From nobody Wed Feb 11 13:58:00 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 41646C76196 for ; Fri, 7 Apr 2023 02:15:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240430AbjDGCPT (ORCPT ); Thu, 6 Apr 2023 22:15:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240067AbjDGCPH (ORCPT ); Thu, 6 Apr 2023 22:15:07 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D9E12173E for ; Thu, 6 Apr 2023 19:15:05 -0700 (PDT) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8BxfdqofC9knqkXAA--.25310S3; Fri, 07 Apr 2023 10:15:04 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxSL2lfC9k2cEXAA--.21395S5; Fri, 07 Apr 2023 10:15:04 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , WANG Xuerui Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, loongson-kernel@lists.loongnix.cn Subject: [RFC PATCH 3/3] LoongArch: Add uprobes support Date: Fri, 7 Apr 2023 10:15:01 +0800 Message-Id: <1680833701-1727-4-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1680833701-1727-1-git-send-email-yangtiezhu@loongson.cn> References: <1680833701-1727-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf8DxSL2lfC9k2cEXAA--.21395S5 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBjvJXoWxKF4xtr13uFyktryUuFW3KFg_yoW3Jr1Upa yDAF13XF4DGas7Gry7ArZ8Zr1FyrWkWw47ZFy2ka4Fy3W2qryrXrn2qrWqvFyFy39YgFW0 qa4rKFWY9FW3J3DanT9S1TB71UUUUUJqnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj qI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUIcSsGvfJTRUUU b3kYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s 1l1IIY67AEw4v_Jrv_JF1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwA2z4 x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv6xkF7I0E14v26F4UJVW0owAa w2AFwI0_Jrv_JF1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa020Ex4CE44 I27wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jw0_WrylYx0Ex4A2 jsIE14v26r4j6F4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20x vY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwCFI7km07C267AKxVWUXVWUAwC20s02 6c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF 0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVW8JVW5JwCI42IY6xIIjxv20xvE c7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14 v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x 07jz2NtUUUUU= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Uprobes is the user-space counterpart to kprobes, this commit adds uprobes support for LoongArch. Signed-off-by: Tiezhu Yang --- arch/loongarch/Kconfig | 3 + arch/loongarch/include/asm/uprobes.h | 36 +++++++++ arch/loongarch/kernel/Makefile | 1 + arch/loongarch/kernel/traps.c | 7 +- arch/loongarch/kernel/uprobes.c | 138 +++++++++++++++++++++++++++++++= ++++ 5 files changed, 181 insertions(+), 4 deletions(-) create mode 100644 arch/loongarch/include/asm/uprobes.h create mode 100644 arch/loongarch/kernel/uprobes.c diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 7fd5125..ab66ad2 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -574,6 +574,9 @@ config ARCH_MMAP_RND_BITS_MIN config ARCH_MMAP_RND_BITS_MAX default 18 =20 +config ARCH_SUPPORTS_UPROBES + def_bool y + menu "Power management options" =20 config ARCH_SUSPEND_POSSIBLE diff --git a/arch/loongarch/include/asm/uprobes.h b/arch/loongarch/include/= asm/uprobes.h new file mode 100644 index 0000000..c6ffcb7 --- /dev/null +++ b/arch/loongarch/include/asm/uprobes.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __ASM_LOONGARCH_UPROBES_H +#define __ASM_LOONGARCH_UPROBES_H + +#include + +typedef u32 uprobe_opcode_t; + +#define MAX_UINSN_BYTES LOONGARCH_INSN_SIZE +#define UPROBE_XOL_SLOT_BYTES MAX_UINSN_BYTES + +#define UPROBE_XOLBP_INSN larch_insn_gen_break(BRK_UPROBE_XOLBP) +#define UPROBE_SWBP_INSN larch_insn_gen_break(BRK_UPROBE_BP) +#define UPROBE_SWBP_INSN_SIZE LOONGARCH_INSN_SIZE + +struct arch_uprobe { + union { + u32 insn[MAX_UINSN_BYTES]; + u32 ixol[MAX_UINSN_BYTES]; + }; + bool simulate; +}; + +struct arch_uprobe_task { + unsigned long saved_trap_nr; +}; + +#ifdef CONFIG_UPROBES +bool uprobe_breakpoint_handler(struct pt_regs *regs); +bool uprobe_singlestep_handler(struct pt_regs *regs); +#else /* !CONFIG_UPROBES */ +static inline bool uprobe_breakpoint_handler(struct pt_regs *regs) { retur= n false; } +static inline bool uprobe_singlestep_handler(struct pt_regs *regs) { retur= n false; } +#endif /* CONFIG_UPROBES */ + +#endif /* __ASM_LOONGARCH_UPROBES_H */ diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile index 78d4e33..67b9c26 100644 --- a/arch/loongarch/kernel/Makefile +++ b/arch/loongarch/kernel/Makefile @@ -53,5 +53,6 @@ obj-$(CONFIG_PERF_EVENTS) +=3D perf_event.o perf_regs.o obj-$(CONFIG_HAVE_HW_BREAKPOINT) +=3D hw_breakpoint.o =20 obj-$(CONFIG_KPROBES) +=3D kprobes.o kprobes_trampoline.o +obj-$(CONFIG_UPROBES) +=3D uprobes.o =20 CPPFLAGS_vmlinux.lds :=3D $(KBUILD_CFLAGS) diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c index de8ebe2..ef6b749 100644 --- a/arch/loongarch/kernel/traps.c +++ b/arch/loongarch/kernel/traps.c @@ -45,6 +45,7 @@ #include #include #include +#include =20 #include "access-helper.h" =20 @@ -462,14 +463,12 @@ asmlinkage void noinstr do_bp(struct pt_regs *regs) else break; case BRK_UPROBE_BP: - if (notify_die(DIE_UPROBE, "Uprobe", regs, bcode, - current->thread.trap_nr, SIGTRAP) =3D=3D NOTIFY_STOP) + if (uprobe_breakpoint_handler(regs)) goto out; else break; case BRK_UPROBE_XOLBP: - if (notify_die(DIE_UPROBE_XOL, "Uprobe_XOL", regs, bcode, - current->thread.trap_nr, SIGTRAP) =3D=3D NOTIFY_STOP) + if (uprobe_singlestep_handler(regs)) goto out; else break; diff --git a/arch/loongarch/kernel/uprobes.c b/arch/loongarch/kernel/uprobe= s.c new file mode 100644 index 0000000..afdeff3 --- /dev/null +++ b/arch/loongarch/kernel/uprobes.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include + +#define UPROBE_TRAP_NR UINT_MAX + +void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr, + void *src, unsigned long len) +{ + void *kaddr =3D kmap_local_page(page); + void *dst =3D kaddr + (vaddr & ~PAGE_MASK); + + memcpy(dst, src, len); + flush_icache_range((unsigned long)dst, (unsigned long)dst + len); + kunmap_local(kaddr); +} + +unsigned long uprobe_get_swbp_addr(struct pt_regs *regs) +{ + return instruction_pointer(regs); +} + +int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, + struct mm_struct *mm, unsigned long addr) +{ + if (addr & 0x3) + return -EILSEQ; + + if (insns_not_supported(auprobe->insn[0])) + return -EINVAL; + + if (insns_need_simulation(auprobe->insn[0])) { + auprobe->ixol[0] =3D larch_insn_gen_nop(); + auprobe->simulate =3D true; + } else { + auprobe->ixol[0] =3D auprobe->insn[0]; + auprobe->simulate =3D false; + } + + auprobe->ixol[1] =3D UPROBE_XOLBP_INSN; + + return 0; +} + +int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + struct uprobe_task *utask =3D current->utask; + + utask->autask.saved_trap_nr =3D current->thread.trap_nr; + current->thread.trap_nr =3D UPROBE_TRAP_NR; + + instruction_pointer_set(regs, utask->xol_vaddr); + + return 0; +} + +int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) +{ + struct uprobe_task *utask =3D current->utask; + + WARN_ON_ONCE(current->thread.trap_nr !=3D UPROBE_TRAP_NR); + + instruction_pointer_set(regs, utask->vaddr + 4); + + return 0; +} + +void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *re= gs) +{ + struct uprobe_task *utask =3D current->utask; + + /* Task has received a fatal signal, so reset back to probed address. */ + instruction_pointer_set(regs, utask->vaddr); +} + +bool arch_uprobe_xol_was_trapped(struct task_struct *t) +{ + if (t->thread.trap_nr !=3D UPROBE_TRAP_NR) + return true; + + return false; +} + +/* Return true if instruction was emulated, false otherwise. */ +bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *r= egs) +{ + if (!auprobe->simulate) + return false; + + arch_simulate_insn(auprobe->insn[0], regs); + + return true; +} + +unsigned long arch_uretprobe_hijack_return_addr(unsigned long trampoline_v= addr, + struct pt_regs *regs) +{ + unsigned long ra =3D regs->regs[1]; + + /* Replace the return addr with trampoline addr */ + regs->regs[1] =3D trampoline_vaddr; + + return ra; +} + +bool arch_uretprobe_is_alive(struct return_instance *ret, + enum rp_check ctx, struct pt_regs *regs) +{ + if (ctx =3D=3D RP_CHECK_CHAIN_CALL) + return regs->regs[3] <=3D ret->stack; + else + return regs->regs[3] < ret->stack; +} + +int arch_uprobe_exception_notify(struct notifier_block *self, + unsigned long val, void *data) +{ + return NOTIFY_DONE; +} + +bool uprobe_breakpoint_handler(struct pt_regs *regs) +{ + if (uprobe_pre_sstep_notifier(regs)) + return true; + + return false; +} + +bool uprobe_singlestep_handler(struct pt_regs *regs) +{ + if (uprobe_post_sstep_notifier(regs)) + return true; + + return false; +} --=20 2.1.0