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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 1C8B9C433E0 for ; Mon, 13 Jul 2020 23:39:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF88721473 for ; Mon, 13 Jul 2020 23:39:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594683593; bh=BqEz/f5EgOhbPz+CU1f1NcmNVhcNDCUYDV+CNGgvdrc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vNE514LhIfd/jqA4r+qq3lpO2qH+lkbhp/ZWgrlEQgZGB++dvg1xm2t5Evvr6YAlf gg+R+2zAqj/ytydu2KP1aIcMG5ckrsvlkUKkx3IJdEJMgj/KTThSH+n623Rk3lTjSs 13aZaa4A0c4W2vO4d0CEP1/KUSWG+CV1dYQ+9cuU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726352AbgGMXjw (ORCPT ); Mon, 13 Jul 2020 19:39:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:51494 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726339AbgGMXjv (ORCPT ); Mon, 13 Jul 2020 19:39:51 -0400 Received: from localhost.localdomain (unknown [89.208.247.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 309AA214D8; Mon, 13 Jul 2020 23:39:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594683590; bh=BqEz/f5EgOhbPz+CU1f1NcmNVhcNDCUYDV+CNGgvdrc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V9ZIKblLGwYONe9HvzhlkN/O3io2XrTOXy+jVDuegkTjK69W18qfpBQzUGOCYTAnP rHZ+WA8FtP4UU0xJgsHa6AbKMGHIK02QcOOIKcI/ubCe4Lp/iSVvU9ZdkGwL+QKRXX bEbZSY9Alp3+gkDimvTLh8OZNdVlXmWwku6iRlxs= From: guoren@kernel.org To: palmerdabbelt@google.com, paul.walmsley@sifive.com, mhiramat@kernel.org, oleg@redhat.com Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, anup@brainfault.org, linux-csky@vger.kernel.org, greentime.hu@sifive.com, zong.li@sifive.com, guoren@kernel.org, me@packi.ch, bjorn.topel@gmail.com, Guo Ren Subject: [PATCH v3 1/7] RISC-V: Implement ptrace regs and stack API Date: Mon, 13 Jul 2020 23:39:16 +0000 Message-Id: <1594683562-68149-2-git-send-email-guoren@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1594683562-68149-1-git-send-email-guoren@kernel.org> References: <1594683562-68149-1-git-send-email-guoren@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-csky-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-csky@vger.kernel.org From: Patrick Stählin Needed for kprobes support. Copied and adapted from arm64 code. Guo Ren fixup pt_regs type for linux-5.8-rc1. Signed-off-by: Patrick Stählin Signed-off-by: Guo Ren Reviewed-by: Pekka Enberg Reviewed-by: Zong Li --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/ptrace.h | 29 ++++++++++++ arch/riscv/kernel/ptrace.c | 99 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 129 insertions(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 3230c1d..e70449a 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -78,6 +78,7 @@ config RISCV select SPARSE_IRQ select SYSCTL_EXCEPTION_TRACE select THREAD_INFO_IN_TASK + select HAVE_REGS_AND_STACK_ACCESS_API config ARCH_MMAP_RND_BITS_MIN default 18 if 64BIT diff --git a/arch/riscv/include/asm/ptrace.h b/arch/riscv/include/asm/ptrace.h index ee49f80..23372bb 100644 --- a/arch/riscv/include/asm/ptrace.h +++ b/arch/riscv/include/asm/ptrace.h @@ -8,6 +8,7 @@ #include #include +#include #ifndef __ASSEMBLY__ @@ -60,6 +61,7 @@ struct pt_regs { #define user_mode(regs) (((regs)->status & SR_PP) == 0) +#define MAX_REG_OFFSET offsetof(struct pt_regs, orig_a0) /* Helpers for working with the instruction pointer */ static inline unsigned long instruction_pointer(struct pt_regs *regs) @@ -85,6 +87,12 @@ static inline void user_stack_pointer_set(struct pt_regs *regs, regs->sp = val; } +/* Valid only for Kernel mode traps. */ +static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) +{ + return regs->sp; +} + /* Helpers for working with the frame pointer */ static inline unsigned long frame_pointer(struct pt_regs *regs) { @@ -101,6 +109,27 @@ static inline unsigned long regs_return_value(struct pt_regs *regs) return