| Message ID | 20241006231938.4382-1-pvmohammedanees2003@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v2] net: dsa: Fix conditional handling of Wake-on-Lan configuration in dsa_user_set_wol | expand |
On Mon, Oct 07, 2024 at 04:49:38AM +0530, Mohammed Anees wrote: > In the original implementation of dsa_user_set_wol(), the return > value of phylink_ethtool_set_wol() was not checked, which could > lead to errors being ignored. This wouldn't matter if it returned > -EOPNOTSUPP, since that indicates the PHY layer doesn't support > the option, but if any other value is returned, it is problematic > and must be checked. The solution is to check the return value of > phylink_ethtool_set_wol(), and if it returns anything other than > -EOPNOTSUPP, immediately return the error. Only if it returns > -EOPNOTSUPP should the function proceed to check whether WoL can > be set by ds->ops->set_wol(). > > Fixes: 57719771a244 ("Merge tag 'sound-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound") > Signed-off-by: Mohammed Anees <pvmohammedanees2003@gmail.com> > --- > v2: > - Added error checking for phylink_ethtool_set_wol(), ensuring correct > handling compared to v1. I don't think this adds "correct handing". See my reply to the first version. pw-bot: cr
Hi Mohammed, kernel test robot noticed the following build errors: [auto build test ERROR on net/main] [also build test ERROR on net-next/main linus/master v6.12-rc2 next-20241004] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Mohammed-Anees/net-dsa-Fix-conditional-handling-of-Wake-on-Lan-configuration-in-dsa_user_set_wol/20241007-072229 base: net/main patch link: https://lore.kernel.org/r/20241006231938.4382-1-pvmohammedanees2003%40gmail.com patch subject: [PATCH v2] net: dsa: Fix conditional handling of Wake-on-Lan configuration in dsa_user_set_wol config: arc-allmodconfig (https://download.01.org/0day-ci/archive/20241008/202410080459.sbnWWj91-lkp@intel.com/config) compiler: arceb-elf-gcc (GCC) 13.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241008/202410080459.sbnWWj91-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> | Closes: https://lore.kernel.org/oe-kbuild-all/202410080459.sbnWWj91-lkp@intel.com/ All errors (new ones prefixed by >>): net/dsa/user.c: In function 'dsa_user_set_wol': >> net/dsa/user.c:1220:13: error: void value not ignored as it ought to be 1220 | ret = phylink_ethtool_get_wol(dp->pl, w); | ^ Kconfig warnings: (for reference only) WARNING: unmet direct dependencies detected for GET_FREE_REGION Depends on [n]: SPARSEMEM [=n] Selected by [m]: - RESOURCE_KUNIT_TEST [=m] && RUNTIME_TESTING_MENU [=y] && KUNIT [=m] vim +1220 net/dsa/user.c 1213 1214 static int dsa_user_set_wol(struct net_device *dev, struct ethtool_wolinfo *w) 1215 { 1216 struct dsa_port *dp = dsa_user_to_port(dev); 1217 struct dsa_switch *ds = dp->ds; 1218 int ret; 1219 > 1220 ret = phylink_ethtool_get_wol(dp->pl, w); 1221 1222 if (ret != -EOPNOTSUPP) 1223 return ret; 1224 1225 if (ds->ops->set_wol) 1226 return ds->ops->set_wol(ds, dp->index, w); 1227 1228 return -EOPNOTSUPP; 1229 } 1230
Hi Mohammed, On Mon, Oct 07, 2024 at 04:49:38AM +0530, Mohammed Anees wrote: > In the original implementation of dsa_user_set_wol(), the return > value of phylink_ethtool_set_wol() was not checked, which could > lead to errors being ignored. This wouldn't matter if it returned > -EOPNOTSUPP, since that indicates the PHY layer doesn't support > the option, but if any other value is returned, it is problematic > and must be checked. The solution is to check the return value of > phylink_ethtool_set_wol(), and if it returns anything other than > -EOPNOTSUPP, immediately return the error. Only if it returns > -EOPNOTSUPP should the function proceed to check whether WoL can > be set by