From: guoren@kernel.org
To: arnd@arndb.de, guoren@kernel.org, palmer@rivosinc.com,
tglx@linutronix.de, peterz@infradead.org, luto@kernel.org,
conor.dooley@microchip.com, heiko@sntech.de, jszhang@kernel.org,
lazyparser@gmail.com, falcon@tinylab.org, chenhuacai@kernel.org,
apatel@ventanamicro.com, atishp@atishpatra.org,
palmer@dabbelt.com, paul.walmsley@sifive.com,
mark.rutland@arm.com, zouyipeng@huawei.com,
bigeasy@linutronix.de, David.Laight@aculab.com,
chenzhongjin@huawei.com, greentime.hu@sifive.com,
andy.chiu@sifive.com
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-riscv@lists.infradead.org
Subject: [PATCH -next V8 13/14] riscv: consolidate ret_from_kernel_thread into ret_from_fork
Date: Thu, 3 Nov 2022 03:50:46 -0400 [thread overview]
Message-ID: <20221103075047.1634923-14-guoren@kernel.org> (raw)
In-Reply-To: <20221103075047.1634923-1-guoren@kernel.org>
From: Jisheng Zhang <jszhang@kernel.org>
The ret_from_kernel_thread() behaves similarly with ret_from_fork(),
the only difference is whether call the fn(arg) or not, this can be
achieved by testing fn is NULL or not, I.E s0 is 0 or not. Many
architectures have done the same thing, it make entry.S more clean.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
arch/riscv/kernel/entry.S | 12 +++---------
arch/riscv/kernel/process.c | 5 ++---
2 files changed, 5 insertions(+), 12 deletions(-)
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index b1babad5f829..d4c061f7fbfa 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -132,7 +132,6 @@ END(handle_exception)
* caller list:
* - handle_exception
* - ret_from_fork
- * - ret_from_kernel_thread
*/
ENTRY(ret_from_exception)
REG_L s0, PT_STATUS(sp)
@@ -326,20 +325,15 @@ END(handle_kernel_stack_overflow)
ENTRY(ret_from_fork)
call schedule_tail
- move a0, sp /* pt_regs */
- la ra, ret_from_exception
- tail syscall_exit_to_user_mode
-ENDPROC(ret_from_fork)
-
-ENTRY(ret_from_kernel_thread)
- call schedule_tail
+ beqz s0, 1f /* not from kernel thread */
/* Call fn(arg) */
move a0, s1
jalr s0
+1:
move a0, sp /* pt_regs */
la ra, ret_from_exception
tail syscall_exit_to_user_mode
-ENDPROC(ret_from_kernel_thread)
+ENDPROC(ret_from_fork)
/*
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index b0c63e8e867e..5108c76a14dd 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -34,7 +34,6 @@ EXPORT_SYMBOL(__stack_chk_guard);
#endif
extern asmlinkage void ret_from_fork(void);
-extern asmlinkage void ret_from_kernel_thread(void);
void arch_cpu_idle(void)
{
@@ -172,7 +171,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
/* Supervisor/Machine, irqs on: */
childregs->status = SR_PP | SR_PIE;
- p->thread.ra = (unsigned long)ret_from_kernel_thread;
p->thread.s[0] = (unsigned long)args->fn;
p->thread.s[1] = (unsigned long)args->fn_arg;
} else {
@@ -182,8 +180,9 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
if (clone_flags & CLONE_SETTLS)
childregs->tp = tls;
childregs->a0 = 0; /* Return value of fork() */
- p->thread.ra = (unsigned long)ret_from_fork;
+ p->thread.s[0] = 0;
}
+ p->thread.ra = (unsigned long)ret_from_fork;
p->thread.sp = (unsigned long)childregs; /* kernel sp */
return 0;
}
--
2.36.1
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next prev parent reply other threads:[~2022-11-03 7:53 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-03 7:50 [PATCH -next V8 00/14] riscv: Add GENERIC_ENTRY support and related features guoren
2022-11-03 7:50 ` [PATCH -next V8 01/14] compiler_types.h: Add __noinstr_section() for noinstr guoren
2022-12-05 9:12 ` Björn Töpel
2022-11-03 7:50 ` [PATCH -next V8 02/14] riscv: elf_kexec: Fixup compile warning guoren
2022-12-05 9:13 ` Björn Töpel
2022-12-06 4:39 ` Guo Ren
2022-11-03 7:50 ` [PATCH -next V8 03/14] riscv: compat_syscall_table: " guoren
2022-12-05 9:13 ` Björn Töpel
2022-11-03 7:50 ` [PATCH -next V8 04/14] riscv: ptrace: Remove duplicate operation guoren
2022-12-05 9:34 ` Björn Töpel
2022-12-06 4:41 ` Guo Ren
2022-11-03 7:50 ` [PATCH -next V8 05/14] riscv: traps: Add noinstr to prevent instrumentation inserted guoren
2022-11-03 7:50 ` [PATCH -next V8 06/14] riscv: convert to generic entry guoren
2022-11-27 16:25 ` Ben Hutchings
2022-11-28 2:42 ` Guo Ren
2022-12-05 10:49 ` Björn Töpel
2022-12-06 6:39 ` Guo Ren
2022-11-03 7:50 ` [PATCH -next V8 07/14] riscv: Support HAVE_IRQ_EXIT_ON_IRQ_STACK guoren
2022-11-03 7:50 ` [PATCH -next V8 08/14] riscv: Support HAVE_SOFTIRQ_ON_OWN_STACK guoren
2022-11-03 7:50 ` [PATCH -next V8 09/14] riscv: Add config of thread stack size guoren
2022-11-03 7:50 ` [PATCH -next V8 10/14] riscv: Typo fixup for addi -> andi in comment guoren
2022-12-05 9:18 ` Björn Töpel
2022-11-03 7:50 ` [PATCH -next V8 11/14] riscv: Add support for STACKLEAK gcc plugin guoren
2022-11-03 7:50 ` [PATCH -next V8 12/14] riscv: remove extra level wrappers of trace_hardirqs_{on,off} guoren
2022-11-03 7:50 ` guoren [this message]
2022-11-03 7:50 ` [PATCH -next V8 14/14] riscv: entry: consolidate general regs saving/restoring guoren
2022-11-23 15:26 ` [PATCH -next V8 00/14] riscv: Add GENERIC_ENTRY support and related features Jisheng Zhang
2022-12-05 9:46 ` Björn Töpel
2022-12-06 6:12 ` Guo Ren
2022-12-06 7:03 ` Björn Töpel
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