From nobody Sun Sep 14 22:15:24 2025 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 34AA1C00A5A for ; Wed, 18 Jan 2023 02:01:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229622AbjARCBL (ORCPT ); Tue, 17 Jan 2023 21:01:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229379AbjARCBK (ORCPT ); Tue, 17 Jan 2023 21:01:10 -0500 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 262B44614E for ; Tue, 17 Jan 2023 18:01:04 -0800 (PST) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8BxqOngUsdjQD0CAA--.2975S3; Wed, 18 Jan 2023 10:01:04 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxTuTeUsdjPhYbAA--.17049S3; Wed, 18 Jan 2023 10:01:02 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , WANG Xuerui , Masami Hiramatsu Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v12 1/5] LoongArch: Simulate branch and PC* instructions Date: Wed, 18 Jan 2023 10:00:57 +0800 Message-Id: <1674007261-9198-2-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1674007261-9198-1-git-send-email-yangtiezhu@loongson.cn> References: <1674007261-9198-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf8DxTuTeUsdjPhYbAA--.17049S3 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBjvJXoW3WrWkAF4kWFyxWF1kGF4xtFb_yoW7trWfpr ZxAr1kGr4DZryfCrWjqr1vvr45tr4rur43u3ZxCw13CF17Zry5GrykGr4jvFy0kw4Utry0 ga1avw4j9F4ayaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj qI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUIcSsGvfJTRUUU b7AYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s 1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwA2z4 x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4UJVWxJr1l e2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa020Ex4CE44I27wAqx4xG64xvF2 IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_JF0_Jw1lYx0Ex4A2jsIE14v26r1j6r4U McvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x0EwIxGrwCFx2 IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v2 6r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67 AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IY s7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr 0_GrUvcSsGvfC2KfnxnUUI43ZEXa7IU1LiSJUUUUU== 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" According to LoongArch Reference Manual, simulate branch and PC* instructions, this is preparation for later patch. Link: https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.= html#branch-instructions Link: https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.= html#_pcaddi_pcaddu121_pcaddu18l_pcalau12i Co-developed-by: Jinyang He Signed-off-by: Jinyang He Signed-off-by: Tiezhu Yang Tested-by: Jeff Xie --- arch/loongarch/include/asm/inst.h | 5 ++ arch/loongarch/include/asm/ptrace.h | 1 + arch/loongarch/kernel/inst.c | 123 ++++++++++++++++++++++++++++++++= ++++ 3 files changed, 129 insertions(+) diff --git a/arch/loongarch/include/asm/inst.h b/arch/loongarch/include/asm= /inst.h index 7eedd83..a5dad39 100644 --- a/arch/loongarch/include/asm/inst.h +++ b/arch/loongarch/include/asm/inst.h @@ -7,6 +7,7 @@ =20 #include #include +#include =20 #define INSN_NOP 0x03400000 #define INSN_BREAK 0x002a0000 @@ -32,6 +33,7 @@ enum reg1i20_op { lu12iw_op =3D 0x0a, lu32id_op =3D 0x0b, pcaddi_op =3D 0x0c, + pcalau12i_op =3D 0x0d, pcaddu12i_op =3D 0x0e, pcaddu18i_op =3D 0x0f, }; @@ -351,6 +353,9 @@ static inline bool is_stack_alloc_ins(union loongarch_i= nstruction *ip) is_imm12_negative(ip->reg2i12_format.immediate); } =20 +void simu_pc(struct pt_regs *regs, union loongarch_instruction insn); +void simu_branch(struct pt_regs *regs, union loongarch_instruction insn); + int larch_insn_read(void *addr, u32 *insnp); int larch_insn_write(void *addr, u32 insn); int larch_insn_patch_text(void *addr, u32 insn); diff --git a/arch/loongarch/include/asm/ptrace.h b/arch/loongarch/include/a= sm/ptrace.h index 59c4608..58596c4 100644 --- a/arch/loongarch/include/asm/ptrace.h +++ b/arch/loongarch/include/asm/ptrace.h @@ -6,6 +6,7 @@ #define _ASM_PTRACE_H =20 #include +#include #include #include =20 diff --git a/arch/loongarch/kernel/inst.c b/arch/loongarch/kernel/inst.c index badc590..258ef26 100644 --- a/arch/loongarch/kernel/inst.c +++ b/arch/loongarch/kernel/inst.c @@ -10,6 +10,129 @@ =20 static DEFINE_RAW_SPINLOCK(patch_lock); =20 +void simu_pc(struct pt_regs *regs, union loongarch_instruction insn) +{ + unsigned long pc =3D regs->csr_era; + unsigned int rd =3D insn.reg1i20_format.rd; + unsigned int imm =3D insn.reg1i20_format.immediate; + + if (pc & 3) { + pr_warn("%s: invalid pc 0x%lx\n", __func__, pc); + return; + } + + switch (insn.reg1i20_format.opcode) { + case pcaddi_op: + regs->regs[rd] =3D pc + sign_extend64(imm << 2, 21); + break; + case pcaddu12i_op: + regs->regs[rd] =3D pc + sign_extend64(imm << 12, 31); + break; + case pcaddu18i_op: + regs->regs[rd] =3D pc + sign_extend64(imm << 18, 37); + break; + case pcalau12i_op: + regs->regs[rd] =3D pc + sign_extend64(imm << 12, 31); + regs->regs[rd] &=3D ~((1 << 12) - 1); + break; + default: + pr_info("%s: unknown opcode\n", __func__); + return; + } + + regs->csr_era +=3D LOONGARCH_INSN_SIZE; +} + +void simu_branch(struct pt_regs *regs, union