ds->ops->set_wol(). > > Fixes: 57719771a244 ("Merge tag 'sound-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound") The Fixes: tag is completely bogus. It's supposed to point to the commit which introduced the issue (aka what 'git bisect' would land on). > Signed-off-by: Mohammed Anees <pvmohammedanees2003@gmail.com> > --- > v2: > - Added error checking for phylink_ethtool_set_wol(), ensuring correct > handling compared to v1. > ___ this should have been "---" not "___". > net/dsa/user.c | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > diff --git a/net/dsa/user.c b/net/dsa/user.c > index 74eda9b30608..bae5ed22db91 100644 > --- a/net/dsa/user.c > +++ b/net/dsa/user.c > @@ -1215,14 +1215,17 @@ static int dsa_user_set_wol(struct net_device *dev, struct ethtool_wolinfo *w) > - phylink_ethtool_set_wol(dp->pl, w); > + ret = phylink_ethtool_get_wol(dp->pl, w); Could you tell us a bit about your motivation for making a change? How have you noticed the lack of error checking in phylink_ethtool_set_wol()? What user-visible problem has it caused? Since patches with Fixes: tags to older than net-next commits get backported to stable kernels, the triage rules from Documentation/process/stable-kernel-rules.rst apply. If this is purely theoretical and you are not already testing this, then please do so. (it seems you aren't, because you replaced phylink_ethtool_get_wol() with phylink_ethtool_set_wol()). Luckily, you could somewhat exercise the code paths using the dsa_loop mock-up driver even if you don't have a supported hardware switch. It isn't the same as the real thing, but with some instrumentation and carefully chosen test cases and simulated return codes, I could see it being used to prove a point. If you don't have the interest of testing this patch, then I would request you to abandon it. The topic of combining MAC WoL with PHY WoL is not trivial and a theoretical "fix" can make things that used to work stop working. It's unlikely that basing patches off of a chat on the mailing list is going to make things better if it all stays theoretical and no one tests anything, even if that chat is with Andrew and Russell, the opinions of both of whom are extremely respectable in this area. In principle there's also the option of requesting somebody else to test if you cannot, like the submitter of the blamed patch, if there's reasonable suspicion that something is not right. In this case, interesting thing, the phylink_ethtool_set_wol() call got introduced in commit aab9c4067d23 ("net: dsa: Plug in PHYLINK support") by Florian, but there was no phy_ethtool_set_wol() prior to that. So it's not clear at all what use cases came to depend upon the phylink_ethtool_set_wol() call in the meantime since 2018. I'm not convinced that said commit voluntarily introduced the call. If this is not an exclusively theoretical issue and this was just an honest mistake, then please do continue the patch submission process. But for my curiosity, what platform are you experimenting on?
Hi Vladimir, Thank you for your thoughtful feedback; I really appreciate it. I want to be honest, I’m quite new to this process and have been exploring the the code to learn as much as I can, which was when i noticed this. I was excited to contribute and took a more theoretical approach without fully grasping the importance of testing to see if this is ever possible. I completely understand your points now and apologize for not testing this. I haven’t had the chance to experiment with it on any platform yet, but I plan to do so to see if I encounter any issues. If I do run into problems, I’ll definitely continue with this patch and work on resolving them. Thanks once more for your guidance and for clarifying the intricacies of MAC WoL and PHY WoL interaction.
