From: Chen Zhongjin <chenzhongjin@huawei.com>
To: <linux-kernel@vger.kernel.org>, <linux-riscv@lists.infradead.org>,
<linux-perf-users@vger.kernel.org>
Cc: <paul.walmsley@sifive.com>, <palmer@dabbelt.com>,
<aou@eecs.berkeley.edu>, <peterz@infradead.org>,
<mingo@redhat.com>, <acme@kernel.org>, <mark.rutland@arm.com>,
<alexander.shishkin@linux.intel.com>, <namhyung@kernel.org>,
<jolsa@kernel.org>, <guoren@kernel.org>, <nsaenzju@redhat.com>,
<frederic@kernel.org>, <changbin.du@intel.com>,
<vincent.chen@sifive.com>, <ardb@kernel.org>,
<mhiramat@kernel.org>, <rostedt@goodmis.org>,
<keescook@chromium.org>, <catalin.marinas@arm.com>,
<chenzhongjin@huawei.com>
Subject: [PATCH -next 4/7] riscv: syscall: Don't clobber s0 when syscall
Date: Tue, 20 Sep 2022 23:11:59 +0800 [thread overview]
Message-ID: <20220920151202.180057-5-chenzhongjin@huawei.com> (raw)
In-Reply-To: <20220920151202.180057-1-chenzhongjin@huawei.com>
syscall uses s0 to load address of sys_call_table.
Since now we uses s0 to save pt_regs for unwinding, clobber
s0 can make unwinder treat s0 as pt_regs address. Use s1 for
this job.
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
---
arch/riscv/kernel/entry.S | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index ecb15c7430b4..a3b14a649782 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -205,33 +205,33 @@ handle_syscall:
check_syscall_nr:
/* Check to make sure we don't jump to a bogus syscall number. */
li t0, __NR_syscalls
- la s0, sys_ni_syscall
+ la s1, sys_ni_syscall
/*
* Syscall number held in a7.
* If syscall number is above allowed value, redirect to ni_syscall.
*/
bgeu a7, t0, 3f
#ifdef CONFIG_COMPAT
- REG_L s0, PT_STATUS(sp)
- srli s0, s0, SR_UXL_SHIFT
- andi s0, s0, (SR_UXL >> SR_UXL_SHIFT)
+ REG_L s1, PT_STATUS(sp)
+ srli s1, s1, SR_UXL_SHIFT
+ andi s1, s1, (SR_UXL >> SR_UXL_SHIFT)
li t0, (SR_UXL_32 >> SR_UXL_SHIFT)
- sub t0, s0, t0
+ sub t0, s1, t0
bnez t0, 1f
/* Call compat_syscall */
- la s0, compat_sys_call_table
+ la s1, compat_sys_call_table
j 2f
1:
#endif
/* Call syscall */
- la s0, sys_call_table
+ la s1, sys_call_table
2:
slli t0, a7, RISCV_LGPTR
- add s0, s0, t0
- REG_L s0, 0(s0)
+ add s1, s1, t0
+ REG_L s1, 0(s1)
3:
- jalr s0
+ jalr s1
ret_from_syscall:
/* Set user a0 to kernel a0 */
--
2.17.1
next prev parent reply other threads:[~2022-09-20 15:16 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-20 15:11 [PATCH -next 0/7] riscv: Improvments for stacktrace Chen Zhongjin
2022-09-20 15:11 ` [PATCH -next 1/7] riscv: stacktrace: Replace walk_stackframe with arch_stack_walk Chen Zhongjin
2022-09-20 15:11 ` [PATCH -next 2/7] riscv: stacktrace: Introduce unwind functions Chen Zhongjin
2022-09-20 15:11 ` [PATCH -next 3/7] riscv: stacktrace: Save pt_regs in encoded fp on irq entry Chen Zhongjin
2022-09-21 2:13 ` Guo Ren
2022-09-20 15:11 ` Chen Zhongjin [this message]
2022-09-21 1:30 ` [PATCH -next 4/7] riscv: syscall: Don't clobber s0 when syscall Guo Ren
2022-09-21 2:16 ` Guo Ren
2022-09-20 15:12 ` [PATCH -next 5/7] riscv: stacktrace: Implement stacktrace for irq Chen Zhongjin
2022-09-20 15:12 ` [PATCH -next 6/7] riscv: stacktrace: Fix unwinding on ftrace_regs_call Chen Zhongjin
2022-09-21 1:43 ` Guo Ren
2022-09-21 3:00 ` Chen Zhongjin
2022-09-20 15:12 ` [PATCH -next 7/7] riscv: stacktrace: Fix unwinding on __kretporbe_trampoline Chen Zhongjin
2022-09-21 2:30 ` [PATCH -next 0/7] riscv: Improvments for stacktrace Guo Ren
2022-09-21 12:33 ` Chen Zhongjin
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