From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2D08C433EF for ; Fri, 17 Sep 2021 21:10:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA1FE61074 for ; Fri, 17 Sep 2021 21:10:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239609AbhIQVMS (ORCPT ); Fri, 17 Sep 2021 17:12:18 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:44214 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230515AbhIQVMQ (ORCPT ); Fri, 17 Sep 2021 17:12:16 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]:55598) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mRL8F-009l5g-J3; Fri, 17 Sep 2021 15:10:51 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:44740 helo=email.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mRL8B-00HJna-Vd; Fri, 17 Sep 2021 15:10:51 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Huacai Chen Cc: Arnd Bergmann , Andy Lutomirski , Thomas Gleixner , Peter Zijlstra , Andrew Morton , David Airlie , Jonathan Corbet , Linus Torvalds , linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Xuefeng Li , Yanteng Si , Huacai Chen , Jiaxun Yang References: <20210917035736.3934017-1-chenhuacai@loongson.cn> <20210917035736.3934017-15-chenhuacai@loongson.cn> Date: Fri, 17 Sep 2021 16:10:21 -0500 In-Reply-To: <20210917035736.3934017-15-chenhuacai@loongson.cn> (Huacai Chen's message of "Fri, 17 Sep 2021 11:57:28 +0800") Message-ID: <87tuii52o2.fsf@disp2133> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1mRL8B-00HJna-Vd;;;mid=<87tuii52o2.fsf@disp2133>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+PPoM3ZGOMiHsYfvi/0SL3WmNg37yXcK4= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [PATCH V3 14/22] LoongArch: Add signal handling support X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Huacai Chen writes: > This patch adds signal handling support for LoongArch. My overall impression is that it looks like this code has a lot of boilerplate code copied from mips that mips needs because of it's long history, but that a fresh architecture should not need. For example does LoongArch have a version without built in floating point support? To the best of my knowledge it has been decades since anyone built a cpu capable of running Linux that doesn't have built in floating point support. Similarly this includes code for parameterize some of the userspace ABI. Since you only have a single userspace ABI there should not need to be any parameters. So removing the unnecessary parameters should simplify the code. I have a few more comments inline along the same lines. Eric > Signed-off-by: Huacai Chen > --- > arch/loongarch/include/asm/abi.h | 27 ++ > arch/loongarch/include/uapi/asm/sigcontext.h | 40 ++ > arch/loongarch/include/uapi/asm/ucontext.h | 35 ++ > arch/loongarch/kernel/signal-common.h | 38 ++ > arch/loongarch/kernel/signal.c | 467 +++++++++++++++++++ > 5 files changed, 607 insertions(+) > create mode 100644 arch/loongarch/include/asm/abi.h > create mode 100644 arch/loongarch/include/uapi/asm/sigcontext.h > create mode 100644 arch/loongarch/include/uapi/asm/ucontext.h > create mode 100644 arch/loongarch/kernel/signal-common.h > create mode 100644 arch/loongarch/kernel/signal.c > > diff --git a/arch/loongarch/include/asm/abi.h b/arch/loongarch/include/asm/abi.h > new file mode 100644 > index 000000000000..ced8534db4df > --- /dev/null > +++ b/arch/loongarch/include/asm/abi.h > @@ -0,0 +1,27 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright (C) 2020-2021 Loongson Technology