall_entry(regs))
-		ret = -1L;
-
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 		trace_sys_enter(regs, regs->orig_ax);
 
@@ -189,17 +134,6 @@ long syscall_trace_enter_phase2(struct pt_regs *regs, u32 arch,
 	return ret ?: regs->orig_ax;
 }
 
-long syscall_trace_enter(struct pt_regs *regs)
-{
-	u32 arch = in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
-	unsigned long phase1_result = syscall_trace_enter_phase1(regs, arch);
-
-	if (phase1_result == 0)
-		return regs->orig_ax;
-	else
-		return syscall_trace_enter_phase2(regs, arch, phase1_result);
-}
-
 #define EXIT_TO_USERMODE_LOOP_FLAGS				\
 	(_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_UPROBE |	\
 	 _TIF_NEED_RESCHED | _TIF_USER_RETURN_NOTIFY)
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 75fc719b7f31..636c4b341f36 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -207,7 +207,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	 */
 	regs->orig_ax = syscall_nr;
 	regs->ax = -ENOSYS;
-	tmp = secure_computing();
+	tmp = secure_computing(NULL);
 	if ((!tmp && regs->orig_ax != syscall_nr) || regs->ip != address) {
 		warn_bad_vsyscall(KERN_DEBUG, regs,
 				  "seccomp tried to change syscall nr or ip");
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 6271281f947d..2b5d686ea9f3 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -83,12 +83,6 @@ extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
 			 int error_code, int si_code);
 
 
-extern unsigned long syscall_trace_enter_phase1(struct pt_regs *, u32 arch);
-extern long syscall_trace_enter_phase2(struct pt_regs *, u32 arch,
-				       unsigned long phase1_result);
-
-extern long syscall_trace_enter(struct pt_regs *);
-
 static inline unsigned long regs_return_value(struct pt_regs *regs)
 {
 	return regs->ax;
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-10-13 20:26:03 +0000