loongarch_instruction insn) +{ + unsigned int imm, imm_l, imm_h, rd, rj; + unsigned long pc =3D regs->csr_era; + + if (pc & 3) { + pr_warn("%s: invalid pc 0x%lx\n", __func__, pc); + return; + } + + imm_l =3D insn.reg0i26_format.immediate_l; + imm_h =3D insn.reg0i26_format.immediate_h; + switch (insn.reg0i26_format.opcode) { + case b_op: + regs->csr_era =3D pc + sign_extend64((imm_h << 16 | imm_l) << 2, 27); + return; + case bl_op: + regs->csr_era =3D pc + sign_extend64((imm_h << 16 | imm_l) << 2, 27); + regs->regs[1] =3D pc + LOONGARCH_INSN_SIZE; + return; + } + + imm_l =3D insn.reg1i21_format.immediate_l; + imm_h =3D insn.reg1i21_format.immediate_h; + rj =3D insn.reg1i21_format.rj; + switch (insn.reg1i21_format.opcode) { + case beqz_op: + if (regs->regs[rj] =3D=3D 0) + regs->csr_era =3D pc + sign_extend64((imm_h << 16 | imm_l) << 2, 22); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + return; + case bnez_op: + if (regs->regs[rj] !=3D 0) + regs->csr_era =3D pc + sign_extend64((imm_h << 16 | imm_l) << 2, 22); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + return; + } + + imm =3D insn.reg2i16_format.immediate; + rj =3D insn.reg2i16_format.rj; + rd =3D insn.reg2i16_format.rd; + switch (insn.reg2i16_format.opcode) { + case beq_op: + if (regs->regs[rj] =3D=3D regs->regs[rd]) + regs->csr_era =3D pc + sign_extend64(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case bne_op: + if (regs->regs[rj] !=3D regs->regs[rd]) + regs->csr_era =3D pc + sign_extend64(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case blt_op: + if ((long)regs->regs[rj] < (long)regs->regs[rd]) + regs->csr_era =3D pc + sign_extend64(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case bge_op: + if ((long)regs->regs[rj] >=3D (long)regs->regs[rd]) + regs->csr_era =3D pc + sign_extend64(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case bltu_op: + if (regs->regs[rj] < regs->regs[rd]) + regs->csr_era =3D pc + sign_extend64(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case bgeu_op: + if (regs->regs[rj] >=3D regs->regs[rd]) + regs->csr_era =3D pc + sign_extend64(imm << 2, 17); + else + regs->csr_era =3D pc + LOONGARCH_INSN_SIZE; + break; + case jirl_op: + regs->csr_era =3D regs->regs[rj] + sign_extend64(imm << 2, 17); + regs->regs[rd] =3D pc + LOONGARCH_INSN_SIZE; + break; + default: + pr_info("%s: unknown opcode\n", __func__); + return; + } +} + int larch_insn_read(void *addr, u32 *insnp) { int ret; --=20 2.1.0 From nobody Sun Sep 14 22:15:24 2025 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 DFFEDC38142 for ; Wed, 18 Jan 2023 02:01:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229675AbjARCBg (ORCPT ); Tue, 17 Jan 2023 21:01:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229597AbjARCBL (ORCPT ); Tue, 17 Jan 2023 21:01:11 -0500 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 8CD4332520 for ; Tue, 17 Jan 2023 18:01:05 -0800 (PST) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8Bxb+vgUsdjRT0CAA--.6839S3; Wed, 18 Jan 2023 10:01:04 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxTuTeUsdjPhYbAA--.17049S4; Wed, 18 Jan 2023 10:01:04 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , WANG Xuerui , Masami Hiramatsu Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v12 2/5] LoongArch: Add kprobe support Date: Wed, 18 Jan 2023 10:00:58 +0800 Message-Id: <1674007261-9198-3-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1674007261-9198-1-git-send-email-yangtiezhu@loongson.cn> References: <1674007261-9198-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf8DxTuTeUsdjPhYbAA--.17049S4 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBjvAXoW3Kry8GF4kAF4UAw1UZrykuFg_yoW8WFW5Jo WSvF4DWw40gr4IgFWFyr1kJF1Uu3W0gFZ5AryFyFsxuw1kAr1rXr17Cr4rJa42qr4Fgw4x u345Zw1fGrZ3CFnxn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7ZEXasCq-sGcSsGvf J3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU0xBIdaVrnRJU UUk2b4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2IYs7xG6rWj6s 0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Gr0_Xr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1l84 ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AKxVW8Jr0_Cr1U M2AIxVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI12xvs2x26I8E6xACxx1l5I8CrVACY4 xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1q6rW5McIj6I8E87Iv67AKxVW8JVWx JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41l42xK82IYc2Ij64vIr41l4I 8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AK xVWUGVWUWwC2zVAF1VAY17CE14v26r126r1DMIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcV AFwI0_JFI_Gr1lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8I cIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r 4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxUcCD7UUUUU 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" Kprobe allows you to trap at almost any kernel address and execute a callback function, this commit adds kprobe support for LoongArch. Signed-off-by: Tiezhu Yang Tested-by: Jeff Xie --- arch/loongarch/Kconfig | 1 + arch/loongarch/include/asm/inst.h | 15 ++ arch/loongarch/include/asm/kprobes.h | 58 ++++++ arch/loongarch/kernel/Makefile | 2 + arch/loongarch/kernel/kprobes.c | 378 +++++++++++++++++++++++++++++++= ++++ arch/loongarch/kernel/traps.c | 11 +- arch/loongarch/mm/fault.c | 3 + 7 files changed, 463 insertions(+), 5 deletions(-) create mode 100644 arch/loongarch/include/asm/kprobes.h create mode 100644 arch/loongarch/kernel/kprobes.c diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 9be74ec..ce930f2 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -103,6 +103,7 @@ config LOONGARCH select HAVE_IOREMAP_PROT select HAVE_IRQ_EXIT_ON_IRQ_STACK select HAVE_IRQ_TIME_ACCOUNTING + select HAVE_KPROBES select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI select HAVE_PCI diff --git a/arch/loongarch/include/asm/inst.h b/arch/loongarch/include/asm= /inst.h index a5dad39..ba18ce8 100644 --- a/arch/loongarch/include/asm/inst.h +++ b/arch/loongarch/include/asm/inst.h @@ -24,6 +24,10 @@ =20 #define ADDR_IMM(addr, INSN) ((addr & ADDR_IMMMASK_##INSN) >> ADDR_IMMSHIF= T_##INSN) =20 +enum reg0i15_op { + break_op =3D 0x54, +}; + enum reg0i26_op { b_op =3D 0x14, bl_op =3D 0x15, @@ -180,6 +184,11 @@ enum reg3sa2_op { alsld_op =3D 0x16, }; =20 +struct reg0i15_format { + unsigned int immediate : 15; + unsigned int opcode : 17; +}; + struct reg0i26_format { unsigned int immediate_h : 10; unsigned int immediate_l : 16; @@ -265,6 +274,7 @@ struct reg3sa2_format { =20 union loongarch_instruction { unsigned int word; + struct reg0i15_format reg0i15_format; struct reg0i26_format reg0i26_format; struct reg1i20_format reg1i20_format; struct reg1i21_format reg1i21_format; @@ -323,6 +333,11 @@ static inline bool is_imm_negative(unsigned long val, = unsigned int bit) return val & (1UL << (bit - 1)); } =20 +static inline bool is_break_ins(union loongarch_instruction *ip) +{ + return ip->reg0i15_format.opcode =3D=3D break_op; +} + static inline bool is_pc_ins(union loongarch_instruction *ip) { return ip->reg1i20_format.opcode >=3D pcaddi_op && diff --git a/arch/loongarch/include/asm/kprobes.h b/arch/loongarch/include/= asm/kprobes.h new file mode 100644 index 0000000..7b9fc3e --- /dev/null +++ b/arch/loongarch/include/asm/kprobes.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __ASM_LOONGARCH_KPROBES_H +#define __ASM_LOONGARCH_KPROBES_H + +#include + +#ifdef CONFIG_KPROBES + +#include +#include + +#define __ARCH_WANT_KPROBES_INSN_SLOT +#define MAX_INSN_SIZE 2 + +#define flush_insn_slot(p) \ +do { \ + if (p->addr) \ + flush_icache_range((unsigned long)p->addr, \ + (unsigned long)p->addr + \ + (MAX_INSN_SIZE * sizeof(kprobe_opcode_t))); \ +} while (0) + +#define kretprobe_blacklist_size 0 + +typedef union loongarch_instruction kprobe_opcode_t; + +/* Architecture specific copy of original instruction */ +struct arch_specific_insn { + /* copy of the original instruction */ + kprobe_opcode_t *insn; + /* restore address after simulation */ + unsigned long restore; +}; + +struct prev_kprobe { + struct kprobe *kp; + unsigned int status; +}; + +/* per-cpu kprobe control block */ +struct kprobe_ctlblk { + unsigned int kprobe_status; + unsigned long saved_status; + struct prev_kprobe prev_kprobe; +}; + +void arch_remove_kprobe(struct kprobe *p); +bool kprobe_fault_handler(struct pt_regs *regs, int trapnr); +bool kprobe_breakpoint_handler(struct pt_regs *regs); +bool kprobe_singlestep_handler(struct pt_regs *regs); + +#else /* !CONFIG_KPROBES */ + +static inline bool kprobe_breakpoint_handler(struct pt_regs *regs) { retur= n false; } +static inline bool kprobe_singlestep_handler(struct pt_regs *regs) { retur= n false; } + +#endif /* CONFIG_KPROBES */ +#endif /* __ASM_LOONGARCH_KPROBES_H */ diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile index c8cfbd5..017ac59 100644 --- a/arch/loongarch/kernel/Makefile +++ b/arch/loongarch/kernel/Makefile @@ -47,4 +47,6 @@ obj-$(CONFIG_UNWINDER_PROLOGUE) +=3D unwind_prologue.o =20 obj-$(CONFIG_PERF_EVENTS) +=3D perf_event.o perf_regs.o =20 +obj-$(CONFIG_KPROBES) +=3D kprobes.o + CPPFLAGS_vmlinux.lds :=3D $(KBUILD_CFLAGS) diff --git a/arch/loongarch/kernel/kprobes.c b/arch/loongarch/kernel/kprobe= s.c new file mode 100644 index 0000000..a0c2f9d --- /dev/null +++ b/arch/loongarch/kernel/kprobes.c @@ -0,0 +1,378 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include + +static const union loongarch_instruction breakpoint_insn =3D { + .reg0i15_format =3D { + .opcode =3D break_op, + .immediate =3D BRK_KPROBE_BP, + } +}; + +static const union loongarch_instruction singlestep_insn =3D { + .reg0i15_format =3D { + .opcode =3D break_op, + .immediate =3D BRK_KPROBE_SSTEPBP, + } +}; + +DEFINE_PER_CPU(struct kprobe *, current_kprobe); +DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); + +static void post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, s= truct pt_regs *); + +static bool insns_not_supported(union loongarch_instruction insn) +{ + switch (insn.reg2i14_format.opcode) { + case llw_op: + case lld_op: + case scw_op: + case scd_op: + pr_notice("kprobe: ll and sc instructions are not supported\n"); + return true; + } + + switch (insn.reg1i21_format.opcode) { + case bceqz_op: + pr_notice("kprobe: bceqz and bcnez