drivers/thunderbolt/tmu.c:617 tb_switch_tmu_change_mode() warn: missing unwind goto?

drivers/thunderbolt/tmu.c:617 tb_switch_tmu_change_mode() warn: missing unwind goto?

[Dan Carpenter]

Hi Mika,

FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   4652b8e4f3ffa48c706ec334f048c217a7d9750d
commit: c437dcb18310f296eb9db58a361f309f7817014d thunderbolt: Fix a couple of style issues in TMU code
config: i386-randconfig-141-20231102 (https://download.01.org/0day-ci/archive/20231103/202311030814.AXtCk7PO-lkp@intel.com/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce: (https://download.01.org/0day-ci/archive/20231103/202311030814.AXtCk7PO-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202311030814.AXtCk7PO-lkp@intel.com/

smatch warnings:
drivers/thunderbolt/tmu.c:617 tb_switch_tmu_change_mode() warn: missing unwind goto?

vim +617 drivers/thunderbolt/tmu.c

c437dcb18310f2 Mika Westerberg 2022-10-07  596  static int tb_switch_tmu_change_mode(struct tb_switch *sw)
b017a46d486cd4 Gil Fine        2022-05-26  597  {
b017a46d486cd4 Gil Fine        2022-05-26  598  	struct tb_port *up, *down;
b017a46d486cd4 Gil Fine        2022-05-26  599  	int ret;
b017a46d486cd4 Gil Fine        2022-05-26  600  
b017a46d486cd4 Gil Fine        2022-05-26  601  	up = tb_upstream_port(sw);
7ce542219b6323 Gil Fine        2022-09-23  602  	down = tb_switch_downstream_port(sw);
b017a46d486cd4 Gil Fine        2022-05-26  603  	ret = tb_port_tmu_set_unidirectional(down, sw->tmu.unidirectional_request);
b017a46d486cd4 Gil Fine        2022-05-26  604  	if (ret)
b017a46d486cd4 Gil Fine        2022-05-26  605  		goto out;
b017a46d486cd4 Gil Fine        2022-05-26  606  
b017a46d486cd4 Gil Fine        2022-05-26  607  	if (sw->tmu.unidirectional_request)
7ce542219b6323 Gil Fine        2022-09-23  608  		ret = tb_switch_tmu_rate_write(tb_switch_parent(sw),
7ce542219b6323 Gil Fine        2022-09-23  609  					       sw->tmu.rate_request);
b017a46d486cd4 Gil Fine        2022-05-26  610  	else
b017a46d486cd4 Gil Fine        2022-05-26  611  		ret = tb_switch_tmu_rate_write(sw, sw->tmu.rate_request);
b017a46d486cd4 Gil Fine        2022-05-26  612  	if (ret)
b017a46d486cd4 Gil Fine        2022-05-26  613  		return ret;

These error paths should be goto out;

b017a46d486cd4 Gil Fine        2022-05-26  614  
b017a46d486cd4 Gil Fine        2022-05-26  615  	ret = tb_switch_set_tmu_mode_params(sw, sw->tmu.rate_request);
b017a46d486cd4 Gil Fine        2022-05-26  616  	if (ret)
b017a46d486cd4 Gil Fine        2022-05-26 @617  		return ret;

Same.  (I guess before goto out was a do-nothing goto so it didn't
matter).

b017a46d486cd4 Gil Fine        2022-05-26  618  
b017a46d486cd4 Gil Fine        2022-05-26  619  	ret = tb_port_tmu_set_unidirectional(up, sw->tmu.unidirectional_request);
b017a46d486cd4 Gil Fine        2022-05-26  620  	if (ret)
b017a46d486cd4 Gil Fine        2022-05-26  621  		goto out;
b017a46d486cd4 Gil Fine        2022-05-26  622  
b017a46d486cd4 Gil Fine        2022-05-26  623  	ret = tb_port_tmu_time_sync_enable(down);
b017a46d486cd4 Gil Fine        2022-05-26  624  	if (ret)
b017a46d486cd4 Gil Fine        2022-05-26  625  		goto out;
b017a46d486cd4 Gil Fine        2022-05-26  626  
b017a46d486cd4 Gil Fine        2022-05-26  627  	ret = tb_port_tmu_time_sync_enable(up);
b017a46d486cd4 Gil Fine        2022-05-26  628  	if (ret)
b017a46d486cd4 Gil Fine        2022-05-26  629  		goto out;
b017a46d486cd4 Gil Fine        2022-05-26  630  
b017a46d486cd4 Gil Fine        2022-05-26  631  	return 0;
b017a46d486cd4 Gil Fine        2022-05-26  632  
b017a46d486cd4 Gil Fine        2022-05-26  633  out:
c437dcb18310f2 Mika Westerberg 2022-10-07  634  	tb_switch_tmu_change_mode_prev(sw);
b017a46d486cd4 Gil Fine        2022-05-26  635  	return ret;
b017a46d486cd4 Gil Fine        2022-05-26  636  }

