[PATCH 1/4] samples/kprobe: convert the printk to pr_info/pr_err

[PATCH 1/4] samples/kprobe: convert the printk to pr_info/pr_err

[Huang Shijie]

We prefer to use the pr_* to print out the log now, this patch converts
the printk to pr_info. In the error path, use the pr_err to replace the
printk.

Signed-off-by: Huang Shijie <shijie.huang@arm.com>
---
 samples/kprobes/kprobe_example.c | 29 ++++++++++++-----------------
 1 file changed, 12 insertions(+), 17 deletions(-)

diff --git a/samples/kprobes/kprobe_example.c b/samples/kprobes/kprobe_example.c
index d1fdefc..3754dac 100644
--- a/samples/kprobes/kprobe_example.c
+++ b/samples/kprobes/kprobe_example.c
@@ -27,23 +27,19 @@ static struct kprobe kp = {
 static int handler_pre(struct kprobe *p, struct pt_regs *regs)
 {
 #ifdef CONFIG_X86
-	printk(KERN_INFO "<%s> pre_handler: p->addr = 0x%p, ip = %lx,"
-			" flags = 0x%lx\n",
+	pr_info("<%s> pre_handler: p->addr = 0x%p, ip = %lx, flags = 0x%lx\n",
 		p->symbol_name, p->addr, regs->ip, regs->flags);
 #endif
 #ifdef CONFIG_PPC
-	printk(KERN_INFO "<%s> pre_handler: p->addr = 0x%p, nip = 0x%lx,"
-			" msr = 0x%lx\n",
+	pr_info("<%s> pre_handler: p->addr = 0x%p, nip = 0x%lx, msr = 0x%lx\n",
 		p->symbol_name, p->addr, regs->nip, regs->msr);
 #endif
 #ifdef CONFIG_MIPS
-	printk(KERN_INFO "<%s> pre_handler: p->addr = 0x%p, epc = 0x%lx,"
-			" status = 0x%lx\n",
+	pr_info("<%s> pre_handler: p->addr = 0x%p, epc = 0x%lx, status = 0x%lx\n",
 		p->symbol_name, p->addr, regs->cp0_epc, regs->cp0_status);
 #endif
 #ifdef CONFIG_TILEGX
-	printk(KERN_INFO "<%s> pre_handler: p->addr = 0x%p, pc = 0x%lx,"
-			" ex1 = 0x%lx\n",
+	pr_info("<%s> pre_handler: p->addr = 0x%p, pc = 0x%lx, ex1 = 0x%lx\n",
 		p->symbol_name, p->addr, regs->pc, regs->ex1);
 #endif
 
@@ -61,19 +57,19 @@ static void handler_post(struct kprobe *p, struct pt_regs *regs,
 				unsigned long flags)
 {
 #ifdef CONFIG_X86
-	printk(KERN_INFO "<%s> post_handler: p->addr = 0x%p, flags = 0x%lx\n",
+	pr_info("<%s> post_handler: p->addr = 0x%p, flags = 0x%lx\n",
 		p->symbol_name, p->addr, regs->flags);
 #endif
 #ifdef CONFIG_PPC
-	printk(KERN_INFO "<%s> post_handler: p->addr = 0x%p, msr = 0x%lx\n",
+	pr_info("<%s> post_handler: p->addr = 0x%p, msr = 0x%lx\n",
 		p->symbol_name, p->addr, regs->msr);
 #endif
 #ifdef CONFIG_MIPS
-	printk(KERN_INFO "<%s> post_handler: p->addr = 0x%p, status = 0x%lx\n",
+	pr_info("<%s> post_handler: p->addr = 0x%p, status = 0x%lx\n",
 		p->symbol_name, p->addr, regs->cp0_status);
 #endif
 #ifdef CONFIG_TILEGX
-	printk(KERN_INFO "<%s> post_handler: p->addr = 0x%p, ex1 = 0x%lx\n",
+	pr_info("<%s> post_handler: p->addr = 0x%p, ex1 = 0x%lx\n",
 		p->symbol_name, p->addr, regs->ex1);
 #endif
 #ifdef CONFIG_ARM64
@@ -89,8 +85,7 @@ static void handler_post(struct kprobe *p, struct pt_regs *regs,
  */
 static int handler_fault(struct kprobe *p, struct pt_regs *regs, int trapnr)
 {
-	printk(KERN_INFO "fault_handler: p->addr = 0x%p, trap #%dn",
-		p->addr, trapnr);
+	pr_info("fault_handler: p->addr = 0x%p, trap #%dn", p->addr, trapnr);
 	/* Return 0 because we don't handle the fault. */
 	return 0;
 }
@@ -104,17 +99,17 @@ static int __init kprobe_init(void)
 
 	ret = register_kprobe(&kp);
 	if (ret < 0) {
-		printk(KERN_INFO "register_kprobe failed, returned %d\n", ret);
+		pr_err("register_kprobe failed, returned %d\n", ret);
 		return ret;
 	}
-	printk(KERN_INFO "Planted kprobe at %p\n", kp.addr);
+	pr_info("Planted kprobe at %p\n", kp.addr);
 	return 0;
 }
 
 static void __exit kprobe_exit(void)
 {
 	unregister_kprobe(&kp);
-	printk(KERN_INFO "kprobe at %p unregistered\n", kp.addr);
+	pr_info("kprobe at %p unregistered\n", kp.addr);
 }
 
 module_init(kprobe_init)
-- 
2.5.5

[PATCH 2/4] samples/jprobe: convert the printk to pr_info/pr_err

[Huang Shijie]

We prefer to use the pr_* to print out the log now, this patch converts
the printk to pr_info. In the error path, use the pr_err to replace the
printk.

