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authorIngo Molnar <mingo@elte.hu>2010-02-27 10:06:10 +0100
committerIngo Molnar <mingo@elte.hu>2010-02-27 10:06:10 +0100
commit6fb83029db161141d68cf019760a893d03d0682b (patch)
tree6f149c23cedc9b2a5f72b5b90ab8426b39afbb7c
parentMerge branch 'tip/tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/... (diff)
parenttracing/kprobes: Add short documentation for HAVE_REGS_AND_STACK_ACCESS_API (diff)
downloadlinux-6fb83029db161141d68cf019760a893d03d0682b.tar.xz
linux-6fb83029db161141d68cf019760a893d03d0682b.zip
Merge branch 'tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into tracing/core
-rw-r--r--Documentation/trace/ftrace-design.txt5
-rw-r--r--arch/Kconfig8
-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/include/asm/ptrace.h13
-rw-r--r--arch/s390/include/asm/syscall.h7
-rw-r--r--arch/s390/kernel/ftrace.c10
-rw-r--r--arch/s390/kernel/ptrace.c58
-rw-r--r--arch/sh/include/asm/syscall.h2
-rw-r--r--arch/sh/kernel/ftrace.c9
-rw-r--r--arch/sparc/include/asm/syscall.h7
-rw-r--r--arch/sparc/kernel/ftrace.c11
-rw-r--r--arch/x86/Kconfig1
-rw-r--r--arch/x86/include/asm/syscall.h2
-rw-r--r--arch/x86/kernel/ftrace.c10
-rw-r--r--include/linux/ftrace.h6
-rw-r--r--kernel/trace/Kconfig2
-rw-r--r--kernel/trace/trace_syscalls.c5
17 files changed, 112 insertions, 45 deletions
diff --git a/Documentation/trace/ftrace-design.txt b/Documentation/trace/ftrace-design.txt
index 6a5a579126b0..f1f81afee8a0 100644
--- a/Documentation/trace/ftrace-design.txt
+++ b/Documentation/trace/ftrace-design.txt
@@ -238,11 +238,10 @@ 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 <asm/unistd.h> 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/Kconfig b/arch/Kconfig
index 9d055b4f0585..50877ef25844 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -121,6 +121,14 @@ config HAVE_DMA_ATTRS
config USE_GENERIC_SMP_HELPERS
bool
+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
help
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index c80235206c01..2590ce20157d 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 95dcf183a28d..dd2d913afcae 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/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
index e0a73d3eb837..8429686951f9 100644
--- a/arch/s390/include/asm/syscall.h
+++ b/arch/s390/include/asm/syscall.h
@@ -15,6 +15,13 @@
#include <linux/sched.h>
#include <asm/ptrace.h>
+/*
+ * 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 5a82bc68193e..9e69449e77ad 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/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 7cf464234419..33fdc5a79764 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -992,3 +992,61 @@ 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;
+}
diff --git a/arch/sh/include/asm/syscall.h b/arch/sh/include/asm/syscall.h
index 6a381429ee9d..aa7777bdc370 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 a48cdedc73b5..30e13196d35b 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 7486c605e23c..025a02ad2e31 100644
--- a/arch/sparc/include/asm/syscall.h
+++ b/arch/sparc/include/asm/syscall.h
@@ -5,6 +5,13 @@
#include <linux/sched.h>
#include <asm/ptrace.h>
+/*
+ * 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 29973daa9930..9103a56b39e8 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/Kconfig b/arch/x86/Kconfig
index eb4092568f9e..0896008f7509 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/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index 8d33bc5462d1..c4a348f7bd43 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -16,6 +16,8 @@
#include <linux/sched.h>
#include <linux/err.h>
+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 605ef196fdd6..cd37469b54ee 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -510,13 +510,3 @@ 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 0b4f97d24d7f..1cbb36f2759c 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/Kconfig b/kernel/trace/Kconfig
index e6b99b8c3d35..13e13d428cd3 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -440,7 +440,7 @@ 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
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 8cdda95da81a..a1834dda85f4 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;