instructions are not supported\n"); + return true; + } + + return false; +} +NOKPROBE_SYMBOL(insns_not_supported); + +static bool insn_need_simulation(struct kprobe *p) +{ + if (is_pc_ins(&p->opcode)) + return true; + + if (is_branch_ins(&p->opcode)) + return true; + + return false; +} +NOKPROBE_SYMBOL(insn_need_simulation); + +static void arch_simulate_insn(struct kprobe *p, struct pt_regs *regs) +{ + if (is_pc_ins(&p->opcode)) + simu_pc(regs, p->opcode); + else if (is_branch_ins(&p->opcode)) + simu_branch(regs, p->opcode); +} +NOKPROBE_SYMBOL(arch_simulate_insn); + +static void arch_prepare_ss_slot(struct kprobe *p) +{ + p->ainsn.insn[0] =3D *p->addr; + p->ainsn.insn[1] =3D singlestep_insn; + p->ainsn.restore =3D (unsigned long)p->addr + LOONGARCH_INSN_SIZE; +} +NOKPROBE_SYMBOL(arch_prepare_ss_slot); + +static void arch_prepare_simulate(struct kprobe *p) +{ + p->ainsn.restore =3D 0; +} +NOKPROBE_SYMBOL(arch_prepare_simulate); + +int arch_prepare_kprobe(struct kprobe *p) +{ + /* copy instruction */ + p->opcode =3D *p->addr; + + /* decode instruction */ + if (insns_not_supported(p->opcode)) + return -EINVAL; + + if (insn_need_simulation(p)) { + p->ainsn.insn =3D NULL; + } else { + p->ainsn.insn =3D get_insn_slot(); + if (!p->ainsn.insn) + return -ENOMEM; + } + + /* prepare the instruction */ + if (p->ainsn.insn) + arch_prepare_ss_slot(p); + else + arch_prepare_simulate(p); + + return 0; +} +NOKPROBE_SYMBOL(arch_prepare_kprobe); + +/* Install breakpoint in text */ +void arch_arm_kprobe(struct kprobe *p) +{ + *p->addr =3D breakpoint_insn; + flush_insn_slot(p); +} +NOKPROBE_SYMBOL(arch_arm_kprobe); + +/* Remove breakpoint from text */ +void arch_disarm_kprobe(struct kprobe *p) +{ + *p->addr =3D p->opcode; + flush_insn_slot(p); +} +NOKPROBE_SYMBOL(arch_disarm_kprobe); + +void arch_remove_kprobe(struct kprobe *p) +{ + if (p->ainsn.insn) { + free_insn_slot(p->ainsn.insn, 0); + p->ainsn.insn =3D NULL; + } +} +NOKPROBE_SYMBOL(arch_remove_kprobe); + +static void save_previous_kprobe(struct kprobe_ctlblk *kcb) +{ + kcb->prev_kprobe.kp =3D kprobe_running(); + kcb->prev_kprobe.status =3D kcb->kprobe_status; +} +NOKPROBE_SYMBOL(save_previous_kprobe); + +static void restore_previous_kprobe(struct kprobe_ctlblk *kcb) +{ + __this_cpu_write(current_kprobe, kcb->prev_kprobe.kp); + kcb->kprobe_status =3D kcb->prev_kprobe.status; +} +NOKPROBE_SYMBOL(restore_previous_kprobe); + +static void set_current_kprobe(struct kprobe *p) +{ + __this_cpu_write(current_kprobe, p); +} +NOKPROBE_SYMBOL(set_current_kprobe); + +/* + * Interrupts need to be disabled before single-step mode is set, + * and not reenabled until after single-step mode ends. + * Without disabling interrupt on local CPU, there is a chance of + * interrupt occurrence in the period of exception return and start + * of out-of-line single-step, that result in wrongly single stepping + * into the interrupt handler. + */ +static void save_local_irqflag(struct kprobe_ctlblk *kcb, + struct pt_regs *regs) +{ + kcb->saved_status =3D regs->csr_prmd; + regs->csr_prmd &=3D ~CSR_PRMD_PIE; +} +NOKPROBE_SYMBOL(save_local_irqflag); + +static void restore_local_irqflag(struct kprobe_ctlblk *kcb, + struct pt_regs *regs) +{ + regs->csr_prmd =3D kcb->saved_status; +} +NOKPROBE_SYMBOL(restore_local_irqflag); + +static void setup_singlestep(struct kprobe *p, struct pt_regs *regs, + struct kprobe_ctlblk *kcb, int reenter) +{ + if (reenter) { + save_previous_kprobe(kcb); + set_current_kprobe(p); + kcb->kprobe_status =3D KPROBE_REENTER; + } else { + kcb->kprobe_status =3D KPROBE_HIT_SS; + } + + if (p->ainsn.insn) { + /* IRQs and single stepping do not mix well */ + save_local_irqflag(kcb, regs); + /* set ip register to prepare for single stepping */ + regs->csr_era =3D (unsigned long)p->ainsn.insn; + } else { + /* simulate single steping */ + arch_simulate_insn(p, regs); + /* now go for post processing */ + post_kprobe_handler(p, kcb, regs); + } +} +NOKPROBE_SYMBOL(setup_singlestep); + +static bool reenter_kprobe(struct kprobe *p, struct pt_regs *regs, + struct kprobe_ctlblk *kcb) +{ + switch (kcb->kprobe_status) { + case KPROBE_HIT_SSDONE: + case KPROBE_HIT_ACTIVE: + case KPROBE_HIT_SS: + kprobes_inc_nmissed_count(p); + setup_singlestep(p, regs, kcb, 1); + break; + case KPROBE_REENTER: + pr_warn("Failed to recover from reentered kprobes.\n"); + dump_kprobe(p); + WARN_ON_ONCE(1); + break; + default: + WARN_ON(1); + return false; + } + + return true; +} +NOKPROBE_SYMBOL(reenter_kprobe); + +static void post_kprobe_handler(struct kprobe *cur, struct kprobe_ctlblk *= kcb, + struct pt_regs *regs) +{ + /* return addr restore if non-branching insn */ + if (cur->ainsn.restore !