Hi Mohammed,
kernel test robot noticed the following build errors:
[auto build test ERROR on net/main]
[also build test ERROR on net-next/main linus/master v6.12-rc2 next-20241004]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Mohammed-Anees/net-dsa-Fix-conditional-handling-of-Wake-on-Lan-configuration-in-dsa_user_set_wol/20241007-072229
base: net/main
patch link: https://lore.kernel.org/r/20241006231938.4382-1-pvmohammedanees2003%40gmail.com
patch subject: [PATCH v2] net: dsa: Fix conditional handling of Wake-on-Lan configuration in dsa_user_set_wol
config: s390-allmodconfig (https://download.01.org/0day-ci/archive/20241008/202410080616.wpZV4fAa-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project fef3566a25ff0e34fb87339ba5e13eca17cec00f)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241008/202410080616.wpZV4fAa-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>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410080616.wpZV4fAa-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from net/dsa/user.c:8:
In file included from include/linux/etherdevice.h:20:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:17:
In file included from include/linux/bvec.h:10:
In file included from include/linux/highmem.h:10:
In file included from include/linux/mm.h:2213:
include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
504 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
505 | item];
| ~~~~
include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
511 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
512 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
518 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
| ~~~~~~~~~~~ ^ ~~~
include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
524 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~ ^
525 | NR_VM_NUMA_EVENT_ITEMS +
| ~~~~~~~~~~~~~~~~~~~~~~
In file included from net/dsa/user.c:8:
In file included from include/linux/etherdevice.h:20:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:28:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:93:
include/asm-generic/io.h:548:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
548 | val = __raw_readb(PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:561:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
561 | val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
| ~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu'
37 | #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
| ^
include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16'
102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
| ^
In file included from net/dsa/user.c:8:
In file included from include/linux/etherdevice.h:20:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:28:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:93:
include/asm-generic/io.h:574:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
574 | val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
| ~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu'
35 | #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
| ^
include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32'
115 | #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
| ^
In file included from net/dsa/user.c:8:
In file included from include/linux/etherdevice.h:20:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:28:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:93:
include/asm-generic/io.h:585:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
585 | __raw_writeb(value, PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:595:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
595 | __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:605:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
605 | __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:693:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
693 | readsb(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:701:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
701 | readsw(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:709:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
709 | readsl(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:718:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
718 | writesb(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:727:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
727 | writesw(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
include/asm-generic/io.h:736:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
736 | writesl(PCI_IOBASE + addr, buffer, count);
| ~~~~~~~~~~ ^
>> net/dsa/user.c:1220:6: error: assigning to 'int' from incompatible type 'void'
1220 | ret = phylink_ethtool_get_wol(dp->pl, w);
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
16 warnings and 1 error generated.
Kconfig warnings: (for reference only)
WARNING: unmet direct dependencies detected for MODVERSIONS
Depends on [n]: MODULES [=y] && !COMPILE_TEST [=y]
Selected by [y]:
- RANDSTRUCT_FULL [=y] && (CC_HAS_RANDSTRUCT [=y] || GCC_PLUGINS [=n]) && MODULES [=y]
vim +1220 net/dsa/user.c
1213
1214 static int dsa_user_set_wol(struct net_device *dev, struct ethtool_wolinfo *w)
1215 {
1216 struct dsa_port *dp = dsa_user_to_port(dev);
1217 struct dsa_switch *ds = dp->ds;
1218 int ret;
1219
> 1220 ret = phylink_ethtool_get_wol(dp->pl, w);
1221
1222 if (ret != -EOPNOTSUPP)
1223 return ret;
1224
1225 if (ds->ops->set_wol)
1226 return ds->ops->set_wol(ds, dp->index, w);
1227
1228 return -EOPNOTSUPP;
1229 }
1230
diff --git a/net/dsa/user.c b/net/dsa/user.c index 74eda9b30608..bae5ed22db91 100644 --- a/net/dsa/user.c +++ b/net/dsa/user.c @@ -1215,14 +1215,17 @@ static int dsa_user_set_wol(struct net_device *dev, struct ethtool_wolinfo *w) { struct dsa_port *dp = dsa_user_to_port(dev); struct dsa_switch *ds = dp->ds; - int ret = -EOPNOTSUPP; - - phylink_ethtool_set_wol(dp->pl, w); - + int ret; + + ret = phylink_ethtool_get_wol(dp->pl, w); + + if (ret != -EOPNOTSUPP) + return ret; + if (ds->ops->set_wol) - ret = ds->ops->set_wol(ds, dp->index, w); + return ds->ops->set_wol(ds, dp->index, w); - return ret; + return -EOPNOTSUPP; } static int dsa_user_set_eee(struct net_device *dev, struct ethtool_keee *e)
In the original implementation of dsa_user_set_wol(), the return value of phylink_ethtool_set_wol() was not checked, which could lead to errors being ignored. This wouldn't matter if it returned -EOPNOTSUPP, since that indicates the PHY layer doesn't support the option, but if any other value is returned, it is problematic and must be checked. The solution is to check the return value of phylink_ethtool_set_wol(), and if it returns anything other than -EOPNOTSUPP, immediately return the error. Only if it returns -EOPNOTSUPP should the function proceed to check whether WoL can be set by ds->ops->set_wol(). Fixes: 57719771a244 ("Merge tag 'sound-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound") Signed-off-by: Mohammed Anees <pvmohammedanees2003@gmail.com> --- v2: - Added error checking for phylink_ethtool_set_wol(), ensuring correct handling compared to v1.