[DPU PATCH 16/19] drm/msm: dpu: Remove panic from dpu debug dump

Sean Paul
2018-06-20T20:48:38Z

Better not to allow arbitrary panics of the kernel when poking debugfs
files.

Signed-off-by: Sean Paul <seanpaul@chromium.org>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 2 +-
.../drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 2 +-
.../drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 2 +-
drivers/gpu/drm/msm/dpu_dbg.c | 31 +++----------------
drivers/gpu/drm/msm/dpu_dbg.h | 4 ---
5 files changed, 8 insertions(+), 33 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 5ff627827be9..3519f7e84f0f 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -1563,7 +1563,7 @@ void dpu_encoder_helper_hw_reset(struct dpu_encoder_phys *phys_enc)
rc = ctl->ops.reset(ctl);
if (rc) {
DPU_ERROR_ENC(dpu_enc, "ctl %d reset failure\n", ctl->idx);
- DPU_DBG_DUMP("dbg_bus", "vbif_dbg_bus", "panic");
+ DPU_DBG_DUMP("dbg_bus", "vbif_dbg_bus");
}

phys_enc->enable_state = DPU_ENC_ENABLED;
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
index 5589d1289da9..19f5b5064ed8 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
@@ -262,7 +262,7 @@ static int _dpu_encoder_phys_cmd_handle_ppdone_timeout(
atomic_read(&phys_enc->pending_kickoff_cnt));

dpu_encoder_helper_unregister_irq(phys_enc, INTR_IDX_RDPTR);
- DPU_DBG_DUMP("dbg_bus", "vbif_dbg_bus", "panic");
+ DPU_DBG_DUMP("dbg_bus", "vbif_dbg_bus");
}

atomic_add_unless(&phys_enc->pending_kickoff_cnt, -1, 0);
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
index 8ac7f0537c05..54f4e78cf1fd 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
@@ -638,7 +638,7 @@ static void dpu_encoder_phys_vid_prepare_for_kickoff(
DPU_ERROR_VIDENC(vid_enc, "ctl %d reset failure: %d\n",
ctl->idx, rc);
dpu_encoder_helper_unregister_irq(phys_enc, INTR_IDX_VSYNC);
- DPU_DBG_DUMP("dbg_bus", "vbif_dbg_bus", "panic");
+ DPU_DBG_DUMP("dbg_bus", "vbif_dbg_bus");
}
}

diff --git a/drivers/gpu/drm/msm/dpu_dbg.c b/drivers/gpu/drm/msm/dpu_dbg.c
index 3572e3cbec6c..2a9b8c732e33 100644
--- a/drivers/gpu/drm/msm/dpu_dbg.c
+++ b/drivers/gpu/drm/msm/dpu_dbg.c
@@ -26,7 +26,6 @@
#include "disp/dpu1/dpu_hw_catalog.h"

-#define DEFAULT_PANIC 1
#define DEFAULT_DBGBUS_DPU DPU_DBG_DUMP_IN_MEM
#define DEFAULT_DBGBUS_VBIFRT DPU_DBG_DUMP_IN_MEM
#define REG_BASE_NAME_LEN 80
@@ -128,9 +127,7 @@ struct dpu_dbg_vbif_debug_bus {
* struct dpu_dbg_base - global dpu debug base structure
* @reg_base_list: list of register dumping regions
* @dev: device pointer
- * @panic_on_err: whether to kernel panic after triggering dump via debugfs
* @dump_work: work struct for deferring register dump work to separate thread
- * @work_panic: panic after dump if internal user passed "panic" special region
* @dbgbus_dpu: debug bus structure for the dpu
* @dbgbus_vbif_rt: debug bus structure for the realtime vbif
* @dsi_dbg_bus: dump dsi debug bus register
@@ -139,9 +136,7 @@ static struct dpu_dbg_base {
struct list_head reg_base_list;
struct device *dev;

- u32 panic_on_err;
struct work_struct dump_work;
- bool work_panic;

struct dpu_dbg_dpu_debug_bus dbgbus_dpu;
struct dpu_dbg_vbif_debug_bus dbgbus_vbif_rt;
@@ -2230,22 +2225,18 @@ static void _dpu_dbg_dump_vbif_dbg_bus(struct dpu_dbg_vbif_debug_bus *bus)

/**
* _dpu_dump_array - dump array of register bases
- * @do_panic: whether to trigger a panic after dumping
* @name: string indicating origin of dump
* @dump_dbgbus_dpu: whether to dump the dpu debug bus
* @dump_dbgbus_vbif_rt: whether to dump the vbif rt debug bus
*/
-static void _dpu_dump_array(bool do_panic, const char *name,
- bool dump_dbgbus_dpu, bool dump_dbgbus_vbif_rt)
+static void _dpu_dump_array(const char *name, bool dump_dbgbus_dpu,
+ bool dump_dbgbus_vbif_rt)
{
if (dump_dbgbus_dpu)
_dpu_dbg_dump_dpu_dbg_bus(&dpu_dbg_base.dbgbus_dpu);

if (dump_dbgbus_vbif_rt)
_dpu_dbg_dump_vbif_dbg_bus(&dpu_dbg_base.dbgbus_vbif_rt);
-
- if (do_panic && dpu_dbg_base.panic_on_err)
- panic(name);
}