=3D 0) + instruction_pointer_set(regs, cur->ainsn.restore); + + /* restore back original saved kprobe variables and continue */ + if (kcb->kprobe_status =3D=3D KPROBE_REENTER) { + restore_previous_kprobe(kcb); + preempt_enable_no_resched(); + return; + } + + /* + * update the kcb status even if the cur->post_handler is + * not set because reset_curent_kprobe() doesn't update kcb. + */ + kcb->kprobe_status =3D KPROBE_HIT_SSDONE; + if (cur->post_handler) + cur->post_handler(cur, regs, 0); + + reset_current_kprobe(); + preempt_enable_no_resched(); +} +NOKPROBE_SYMBOL(post_kprobe_handler); + +bool kprobe_breakpoint_handler(struct pt_regs *regs) +{ + struct kprobe_ctlblk *kcb; + struct kprobe *p, *cur_kprobe; + kprobe_opcode_t *addr =3D (kprobe_opcode_t *)regs->csr_era; + + /* + * We don't want to be preempted for the entire + * duration of kprobe processing. + */ + preempt_disable(); + kcb =3D get_kprobe_ctlblk(); + cur_kprobe =3D kprobe_running(); + + p =3D get_kprobe(addr); + if (p) { + if (cur_kprobe) { + if (reenter_kprobe(p, regs, kcb)) + return true; + } else { + /* Probe hit */ + set_current_kprobe(p); + kcb->kprobe_status =3D KPROBE_HIT_ACTIVE; + + /* + * If we have no pre-handler or it returned 0, we + * continue with normal processing. If we have a + * pre-handler and it returned non-zero, it will + * modify the execution path and no need to single + * stepping. Let's just reset current kprobe and exit. + * + * pre_handler can hit a breakpoint and can step thru + * before return. + */ + if (!p->pre_handler || !p->pre_handler(p, regs)) { + setup_singlestep(p, regs, kcb, 0); + } else { + reset_current_kprobe(); + preempt_enable_no_resched(); + } + return true; + } + } + + if (addr->word !=3D breakpoint_insn.word) { + /* + * The breakpoint instruction was removed right + * after we hit it. Another cpu has removed + * either a probepoint or a debugger breakpoint + * at this address. In either case, no further + * handling of this interrupt is appropriate. + * Return back to original instruction, and continue. + */ + regs->csr_era =3D (unsigned long)addr; + preempt_enable_no_resched(); + return true; + } + + preempt_enable_no_resched(); + return false; +} +NOKPROBE_SYMBOL(kprobe_breakpoint_handler); + +bool kprobe_singlestep_handler(struct pt_regs *regs) +{ + struct kprobe *cur =3D kprobe_running(); + struct kprobe_ctlblk *kcb =3D get_kprobe_ctlblk(); + unsigned long addr =3D instruction_pointer(regs); + + if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) && + ((unsigned long)&cur->ainsn.insn[1] =3D=3D addr)) { + restore_local_irqflag(kcb, regs); + post_kprobe_handler(cur, kcb, regs); + return true; + } + + preempt_enable_no_resched(); + return false; +} +NOKPROBE_SYMBOL(kprobe_singlestep_handler); + +bool kprobe_fault_handler(struct pt_regs *regs, int trapnr) +{ + struct kprobe *cur =3D kprobe_running(); + struct kprobe_ctlblk *kcb =3D get_kprobe_ctlblk(); + + switch (kcb->kprobe_status) { + case KPROBE_HIT_SS: + case KPROBE_REENTER: + /* + * We are here because the instruction being single + * stepped caused a page fault. We reset the current + * kprobe and the ip points back to the probe address + * and allow the page fault handler to continue as a + * normal page fault. + */ + regs->csr_era =3D (unsigned long)cur->addr; + WARN_ON_ONCE(!instruction_pointer(regs)); + + if (kcb->kprobe_status =3D=3D KPROBE_REENTER) { + restore_previous_kprobe(kcb); + } else { + restore_local_irqflag(kcb, regs); + reset_current_kprobe(); + } + preempt_enable_no_resched(); + break; + } + return false; +} +NOKPROBE_SYMBOL(kprobe_fault_handler); + +/* + * Provide a blacklist of symbols identifying ranges which cannot be kprob= ed. + * This blacklist is exposed to userspace via debugfs (kprobes/blacklist). + */ +int __init arch_populate_kprobe_blacklist(void) +{ + return kprobe_add_area_blacklist((unsigned long)__irqentry_text_start, + (unsigned long)__irqentry_text_end); +} + +int __init arch_init_kprobes(void) +{ + return 0; +} diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c index 8029757..18aa217 100644 --- a/arch/loongarch/kernel/traps.c +++ b/arch/loongarch/kernel/traps.c @@ -432,7 +432,10 @@ asmlinkage void noinstr do_bp(struct pt_regs *regs) unsigned long era =3D exception_era(regs); irqentry_state_t state =3D irqentry_enter(regs); =20 - local_irq_enable(); + /* Enable interrupt if enabled in parent context */ + if (likely(regs->csr_prmd & CSR_PRMD_PIE)) + local_irq_enable(); + current->thread.trap_nr =3D read_csr_excode(); if (__get_inst(&opcode, (u32 *)era, user)) goto out_sigsegv; @@ -445,14 +448,12 @@ asmlinkage void noinstr do_bp(struct pt_regs *regs) */ switch (bcode) { case BRK_KPROBE_BP: - if (notify_die(DIE_BREAK, "Kprobe", regs, bcode, - current->thread.trap_nr, SIGTRAP) =3D=3D NOTIFY_STOP) + if (kprobe_breakpoint_handler(regs)) goto out; else break; case BRK_KPROBE_SSTEPBP: - if (notify_die(DIE_SSTEPBP, "Kprobe_SingleStep", regs, bcode, - current->thread.trap_nr, SIGTRAP) =3D=3D NOTIFY_STOP) + if (kprobe_singlestep_handler(regs)) goto out; else break; diff --git a/arch/loongarch/mm/fault.c b/arch/loongarch/mm/fault.c index 1ccd536..449087b 100644 --- a/arch/loongarch/mm/fault.c +++ b/arch/loongarch/mm/fault.c @@ -135,6 +135,9 @@ static void __kprobes __do_page_fault(struct pt_regs *r= egs, struct vm_area_struct *vma =3D NULL; vm_fault_t fault; =20 + if (kprobe_page_fault(regs, current->thread.trap_nr)) + return; + /* * We fault-in kernel-space virtual memory on-demand. The * 'reference' page table is init_mm.pgd. --=20 2.1.0 From nobody Sun Sep 14 22:15:24 2025 