Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752453AbbF3KvX (ORCPT ); Tue, 30 Jun 2015 06:51:23 -0400 Received: from mail-ie0-f182.google.com ([209.85.223.182]:34700 "EHLO mail-ie0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750980AbbF3KvO (ORCPT ); Tue, 30 Jun 2015 06:51:14 -0400 MIME-Version: 1.0 In-Reply-To: <5591903D.7090108@linaro.org> References: <1434395229-6654-1-git-send-email-dave.long@linaro.org> <1434395229-6654-2-git-send-email-dave.long@linaro.org> <5591903D.7090108@linaro.org> Date: Tue, 30 Jun 2015 11:51:13 +0100 Message-ID: Subject: Re: [PATCH v7 1/7] arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature From: Steve Capper To: David Long Cc: Catalin Marinas , Will Deacon , "linux-arm-kernel@lists.infradead.org" , Russell King , sandeepa.s.prabhu@gmail.com, William Cohen , "Jon Medhurst (Tixy)" , Masami Hiramatsu , Ananth N Mavinakayanahalli , Anil S Keshavamurthy , David Miller , Mark Brown , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6579 Lines: 189 On 29 June 2015 at 19:36, David Long wrote: > On 06/29/15 13:23, Steve Capper wrote: >> >> On 15 June 2015 at 20:07, David Long wrote: >>> >>> From: "David A. Long" >>> >>> Add HAVE_REGS_AND_STACK_ACCESS_API feature for arm64. >>> >>> Signed-off-by: David A. Long >>> --- >>> arch/arm64/Kconfig | 1 + >>> arch/arm64/include/asm/ptrace.h | 25 +++++++++++++ >>> arch/arm64/kernel/ptrace.c | 77 >>> +++++++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 103 insertions(+) >>> >>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >>> index 7796af4..966091f 100644 >>> --- a/arch/arm64/Kconfig >>> +++ b/arch/arm64/Kconfig >>> @@ -68,6 +68,7 @@ config ARM64 >>> select HAVE_PERF_EVENTS >>> select HAVE_PERF_REGS >>> select HAVE_PERF_USER_STACK_DUMP >>> + select HAVE_REGS_AND_STACK_ACCESS_API >>> select HAVE_RCU_TABLE_FREE >>> select HAVE_SYSCALL_TRACEPOINTS >>> select IRQ_DOMAIN >>> diff --git a/arch/arm64/include/asm/ptrace.h >>> b/arch/arm64/include/asm/ptrace.h >>> index d6dd9fd..8f440e9 100644 >>> --- a/arch/arm64/include/asm/ptrace.h >>> +++ b/arch/arm64/include/asm/ptrace.h >>> @@ -118,6 +118,8 @@ struct pt_regs { >>> u64 syscallno; >>> }; >>> >>> +#define MAX_REG_OFFSET (sizeof(struct user_pt_regs) - sizeof(u64)) >>> + >>> #define arch_has_single_step() (1) >>> >>> #ifdef CONFIG_COMPAT >>> @@ -146,6 +148,29 @@ struct pt_regs { >>> #define user_stack_pointer(regs) \ >>> (!compat_user_mode(regs) ? (regs)->sp : (regs)->compat_sp) >>> >>> +/** >>> + * regs_get_register() - get register value from its offset >>> + * @regs: pt_regs from which register value is gotten >>> + * @offset: offset number 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 u64 regs_get_register(struct pt_regs *regs, >>> + unsigned int offset) >>> +{ >>> + if (unlikely(offset > MAX_REG_OFFSET)) >>> + return 0; >>> + return *(u64 *)((u64)regs + offset); >> >> >> Why not: >> return regs->regs[offset]; >> > > This would not be correct. The offset is a byte offset and your code