Signed-off-by: Huang Shijie <shijie.huang@arm.com>
---
 samples/kprobes/jprobe_example.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/samples/kprobes/jprobe_example.c b/samples/kprobes/jprobe_example.c
index c3108bb..e3c0a40 100644
--- a/samples/kprobes/jprobe_example.c
+++ b/samples/kprobes/jprobe_example.c
@@ -48,10 +48,10 @@ static int __init jprobe_init(void)
 
 	ret = register_jprobe(&my_jprobe);
 	if (ret < 0) {
-		printk(KERN_INFO "register_jprobe failed, returned %d\n", ret);
+		pr_err("register_jprobe failed, returned %d\n", ret);
 		return -1;
 	}
-	printk(KERN_INFO "Planted jprobe at %p, handler addr %p\n",
+	pr_info("Planted jprobe at %p, handler addr %p\n",
 	       my_jprobe.kp.addr, my_jprobe.entry);
 	return 0;
 }
@@ -59,7 +59,7 @@ static int __init jprobe_init(void)
 static void __exit jprobe_exit(void)
 {
 	unregister_jprobe(&my_jprobe);
-	printk(KERN_INFO "jprobe at %p unregistered\n", my_jprobe.kp.addr);
+	pr_info("jprobe at %p unregistered\n", my_jprobe.kp.addr);
 }
 
 module_init(jprobe_init)
-- 
2.5.5

[PATCH 3/4] samples/kretprobe: convert the printk to pr_info/pr_err

[Huang Shijie]

We prefer to use the pr_* to print out the log now, this patch converts
the printk to pr_info. In the error path, use the pr_err to replace the
printk.

Signed-off-by: Huang Shijie <shijie.huang@arm.com>
---
 samples/kprobes/kretprobe_example.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/samples/kprobes/kretprobe_example.c b/samples/kprobes/kretprobe_example.c
index ebb1d1a..adc83e9 100644
--- a/samples/kprobes/kretprobe_example.c
+++ b/samples/kprobes/kretprobe_example.c
@@ -62,7 +62,7 @@ static int ret_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
 
 	now = ktime_get();
 	delta = ktime_to_ns(ktime_sub(now, data->entry_stamp));
-	printk(KERN_INFO "%s returned %d and took %lld ns to execute\n",
+	pr_info("%s returned %d and took %lld ns to execute\n",
 			func_name, retval, (long long)delta);
 	return 0;
 }
@@ -82,11 +82,10 @@ static int __init kretprobe_init(void)
 	my_kretprobe.kp.symbol_name = func_name;
 	ret = register_kretprobe(&my_kretprobe);
 	if (ret < 0) {
-		printk(KERN_INFO "register_kretprobe failed, returned %d\n",
-				ret);
+		pr_err("register_kretprobe failed, returned %d\n", ret);
 		return -1;
 	}
-	printk(KERN_INFO "Planted return probe at %s: %p\n",
+	pr_info("Planted return probe at %s: %p\n",
 			my_kretprobe.kp.symbol_name, my_kretprobe.kp.addr);
 	return 0;
 }
@@ -94,11 +93,10 @@ static int __init kretprobe_init(void)
 static void __exit kretprobe_exit(void)
 {
 	unregister_kretprobe(&my_kretprobe);
-	printk(KERN_INFO "kretprobe at %p unregistered\n",
-			my_kretprobe.kp.addr);
+	pr_info("kretprobe at %p unregistered\n", my_kretprobe.kp.addr);
 
 	/* nmissed > 0 suggests that maxactive was set too low. */
-	printk(KERN_INFO "Missed probing %d instances of %s\n",
+	pr_info("Missed probing %d instances of %s\n",
 		my_kretprobe.nmissed, my_kretprobe.kp.symbol_name);
 }
 
-- 
2.5.5

[PATCH 4/4] samples/kretprobe: fix the wrong type

[Huang Shijie]

The regs_return_value() returns "unsigned long" or "long" value.
But the retval is int type now, it may cause overflow, the log may
becomes:
    .................
    [ 2911.078869] do_brk returned -2003877888 and took 4620 ns to execute
    ................

This patch converts the retval to "unsigned long" type, and fix the
overflow issue.

Signed-off-by: Huang Shijie <shijie.huang@arm.com>
---
 samples/kprobes/kretprobe_example.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/samples/kprobes/kretprobe_example.c b/samples/kprobes/kretprobe_example.c
index adc83e9..7f9060f 100644
--- a/samples/kprobes/kretprobe_example.c
+++ b/samples/kprobes/kretprobe_example.c
@@ -55,14 +55,14 @@ static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
  */
 static int ret_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
 {
-	int retval = regs_return_value(regs);
+	unsigned long retval = regs_return_value(regs);
 	struct my_data *data = (struct my_data *)ri->data;
 	s64 delta;
 	ktime_t now;
 
 	now = ktime_get();
 	delta = ktime_to_ns(ktime_sub(now, data->entry_stamp));
-	pr_info("%s returned %d and took %lld ns to execute\n",
+	pr_info("%s returned %lu and took %lld ns to execute\n",
 			func_name, retval, (long long)delta);
 	return 0;
 }
-- 
2.5.5