regs->a0; } +extern int regs_query_register_offset(const char *name); +extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, + unsigned int n); + +/** + * regs_get_register() - get register value from its offset + * @regs: pt_regs from which register value is gotten + * @offset: offset of the register. + * + * regs_get_register returns the value of a register whose offset from @regs. + * The @offset is the offset of the register in struct pt_regs. + * If @offset is bigger than MAX_REG_OFFSET, this returns 0. + */ +static inline unsigned long regs_get_register(struct pt_regs *regs, + unsigned int offset) +{ + if (unlikely(offset > MAX_REG_OFFSET)) + return 0; + + return *(unsigned long *)((unsigned long)regs + offset); +} #endif /* __ASSEMBLY__ */ #endif /* _ASM_RISCV_PTRACE_H */ diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c index 444dc7b..a11c692 100644 --- a/arch/riscv/kernel/ptrace.c +++ b/arch/riscv/kernel/ptrace.c @@ -125,6 +125,105 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) return &riscv_user_native_view; } +struct pt_regs_offset { + const char *name; + int offset; +}; + +#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)} +#define REG_OFFSET_END {.name = NULL, .offset = 0} + +static const struct pt_regs_offset regoffset_table[] = { + REG_OFFSET_NAME(epc), + REG_OFFSET_NAME(ra), + REG_OFFSET_NAME(sp), + REG_OFFSET_NAME(gp), + REG_OFFSET_NAME(tp), + REG_OFFSET_NAME(t0), + REG_OFFSET_NAME(t1), + REG_OFFSET_NAME(t2), + REG_OFFSET_NAME(s0), + REG_OFFSET_NAME(s1), + REG_OFFSET_NAME(a0), + REG_OFFSET_NAME(a1), + REG_OFFSET_NAME(a2), + REG_OFFSET_NAME(a3), + REG_OFFSET_NAME(a4), + REG_OFFSET_NAME(a5), + REG_OFFSET_NAME(a6), + REG_OFFSET_NAME(a7), + REG_OFFSET_NAME(s2), + REG_OFFSET_NAME(s3), + REG_OFFSET_NAME(s4), + REG_OFFSET_NAME(s5), + REG_OFFSET_NAME(s6), + REG_OFFSET_NAME(s7), + REG_OFFSET_NAME(s8), + REG_OFFSET_NAME(s9), + REG_OFFSET_NAME(s10), + REG_OFFSET_NAME(s11), + REG_OFFSET_NAME(t3), + REG_OFFSET_NAME(t4), + REG_OFFSET_NAME(t5), + REG_OFFSET_NAME(t6), + REG_OFFSET_NAME(status), + REG_OFFSET_NAME(badaddr), + REG_OFFSET_NAME(cause), + REG_OFFSET_NAME(orig_a0), + REG_OFFSET_END, +}; + +/** + * regs_query_register_offset() - query register offset from its name + * @name: the name of a register + * + * regs_query_register_offset() returns the offset of a register in struct + * pt_regs from its name. If the name is invalid, this returns -EINVAL; + */ +int regs_query_register_offset(const char *name) +{ + const struct pt_regs_offset *roff; + + for (roff = regoffset_table; roff->name != NULL; roff++) + if (!strcmp(roff->name, name)) + return roff->offset; + return -EINVAL; +} + +/** + * regs_within_kernel_stack() - check the address in the stack + * @regs: pt_regs which contains kernel stack pointer. + * @addr: address which is checked. + * + * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). + * If @addr is within the kernel stack, it returns true. If not, returns false. + */ +static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) +{ + return (addr & ~(THREAD_SIZE - 1)) == + (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)); +} + +/** + * regs_get_kernel_stack_nth() - get Nth entry of the stack + * @regs: pt_regs which contains kernel stack pointer. + * @n: stack entry number. + * + * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which + * is specified by @regs. If the @n th entry is NOT in the kernel stack, + * this returns 0. + */ +unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n) +{ + unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); + + addr += n; + if (regs_within_kernel_stack(regs, (unsigned long)addr)) + return *addr; + else + return 0; +} + void ptrace_disable(struct task_struct *child) { clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); -- 2.7.4