would > index eight times that amount into the structure. The offset needs to > remain a byte offset so architecture-independent code does not need to know > the architecture-specific layout of the structure. Ahh, apologies. Thank you, I substituted offset as index in my head. > > >>> +} >>> + >>> +/* 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->regs[0]; >>> diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c >>> index d882b83..f6199a5 100644 >>> --- a/arch/arm64/kernel/ptrace.c >>> +++ b/arch/arm64/kernel/ptrace.c >>> @@ -48,6 +48,83 @@ >>> #define CREATE_TRACE_POINTS >>> #include >>> >>> +#define ARM_pstate pstate >>> +#define ARM_pc pc >>> +#define ARM_sp sp >>> +#define ARM_x30 regs[30] >>> +#define ARM_x29 regs[29] >>> +#define ARM_x28 regs[28] >>> +#define ARM_x27 regs[27] >>> +#define ARM_x26 regs[26] >>> +#define ARM_x25 regs[25] >>> +#define ARM_x24 regs[24] >>> +#define ARM_x23 regs[23] >>> +#define ARM_x22 regs[22] >>> +#define ARM_x21 regs[21] >>> +#define ARM_x20 regs[20] >>> +#define ARM_x19 regs[19] >>> +#define ARM_x18 regs[18] >>> +#define ARM_x17 regs[17] >>> +#define ARM_x16 regs[16] >>> +#define ARM_x15 regs[15] >>> +#define ARM_x14 regs[14] >>> +#define ARM_x13 regs[13] >>> +#define ARM_x12 regs[12] >>> +#define ARM_x11 regs[11] >>> +#define ARM_x10 regs[10] >>> +#define ARM_x9 regs[9] >>> +#define ARM_x8 regs[8] >>> +#define ARM_x7 regs[7] >>> +#define ARM_x6 regs[6] >>> +#define ARM_x5 regs[5] >>> +#define ARM_x4 regs[4] >>> +#define ARM_x3 regs[3] >>> +#define ARM_x2 regs[2] >>> +#define ARM_x1 regs[1] >>> +#define ARM_x0 regs[0] >>> + >>> +#define REG_OFFSET_NAME(r) \ >>> + {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)} >>> +#define REG_OFFSET_END {.name = NULL, .offset = 0} >>> + >>> +const struct pt_regs_offset regs_offset_table[] = { >>> + REG_OFFSET_NAME(x0), >>> + REG_OFFSET_NAME(x1), >>> + REG_OFFSET_NAME(x2), >>> + REG_OFFSET_NAME(x3), >>> + REG_OFFSET_NAME(x4), >>> + REG_OFFSET_NAME(x5), >>> + REG_OFFSET_NAME(x6), >>> + REG_OFFSET_NAME(x7), >>> + REG_OFFSET_NAME(x8), >>> + REG_OFFSET_NAME(x9), >>> + REG_OFFSET_NAME(x10), >>> + REG_OFFSET_NAME(x11), >>> + REG_OFFSET_NAME(x12), >>> + REG_OFFSET_NAME(x13), >>> + REG_OFFSET_NAME(x14), >>> + REG_OFFSET_NAME(x15), >>> + REG_OFFSET_NAME(x16), >>> + REG_OFFSET_NAME(x17), >>> + REG_OFFSET_NAME(x18), >>> + REG_OFFSET_NAME(x19), >>> + REG_OFFSET_NAME(x20), >>> + REG_OFFSET_NAME(x21), >>> + REG_OFFSET_NAME(x22), >>> + REG_OFFSET_NAME(x23), >>> + REG_OFFSET_NAME(x24), >>> + REG_OFFSET_NAME(x25), >>> + REG_OFFSET_NAME(x26), >>> + REG_OFFSET_NAME(x27), >>> + REG_OFFSET_NAME(x28), >>> + REG_OFFSET_NAME(x29), >>> + REG_OFFSET_NAME(x30), >>> + REG_OFFSET_NAME(sp), >>> + REG_OFFSET_NAME(pc), >>> + REG_OFFSET_NAME(pstate), >>> + REG_OFFSET_END, >>> +}; >>> + >>> /* >>> * TODO: does not yet catch signals sent when the child dies. >>> * in exit.c or in signal.c. >>> -- >>> 1.8.1.2 >>> > > Thanks, > -dl > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/