sh: Add ftrace syscall tracing support
Now that I've added TIF_SYSCALL_FTRACE the thread flags do not fit into
a single byte any more. Code testing them now needs to be aware of the
upper and lower bytes.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/Makefile_32 b/arch/sh/kernel/Makefile_32
index 9411e3e..fee924a 100644
--- a/arch/sh/kernel/Makefile_32
+++ b/arch/sh/kernel/Makefile_32
@@ -29,6 +29,7 @@
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_GENERIC_GPIO) += gpio.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
+obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o
obj-$(CONFIG_DUMP_CODE) += disassemble.o
obj-$(CONFIG_HIBERNATION) += swsusp.o
diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S
index d62359c..d621756 100644
--- a/arch/sh/kernel/entry-common.S
+++ b/arch/sh/kernel/entry-common.S
@@ -131,7 +131,7 @@
nop
#endif
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
- tst #_TIF_WORK_MASK, r0
+ tst #(_TIF_WORK_MASK & 0xff), r0
bt/s __restore_all
tst #_TIF_NEED_RESCHED, r0
@@ -163,7 +163,7 @@
#endif
!
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
- tst #_TIF_WORK_MASK, r0
+ tst #(_TIF_WORK_MASK & 0xff), r0
bt __restore_all
bra work_pending
tst #_TIF_NEED_RESCHED, r0
@@ -181,7 +181,7 @@
syscall_exit_work:
! r0: current_thread_info->flags
! r8: current_thread_info
- tst #_TIF_WORK_SYSCALL_MASK, r0
+ tst #(_TIF_WORK_SYSCALL_MASK & 0xff), r0
bt/s work_pending
tst #_TIF_NEED_RESCHED, r0
#ifdef CONFIG_TRACE_IRQFLAGS
@@ -331,8 +331,12 @@
!
get_current_thread_info r8, r10
mov.l @(TI_FLAGS,r8), r8
- mov #_TIF_WORK_SYSCALL_MASK, r10
+ mov #(_TIF_WORK_SYSCALL_MASK & 0xff), r10
+ mov #(_TIF_WORK_SYSCALL_MASK >> 8), r9
tst r10, r8
+ shll8 r9
+ bf syscall_trace_entry
+ tst r9, r8
bf syscall_trace_entry
!
mov.l 2f, r8 ! Number of syscalls
@@ -359,7 +363,11 @@
!
get_current_thread_info r8, r0
mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
- tst #_TIF_ALLWORK_MASK, r0
+ tst #(_TIF_ALLWORK_MASK & 0xff), r0
+ mov #(_TIF_ALLWORK_MASK >> 8), r1
+ bf syscall_exit_work
+ shlr8 r0
+ tst r0, r1
bf syscall_exit_work
bra __restore_all
nop
diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c
index 066f37d..4f62ece 100644
--- a/arch/sh/kernel/ftrace.c
+++ b/arch/sh/kernel/ftrace.c
@@ -18,6 +18,8 @@
#include <linux/io.h>
#include <asm/ftrace.h>
#include <asm/cacheflush.h>
+#include <asm/unistd.h>
+#include <trace/syscall.h>
static unsigned char ftrace_replaced_code[MCOUNT_INSN_SIZE];
@@ -131,3 +133,69 @@
return 0;
}
+
+#ifdef CONFIG_FTRACE_SYSCALLS
+
+extern unsigned long __start_syscalls_metadata[];
+extern unsigned long __stop_syscalls_metadata[];
+extern unsigned long *sys_call_table;
+
+static struct syscall_metadata **syscalls_metadata;
+
+static struct syscall_metadata *find_syscall_meta(unsigned long *syscall)
+{
+ struct syscall_metadata *start;
+ struct syscall_metadata *stop;
+ char str[KSYM_SYMBOL_LEN];
+
+
+ start = (struct syscall_metadata *)__start_syscalls_metadata;
+ stop = (struct syscall_metadata *)__stop_syscalls_metadata;
+ kallsyms_lookup((unsigned long) syscall, NULL, NULL, NULL, str);
+
+ for ( ; start < stop; start++) {
+ if (start->name && !strcmp(start->name, str))
+ return start;
+ }
+
+ return NULL;
+}
+
+#define FTRACE_SYSCALL_MAX (NR_syscalls - 1)
+
+struct syscall_metadata *syscall_nr_to_meta(int nr)
+{
+ if (!syscalls_metadata || nr >= FTRACE_SYSCALL_MAX || nr < 0)
+ return NULL;
+
+ return syscalls_metadata[nr];
+}
+
+void arch_init_ftrace_syscalls(void)
+{
+ int i;
+ struct syscall_metadata *meta;
+ unsigned long **psys_syscall_table = &sys_call_table;
+ static atomic_t refs;
+
+ if (atomic_inc_return(&refs) != 1)
+ goto end;
+
+ syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
+ FTRACE_SYSCALL_MAX, GFP_KERNEL);
+ if (!syscalls_metadata) {
+ WARN_ON(1);
+ return;
+ }
+
+ for (i = 0; i < FTRACE_SYSCALL_MAX; i++) {
+ meta = find_syscall_meta(psys_syscall_table[i]);
+ syscalls_metadata[i] = meta;
+ }
+ return;
+
+ /* Paranoid: avoid overflow */
+end:
+ atomic_dec(&refs);
+}
+#endif /* CONFIG_FTRACE_SYSCALLS */
diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c
index 3392e83..c198ece 100644
--- a/arch/sh/kernel/ptrace_32.c
+++ b/arch/sh/kernel/ptrace_32.c
@@ -34,6 +34,8 @@
#include <asm/syscalls.h>
#include <asm/fpu.h>
+#include <trace/syscall.h>
+
/*
* This routine will get a word off of the process kernel stack.
*/
@@ -459,6 +461,9 @@
*/
ret = -1L;
+ if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
+ ftrace_syscall_enter(regs);
+
if (unlikely(current->audit_context))
audit_syscall_entry(audit_arch(), regs->regs[3],
regs->regs[4], regs->regs[5],
@@ -475,6 +480,9 @@
audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
regs->regs[0]);
+ if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
+ ftrace_syscall_exit(regs);
+
step = test_thread_flag(TIF_SINGLESTEP);
if (step || test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, step);