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 B9140C38142 for ; Wed, 18 Jan 2023 02:01:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229606AbjARCBZ (ORCPT ); Tue, 17 Jan 2023 21:01:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39176 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229571AbjARCBL (ORCPT ); Tue, 17 Jan 2023 21:01:11 -0500 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BE1303D921 for ; Tue, 17 Jan 2023 18:01:05 -0800 (PST) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8DxTuvgUsdjSz0CAA--.6830S3; Wed, 18 Jan 2023 10:01:04 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxTuTeUsdjPhYbAA--.17049S5; Wed, 18 Jan 2023 10:01:04 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , WANG Xuerui , Masami Hiramatsu Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v12 3/5] LoongArch: Add kretprobe support Date: Wed, 18 Jan 2023 10:00:59 +0800 Message-Id: <1674007261-9198-4-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1674007261-9198-1-git-send-email-yangtiezhu@loongson.cn> References: <1674007261-9198-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf8DxTuTeUsdjPhYbAA--.17049S5 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBjvJXoWxtrykKryfXF4xWFWDAF17trb_yoW7Cr1DpF 9rArn8Wr4S9rnYvr9xt3yF9FyUtr1kuw42gFyxJrWrGF4UWryUXr1xGr9rZFW3Kws8tr1S qr1fGrW5tFW3J37anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj qI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUIcSsGvfJTRUUU b28YFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s 1l1IIY67AEw4v_Jrv_JF1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwA2z4 x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4UJVWxJr1l e2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa020Ex4CE44I27wAqx4xG64xvF2 IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jw0_WrylYx0Ex4A2jsIE14v26r4j6F4U McvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x0EwIxGrwCFx2 IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v2 6r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67 AKxVW8JVW5JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IY s7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr 0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07josjUUUUUU= 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" Use the generic kretprobe trampoline handler to add kretprobe support for LoongArch. Signed-off-by: Tiezhu Yang Tested-by: Jeff Xie --- arch/loongarch/Kconfig | 1 + arch/loongarch/include/asm/kprobes.h | 3 + arch/loongarch/kernel/Makefile | 2 +- arch/loongarch/kernel/kprobes.c | 27 +++++++++ arch/loongarch/kernel/kprobes_trampoline.S | 96 ++++++++++++++++++++++++++= ++++ 5 files changed, 128 insertions(+), 1 deletion(-) create mode 100644 arch/loongarch/kernel/kprobes_trampoline.S diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index ce930f2..134a2f8 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -104,6 +104,7 @@ config LOONGARCH select HAVE_IRQ_EXIT_ON_IRQ_STACK select HAVE_IRQ_TIME_ACCOUNTING select HAVE_KPROBES + select HAVE_KRETPROBES select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI select HAVE_PCI diff --git a/arch/loongarch/include/asm/kprobes.h b/arch/loongarch/include/= asm/kprobes.h index 7b9fc3e..798020a 100644 --- a/arch/loongarch/include/asm/kprobes.h +++ b/arch/loongarch/include/asm/kprobes.h @@ -49,6 +49,9 @@ bool kprobe_fault_handler(struct pt_regs *regs, int trapn= r); bool kprobe_breakpoint_handler(struct pt_regs *regs); bool kprobe_singlestep_handler(struct pt_regs *regs); =20 +void __kretprobe_trampoline(void); +void *trampoline_probe_handler(struct pt_regs *regs); + #else /* !CONFIG_KPROBES */ =20 static inline bool kprobe_breakpoint_handler(struct pt_regs *regs) { retur= n false; } diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile index 017ac59..45c78ae 100644 --- a/arch/loongarch/kernel/Makefile +++ b/arch/loongarch/kernel/Makefile @@ -47,6 +47,6 @@ obj-$(CONFIG_UNWINDER_PROLOGUE) +=3D unwind_prologue.o =20 obj-$(CONFIG_PERF_EVENTS) +=3D perf_event.o perf_regs.o =20 -obj-$(CONFIG_KPROBES) +=3D kprobes.o +obj-$(CONFIG_KPROBES) +=3D kprobes.o kprobes_trampoline.o =20 CPPFLAGS_vmlinux.lds :=3D $(KBUILD_CFLAGS) diff --git a/arch/loongarch/kernel/kprobes.c b/arch/loongarch/kernel/kprobe= s.c index a0c2f9d..ced9c4c 100644 --- a/arch/loongarch/kernel/kprobes.c +++ b/arch/loongarch/kernel/kprobes.c @@ -372,6 +372,33 @@ int __init arch_populate_kprobe_blacklist(void) (unsigned long)__irqentry_text_end); } =20 +/* Called from __kretprobe_trampoline */ +void __used *trampoline_probe_handler(struct pt_regs *regs) +{ + return (void *)kretprobe_trampoline_handler(regs, NULL); +} +NOKPROBE_SYMBOL(trampoline_probe_handler); + +/* assembler function that handles the kretprobes must not be probed itsel= f */ +NOKPROBE_SYMBOL(__kretprobe_trampoline); + +void arch_prepare_kretprobe(struct kretprobe_instance *ri, + struct pt_regs *regs) +{ + ri->ret_addr =3D (kprobe_opcode_t *)regs->regs[1]; + ri->fp =3D NULL; + + /* Replace the return addr with trampoline addr */ + regs->regs[1] =3D (unsigned long)&__kretprobe_trampoline; +} +NOKPROBE_SYMBOL(arch_prepare_kretprobe); + +int arch_trampoline_kprobe(struct