2023-09-12 07:20:26

by Yang Yang

[permalink] [raw]
Subject: [PATCH 5.10-rt] arm64: signal: Use ARCH_RT_DELAYS_SIGNAL_SEND

From: Wang Yong <[email protected]>

The ltp test prompts the following bug information under the 5.10 kernel:
BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:969
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 796, name: cat
Preemption disabled at:
[<ffffffe40f433980>] do_debug_exception+0x60/0x180
CPU: 3 PID: 796 Comm: cat Not tainted 5.10.59-rt52-KERNEL_VERSION #38
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x198
show_stack+0x20/0x30
dump_stack+0xf0/0x13c
___might_sleep+0x140/0x178
rt_spin_lock+0x30/0x90
force_sig_info_to_task+0x30/0xe0
force_sig_fault_to_task+0x54/0x78
force_sig_fault+0x1c/0x28
arm64_force_sig_fault+0x48/0x78
send_user_sigtrap+0x4c/0x80
brk_handler+0x3c/0x68
do_debug_exception+0xac/0x180
el0_dbg+0x34/0x58
el0_sync_handler+0x50/0xb8
el0_sync+0x180/0x1c0

It has been fixed by
0c34700de5e7 ("arm64: signal: Use ARCH_RT_DELAYS_SIGNAL_SEND.") in
higher versions of the kernel. This patch needs to be compatible with 5.10.
5.10 kernel does not have signal.h file, so adding signal.h file to
define ARCH_RT_DELAYS_SIGNAL_SEND.

Signed-off-by: Wang Yong <[email protected]>
Cc: Xuexin Jiang <[email protected]>
Cc: Yang Yang <[email protected]>
Cc: Xiaokai Ran <[email protected]>
---
arch/arm64/include/asm/signal.h | 12 ++++++++++++
arch/arm64/kernel/signal.c | 9 +++++++++
2 files changed, 21 insertions(+)
create mode 100644 arch/arm64/include/asm/signal.h

diff --git a/arch/arm64/include/asm/signal.h b/arch/arm64/include/asm/signal.h
new file mode 100644
index 000000000..0fb418cf4
--- /dev/null
+++ b/arch/arm64/include/asm/signal.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ARM64_ASM_SIGNAL_H
+#define __ARM64_ASM_SIGNAL_H
+
+#include <uapi/asm/signal.h>
+#include <uapi/asm/siginfo.h>
+
+#if defined(CONFIG_PREEMPT_RT)
+#define ARCH_RT_DELAYS_SIGNAL_SEND
+#endif
+
+#endif
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index fe94a3e1f..538d4aadb 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -927,6 +927,15 @@ asmlinkage void do_notify_resume(struct pt_regs *regs,
} else {
local_daif_restore(DAIF_PROCCTX);

+#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
+ if (unlikely(current->forced_info.si_signo)) {
+ struct task_struct *t = current;
+
+ force_sig_info(&t->forced_info);
+ t->forced_info.si_signo = 0;
+ }
+#endif
+
if (thread_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);

--
2.25.1


Subject: Re: [PATCH 5.10-rt] arm64: signal: Use ARCH_RT_DELAYS_SIGNAL_SEND

On Tue, Sep 12, 2023 at 03:14:28PM +0800, [email protected] wrote:
> From: Wang Yong <[email protected]>
>
> The ltp test prompts the following bug information under the 5.10 kernel:
> BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:969
> in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 796, name: cat
> Preemption disabled at:
> [<ffffffe40f433980>] do_debug_exception+0x60/0x180
> CPU: 3 PID: 796 Comm: cat Not tainted 5.10.59-rt52-KERNEL_VERSION #38
> Hardware name: linux,dummy-virt (DT)
> Call trace:
> dump_backtrace+0x0/0x198
> show_stack+0x20/0x30
> dump_stack+0xf0/0x13c
> ___might_sleep+0x140/0x178
> rt_spin_lock+0x30/0x90
> force_sig_info_to_task+0x30/0xe0
> force_sig_fault_to_task+0x54/0x78
> force_sig_fault+0x1c/0x28
> arm64_force_sig_fault+0x48/0x78
> send_user_sigtrap+0x4c/0x80
> brk_handler+0x3c/0x68
> do_debug_exception+0xac/0x180
> el0_dbg+0x34/0x58
> el0_sync_handler+0x50/0xb8
> el0_sync+0x180/0x1c0
>
> It has been fixed by
> 0c34700de5e7 ("arm64: signal: Use ARCH_RT_DELAYS_SIGNAL_SEND.") in
> higher versions of the kernel. This patch needs to be compatible with 5.10.
> 5.10 kernel does not have signal.h file, so adding signal.h file to
> define ARCH_RT_DELAYS_SIGNAL_SEND.
>
> Signed-off-by: Wang Yong <[email protected]>
> Cc: Xuexin Jiang <[email protected]>
> Cc: Yang Yang <[email protected]>
> Cc: Xiaokai Ran <[email protected]>
> ---

Thank you for this fix. I will add it to the release candidate that will
be posted on Friday.

Best regards,
Luis

> arch/arm64/include/asm/signal.h | 12 ++++++++++++
> arch/arm64/kernel/signal.c | 9 +++++++++
> 2 files changed, 21 insertions(+)
> create mode 100644 arch/arm64/include/asm/signal.h
>
> diff --git a/arch/arm64/include/asm/signal.h b/arch/arm64/include/asm/signal.h
> new file mode 100644
> index 000000000..0fb418cf4
> --- /dev/null
> +++ b/arch/arm64/include/asm/signal.h
> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __ARM64_ASM_SIGNAL_H
> +#define __ARM64_ASM_SIGNAL_H
> +
> +#include <uapi/asm/signal.h>
> +#include <uapi/asm/siginfo.h>
> +
> +#if defined(CONFIG_PREEMPT_RT)
> +#define ARCH_RT_DELAYS_SIGNAL_SEND
> +#endif
> +
> +#endif
> diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
> index fe94a3e1f..538d4aadb 100644
> --- a/arch/arm64/kernel/signal.c
> +++ b/arch/arm64/kernel/signal.c
> @@ -927,6 +927,15 @@ asmlinkage void do_notify_resume(struct pt_regs *regs,
> } else {
> local_daif_restore(DAIF_PROCCTX);
>
> +#ifdef ARCH_RT_DELAYS_SIGNAL_SEND
> + if (unlikely(current->forced_info.si_signo)) {
> + struct task_struct *t = current;
> +
> + force_sig_info(&t->forced_info);
> + t->forced_info.si_signo = 0;
> + }
> +#endif
> +
> if (thread_flags & _TIF_UPROBE)
> uprobe_notify_resume(regs);
>
> --
> 2.25.1
>
---end quoted text---