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/Kconfig b/arch/sh/Kconfig
index 801a4a7..29e41ec 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -32,6 +32,7 @@
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_DYNAMIC_FTRACE
select HAVE_FUNCTION_TRACE_MCOUNT_TEST
+ select HAVE_FTRACE_SYSCALLS
select HAVE_ARCH_KGDB
select ARCH_HIBERNATION_POSSIBLE if MMU
diff --git a/arch/sh/include/asm/syscall_32.h b/arch/sh/include/asm/syscall_32.h
index 6f83f2c..7d80df4 100644
--- a/arch/sh/include/asm/syscall_32.h
+++ b/arch/sh/include/asm/syscall_32.h
@@ -65,6 +65,7 @@
case 3: args[2] = regs->regs[6];
case 2: args[1] = regs->regs[5];
case 1: args[0] = regs->regs[4];
+ case 0:
break;
default:
BUG();
diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h
index f09ac48..499e315 100644
--- a/arch/sh/include/asm/thread_info.h
+++ b/arch/sh/include/asm/thread_info.h
@@ -97,7 +97,7 @@
extern struct thread_info *alloc_thread_info(struct task_struct *tsk);
extern void free_thread_info(struct thread_info *ti);
-
+
#endif /* THREAD_SHIFT < PAGE_SHIFT */
#endif /* __ASSEMBLY__ */
@@ -116,6 +116,7 @@
#define TIF_SYSCALL_AUDIT 5 /* syscall auditing active */
#define TIF_SECCOMP 6 /* secure computing */
#define TIF_NOTIFY_RESUME 7 /* callback before returning to user */
+#define TIF_SYSCALL_FTRACE 8 /* for ftrace syscall instrumentation */
#define TIF_USEDFPU 16 /* FPU was used by this task this quantum (SMP) */
#define TIF_POLLING_NRFLAG 17 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 18
@@ -129,25 +130,27 @@
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
+#define _TIF_SYSCALL_FTRACE (1 << TIF_SYSCALL_FTRACE)
#define _TIF_USEDFPU (1 << TIF_USEDFPU)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_FREEZE (1 << TIF_FREEZE)
/*
- * _TIF_ALLWORK_MASK and _TIF_WORK_MASK need to fit within a byte, or we
+ * _TIF_ALLWORK_MASK and _TIF_WORK_MASK need to fit within 2 bytes, or we
* blow the tst immediate size constraints and need to fix up
* arch/sh/kernel/entry-common.S.
*/
/* work to do in syscall trace */
#define _TIF_WORK_SYSCALL_MASK (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP | \
- _TIF_SYSCALL_AUDIT | _TIF_SECCOMP)
+ _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
+ _TIF_SYSCALL_FTRACE)
/* work to do on any return to u-space */
#define _TIF_ALLWORK_MASK (_TIF_SYSCALL_TRACE | _TIF_SIGPENDING | \
_TIF_NEED_RESCHED | _TIF_SYSCALL_AUDIT | \
_TIF_SINGLESTEP | _TIF_RESTORE_SIGMASK | \
- _TIF_NOTIFY_RESUME)
+ _TIF_NOTIFY_RESUME | _TIF_SYSCALL_FTRACE)
/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK (_TIF_ALLWORK_MASK & ~(_TIF_SYSCALL_TRACE | \
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);
diff --git a/arch/sh/lib/mcount.S b/arch/sh/lib/mcount.S
index cb87ef5..71e87f9 100644
--- a/arch/sh/lib/mcount.S
+++ b/arch/sh/lib/mcount.S
@@ -72,7 +72,7 @@
mov.l @r0, r0
tst r0, r0
bf ftrace_stub
-
+
MCOUNT_ENTER()
.globl ftrace_call