kprobe *p) +{ + return 0; +} +NOKPROBE_SYMBOL(arch_trampoline_kprobe); + int __init arch_init_kprobes(void) { return 0; diff --git a/arch/loongarch/kernel/kprobes_trampoline.S b/arch/loongarch/ke= rnel/kprobes_trampoline.S new file mode 100644 index 0000000..af94b0d --- /dev/null +++ b/arch/loongarch/kernel/kprobes_trampoline.S @@ -0,0 +1,96 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +#include +#include + + .text + + .macro save_all_base_regs + cfi_st ra, PT_R1 + cfi_st tp, PT_R2 + cfi_st a0, PT_R4 + cfi_st a1, PT_R5 + cfi_st a2, PT_R6 + cfi_st a3, PT_R7 + cfi_st a4, PT_R8 + cfi_st a5, PT_R9 + cfi_st a6, PT_R10 + cfi_st a7, PT_R11 + cfi_st t0, PT_R12 + cfi_st t1, PT_R13 + cfi_st t2, PT_R14 + cfi_st t3, PT_R15 + cfi_st t4, PT_R16 + cfi_st t5, PT_R17 + cfi_st t6, PT_R18 + cfi_st t7, PT_R19 + cfi_st t8, PT_R20 + cfi_st u0, PT_R21 + cfi_st fp, PT_R22 + cfi_st s0, PT_R23 + cfi_st s1, PT_R24 + cfi_st s2, PT_R25 + cfi_st s3, PT_R26 + cfi_st s4, PT_R27 + cfi_st s5, PT_R28 + cfi_st s6, PT_R29 + cfi_st s7, PT_R30 + cfi_st s8, PT_R31 + csrrd t0, LOONGARCH_CSR_CRMD + andi t0, t0, 0x7 /* extract bit[1:0] PLV, bit[2] IE */ + LONG_S t0, sp, PT_CRMD + .endm + + .macro restore_all_base_regs + cfi_ld tp, PT_R2 + cfi_ld a0, PT_R4 + cfi_ld a1, PT_R5 + cfi_ld a2, PT_R6 + cfi_ld a3, PT_R7 + cfi_ld a4, PT_R8 + cfi_ld a5, PT_R9 + cfi_ld a6, PT_R10 + cfi_ld a7, PT_R11 + cfi_ld t0, PT_R12 + cfi_ld t1, PT_R13 + cfi_ld t2, PT_R14 + cfi_ld t3, PT_R15 + cfi_ld t4, PT_R16 + cfi_ld t5, PT_R17 + cfi_ld t6, PT_R18 + cfi_ld t7, PT_R19 + cfi_ld t8, PT_R20 + cfi_ld u0, PT_R21 + cfi_ld fp, PT_R22 + cfi_ld s0, PT_R23 + cfi_ld s1, PT_R24 + cfi_ld s2, PT_R25 + cfi_ld s3, PT_R26 + cfi_ld s4, PT_R27 + cfi_ld s5, PT_R28 + cfi_ld s6, PT_R29 + cfi_ld s7, PT_R30 + cfi_ld s8, PT_R31 + LONG_L t0, sp, PT_CRMD + li.d t1, 0x7 /* mask bit[1:0] PLV, bit[2] IE */ + csrxchg t0, t1, LOONGARCH_CSR_CRMD + .endm + +SYM_CODE_START(__kretprobe_trampoline) + addi.d sp, sp, -PT_SIZE + save_all_base_regs + + addi.d t0, sp, PT_SIZE + LONG_S t0, sp, PT_R3 + + move a0, sp /* pt_regs */ + + bl trampoline_probe_handler + + /* use the result as the return-address */ + move ra, a0 + + restore_all_base_regs + addi.d sp, sp, PT_SIZE + + jr ra +SYM_CODE_END(__kretprobe_trampoline) --=20 2.1.0 From nobody Sun Sep 14 22:15:24 2025 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 2B06AC00A5A for ; Wed, 18 Jan 2023 02:01:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229647AbjARCBW (ORCPT ); Tue, 17 Jan 2023 21:01:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229588AbjARCBL (ORCPT ); Tue, 17 Jan 2023 21:01:11 -0500 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 174334F870 for ; Tue, 17 Jan 2023 18:01:06 -0800 (PST) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8BxLuviUsdjTz0CAA--.6819S3; Wed, 18 Jan 2023 10:01:06 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxTuTeUsdjPhYbAA--.17049S6; Wed, 18 Jan 2023 10:01:04 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , WANG Xuerui , Masami Hiramatsu Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v12 4/5] LoongArch: Mark some assembler symbols as non-kprobe-able Date: Wed, 18 Jan 2023 10:01:00 +0800 Message-Id: <1674007261-9198-5-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1674007261-9198-1-git-send-email-yangtiezhu@loongson.cn> References: <1674007261-9198-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf8DxTuTeUsdjPhYbAA--.17049S6 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBjvJXoW7uw45Wr4fCw45ZrWUGFW7urg_yoW8Kr17pw 1DAr4vgrs5Gr1fJry7tF1UZ3yDZws7Gr12v3W29FW8CF47WF18Zry093yDXFyxtw43GFWF qFn5J3929F4UJa7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj qI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUIcSsGvfJTRUUU b28YFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s 1l1IIY67AEw4v_Jrv_JF1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwA2z4 x0Y4vEx4A2jsIE14v26r4UJVWxJr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4UJVWxJr1l e2I262IYc4CY6c8Ij28IcVAaY2xG8wAqjxCEc2xF0cIa020Ex4CE44I27wAqx4xG64xvF2 IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jw0_WrylYx0Ex4A2jsIE14v26r4j6F4U McvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x0EwIxGrwCFx2 IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v2 6r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67 AKxVW8JVW5JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IY s7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr 0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07josjUUUUUU= 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" Some assembler symbols are not kprobe safe, such as handle_syscall (used as syscall exception handler), *memcpy* (may cause recursive exceptions), they can not be instrumented, just blacklist them for kprobing. Here is a related problem and discussion: Link: https://lore.kernel.org/lkml/20230114143859.7ccc45c1c5d9ce302113ab0a@= kernel.org/ Signed-off-by: Tiezhu Yang Tested-by: Jeff Xie --- arch/loongarch/include/asm/asm.h | 10 ++++++++++ arch/loongarch/kernel/entry.S | 1 + arch/loongarch/lib/memcpy.S | 3 +++ 3 files changed, 14 insertions(+) diff --git a/arch/loongarch/include/asm/asm.h