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: drivers/thunderbolt/tmu.c:617 tb_switch_tmu_change_mode() warn: missing unwind goto?

[Mika Westerberg]

Hi Dan,

On Fri, Nov 03, 2023 at 09:01:34AM +0300, Dan Carpenter wrote:
> Hi Mika,
> 
> FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant.
> 
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   4652b8e4f3ffa48c706ec334f048c217a7d9750d
> commit: c437dcb18310f296eb9db58a361f309f7817014d thunderbolt: Fix a couple of style issues in TMU code
> config: i386-randconfig-141-20231102 (https://download.01.org/0day-ci/archive/20231103/202311030814.AXtCk7PO-lkp@intel.com/config)
> compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
> reproduce: (https://download.01.org/0day-ci/archive/20231103/202311030814.AXtCk7PO-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> | Closes: https://lore.kernel.org/r/202311030814.AXtCk7PO-lkp@intel.com/
> 
> smatch warnings:
> drivers/thunderbolt/tmu.c:617 tb_switch_tmu_change_mode() warn: missing unwind goto?
> 
> vim +617 drivers/thunderbolt/tmu.c
> 
> c437dcb18310f2 Mika Westerberg 2022-10-07  596  static int tb_switch_tmu_change_mode(struct tb_switch *sw)
> b017a46d486cd4 Gil Fine        2022-05-26  597  {
> b017a46d486cd4 Gil Fine        2022-05-26  598  	struct tb_port *up, *down;
> b017a46d486cd4 Gil Fine        2022-05-26  599  	int ret;
> b017a46d486cd4 Gil Fine        2022-05-26  600  
> b017a46d486cd4 Gil Fine        2022-05-26  601  	up = tb_upstream_port(sw);
> 7ce542219b6323 Gil Fine        2022-09-23  602  	down = tb_switch_downstream_port(sw);
> b017a46d486cd4 Gil Fine        2022-05-26  603  	ret = tb_port_tmu_set_unidirectional(down, sw->tmu.unidirectional_request);
> b017a46d486cd4 Gil Fine        2022-05-26  604  	if (ret)
> b017a46d486cd4 Gil Fine        2022-05-26  605  		goto out;
> b017a46d486cd4 Gil Fine        2022-05-26  606  
> b017a46d486cd4 Gil Fine        2022-05-26  607  	if (sw->tmu.unidirectional_request)
> 7ce542219b6323 Gil Fine        2022-09-23  608  		ret = tb_switch_tmu_rate_write(tb_switch_parent(sw),
> 7ce542219b6323 Gil Fine        2022-09-23  609  					       sw->tmu.rate_request);
> b017a46d486cd4 Gil Fine        2022-05-26  610  	else
> b017a46d486cd4 Gil Fine        2022-05-26  611  		ret = tb_switch_tmu_rate_write(sw, sw->tmu.rate_request);
> b017a46d486cd4 Gil Fine        2022-05-26  612  	if (ret)
> b017a46d486cd4 Gil Fine        2022-05-26  613  		return ret;
> 
> These error paths should be goto out;
> 
> b017a46d486cd4 Gil Fine        2022-05-26  614  
> b017a46d486cd4 Gil Fine        2022-05-26  615  	ret = tb_switch_set_tmu_mode_params(sw, sw->tmu.rate_request);
> b017a46d486cd4 Gil Fine        2022-05-26  616  	if (ret)
> b017a46d486cd4 Gil Fine        2022-05-26 @617  		return ret;
> 
> Same.  (I guess before goto out was a do-nothing goto so it didn't
> matter).

Thanks for the report!

This code is different now in the mainline but this one is still there
and I agree it should goto out.

I will send a fix after -rc1 is released.