Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752134AbbHKRba (ORCPT ); Tue, 11 Aug 2015 13:31:30 -0400 Received: from foss.arm.com ([217.140.101.70]:54548 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751657AbbHKRb2 (ORCPT ); Tue, 11 Aug 2015 13:31:28 -0400 Date: Tue, 11 Aug 2015 18:31:21 +0100 From: Will Deacon To: David Long Cc: Catalin Marinas , "linux-arm-kernel@lists.infradead.org" , Russell King , "sandeepa.s.prabhu@gmail.com" , William Cohen , Steve Capper , "Jon Medhurst (Tixy)" , Masami Hiramatsu , Ananth N Mavinakayanahalli , Anil S Keshavamurthy , "davem@davemloft.net" , Mark Brown , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v8 1/7] arm64: Add HAVE_REGS_AND_STACK_ACCESS_API feature Message-ID: <20150811173121.GC29880@arm.com> References: <1439254364-15362-1-git-send-email-dave.long@linaro.org> <1439254364-15362-2-git-send-email-dave.long@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1439254364-15362-2-git-send-email-dave.long@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5217 Lines: 170 Hi David, On Tue, Aug 11, 2015 at 01:52:38AM +0100, 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 318175f..ef5d726 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -70,6 +70,7 @@ 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)) Can you not use offset_of(struct user_pt_regs, pstate) here? > + > #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); > +} Is this guaranteed only to be called on kernel-mode regs, or do we need to deal with compat tasks too? > + > +/* 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] I've said it before, but I really don't like these macros. I'd rather rework the following REG_OFFSET_NAME to be GPR_OFFSET_NAME which could prefix the "x" in the name field. > + > +#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), Does this interact badly with perf tools, which expect to pass "lr" for x30? (see tools/perf/arch/arm64/include/perf_regs.h). Will -- 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/