Corporation Limited > + */ > +#ifndef _ASM_ABI_H > +#define _ASM_ABI_H > + > +#include > + > +#include > +#include > +#include > + > +struct loongarch_abi { > + const unsigned long restart; > + const int audit_arch; > + > + unsigned int off_sc_fpregs; > + unsigned int off_sc_fcc; > + unsigned int off_sc_fcsr; > + unsigned int off_sc_vcsr; > + unsigned int off_sc_flags; > + > + struct loongarch_vdso_info *vdso; > +}; This header file is confusing. It says ABI but it isn't under the uapi tree. On mips with decades of history and a nabi, oabi, etc, the similar header file which includes function pointers makes a smidgen of sense. Since you aren't mips and your architecture is new you should be able to have a single userspace ABI and hard code everything. At least to get started with. That should make for simpler code as well. > + > +#endif /* _ASM_ABI_H */ > diff --git a/arch/loongarch/include/uapi/asm/sigcontext.h b/arch/loongarch/include/uapi/asm/sigcontext.h > new file mode 100644 > index 000000000000..da0e5bac2d80 > --- /dev/null > +++ b/arch/loongarch/include/uapi/asm/sigcontext.h > @@ -0,0 +1,40 @@ > +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ > +/* > + * Author: Hanlu Li > + * Huacai Chen > + * > + * Copyright (C) 2020-2021 Loongson Technology Corporation Limited > + */ > +#ifndef _UAPI_ASM_SIGCONTEXT_H > +#define _UAPI_ASM_SIGCONTEXT_H > + > +#include > +#include > + > +/* scalar FP context was used */ > +#define USED_FP (1 << 0) > + > +/* extended context was used, see struct extcontext for details */ > +#define USED_EXTCONTEXT (1 << 1) > + > +#include > +/* > + * Keep this struct definition in sync with the sigcontext fragment > + * in arch/loongarch/kernel/asm-offsets.c If this is uapi this can't change (except for consuming the reserved fields). Making this comment misleading. > + * > + */ > +struct sigcontext { > + __u64 sc_pc; > + __u64 sc_regs[32]; > + __u32 sc_flags; > + > + __u32 sc_fcsr; > + __u32 sc_vcsr; You might want to document the 32bit hole in your structure here. > + __u64 sc_fcc; > + __u64 sc_scr[4]; > + > + union fpureg sc_fpregs[32] FPU_ALIGN; > + __u8 sc_reserved[4096] __attribute__((__aligned__(16))); > +}; > + > +#endif /* _UAPI_ASM_SIGCONTEXT_H */ > diff --git a/arch/loongarch/include/uapi/asm/ucontext.h b/arch/loongarch/include/uapi/asm/ucontext.h > new file mode 100644 > index 000000000000..12577e22b1c7 > --- /dev/null > +++ b/arch/loongarch/include/uapi/asm/ucontext.h > @@ -0,0 +1,35 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +#ifndef __LOONGARCH_UAPI_ASM_UCONTEXT_H > +#define __LOONGARCH_UAPI_ASM_UCONTEXT_H > + > +/** > + * struct ucontext - user context structure > + * @uc_flags: > + * @uc_link: > + * @uc_stack: > + * @uc_mcontext: holds basic processor state > + * @uc_sigmask: > + * @uc_extcontext: holds extended processor state > + */ > +struct ucontext { > + unsigned long uc_flags; > + struct ucontext *uc_link; > + stack_t uc_stack; > + sigset_t uc_sigmask; > + /* There's some padding here to allow sigset_t to be expanded in the > + * future. Though this is unlikely, other architectures put uc_sigmask > + * at the end of this structure and explicitly state it can be > + * expanded, so we didn't want to box ourselves in here. */ > + __u8 __unused[1024 / 8 - sizeof(sigset_t)]; > + /* We can't put uc_sigmask at the end of this structure because we need > + * to be able to expand sigcontext in the future. For example, the > + * vector ISA extension will almost certainly add