misc: tegra-profiler: prevent infinite loop

* Prevent false recursion in mixed mode.
* Unwinding based on frame pointers: do not save lr address
  if previous frame is incorrect.

Bug 1619030

Change-Id: Iadeb8ca87ead576b18821964878cddf7aa94cf27
Signed-off-by: Igor Nabirushkin <inabirushkin@nvidia.com>
Reviewed-on: http://git-master/r/715291
(cherry picked from commit d8e79953332c96786da5f57475013b045d7ef817)
Reviewed-on: http://git-master/r/747752
GVS: Gerrit_Virtual_Submit
Reviewed-by: Andrey Trachenko <atrachenko@nvidia.com>
Reviewed-by: Winnie Hsu <whsu@nvidia.com>

3 files changed, 22 insertions, 22 deletions

diff --git a/drivers/misc/tegra-profiler/backtrace.c b/drivers/misc/tegra-profiler/backtrace.c
index 675ce85373f4..2dc39b1d018c 100644
--- a/drivers/misc/tegra-profiler/backtrace.c
+++ b/drivers/misc/tegra-profiler/backtrace.c
@@ -27,16 +27,7 @@
 #include "eh_unwind.h"
 #include "dwarf_unwind.h"
 #include "hrt.h"
-
-static inline int
-is_thumb_mode(struct pt_regs *regs)
-{
-#ifdef CONFIG_ARM64
-	return compat_thumb_mode(regs);
-#else
-	return thumb_mode(regs);
-#endif
-}
+#include "tegra.h"
 
 unsigned long
 quadd_user_stack_pointer(struct pt_regs *regs)
@@ -177,6 +168,8 @@ user_backtrace(struct pt_regs *regs,
 	}
 
 	fp_prev = (unsigned long __user *)value_fp;
+	if (fp_prev <= tail)
+		return NULL;
 
 	nr_added = quadd_callchain_store(cc, value_lr, QUADD_UNW_TYPE_FP);
 	if (nr_added == 0)
@@ -186,9 +179,6 @@ user_backtrace(struct pt_regs *regs,
 	    is_ex_entry_exist(regs, value_lr, task))
 		return NULL;
 
-	if (fp_prev <= tail)
-		return NULL;
-
 	return fp_prev;
 }
 
@@ -364,6 +354,8 @@ user_backtrace_compat(struct pt_regs *regs,
 	}
 
 	fp_prev = (u32 __user *)(unsigned long)value_fp;
+	if (fp_prev <= tail)
+		return NULL;
 
 	nr_added = quadd_callchain_store(cc, value_lr, QUADD_UNW_TYPE_FP);
 	if (nr_added == 0)
@@ -373,9 +365,6 @@ user_backtrace_compat(struct pt_regs *regs,
 	    is_ex_entry_exist(regs, value_lr, task))
 		return NULL;
 
-	if (fp_prev <= tail)
-		return NULL;
-
 	return fp_prev;
 }
 
@@ -534,9 +523,11 @@ get_user_callchain_ut(struct pt_regs *regs,
 		      struct task_struct *task)
 {
 	int nr_prev;
+	unsigned long prev_sp;
 
 	do {
 		nr_prev = cc->nr;
+		prev_sp = cc->curr_sp;
 
 		quadd_get_user_cc_dwarf(regs, cc, task);
 		if (nr_prev > 0 && cc->nr == nr_prev)
@@ -545,7 +536,8 @@ get_user_callchain_ut(struct pt_regs *regs,
 		nr_prev = cc->nr;
 
 		quadd_get_user_cc_arm32_ehabi(regs, cc, task);
-	} while (nr_prev != cc->nr);
+	} while (nr_prev != cc->nr &&
+		 (cc->nr <= 1 || cc->curr_sp > prev_sp));
 
 	return cc->nr;
 }
@@ -556,18 +548,26 @@ get_user_callchain_mixed(struct pt_regs *regs,
 		      struct task_struct *task)
 {
 	int nr_prev;
+	unsigned long prev_sp;
 
 	do {
 		nr_prev = cc->nr;
+		prev_sp = cc->curr_sp;
 
 		quadd_get_user_cc_dwarf(regs, cc, task);
 		quadd_get_user_cc_arm32_ehabi(regs, cc, task);
 
-		if (nr_prev != cc->nr)
+		if (nr_prev != cc->nr) {
+			if (cc->nr > 1 &&
+			    cc->curr_sp <= prev_sp)
+				break;
+
 			continue;
+		}
 
 		__get_user_callchain_fp(regs, cc, task);
-	} while (nr_prev != cc->nr);
+	} while (nr_prev != cc->nr &&
+		 (cc->nr <= 1 || cc->curr_sp > prev_sp));
 
 	return cc->nr;
 }
diff --git a/drivers/misc/tegra-profiler/power_clk.c b/drivers/misc/tegra-profiler/power_clk.c
index b29c24dde327..fc31eccb436d 100644
--- a/drivers/misc/tegra-profiler/power_clk.c
+++ b/drivers/misc/tegra-profiler/power_clk.c
@@ -118,11 +118,11 @@ static void make_sample(void)
 		power_rate->emc = 0;
 
 	mutex_unlock(&s->lock);
-
+/*
 	pr_debug("make_sample: cpu: %u/%u/%u/%u, gpu: %u, emc: %u\n",
 		 extra_cpus[0], extra_cpus[1], extra_cpus[2], extra_cpus[3],
 		 power_rate->gpu, power_rate->emc);
-
+*/
 	vec.base = extra_cpus;
 	vec.len = power_rate->nr_cpus * sizeof(extra_cpus[0]);
 
diff --git a/drivers/misc/tegra-profiler/version.h b/drivers/misc/tegra-profiler/version.h
index e92e395940fd..bf4c27597c4a 100644
--- a/drivers/misc/tegra-profiler/version.h
+++ b/drivers/misc/tegra-profiler/version.h
@@ -18,7 +18,7 @@
 #ifndef __QUADD_VERSION_H
 #define __QUADD_VERSION_H
 
-#define QUADD_MODULE_VERSION		"1.94"
+#define QUADD_MODULE_VERSION		"1.95"
 #define QUADD_MODULE_BRANCH		"Dev"
 
 #endif	/* __QUADD_VERSION_H */