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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 652C8C43441 for ; Tue, 13 Nov 2018 19:58:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 32A9622419 for ; Tue, 13 Nov 2018 19:58:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 32A9622419 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=packi.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730913AbeKNF6G (ORCPT ); Wed, 14 Nov 2018 00:58:06 -0500 Received: from mail.binarylogic.ch ([88.198.23.72]:47886 "EHLO mail.binarylogic.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725748AbeKNF6F (ORCPT ); Wed, 14 Nov 2018 00:58:05 -0500 Received: from fortknox.localdomain (unknown [192.168.122.1]) by mail.binarylogic.ch (Postfix) with ESMTP id 0B4CEDF6FF; Tue, 13 Nov 2018 20:58:23 +0100 (CET) From: =?UTF-8?q?Patrick=20St=C3=A4hlin?= To: linux-riscv@lists.infradead.org Cc: linux-kernel@vger.kernel.org, =?UTF-8?q?Patrick=20St=C3=A4hlin?= , Palmer Dabbelt , Albert Ou , Oleg Nesterov Subject: [RFC/RFT 1/2] RISC-V: Implement ptrace regs and stack API Date: Tue, 13 Nov 2018 20:58:03 +0100 Message-Id: <20181113195804.22825-2-me@packi.ch> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181113195804.22825-1-me@packi.ch> References: <20181113195804.22825-1-me@packi.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Needed for kprobes support. Copied and adapted from arm64 code. Signed-off-by: Patrick Stählin --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/ptrace.h | 34 +++++++++++ arch/riscv/kernel/ptrace.c | 99 +++++++++++++++++++++++++++++++++ 3 files changed, 134 insertions(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 55da93f4e818..b157ac82d486 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -43,6 +43,7 @@ config RISCV select RISCV_TIMER select GENERIC_IRQ_MULTI_HANDLER select ARCH_HAS_PTE_SPECIAL + select HAVE_REGS_AND_STACK_ACCESS_API config MMU def_bool y diff --git a/arch/riscv/include/asm/ptrace.h b/arch/riscv/include/asm/ptrace.h index 2c5df945d43c..70c0ad08ac08 100644 --- a/arch/riscv/include/asm/ptrace.h +++ b/arch/riscv/include/asm/ptrace.h @@ -16,6 +16,7 @@ #include #include +#include #ifndef __ASSEMBLY__ @@ -68,6 +69,7 @@ struct pt_regs { #define user_mode(regs) (((regs)->sstatus & SR_SPP) == 0) +#define MAX_REG_OFFSET offsetof(struct pt_regs, orig_a0) /* Helpers for working with the instruction pointer */ #define GET_IP(regs) ((regs)->sepc) @@ -99,6 +101,17 @@ static inline void user_stack_pointer_set(struct pt_regs *regs, SET_USP(regs, val); } +/* Valid only for Kernel mode traps. */ +static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) +{ + return regs->sp; +} + +static inline unsigned long regs_return_value(struct pt_regs *regs) +{ + return regs->a0; +} + /* Helpers for working with the frame pointer */ #define GET_FP(regs) ((regs)->s0) #define SET_FP(regs, val) (GET_FP(regs) = (val)) @@ -113,6 +126,27 @@ static inline void frame_pointer_set(struct pt_regs *regs, SET_FP(regs, val); } +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 60f1e02eed36..5b684e4ffc10 100644 --- a/arch/riscv/kernel/ptrace.c +++ b/arch/riscv/kernel/ptrace.c @@ -130,6 +130,105 @@ 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(sepc), + 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(sstatus), + REG_OFFSET_NAME(sbadaddr), + REG_OFFSET_NAME(scause), + 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); -- 2.17.1