From: Jisheng Zhang <jszhang@kernel.org> To: Paul Walmsley <paul.walmsley@sifive.com>, Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>, Guo Ren <guoren@kernel.org>, Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com> Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH 2/4] riscv: consolidate ret_from_kernel_thread into ret_from_fork Date: Mon, 26 Sep 2022 01:53:54 +0800 [thread overview] Message-ID: <20220925175356.681-3-jszhang@kernel.org> (raw) In-Reply-To: <20220925175356.681-1-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 acchieved by testing fn is NULL or not, I.E s0 is 0 or not. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> --- arch/riscv/kernel/entry.S | 11 +++-------- arch/riscv/kernel/process.c | 5 ++--- 2 files changed, 5 insertions(+), 11 deletions(-) diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 2207cf44a3bc..a3e1ed2fa2ac 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -323,20 +323,15 @@ 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) #ifdef CONFIG_IRQ_STACKS ENTRY(call_on_stack) diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index ceb9ebab6558..67e7cd123ceb 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; } -- 2.34.1
WARNING: multiple messages have this Message-ID (diff)
From: Jisheng Zhang <jszhang@kernel.org> To: Paul Walmsley <paul.walmsley@sifive.com>, Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>, Guo Ren <guoren@kernel.org>, Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com> Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH 2/4] riscv: consolidate ret_from_kernel_thread into ret_from_fork Date: Mon, 26 Sep 2022 01:53:54 +0800 [thread overview] Message-ID: <20220925175356.681-3-jszhang@kernel.org> (raw) In-Reply-To: <20220925175356.681-1-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 acchieved by testing fn is NULL or not, I.E s0 is 0 or not. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> --- arch/riscv/kernel/entry.S | 11 +++-------- arch/riscv/kernel/process.c | 5 ++--- 2 files changed, 5 insertions(+), 11 deletions(-) diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 2207cf44a3bc..a3e1ed2fa2ac 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -323,20 +323,15 @@ 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) #ifdef CONFIG_IRQ_STACKS ENTRY(call_on_stack) diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index ceb9ebab6558..67e7cd123ceb 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; } -- 2.34.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2022-09-25 18:03 UTC|newest] Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-09-25 17:53 [PATCH 0/4] riscv: entry: further clean up and VMAP_STACK fix Jisheng Zhang 2022-09-25 17:53 ` Jisheng Zhang 2022-09-25 17:53 ` [PATCH 1/4] riscv: remove extra level wrappers of trace_hardirqs_{on,off} Jisheng Zhang 2022-09-25 17:53 ` Jisheng Zhang 2022-09-25 23:18 ` Guo Ren 2022-09-25 23:18 ` Guo Ren 2022-09-25 17:53 ` Jisheng Zhang [this message] 2022-09-25 17:53 ` [PATCH 2/4] riscv: consolidate ret_from_kernel_thread into ret_from_fork Jisheng Zhang 2022-09-25 23:25 ` Guo Ren 2022-09-25 23:25 ` Guo Ren 2022-09-26 16:05 ` Jisheng Zhang 2022-09-26 16:05 ` Jisheng Zhang 2022-09-26 23:55 ` Guo Ren 2022-09-26 23:55 ` Guo Ren 2022-09-28 16:40 ` Jisheng Zhang 2022-09-28 16:40 ` Jisheng Zhang 2022-09-30 11:42 ` Guo Ren 2022-09-30 11:42 ` Guo Ren 2022-09-25 17:53 ` [PATCH 3/4] riscv: fix race when vmap stack overflow and remove shadow_stack Jisheng Zhang 2022-09-25 17:53 ` Jisheng Zhang 2022-09-25 23:46 ` Guo Ren 2022-09-25 23:46 ` Guo Ren 2022-09-27 0:18 ` Jisheng Zhang 2022-09-27 0:18 ` Jisheng Zhang 2022-09-27 2:00 ` Guo Ren 2022-09-27 2:00 ` Guo Ren 2022-11-23 17:02 ` Deepak Gupta 2022-11-23 17:02 ` Deepak Gupta 2022-09-25 17:53 ` [PATCH 4/4] riscv: entry: consolidate general regs saving into save_gp Jisheng Zhang 2022-09-25 17:53 ` Jisheng Zhang 2022-09-25 23:29 ` Guo Ren 2022-09-25 23:29 ` Guo Ren
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