/**
@@ -2254,14 +2245,13 @@ static void _dpu_dump_array(bool do_panic, const char *name,
*/
static void _dpu_dump_work(struct work_struct *work)
{
- _dpu_dump_array(dpu_dbg_base.work_panic, "dpudump_workitem",
+ _dpu_dump_array("dpudump_workitem",
dpu_dbg_base.dbgbus_dpu.cmn.include_in_deferred_work,
dpu_dbg_base.dbgbus_vbif_rt.cmn.include_in_deferred_work);
}

void dpu_dbg_dump(bool queue_work, const char *name, ...)
{
- bool do_panic = false;
bool dump_dbgbus_dpu = false;
bool dump_dbgbus_vbif_rt = false;
va_list args;
@@ -2283,23 +2273,18 @@ void dpu_dbg_dump(bool queue_work, const char *name, ...)

if (!strcmp(blk_name, "dsi_dbg_bus"))
dpu_dbg_base.dsi_dbg_bus = true;
-
- if (!strcmp(blk_name, "panic"))
- do_panic = true;
}
va_end(args);

if (queue_work) {
/* schedule work to dump later */
- dpu_dbg_base.work_panic = do_panic;
dpu_dbg_base.dbgbus_dpu.cmn.include_in_deferred_work =
dump_dbgbus_dpu;
dpu_dbg_base.dbgbus_vbif_rt.cmn.include_in_deferred_work =
dump_dbgbus_vbif_rt;
schedule_work(&dpu_dbg_base.dump_work);
} else {
- _dpu_dump_array(do_panic, name, dump_dbgbus_dpu,
- dump_dbgbus_vbif_rt);
+ _dpu_dump_array(name, dump_dbgbus_dpu, dump_dbgbus_vbif_rt);
}
}

@@ -2326,7 +2311,7 @@ static int dpu_dbg_debugfs_open(struct inode *inode, struct file *file)
static ssize_t dpu_dbg_dump_write(struct file *file,
const char __user *user_buf, size_t count, loff_t *ppos)
{
- _dpu_dump_array(dpu_dbg_base.panic_on_err, "dump_debugfs", true, true);
+ _dpu_dump_array("dump_debugfs", true, true);
return count;
}

@@ -2345,8 +2330,6 @@ int dpu_dbg_debugfs_register(struct dentry *debugfs_root)

debugfs_create_file("dump", 0600, debugfs_root, NULL,
&dpu_dbg_dump_fops);
- debugfs_create_u32("panic", 0600, debugfs_root,
- &dpu_dbg_base.panic_on_err);

if (dbg->dbgbus_dpu.entries) {
dbg->dbgbus_dpu.cmn.name = DBGBUS_NAME_DPU;
@@ -2414,10 +2397,6 @@ int dpu_dbg_init(struct device *dev)
dpu_dbg_base.dev = dev;

INIT_WORK(&dpu_dbg_base.dump_work, _dpu_dump_work);
- dpu_dbg_base.work_panic = false;
- dpu_dbg_base.panic_on_err = DEFAULT_PANIC;
-
- pr_info("debug_status: panic:%d\n", dpu_dbg_base.panic_on_err);

return 0;
}
diff --git a/drivers/gpu/drm/msm/dpu_dbg.h b/drivers/gpu/drm/msm/dpu_dbg.h
index dd36c30cf7c0..6a247ce39997 100644
--- a/drivers/gpu/drm/msm/dpu_dbg.h
+++ b/drivers/gpu/drm/msm/dpu_dbg.h
@@ -27,8 +27,6 @@ enum dpu_dbg_dump_flag {
* @va_args: list of named register dump ranges and regions to dump, as
* registered previously through dpu_dbg_reg_register_base and
* dpu_dbg_reg_register_dump_range.
- * Including the special name "panic" will trigger a panic after
- * the dumping work has completed.
*/
#define DPU_DBG_DUMP(...) dpu_dbg_dump(false, __func__, ##__VA_ARGS__, NULL)

@@ -67,8 +65,6 @@ void dpu_dbg_destroy(void);
* @va_args: list of named register dump ranges and regions to dump, as
* registered previously through dpu_dbg_reg_register_base and
* dpu_dbg_reg_register_dump_range.
- * Including the special name "panic" will trigger a panic after
- * the dumping work has completed.
* Returns: none
*/
void dpu_dbg_dump(bool queue_work, const char *name, ...);