b/arch/loongarch/include/asm/= asm.h index 40eea6a..f591b32 100644 --- a/arch/loongarch/include/asm/asm.h +++ b/arch/loongarch/include/asm/asm.h @@ -188,4 +188,14 @@ #define PTRLOG 3 #endif =20 +/* Annotate a function as being unsuitable for kprobes. */ +#ifdef CONFIG_KPROBES +#define _ASM_NOKPROBE(name) \ + .pushsection "_kprobe_blacklist", "aw"; \ + .quad name; \ + .popsection +#else +#define _ASM_NOKPROBE(name) +#endif + #endif /* __ASM_ASM_H */ diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S index d53b631..55e23b1 100644 --- a/arch/loongarch/kernel/entry.S +++ b/arch/loongarch/kernel/entry.S @@ -67,6 +67,7 @@ SYM_FUNC_START(handle_syscall) =20 RESTORE_ALL_AND_RET SYM_FUNC_END(handle_syscall) +_ASM_NOKPROBE(handle_syscall) =20 SYM_CODE_START(ret_from_fork) bl schedule_tail # a0 =3D struct task_struct *prev diff --git a/arch/loongarch/lib/memcpy.S b/arch/loongarch/lib/memcpy.S index 7c07d59..3b7e1de 100644 --- a/arch/loongarch/lib/memcpy.S +++ b/arch/loongarch/lib/memcpy.S @@ -17,6 +17,7 @@ SYM_FUNC_START(memcpy) ALTERNATIVE "b __memcpy_generic", \ "b __memcpy_fast", CPU_FEATURE_UAL SYM_FUNC_END(memcpy) +_ASM_NOKPROBE(memcpy) =20 EXPORT_SYMBOL(memcpy) =20 @@ -41,6 +42,7 @@ SYM_FUNC_START(__memcpy_generic) 2: move a0, a3 jr ra SYM_FUNC_END(__memcpy_generic) +_ASM_NOKPROBE(__memcpy_generic) =20 /* * void *__memcpy_fast(void *dst, const void *src, size_t n) @@ -93,3 +95,4 @@ SYM_FUNC_START(__memcpy_fast) 3: move a0, a3 jr ra SYM_FUNC_END(__memcpy_fast) +_ASM_NOKPROBE(__memcpy_fast) --=20 2.1.0 From nobody Sun Sep 14 22:15:24 2025 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 490B3C38142 for ; Wed, 18 Jan 2023 02:01:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229723AbjARCBb (ORCPT ); Tue, 17 Jan 2023 21:01:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39180 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229608AbjARCBL (ORCPT ); Tue, 17 Jan 2023 21:01:11 -0500 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4368751C4D for ; Tue, 17 Jan 2023 18:01:07 -0800 (PST) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8CxIfDiUsdjUT0CAA--.7087S3; Wed, 18 Jan 2023 10:01:06 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8DxTuTeUsdjPhYbAA--.17049S7; Wed, 18 Jan 2023 10:01:06 +0800 (CST) From: Tiezhu Yang To: Huacai Chen , WANG Xuerui , Masami Hiramatsu Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v12 5/5] samples/kprobes: Add LoongArch support Date: Wed, 18 Jan 2023 10:01:01 +0800 Message-Id: <1674007261-9198-6-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1674007261-9198-1-git-send-email-yangtiezhu@loongson.cn> References: <1674007261-9198-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf8DxTuTeUsdjPhYbAA--.17049S7 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBjvJXoWrZw4rWrW5CF1fJw1xZFWDJwb_yoW8JF1fpF n0y3W5t3yFyw13WFW3Jayvgry0yryjkay8u3ykC34Yya429ry5AF1rKayjyw4kur90qF43 tr1FvryUGF1xZrJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUj1kv1TuYvTs0mT0YCTnIWj qI5I8CrVACY4xI64kE6c02F40Ex7xfYxn0WfASr-VFAUDa7-sFnT9fnUUIcSsGvfJTRUUU b2xYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s 1l1IIY67AEw4v_JrI_Jryl8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVWxJVW8Jr1l84 ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AKxVW8Jr0_Cr1U M2AIxVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI12xvs2x26I8E6xACxx1l5I8CrVACY4 xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1q6rW5McIj6I8E87Iv67AKxVW8JVWx JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41l42xK82IYc2Ij64vIr41l4I 8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AK xVWUGVWUWwC2zVAF1VAY17CE14v26r126r1DMIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcV AFwI0_Xr0_Ar1lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8I cIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r 4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxUcHUqUUUUU 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" Add LoongArch specific info in handler_pre() and handler_post(). Signed-off-by: Tiezhu Yang Tested-by: Jeff Xie --- samples/kprobes/kprobe_example.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/samples/kprobes/kprobe_example.c b/samples/kprobes/kprobe_exam= ple.c index fd346f5..ef44c61 100644 --- a/samples/kprobes/kprobe_example.c +++ b/samples/kprobes/kprobe_example.c @@ -55,6 +55,10 @@ static int __kprobes handler_pre(struct kprobe *p, struc= t pt_regs *regs) pr_info("<%s> p->addr, 0x%p, ip =3D 0x%lx, flags =3D 0x%lx\n", p->symbol_name, p->addr, regs->psw.addr, regs->flags); #endif +#ifdef CONFIG_LOONGARCH + pr_info("<%s> p->addr =3D 0x%p, era =3D 0x%lx, estat =3D 0x%lx\n", + p->symbol_name, p->addr, regs->csr_era, regs->csr_estat); +#endif =20 /* A dump_stack() here will give a stack backtrace */ return 0; @@ -92,6 +96,10 @@ static void __kprobes handler_post(struct kprobe *p, str= uct pt_regs *regs, pr_info("<%s> p->addr, 0x%p, flags =3D 0x%lx\n", p->symbol_name, p->addr, regs->flags); #endif +#ifdef CONFIG_LOONGARCH + pr_info("<%s> p->addr =3D 0x%p, estat =3D 0x%lx\n", + p->symbol_name, p->addr, regs->csr_estat); +#endif } =20 static int __init kprobe_init(void) --=20 2.1.0