ISA state. We want > + * to ensure all user-visible ISA state can be saved and restored via a > + * ucontext, so we're putting this at the end in order to allow for > + * infinite extensibility. Since we know this will be extended and we > + * assume sigset_t won't be extended an extreme amount, we're > + * prioritizing this. */ > + struct sigcontext uc_mcontext; > +}; > + > +#endif /* __LOONGARCH_UAPI_ASM_UCONTEXT_H */ > diff --git a/arch/loongarch/kernel/signal-common.h b/arch/loongarch/kernel/signal-common.h > new file mode 100644 > index 000000000000..1693fbdedeaa > --- /dev/null > +++ b/arch/loongarch/kernel/signal-common.h > @@ -0,0 +1,38 @@ > +/* SPDX-License-Identifier: GPL-2.0+ */ > +/* > + * Author: Hanlu Li > + * Huacai Chen > + * > + * Copyright (C) 2020-2021 Loongson Technology Corporation Limited > + */ > + > +#ifndef __SIGNAL_COMMON_H > +#define __SIGNAL_COMMON_H > + > +/* #define DEBUG_SIG */ > + > +#ifdef DEBUG_SIG > +# define DEBUGP(fmt, args...) printk("%s: " fmt, __func__, ##args) > +#else > +# define DEBUGP(fmt, args...) > +#endif This is only used once in arch/loongarch/kernel/signal.c so you probably want to keep this define local to that file. > +/* > + * Determine which stack to use.. > + */ > +extern void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, > + size_t frame_size); > +/* Check and clear pending FPU exceptions in saved CSR */ > +extern int fpcsr_pending(unsigned int __user *fpcsr); > + > +/* Make sure we will not lose FPU ownership */ > +#define lock_fpu_owner() ({ preempt_disable(); pagefault_disable(); }) > +#define unlock_fpu_owner() ({ pagefault_enable(); preempt_enable(); }) > + > +/* Assembly functions to move context to/from the FPU */ > +extern asmlinkage int > +_save_fp_context(void __user *fpregs, void __user *fcc, void __user *csr); > +extern asmlinkage int > +_restore_fp_context(void __user *fpregs, void __user *fcc, void __user *csr); > + > +#endif /* __SIGNAL_COMMON_H */ > diff --git a/arch/loongarch/kernel/signal.c b/arch/loongarch/kernel/signal.c > new file mode 100644 > index 000000000000..78319d2575c6 > --- /dev/null > +++ b/arch/loongarch/kernel/signal.c > @@ -0,0 +1,467 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Author: Hanlu Li > + * Huacai Chen > + * Copyright (C) 2020-2021 Loongson Technology Corporation Limited > + * > + * Derived from MIPS: > + * Copyright (C) 1991, 1992 Linus Torvalds > + * Copyright (C) 1994 - 2000 Ralf Baechle > + * Copyright (C) 1999, 2000 Silicon Graphics, Inc. > + * Copyright (C) 2014, Imagination Technologies Ltd. > + */ > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "signal-common.h" > + > +static int (*save_fp_context)(void __user *sc); > +static int (*restore_fp_context)(void __user *sc); > + > +struct rt_sigframe { > + struct siginfo rs_info; > + struct ucontext rs_uctx; > +}; > + > +/* > + * Thread saved context copy to/from a signal context presumed to be on the > + * user stack, and therefore accessed with appropriate macros from uaccess.h. > + */ > +static int copy_fp_to_sigcontext(void __user *sc) > +{ > + struct loongarch_abi *abi = current->thread.abi; > + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; > + uint64_t __user *fcc = sc + abi->off_sc_fcc; > + uint32_t __user *csr = sc + abi->off_sc_fcsr; > + int i; > + int err = 0; > + int inc = 1; > + > + for (i = 0; i < NUM_FPU_REGS; i += inc) { > + err |= > + __put_user(get_fpr64(¤t->thread.fpu.fpr[i], 0), > + &fpregs[4*i]); > + } > + err |= __put_user(current->thread.fpu.fcsr, csr); > + err |= __put_user(current->thread.fpu.fcc, fcc); > + > + return err; > +} > + > +static int copy_fp_from_sigcontext(void __user *sc) > +{ > + struct loongarch_abi *abi = current->thread.abi; > + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; > + uint64_t __user *fcc = sc + abi->off_sc_fcc; > + uint32_t __user *csr = sc + abi->off_sc_fcsr; > + int i; > + int err = 0; > + int inc = 1; > + u64 fpr_val; > + > + for (i = 0; i < NUM_FPU_REGS; i += inc) { > + err |= __get_user(fpr_val, &fpregs[4*i]); > + set_fpr64(¤t->thread.fpu.fpr[i], 0, fpr_val); > + } > + err |= __get_user(current->thread.fpu.fcsr, csr); > + err |= __get_user(current->thread.fpu.fcc, fcc); > + > + return err; > +} > + > +/* > + * Wrappers for the assembly _{save,restore}_fp_context functions. > + */ > +static int save_hw_fp_context(void __user *sc) > +{ > + struct loongarch_abi *abi = current->thread.abi; > + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; > + uint64_t __user *fcc = sc + abi->off_sc_fcc; > + uint32_t __user *fcsr = sc + abi->off_sc_fcsr; > + > + return _save_fp_context(fpregs, fcc, fcsr); > +} > + > +static int restore_hw_fp_context(void __user *sc) > +{ > + struct loongarch_abi *abi = current->thread.abi; > + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; > + uint64_t __user *fcc = sc + abi->off_sc_fcc; > + uint32_t __user *csr = sc + abi->off_sc_fcsr; > + > + return _restore_fp_context(fpregs, fcc, csr); > +} > + > +/* > + * Helper routines > + */ > +static int protected_save_fp_context(void __user *sc) > +{ > + int err = 0; > + unsigned int used; > + struct loongarch_abi *abi = current->thread.abi; > + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; > + uint32_t __user *fcc = sc + abi->off_sc_fcsr; > + uint32_t __user *fcsr = sc + abi->off_sc_fcsr; > + uint32_t __user *vcsr = sc + abi->off_sc_vcsr; > + uint32_t __user *flags = sc + abi->off_sc_flags; > + > + used = used_math() ? USED_FP : 0; > + if (!used) > + goto fp_done; > + > + while (1) { > + lock_fpu_owner(); > + if (is_fpu_owner()) > + err = save_fp_context(sc); > + else > + err |= copy_fp_to_sigcontext(sc); > + unlock_fpu_owner(); > + if (likely(!err)) > + break; > + /* touch the sigcontext and try again */ > + err = __put_user(0, &fpregs[0]) | > + __put_user(0, &fpregs[32*4 - 1]) | > + __put_user(0, fcc) | > + __put_user(0, fcsr) | > + __put_user(0, vcsr); > + if (err) > + return err; /* really bad sigcontext */ > + } > + > +fp_done: > + return __put_user(used, flags); > +} > + > +static int protected_restore_fp_context(void __user *sc) > +{ > + unsigned int used; > + int err = 0, sig = 0, tmp __maybe_unused; > + struct loongarch_abi *abi = current->thread.abi; > + uint64_t __user *fpregs = sc + abi->off_sc_fpregs; > + uint32_t __user *fcsr = sc + abi->off_sc_fcsr; > + uint32_t __user *fcc = sc + abi->off_sc_fcsr; > + uint32_t __user *vcsr = sc + abi->off_sc_vcsr; > + uint32_t __user *flags = sc + abi->off_sc_flags; > + > + err = __get_user(used, flags); > + conditional_used_math(used & USED_FP); > + > + /* > + * The signal handler may have used FPU; give it up if the program > + * doesn't want it following sigreturn. > + */ > + if (err || !(used & USED_FP)) > + lose_fpu(0); > + > + if (err) > + return err; > + > + if (!