Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755538Ab0BJQ0O (ORCPT ); Wed, 10 Feb 2010 11:26:14 -0500 Received: from mtagate4.de.ibm.com ([195.212.17.164]:50358 "EHLO mtagate4.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754818Ab0BJQ0M (ORCPT ); Wed, 10 Feb 2010 11:26:12 -0500 Date: Wed, 10 Feb 2010 17:26:10 +0100 From: Heiko Carstens To: Masami Hiramatsu , Frederic Weisbecker , Ingo Molnar Cc: Martin Schwidefsky , linux-kernel@vger.kernel.org Subject: [PATCH 2/2] s390: add pt_regs register and stack access API Message-ID: <20100210162610.GC6933@osiris.boeblingen.de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4423 Lines: 137 From: Heiko Carstens This API is needed for the kprobe-based event tracer. Signed-off-by: Heiko Carstens --- arch/s390/Kconfig | 1 arch/s390/include/asm/ptrace.h | 14 +++++++ arch/s390/kernel/ptrace.c | 76 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 90 insertions(+), 1 deletion(-) --- a/arch/s390/include/asm/ptrace.h +++ b/arch/s390/include/asm/ptrace.h @@ -492,13 +492,25 @@ struct user_regs_struct struct task_struct; extern void user_enable_single_step(struct task_struct *); extern void user_disable_single_step(struct task_struct *); +extern void show_regs(struct pt_regs * regs); #define user_mode(regs) (((regs)->psw.mask & PSW_MASK_PSTATE) != 0) #define instruction_pointer(regs) ((regs)->psw.addr & PSW_ADDR_INSN) #define user_stack_pointer(regs)((regs)->gprs[15]) #define regs_return_value(regs)((regs)->gprs[2]) #define profile_pc(regs) instruction_pointer(regs) -extern void show_regs(struct pt_regs * regs); + +int regs_query_register_offset(const char *name); +const char *regs_query_register_name(unsigned int offset); +unsigned long regs_get_argument_nth(struct pt_regs *regs, unsigned int n); +unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset); +unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n); + +static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) +{ + return regs->gprs[15] & PSW_ADDR_INSN; +} + #endif /* __KERNEL__ */ #endif /* __ASSEMBLY__ */ --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -87,6 +87,7 @@ config S390 select HAVE_SYSCALL_TRACEPOINTS select HAVE_DYNAMIC_FTRACE select HAVE_FUNCTION_GRAPH_TRACER + select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_DEFAULT_NO_SPIN_MUTEXES select HAVE_OPROFILE select HAVE_KPROBES --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -992,3 +992,79 @@ const struct user_regset_view *task_user #endif return &user_s390_view; } + +static const char *gpr_names[NUM_GPRS] = { + "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", + "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", +}; + +unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset) +{ + if (offset >= NUM_GPRS) + return 0; + return regs->gprs[offset]; +} + +int regs_query_register_offset(const char *name) +{ + unsigned long offset; + + if (!name || *name != 'r') + return -EINVAL; + if (strict_strtoul(name + 1, 10, &offset)) + return -EINVAL; + if (offset >= NUM_GPRS) + return -EINVAL; + return offset; +} + +const char *regs_query_register_name(unsigned int offset) +{ + if (offset >= NUM_GPRS) + return NULL; + return gpr_names[offset]; +} + +static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) +{ + unsigned long ksp = kernel_stack_pointer(regs); + + return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(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 specifined 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; + + addr = kernel_stack_pointer(regs) + n * sizeof(long); + if (!regs_within_kernel_stack(regs, addr)) + return 0; + return *(unsigned long *)addr; +} + +/** + * regs_get_argument_nth() - get Nth argument at function call + * @regs:pt_regs which contains registers at function entry. + * @n:argument number. + * + * regs_get_argument_nth() returns @n th argument of a function call. + * Since usually the kernel stack will be changed right after function entry, + * you must use this at function entry. If the @n th entry is NOT in the + * kernel stack or pt_regs, this returns 0. + */ +unsigned long regs_get_argument_nth(struct pt_regs *regs, unsigned int n) +{ + if (n < 5) + return regs->gprs[2 + n]; + n += STACK_FRAME_OVERHEAD / sizeof(long); + return regs_get_kernel_stack_nth(regs, n - 5); +} -- 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/