| Message ID | 20231208031950.47410-1-chentao@kylinos.cn (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v5,iwl-next] i40e: Use correct buffer size in i40e_dbg_command_read | expand |
From: Kunwu Chan <chentao@kylinos.cn> Date: Fri, 8 Dec 2023 11:19:50 +0800 > The size of "i40e_dbg_command_buf" is 256, the size of "name" > depends on "IFNAMSIZ", plus a null character and format size, > the total size is more than 256. > > Improve readability and maintainability by replacing a hardcoded string > allocation and formatting by the use of the kasprintf() helper. > > Fixes: 02e9c290814c ("i40e: debugfs interface") > Suggested-by: Simon Horman <horms@kernel.org> > Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com> > Suggested-by: Tony Nguyen <anthony.l.nguyen@intel.com> > Cc: Kunwu Chan <kunwu.chan@hotmail.com> > Signed-off-by: Kunwu Chan <chentao@kylinos.cn> Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com> Thanks, Olek
On Fri, Dec 08, 2023 at 11:19:50AM +0800, Kunwu Chan wrote: > The size of "i40e_dbg_command_buf" is 256, the size of "name" > depends on "IFNAMSIZ", plus a null character and format size, > the total size is more than 256. > > Improve readability and maintainability by replacing a hardcoded string > allocation and formatting by the use of the kasprintf() helper. > > Fixes: 02e9c290814c ("i40e: debugfs interface") > Suggested-by: Simon Horman <horms@kernel.org> > Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com> > Suggested-by: Tony Nguyen <anthony.l.nguyen@intel.com> > Cc: Kunwu Chan <kunwu.chan@hotmail.com> > Signed-off-by: Kunwu Chan <chentao@kylinos.cn> Reviewed-by: Simon Horman <horms@kernel.org>
> -----Original Message----- > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Kunwu Chan > Sent: Friday, December 8, 2023 8:50 AM > To: Brandeburg, Jesse <jesse.brandeburg@intel.com>; Nguyen, Anthony L <anthony.l.nguyen@intel.com>; davem@davemloft.net; edumazet@google.com; kuba@kernel.org; pabeni@redhat.com; jeffrey.t.kirsher@intel.com; shannon.nelson@amd.com > Cc: Kunwu Chan <chentao@kylinos.cn>; Kunwu Chan <kunwu.chan@hotmail.com>; netdev@vger.kernel.org; linux-kernel@vger.kernel.org; Lobakin, Aleksander <aleksander.lobakin@intel.com>; intel-wired-lan@lists.osuosl.org; Simon Horman <horms@kernel.org> > Subject: [Intel-wired-lan] [PATCH v5 iwl-next] i40e: Use correct buffer size in i40e_dbg_command_read > > The size of "i40e_dbg_command_buf" is 256, the size of "name" > depends on "IFNAMSIZ", plus a null character and format size, > the total size is more than 256. > > Improve readability and maintainability by replacing a hardcoded string > allocation and formatting by the use of the kasprintf() helper. > > Fixes: 02e9c290814c ("i40e: debugfs interface") > Suggested-by: Simon Horman <horms@kernel.org> > Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com> > Suggested-by: Tony Nguyen <anthony.l.nguyen@intel.com> > Cc: Kunwu Chan <kunwu.chan@hotmail.com> > Signed-off-by: Kunwu Chan <chentao@kylinos.cn> > --- > v2 > - Update the size calculation with IFNAMSIZ and sizeof(i40e_dbg_command_buf) > v3 > - Use kasprintf to improve readability and maintainability > v4 > - Fix memory leak in error path > v5 > - Change the order of labels > --- > .../net/ethernet/intel/i40e/i40e_debugfs.c | 20 ++++++++++--------- > 1 file changed, 11 insertions(+), 9 deletions(-) > Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
On 12/17/2023 9:54 PM, Pucha, HimasekharX Reddy wrote: > >> -----Original Message----- >> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Kunwu Chan >> Sent: Friday, December 8, 2023 8:50 AM >> To: Brandeburg, Jesse <jesse.brandeburg@intel.com>; Nguyen, Anthony L <anthony.l.nguyen@intel.com>; davem@davemloft.net; edumazet@google.com; kuba@kernel.org; pabeni@redhat.com; jeffrey.t.kirsher@intel.com; shannon.nelson@amd.com >> Cc: Kunwu Chan <chentao@kylinos.cn>; Kunwu Chan <kunwu.chan@hotmail.com>; netdev@vger.kernel.org; linux-kernel@vger.kernel.org; Lobakin, Aleksander <aleksander.lobakin@intel.com>; intel-wired-lan@lists.osuosl.org; Simon Horman <horms@kernel.org> >> Subject: [Intel-wired-lan] [PATCH v5 iwl-next] i40e: Use correct buffer size in i40e_dbg_command_read >> >> The size of "i40e_dbg_command_buf" is 256, the size of "name" >> depends on "IFNAMSIZ", plus a null character and format size, >> the total size is more than 256. >> >> Improve readability and maintainability by replacing a hardcoded string >> allocation and formatting by the use of the kasprintf() helper. >> >> Fixes: 02e9c290814c ("i40e: debugfs interface") >> Suggested-by: Simon Horman <horms@kernel.org> >> Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com> >> Suggested-by: Tony Nguyen <anthony.l.nguyen@intel.com> >> Cc: Kunwu Chan <kunwu.chan@hotmail.com> >> Signed-off-by: Kunwu Chan <chentao@kylinos.cn> >> --- >> v2 >> - Update the size calculation with IFNAMSIZ and sizeof(i40e_dbg_command_buf) >> v3 >> - Use kasprintf to improve readability and maintainability >> v4 >> - Fix memory leak in error path >> v5 >> - Change the order of labels >> --- >> .../net/ethernet/intel/i40e/i40e_debugfs.c | 20 ++++++++++--------- >> 1 file changed, 11 insertions(+), 9 deletions(-) >> > > Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel) > Much of this debugfs command code was an early driver hack that probably never should have gone upstream in the form that it did. The i40e_dbg_command_buf itself was originally meant as a scratchpad to put the 'last command processed', which was not really very useful, and as a static global that might be written by any number of instances of i40e devices, was problematic from the beginning. Now, unless I'm mistaken, it looks like nothing is writing to the buffer at all anymore, so the buffer and the i40e_dbg_command_read() callback probably should just all go away rather than trying to pretty up some useless code. sln
On 12/19/2023 5:32 PM, Nelson, Shannon wrote: > On 12/17/2023 9:54 PM, Pucha, HimasekharX Reddy wrote: >> >>> -----Original Message----- >>> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf >>> Of Kunwu Chan >>> Subject: [Intel-wired-lan] [PATCH v5 iwl-next] i40e: Use correct >>> buffer size in i40e_dbg_command_read >>> >>> The size of "i40e_dbg_command_buf" is 256, the size of "name" >>> depends on "IFNAMSIZ", plus a null character and format size, >>> the total size is more than 256. >>> >>> Improve readability and maintainability by replacing a hardcoded string >>> allocation and formatting by the use of the kasprintf() helper. >>> >>> Fixes: 02e9c290814c ("i40e: debugfs interface") >>> Suggested-by: Simon Horman <horms@kernel.org> >>> Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com> >>> Suggested-by: Tony Nguyen <anthony.l.nguyen@intel.com> >>> Cc: Kunwu Chan <kunwu.chan@hotmail.com> >>> Signed-off-by: Kunwu Chan <chentao@kylinos.cn> >>> --- ... > Much of this debugfs command code was an early driver hack that probably > never should have gone upstream in the form that it did. The > i40e_dbg_command_buf itself was originally meant as a scratchpad to put > the 'last command processed', which was not really very useful, and as a > static global that might be written by any number of instances of i40e > devices, was problematic from the beginning. Now, unless I'm mistaken, > it looks like nothing is writing to the buffer at all anymore, so the > buffer and the i40e_dbg_command_read() callback probably should just all > go away rather than trying to pretty up some useless code. Thanks for the history Shannon. I'm not seeing the buffer used either so, I agree, we should remove it altogether. Thanks, Tony > sln
diff --git a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c index 88240571721a..78a7200211b2 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c +++ b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c @@ -72,29 +72,31 @@ static ssize_t i40e_dbg_command_read(struct file *filp, char __user *buffer, { struct i40e_pf *pf = filp->private_data; int bytes_not_copied; - int buf_size = 256; char *buf; int len; /* don't allow partial reads */ if (*ppos != 0) return 0; - if (count < buf_size) - return -ENOSPC; - buf = kzalloc(buf_size, GFP_KERNEL); + buf = kasprintf(GFP_KERNEL, "%s: %s\n", + pf->vsi[pf->lan_vsi]->netdev->name, + i40e_dbg_command_buf); if (!buf) return -ENOSPC; - len = snprintf(buf, buf_size, "%s: %s\n", - pf->vsi[pf->lan_vsi]->netdev->name, - i40e_dbg_command_buf); + len = strlen(buf) + 1; + if (count < len) + bytes_not_copied = -ENOSPC; + else if (copy_to_user(buffer, buf, len)) + bytes_not_copied = -EFAULT; + else + bytes_not_copied = 0; - bytes_not_copied = copy_to_user(buffer, buf, len); kfree(buf); if (bytes_not_copied) - return -EFAULT; + return bytes_not_copied; *ppos = len; return len;
The size of "i40e_dbg_command_buf" is 256, the size of "name" depends on "IFNAMSIZ", plus a null character and format size, the total size is more than 256. Improve readability and maintainability by replacing a hardcoded string allocation and formatting by the use of the kasprintf() helper. Fixes: 02e9c290814c ("i40e: debugfs interface") Suggested-by: Simon Horman <horms@kernel.org> Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com> Suggested-by: Tony Nguyen <anthony.l.nguyen@intel.com> Cc: Kunwu Chan <kunwu.chan@hotmail.com> Signed-off-by: Kunwu Chan <chentao@kylinos.cn> --- v2 - Update the size calculation with IFNAMSIZ and sizeof(i40e_dbg_command_buf) v3 - Use kasprintf to improve readability and maintainability v4 - Fix memory leak in error path v5 - Change the order of labels --- .../net/ethernet/intel/i40e/i40e_debugfs.c | 20 ++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-)