From nobody Wed Feb 11 05:10:57 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 AA50DC77B7F for ; Thu, 11 May 2023 08:07:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236672AbjEKIHI (ORCPT ); Thu, 11 May 2023 04:07:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233722AbjEKIGb (ORCPT ); Thu, 11 May 2023 04:06:31 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0C5FB9EEB for ; Thu, 11 May 2023 01:06:22 -0700 (PDT) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8AxGur9oVxkSa0HAA--.12979S3; Thu, 11 May 2023 16:06:21 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Cxqjr5oVxk7XNVAA--.21787S6; Thu, 11 May 2023 16:06:21 +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: [PATCH v4 4/6] LoongArch: Add uprobes support Date: Thu, 11 May 2023 16:06:10 +0800 Message-Id: <1683792372-29338-5-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1683792372-29338-1-git-send-email-yangtiezhu@loongson.cn> References: <1683792372-29338-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf8Cxqjr5oVxk7XNVAA--.21787S6 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBjvJXoW3GryDXF45tF13ZFyxCF1rZwb_yoWfJw4rpa 9rCFy5tF4UG3Z3Jry7JrZ8Zr1rt3ykWw47ZFy2ka4Sy3W2qryrXr1xtrWqvF15A390gFW0 qa4rtFWY9FW3JaUanT9S1TB71UUUUUJqnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj qI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUIcSsGvfJTRUUU b3AYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s 1l1IIY67AEw4v_Jrv_JF1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwA2z4 x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4UJVWxJr1l n4kS14v26r1Y6r17M2AIxVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI12xvs2x26I8E6x ACxx1l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1q6rW5McIj6I8E 87Iv67AKxVW8JVWxJwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41l42xK82 IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1l4IxYO2xFxVAFwI0_Jrv_JF1lx2Iq xVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r 126r1DMIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Xr0_Ar1lIxAIcVC0I7IYx2IY 6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67 AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuY vjxU4AhLUUUUU 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. Here is a simple example with CONFIG_UPROBE_EVENTS=3Dy: # cat test.c #include int add(int a, int b) { return a + b; } int main() { return add(2, 7); } # gcc test.c -o /tmp/test # nm /tmp/test | grep add 0000000120004194 T add # cd /sys/kernel/debug/tracing # echo > uprobe_events # echo "p:myuprobe /tmp/test:0x4194 %r4 %r5" > uprobe_events # echo "r:myuretprobe /tmp/test:0x4194 %r4" >> uprobe_events # echo 1 > events/uprobes/enable # echo 1 > tracing_on # /tmp/test # cat trace ... # TASK-PID CPU# ||||| TIMESTAMP FUNCTION # | | | ||||| | | test-1060 [001] DNZff 1015.770620: myuprobe: (0x120004194= ) arg1=3D0x2 arg2=3D0x7 test-1060 [001] DNZff 1015.770930: myuretprobe: (0x120004= 1f0 <- 0x120004194) arg1=3D0x9 Signed-off-by: Tiezhu Yang --- arch/loongarch/Kconfig | 3 + arch/loongarch/include/asm/uprobes.h | 35 +++++++++ arch/loongarch/kernel/Makefile | 1 + arch/loongarch/kernel/traps.c | 9 +-- arch/loongarch/kernel/uprobes.c | 147 +++++++++++++++++++++++++++++++= ++++ 5 files changed, 190 insertions(+), 5 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 d38b066..6c1b5f3 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -590,6 +590,9 @@ 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..08e2a4c --- /dev/null +++ b/arch/loongarch/include/asm/uprobes.h @@ -0,0 +1,35 @@ +/* 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 8 +#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 { + unsigned long resume_era; + u32 insn[2]; + u32 ixol[2]; + 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 9a72d91..4db2656 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 8db26e4..def4d69 100644 --- a/arch/loongarch/kernel/traps.c +++ b/arch/loongarch/kernel/traps.c @@ -47,6 +47,7 @@ #include #include #include +#include =20 #include "access-helper.h" =20 @@ -689,7 +690,6 @@ asmlinkage void noinstr do_bp(struct pt_regs *regs) if (regs->csr_prmd & CSR_PRMD_PIE) local_irq_enable(); =20 - current->thread.trap_nr =3D read_csr_excode(); if (__get_inst(&opcode, (u32 *)era, user)) goto out_sigsegv; =20 @@ -711,18 +711,17 @@ 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; default: + current->thread.trap_nr =3D read_csr_excode(); if (notify_die(DIE_TRAP, "Break", regs, bcode, current->thread.trap_nr, SIGTRAP) =3D=3D NOTIFY_STOP) goto out; diff --git a/arch/loongarch/kernel/uprobes.c b/arch/loongarch/kernel/uprobe= s.c new file mode 100644 index 0000000..f966b66 --- /dev/null +++ b/arch/loongarch/kernel/uprobes.c @@ -0,0 +1,147 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include + +#define UPROBE_TRAP_NR UINT_MAX + +int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, + struct mm_struct *mm, unsigned long addr) +{ + union loongarch_instruction insn; + + if (addr & 0x3) + return -EILSEQ; + + insn.word =3D auprobe->insn[0]; + + if (insns_not_supported(insn)) + return -EINVAL; + + if (insns_need_simulation(insn)) { + 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); + current->thread.trap_nr =3D utask->autask.saved_trap_nr; + + if (auprobe->simulate) + instruction_pointer_set(regs, auprobe->resume_era); + else + instruction_pointer_set(regs, utask->vaddr + LOONGARCH_INSN_SIZE); + + return 0; +} + +void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *re= gs) +{ + struct uprobe_task *utask =3D current->utask; + + current->thread.trap_nr =3D utask->autask.saved_trap_nr; + 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; +} + +bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *r= egs) +{ + union loongarch_instruction insn; + + if (!auprobe->simulate) + return false; + + insn.word =3D auprobe->insn[0]; + arch_simulate_insn(insn, regs); + auprobe->resume_era =3D regs->csr_era; + + 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]; + + 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; +} + +unsigned long uprobe_get_swbp_addr(struct pt_regs *regs) +{ + return instruction_pointer(regs); +} + +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); +} --=20 2.1.0