From e7b8e675d9c71b868b66f62f725a948047514719 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Tue, 26 Jan 2010 04:40:03 -0500 Subject: tracing: Unify arch_syscall_addr() implementations Most implementations of arch_syscall_addr() are the same, so create a default version in common code and move the one piece that differs (the syscall table) to asm/syscall.h. New arch ports don't have to waste time copying & pasting this simple function. The s390/sparc versions need to be different, so document why. Signed-off-by: Mike Frysinger Acked-by: David S. Miller Acked-by: Paul Mundt Acked-by: Heiko Carstens Cc: Steven Rostedt LKML-Reference: <1264498803-17278-1-git-send-email-vapier@gentoo.org> Signed-off-by: Frederic Weisbecker diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt index 239f14b..99df110 100644 --- a/Documentation/trace/ftrace-design.txt +++ b/Documentation/trace/ftrace-design.txt @@ -218,11 +218,10 @@ HAVE_SYSCALL_TRACEPOINTS You need very few things to get the syscalls tracing in an arch. +- Support HAVE_ARCH_TRACEHOOK (see arch/Kconfig). - Have a NR_syscalls variable in that provides the number of syscalls supported by the arch. -- Implement arch_syscall_addr() that resolves a syscall address from a - syscall number. -- Support the TIF_SYSCALL_TRACEPOINT thread flags +- Support the TIF_SYSCALL_TRACEPOINT thread flags. - Put the trace_sys_enter() and trace_sys_exit() tracepoints calls from ptrace in the ptrace syscalls tracing path. - Tag this arch as HAVE_SYSCALL_TRACEPOINTS. diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h index e0a73d3..8429686 100644 --- a/arch/s390/include/asm/syscall.h +++ b/arch/s390/include/asm/syscall.h @@ -15,6 +15,13 @@ #include #include +/* + * The syscall table always contains 32 bit pointers since we know that the + * address of the function to be called is (way) below 4GB. So the "int" + * type here is what we want [need] for both 32 bit and 64 bit systems. + */ +extern const unsigned int sys_call_table[]; + static inline long syscall_get_nr(struct task_struct *task, struct pt_regs *regs) { diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index 5a82bc6..9e69449 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -200,13 +200,3 @@ out: return parent; } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ - -#ifdef CONFIG_FTRACE_SYSCALLS - -extern unsigned int sys_call_table[]; - -unsigned long __init arch_syscall_addr(int nr) -{ - return (unsigned long)sys_call_table[nr]; -} -#endif diff --git a/arch/sh/include/asm/syscall.h b/arch/sh/include/asm/syscall.h index 6a38142..aa7777b 100644 --- a/arch/sh/include/asm/syscall.h +++ b/arch/sh/include/asm/syscall.h @@ -1,6 +1,8 @@ #ifndef __ASM_SH_SYSCALL_H #define __ASM_SH_SYSCALL_H +extern const unsigned long sys_call_table[]; + #ifdef CONFIG_SUPERH32 # include "syscall_32.h" #else diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c index a48cded..30e1319 100644 --- a/arch/sh/kernel/ftrace.c +++ b/arch/sh/kernel/ftrace.c @@ -399,12 +399,3 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) } } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ - -#ifdef CONFIG_FTRACE_SYSCALLS -extern unsigned long *sys_call_table; - -unsigned long __init arch_syscall_addr(int nr) -{ - return (unsigned long)sys_call_table[nr]; -} -#endif /* CONFIG_FTRACE_SYSCALLS */ diff --git a/arch/sparc/include/asm/syscall.h b/arch/sparc/include/asm/syscall.h index 7486c60..025a02a 100644 --- a/arch/sparc/include/asm/syscall.h +++ b/arch/sparc/include/asm/syscall.h @@ -5,6 +5,13 @@ #include #include +/* + * The syscall table always contains 32 bit pointers since we know that the + * address of the function to be called is (way) below 4GB. So the "int" + * type here is what we want [need] for both 32 bit and 64 bit systems. + */ +extern const unsigned int sys_call_table[]; + /* The system call number is given by the user in %g1 */ static inline long syscall_get_nr(struct task_struct *task, struct pt_regs *regs) diff --git a/arch/sparc/kernel/ftrace.c b/arch/sparc/kernel/ftrace.c index 29973da..9103a56 100644 --- a/arch/sparc/kernel/ftrace.c +++ b/arch/sparc/kernel/ftrace.c @@ -91,14 +91,3 @@ int __init ftrace_dyn_arch_init(void *data) return 0; } #endif - -#ifdef CONFIG_FTRACE_SYSCALLS - -extern unsigned int sys_call_table[]; - -unsigned long __init arch_syscall_addr(int nr) -{ - return (unsigned long)sys_call_table[nr]; -} - -#endif diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h index 8d33bc5..c4a348f 100644 --- a/arch/x86/include/asm/syscall.h +++ b/arch/x86/include/asm/syscall.h @@ -16,6 +16,8 @@ #include #include +extern const unsigned long sys_call_table[]; + /* * Only the low 32 bits of orig_ax are meaningful, so we return int. * This importantly ignores the high bits on 64-bit, so comparisons diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 3096892..0d93a94 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -484,13 +484,3 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, } } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ - -#ifdef CONFIG_FTRACE_SYSCALLS - -extern unsigned long *sys_call_table; - -unsigned long __init arch_syscall_addr(int nr) -{ - return (unsigned long)(&sys_call_table)[nr]; -} -#endif diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 0b4f97d..1cbb36f 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -511,4 +511,10 @@ static inline void trace_hw_branch_oops(void) {} #endif /* CONFIG_HW_BRANCH_TRACER */ +#ifdef CONFIG_FTRACE_SYSCALLS + +unsigned long arch_syscall_addr(int nr); + +#endif /* CONFIG_FTRACE_SYSCALLS */ + #endif /* _LINUX_FTRACE_H */ diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 49cea70..ecf0078 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -394,6 +394,11 @@ int init_syscall_trace(struct ftrace_event_call *call) return id; } +unsigned long __init arch_syscall_addr(int nr) +{ + return (unsigned long)sys_call_table[nr]; +} + int __init init_ftrace_syscalls(void) { struct syscall_metadata *meta; -- cgit v0.10.2 From f850c30c8b426ba1688cb63b1a3e534eed03a138 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 10 Feb 2010 17:25:17 +0100 Subject: tracing/kprobes: Make Kconfig dependencies generic KPROBES_EVENT actually depends on the regs and stack access API (b1cf540f) and not on x86. So introduce a new config option which architectures can select if they have the API implemented and switch x86. Signed-off-by: Heiko Carstens Acked-by: Masami Hiramatsu Cc: Ingo Molnar Cc: Martin Schwidefsky LKML-Reference: <20100210162517.GB6933@osiris.boeblingen.de.ibm.com> Signed-off-by: Frederic Weisbecker diff --git a/arch/Kconfig b/arch/Kconfig index 9d055b4..04e3aa7 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -121,6 +121,9 @@ config HAVE_DMA_ATTRS config USE_GENERIC_SMP_HELPERS bool +config HAVE_REGS_AND_STACK_ACCESS_API + bool + config HAVE_CLK bool help diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 55298e8..07baa12 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -45,6 +45,7 @@ config X86 select HAVE_GENERIC_DMA_COHERENT if X86_32 select HAVE_EFFICIENT_UNALIGNED_ACCESS select USER_STACKTRACE_SUPPORT + select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_DMA_API_DEBUG select HAVE_KERNEL_GZIP select HAVE_KERNEL_BZIP2 diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 6c22d8a..40fef55 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -451,7 +451,7 @@ config BLK_DEV_IO_TRACE config KPROBE_EVENT depends on KPROBES - depends on X86 + depends on HAVE_REGS_AND_STACK_ACCESS_API bool "Enable kprobes-based dynamic events" select TRACING default y -- cgit v0.10.2 From 952974ac61f686896bd4134dae106a886a5589f1 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Fri, 12 Feb 2010 13:38:40 +0100 Subject: s390: Add pt_regs register and stack access API This API is needed for the kprobe-based event tracer. Signed-off-by: Heiko Carstens Reviewed-by: Masami Hiramatsu Cc: Martin Schwidefsky LKML-Reference: <20100212123840.GB27548@osiris.boeblingen.de.ibm.com> Signed-off-by: Frederic Weisbecker diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index c802352..2590ce2 100644 --- 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 diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h index 95dcf18..dd2d913 100644 --- a/arch/s390/include/asm/ptrace.h +++ b/arch/s390/include/asm/ptrace.h @@ -492,13 +492,24 @@ 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_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__ */ diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c index 13815d3..1720f38 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -984,3 +984,61 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) #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; +} -- cgit v0.10.2 From e01292b1fd68ff2abe234d584b06e64344d2c1de Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 18 Feb 2010 14:25:21 +0100 Subject: tracing/kprobes: Add short documentation for HAVE_REGS_AND_STACK_ACCESS_API So that arch developers know how to implement it without the need to dig into changelogs. Reported-by: Mike Frysinger Signed-off-by: Heiko Carstens Acked-by: Masami Hiramatsu Cc: Martin Schwidefsky Cc: "David S . Miller" Cc: Paul Mundt Cc: Steven Rostedt LKML-Reference: <20100218132521.GB2406@osiris.boeblingen.de.ibm.com> [added reference to ptrace.h in the config help] Signed-off-by: Frederic Weisbecker diff --git a/arch/Kconfig b/arch/Kconfig index 04e3aa7..50877ef 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -123,6 +123,11 @@ config USE_GENERIC_SMP_HELPERS config HAVE_REGS_AND_STACK_ACCESS_API bool + help + This symbol should be selected by an architecure if it supports + the API needed to access registers and stack entries from pt_regs, + declared in asm/ptrace.h + For example the kprobes-based event tracer needs this API. config HAVE_CLK bool -- cgit v0.10.2