(used & USED_FP)) > + goto fp_done; > + > + err = sig = fpcsr_pending(fcsr); > + if (err < 0) > + return err; > + > + while (1) { > + lock_fpu_owner(); > + if (is_fpu_owner()) > + err = restore_fp_context(sc); > + else > + err |= copy_fp_from_sigcontext(sc); > + unlock_fpu_owner(); > + if (likely(!err)) > + break; > + /* touch the sigcontext and try again */ > + err = __get_user(tmp, &fpregs[0]) | > + __get_user(tmp, &fpregs[32*4 - 1]) | > + __get_user(tmp, fcc) | > + __get_user(tmp, fcsr) | > + __get_user(tmp, vcsr); > + if (err) > + break; /* really bad sigcontext */ > + } > + > +fp_done: > + return err ?: sig; > +} > + > +static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) > +{ > + int err = 0; > + int i; > + > + err |= __put_user(regs->csr_epc, &sc->sc_pc); > + > + err |= __put_user(0, &sc->sc_regs[0]); > + for (i = 1; i < 32; i++) > + err |= __put_user(regs->regs[i], &sc->sc_regs[i]); > + > + /* > + * Save FPU state to signal context. Signal handler > + * will "inherit" current FPU state. > + */ > + err |= protected_save_fp_context(sc); > + > + return err; > +} > + > +int fpcsr_pending(unsigned int __user *fpcsr) > +{ > + int err, sig = 0; > + unsigned int csr, enabled; > + > + err = __get_user(csr, fpcsr); > + enabled = ((csr & FPU_CSR_ALL_E) << 24); > + /* > + * If the signal handler set some FPU exceptions, clear it and > + * send SIGFPE. > + */ > + if (csr & enabled) { > + csr &= ~enabled; > + err |= __put_user(csr, fpcsr); > + sig = SIGFPE; > + } > + return err ?: sig; > +} > + > +static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) > +{ > + int err = 0; > + int i; > + > + /* Always make any pending restarted system calls return -EINTR */ > + current->restart_block.fn = do_no_restart_syscall; > + > + err |= __get_user(regs->csr_epc, &sc->sc_pc); > + > + for (i = 1; i < 32; i++) > + err |= __get_user(regs->regs[i], &sc->sc_regs[i]); > + > + return err ?: protected_restore_fp_context(sc); > +} > + > +void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, > + size_t frame_size) > +{ > + unsigned long sp; > + > + /* Default to using normal stack */ > + sp = regs->regs[3]; > + sp -= 32; /* Reserve 32-bytes. */ > + > + sp = sigsp(sp, ksig); > + > + return (void __user *)((sp - frame_size) & ALMASK); > +} > + > +/* > + * Atomically swap in the new signal mask, and wait for a signal. > + */ > + > +asmlinkage long sys_rt_sigreturn(void) > +{ > + struct rt_sigframe __user *frame; > + struct pt_regs *regs; > + sigset_t set; > + int sig; > + > + regs = current_pt_regs(); > + frame = (struct rt_sigframe __user *)regs->regs[3]; > + if (!access_ok(frame, sizeof(*frame))) > + goto badframe; > + if (__copy_from_user(&set, &frame->rs_uctx.uc_sigmask, sizeof(set))) > + goto badframe; > + > + set_current_blocked(&set); > + > + sig = restore_sigcontext(regs, &frame->rs_uctx.uc_mcontext); > + if (sig < 0) > + goto badframe; > + else if (sig) > + force_sig(sig); > + > + if (restore_altstack(&frame->rs_uctx.uc_stack)) > + goto badframe; > + > + return regs->regs[4]; > + > +badframe: > + force_sig(SIGSEGV); > + return 0; > +} > + > +static int setup_rt_frame(void *sig_return, struct ksignal *ksig, > + struct pt_regs *regs, sigset_t *set) > +{ > + struct rt_sigframe __user *frame; > + int err = 0; > + > + frame = get_sigframe(ksig, regs, sizeof(*frame)); > + if (!access_ok(frame, sizeof(*frame))) > + return -EFAULT; > + > + /* Create siginfo. */ > + err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info); > + > + /* Create the ucontext. */ > + err |= __put_user(0, &frame->rs_uctx.uc_flags); > + err |= __put_user(NULL, &frame->rs_uctx.uc_link); > + err |= __save_altstack(&frame->rs_uctx.uc_stack, regs->regs[3]); > + err |= setup_sigcontext(regs, &frame->rs_uctx.uc_mcontext); > + err |= __copy_to_user(&frame->rs_uctx.uc_sigmask, set, sizeof(*set)); > + > + if (err) > + return -EFAULT; > + > + /* > + * Arguments to signal handler: > + * > + * a0 = signal number > + * a1 = 0 (should be cause) > + * a2 = pointer to ucontext > + * > + * $25 and c0_epc point to the signal handler, $29 points to > + * the struct rt_sigframe. > + */ > + regs->regs[4] = ksig->sig; > + regs->regs[5] = (unsigned long) &frame->rs_info; > + regs->regs[6] = (unsigned long) &frame->rs_uctx; > + regs->regs[3] = (unsigned long) frame; > + regs->regs[1] = (unsigned long) sig_return; > + regs->csr_epc = (unsigned long) ksig->ka.sa.sa_handler; > + > + DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n", > + current->comm, current->pid, > + frame, regs->csr_epc, regs->regs[1]); > + > + return 0; > +} > + > +struct loongarch_abi loongarch_abi = { > + .restart = __NR_restart_syscall, > +#ifdef CONFIG_32BIT > + .audit_arch = AUDIT_ARCH_LOONGARCH32, > +#else > + .audit_arch = AUDIT_ARCH_LOONGARCH64, > +#endif > + > + .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs), > + .off_sc_fcc = offsetof(struct sigcontext, sc_fcc), > + .off_sc_fcsr = offsetof(struct sigcontext, sc_fcsr), > + .off_sc_vcsr = offsetof(struct sigcontext, sc_vcsr), > + .off_sc_flags = offsetof(struct sigcontext, sc_flags), > + > + .vdso = &vdso_info, > +}; > + > +static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) > +{ > + int ret; > + sigset_t *oldset = sigmask_to_save(); > + struct loongarch_abi *abi = current->thread.abi; > + void *vdso = current->mm->context.vdso; > + > + /* Are we from a system call? */ > + if (regs->regs[0]) { > + switch (regs->regs[4]) { > + case -ERESTART_RESTARTBLOCK: > + case -ERESTARTNOHAND: > + regs->regs[4] = -EINTR; > + break; > + case -ERESTARTSYS: > + if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { > + regs->regs[4] = -EINTR; > + break; > + } > + fallthrough; > + case -ERESTARTNOINTR: > + regs->regs[4] = regs->orig_a0; > + regs->csr_epc -= 4; > + } > + > + regs->regs[0] = 0; /* Don't deal with this again. */ > + } > + > + rseq_signal_deliver(ksig, regs); > + > + ret = setup_rt_frame(vdso + abi->vdso->offset_sigreturn, ksig, regs, oldset); > + > + signal_setup_done(ret, ksig, 0); > +} > + > +void arch_do_signal_or_restart(struct pt_regs *regs, bool has_signal) > +{ > + struct ksignal ksig; > + > + if (has_signal && get_signal(&ksig)) { > + /* Whee! Actually deliver the signal. */ > + handle_signal(&ksig, regs); > + return; > + } > + > + /* Are we from a system call? */ > + if (regs->regs[0]) { > + switch (regs->regs[4]) { > + case -ERESTARTNOHAND: > + case -ERESTARTSYS: > + case -ERESTARTNOINTR: > + regs->regs[4] = regs->orig_a0; > + regs->csr_epc -= 4; > + break; > + > + case -ERESTART_RESTARTBLOCK: > + regs->regs[4] = regs->orig_a0; > + regs->regs[11] = current->thread.abi->restart; > + regs->csr_epc -= 4; > + break; > + } > + regs->regs[0] = 0; /* Don't deal with this again. */ > + } > + > + /* > + * If there's no signal to deliver, we just put the saved sigmask > + * back > + */ > + restore_saved_sigmask(); > +} > + > +static int signal_setup(void) > +{ > + if (cpu_has_fpu) { > + save_fp_context = save_hw_fp_context; > + restore_fp_context = restore_hw_fp_context; > + } else { > + save_fp_context = copy_fp_to_sigcontext; > + restore_fp_context = copy_fp_from_sigcontext; > + } > + > + return 0; > +} > + > +arch_initcall(signal_setup);