From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [RFC v2 PATCH 6/7] x86/regs: syscall_get_nr() returns -1 for a non-system call
Date: Mon, 10 May 2021 11:53:15 -0700 [thread overview]
Message-ID: <20210510185316.3307264-7-hpa@zytor.com> (raw)
In-Reply-To: <20210510185316.3307264-1-hpa@zytor.com>
syscall_get_nr() is defined to return -1 for a non-system call or a
ptrace/seccomp restart; not just any arbitrary number. See comment in
<asm-generic/syscall.h> for the official definition of this function.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
arch/x86/kernel/ptrace.c | 2 +-
arch/x86/kernel/signal.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 87a4143aa7d7..4c208ea3bd9f 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -911,7 +911,7 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 value)
* syscall with TS_COMPAT still set.
*/
regs->orig_ax = value;
- if (syscall_get_nr(child, regs) >= 0)
+ if (syscall_get_nr(child, regs) != -1)
child->thread_info.status |= TS_I386_REGS_POKED;
break;
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index a06cb107c0e8..e12779a2714d 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -713,7 +713,7 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL);
/* Are we from a system call? */
- if (syscall_get_nr(current, regs) >= 0) {
+ if (syscall_get_nr(current, regs) != -1) {
/* If so, check system call restarting.. */
switch (syscall_get_error(current, regs)) {
case -ERESTART_RESTARTBLOCK:
@@ -793,7 +793,7 @@ void arch_do_signal_or_restart(struct pt_regs *regs, bool has_signal)
}
/* Did we come from a system call? */
- if (syscall_get_nr(current, regs) >= 0) {
+ if (syscall_get_nr(current, regs) != -1) {
/* Restart the system call - no handlers present */
switch (syscall_get_error(current, regs)) {
case -ERESTARTNOHAND:
--
2.31.1
next prev parent reply other threads:[~2021-05-10 18:53 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-10 18:53 [RFC v2 PATCH 0/6] x86/entry: cleanups and consistent syscall number handling H. Peter Anvin
2021-05-10 18:53 ` [RFC v2 PATCH 1/7] x86/entry: unify definitions from calling.h and ptrace-abi.h H. Peter Anvin
2021-05-12 9:23 ` [tip: x86/asm] x86/entry: Unify definitions from <asm/calling.h> and <asm/ptrace-abi.h> tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 2/7] x86/entry: reverse arguments to do_syscall_64() H. Peter Anvin
2021-05-12 9:23 ` [tip: x86/asm] x86/entry: Reverse " tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 3/7] x86/syscall: unconditionally prototype {ia32,x32}_sys_call_table[] H. Peter Anvin
2021-05-12 9:23 ` [tip: x86/asm] x86/syscall: Unconditionally " tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 4/7] x86/syscall: maximize MSR_SYSCALL_MASK H. Peter Anvin
2021-05-12 9:23 ` [tip: x86/asm] x86/syscall: Maximize MSR_SYSCALL_MASK tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` [RFC v2 PATCH 5/7] x86/entry: split PUSH_AND_CLEAR_REGS into two submacros H. Peter Anvin
2021-05-12 9:23 ` [tip: x86/asm] x86/entry: Split " tip-bot2 for H. Peter Anvin (Intel)
2021-05-10 18:53 ` H. Peter Anvin [this message]
2021-05-12 9:23 ` [tip: x86/asm] x86/regs: Syscall_get_nr() returns -1 for a non-system call tip-bot2 for H. Peter Anvin
2021-05-10 18:53 ` [RFC v2 PATCH 7/7] x86/entry: use int for syscall number; handle all invalid syscall nrs H. Peter Anvin
2021-05-12 8:51 ` Ingo Molnar
2021-05-12 17:50 ` H. Peter Anvin
2021-05-12 12:09 ` Thomas Gleixner
2021-05-12 18:21 ` H. Peter Anvin
2021-05-12 18:34 ` Thomas Gleixner
2021-05-12 22:09 ` H. Peter Anvin
2021-05-12 22:22 ` Thomas Gleixner
2021-05-12 22:24 ` H. Peter Anvin
2021-05-14 0:38 ` H. Peter Anvin
2021-05-14 3:18 ` Andy Lutomirski
2021-05-14 3:23 ` H. Peter Anvin
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