From be0b454d52659a686a9b82cf7c0783abe108eaf3 Mon Sep 17 00:00:00 2001
From: Omprakash Dhyade <odhyade@codeaurora.org>
Date: Wed, 15 Feb 2017 04:30:15 -0800
Subject: [PATCH] tracing: Modify saved_tgids size for change in
 saved_cmdline_size

saved_tgids is fixed size array but uses index upto
savedcmd->cmdline_num. savedcmd->cmdline_num can change
with modification to saved_cmdlines_size node. Fix
this indexing by making saved_tgid part of savedcmd
and modify it's size with changes to saved_cmdline_size.

Change-Id: Ia493f99a3d86d4624414e7605037a1cad35473a9
Signed-off-by: Omprakash Dhyade <odhyade@codeaurora.org>
---
 kernel/trace/trace.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1d0f1a1ac44c..069aa1aa82b6 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1357,11 +1357,11 @@ void tracing_reset_all_online_cpus(void)
 
 #define SAVED_CMDLINES_DEFAULT 128
 #define NO_CMDLINE_MAP UINT_MAX
-static unsigned saved_tgids[SAVED_CMDLINES_DEFAULT];
 static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;
 struct saved_cmdlines_buffer {
 	unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
 	unsigned *map_cmdline_to_pid;
+	unsigned *saved_tgids;
 	unsigned cmdline_num;
 	int cmdline_idx;
 	char *saved_cmdlines;
@@ -1395,12 +1395,22 @@ static int allocate_cmdlines_buffer(unsigned int val,
 		return -ENOMEM;
 	}
 
+	s->saved_tgids = kmalloc_array(val, sizeof(*s->saved_tgids),
+					GFP_KERNEL);
+	if (!s->saved_tgids) {
+		kfree(s->map_cmdline_to_pid);
+		kfree(s->saved_cmdlines);
+		return -ENOMEM;
+	}
+
 	s->cmdline_idx = 0;
 	s->cmdline_num = val;
 	memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP,
 	       sizeof(s->map_pid_to_cmdline));
 	memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP,
 	       val * sizeof(*s->map_cmdline_to_pid));
+	memset(s->saved_tgids, 0,
+	       val * sizeof(*s->saved_tgids));
 
 	return 0;
 }
@@ -1596,7 +1606,7 @@ static int trace_save_cmdline(struct task_struct *tsk)
 	}
 
 	set_cmdline(idx, tsk->comm);
-	saved_tgids[idx] = tsk->tgid;
+	savedcmd->saved_tgids[idx] = tsk->tgid;
 	arch_spin_unlock(&trace_cmdline_lock);
 
 	return 1;
@@ -1648,7 +1658,7 @@ int trace_find_tgid(int pid)
 	arch_spin_lock(&trace_cmdline_lock);
 	map = savedcmd->map_pid_to_cmdline[pid];
 	if (map != NO_CMDLINE_MAP)
-		tgid = saved_tgids[map];
+		tgid = savedcmd->saved_tgids[map];
 	else
 		tgid = -1;
 
@@ -4221,13 +4231,13 @@ tracing_saved_tgids_read(struct file *file, char __user *ubuf,
 	int pid;
 	int i;
 
-	file_buf = kmalloc(SAVED_CMDLINES_DEFAULT*(16+1+16), GFP_KERNEL);
+	file_buf = kmalloc(savedcmd->cmdline_num*(16+1+16), GFP_KERNEL);
 	if (!file_buf)
 		return -ENOMEM;
 
 	buf = file_buf;
 
-	for (i = 0; i < SAVED_CMDLINES_DEFAULT; i++) {
+	for (i = 0; i < savedcmd->cmdline_num; i++) {
 		int tgid;
 		int r;