[S390] ftrace: add system call tracer support
System call tracer support for s390.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9023cc9..99dc3de 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -84,6 +84,7 @@
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_TRACE_MCOUNT_TEST
select HAVE_FTRACE_MCOUNT_RECORD
+ select HAVE_FTRACE_SYSCALLS
select HAVE_DYNAMIC_FTRACE
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_DEFAULT_NO_SPIN_MUTEXES
diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
index 2429b87..e0a73d3 100644
--- a/arch/s390/include/asm/syscall.h
+++ b/arch/s390/include/asm/syscall.h
@@ -12,6 +12,7 @@
#ifndef _ASM_SYSCALL_H
#define _ASM_SYSCALL_H 1
+#include <linux/sched.h>
#include <asm/ptrace.h>
static inline long syscall_get_nr(struct task_struct *task,
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 2f86653..925bcc6 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -92,6 +92,7 @@
#define TIF_SYSCALL_TRACE 8 /* syscall trace active */
#define TIF_SYSCALL_AUDIT 9 /* syscall auditing active */
#define TIF_SECCOMP 10 /* secure computing */
+#define TIF_SYSCALL_FTRACE 11 /* 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 */
@@ -110,6 +111,7 @@
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1<<TIF_SECCOMP)
+#define _TIF_SYSCALL_FTRACE (1<<TIF_SYSCALL_FTRACE)
#define _TIF_USEDFPU (1<<TIF_USEDFPU)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_31BIT (1<<TIF_31BIT)
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index db25cdc..c4c80a2 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -53,7 +53,8 @@
_TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_MCCK_PENDING)
-_TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | _TIF_SECCOMP>>8)
+_TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
+ _TIF_SECCOMP>>8 | _TIF_SYSCALL_FTRACE>>8)
STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
STACK_SIZE = 1 << STACK_SHIFT
@@ -1108,6 +1109,7 @@
.section .rodata, "a"
#define SYSCALL(esa,esame,emu) .long esa
+ .globl sys_call_table
sys_call_table:
#include "syscalls.S"
#undef SYSCALL
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 3cec9b5..f6618e9 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -56,7 +56,8 @@
_TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_MCCK_PENDING)
-_TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | _TIF_SECCOMP>>8)
+_TIF_SYSCALL = (_TIF_SYSCALL_TRACE>>8 | _TIF_SYSCALL_AUDIT>>8 | \
+ _TIF_SECCOMP>>8 | _TIF_SYSCALL_FTRACE>>8)
#define BASED(name) name-system_call(%r13)
@@ -1059,6 +1060,7 @@
.section .rodata, "a"
#define SYSCALL(esa,esame,emu) .long esame
+ .globl sys_call_table
sys_call_table:
#include "syscalls.S"
#undef SYSCALL
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index c92a109..82ddfd3 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -12,6 +12,7 @@
#include <linux/ftrace.h>
#include <linux/kernel.h>
#include <linux/types.h>
+#include <trace/syscall.h>
#include <asm/lowcore.h>
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -202,3 +203,58 @@
return parent;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+#ifdef CONFIG_FTRACE_SYSCALLS
+
+extern unsigned long __start_syscalls_metadata[];
+extern unsigned long __stop_syscalls_metadata[];
+extern unsigned int sys_call_table[];
+
+static struct syscall_metadata **syscalls_metadata;
+
+struct syscall_metadata *syscall_nr_to_meta(int nr)
+{
+ if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
+ return NULL;
+
+ return syscalls_metadata[nr];
+}
+
+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(syscall, NULL, NULL, NULL, str);
+
+ for ( ; start < stop; start++) {
+ if (start->name && !strcmp(start->name + 3, str + 3))
+ return start;
+ }
+ return NULL;
+}
+
+void arch_init_ftrace_syscalls(void)
+{
+ struct syscall_metadata *meta;
+ int i;
+ static atomic_t refs;
+
+ if (atomic_inc_return(&refs) != 1)
+ goto out;
+ syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) * NR_syscalls,
+ GFP_KERNEL);
+ if (!syscalls_metadata)
+ goto out;
+ for (i = 0; i < NR_syscalls; i++) {
+ meta = find_syscall_meta((unsigned long)sys_call_table[i]);
+ syscalls_metadata[i] = meta;
+ }
+ return;
+out:
+ atomic_dec(&refs);
+}
+#endif
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index b6fc1ae..490b399 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -37,6 +37,7 @@
#include <linux/regset.h>
#include <linux/tracehook.h>
#include <linux/seccomp.h>
+#include <trace/syscall.h>
#include <asm/compat.h>
#include <asm/segment.h>
#include <asm/page.h>
@@ -661,6 +662,9 @@
ret = -1;
}
+ if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
+ ftrace_syscall_enter(regs);
+
if (unlikely(current->audit_context))
audit_syscall_entry(is_compat_task() ?
AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
@@ -676,6 +680,9 @@
audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
regs->gprs[2]);
+ if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
+ ftrace_syscall_exit(regs);
+
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, 0);
}
