Message ID | 1486035113-2305-1-git-send-email-sgruszka@redhat.com |
---|---|
State | Superseded, archived |
Delegated to: | David Miller |
Headers | show |
Hi Stanislaw,
[auto build test WARNING on net-next/master]
[also build test WARNING on v4.10-rc6]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Stanislaw-Gruszka/ethtool-do-not-vzalloc-0-on-registers-dump/20170202-194352
config: i386-randconfig-x001-201705 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
All warnings (new ones prefixed by >>):
In file included from include/linux/uaccess.h:5:0,
from include/net/checksum.h:25,
from include/linux/skbuff.h:31,
from include/linux/if_ether.h:23,
from include/uapi/linux/ethtool.h:18,
from include/linux/ethtool.h:17,
from net/core/ethtool.c:18:
net/core/ethtool.c: In function 'dev_ethtool':
>> arch/x86/include/asm/uaccess.h:722:5: warning: 'regbuf' may be used uninitialized in this function [-Wmaybe-uninitialized]
n = _copy_to_user(to, from, n);
~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
net/core/ethtool.c:1395:8: note: 'regbuf' was declared here
void *regbuf;
^~~~~~
vim +/regbuf +722 arch/x86/include/asm/uaccess.h
0d025d27 Josh Poimboeuf 2016-08-30 706 __bad_copy_user();
3df7b41a Jan Beulich 2013-10-21 707
3df7b41a Jan Beulich 2013-10-21 708 return n;
3df7b41a Jan Beulich 2013-10-21 709 }
3df7b41a Jan Beulich 2013-10-21 710
e6971009 Kees Cook 2016-09-06 711 static __always_inline unsigned long __must_check
7a3d9b0f Jan Beulich 2013-10-21 712 copy_to_user(void __user *to, const void *from, unsigned long n)
7a3d9b0f Jan Beulich 2013-10-21 713 {
7a3d9b0f Jan Beulich 2013-10-21 714 int sz = __compiletime_object_size(from);
7a3d9b0f Jan Beulich 2013-10-21 715
1771c6e1 Andrey Ryabinin 2016-05-20 716 kasan_check_read(from, n);
1771c6e1 Andrey Ryabinin 2016-05-20 717
7a3d9b0f Jan Beulich 2013-10-21 718 might_fault();
7a3d9b0f Jan Beulich 2013-10-21 719
5b710f34 Kees Cook 2016-06-23 720 if (likely(sz < 0 || sz >= n)) {
5b710f34 Kees Cook 2016-06-23 721 check_object_size(from, n, true);
7a3d9b0f Jan Beulich 2013-10-21 @722 n = _copy_to_user(to, from, n);
0d025d27 Josh Poimboeuf 2016-08-30 723 } else if (!__builtin_constant_p(n))
0d025d27 Josh Poimboeuf 2016-08-30 724 copy_user_overflow(sz, n);
7a3d9b0f Jan Beulich 2013-10-21 725 else
0d025d27 Josh Poimboeuf 2016-08-30 726 __bad_copy_user();
7a3d9b0f Jan Beulich 2013-10-21 727
7a3d9b0f Jan Beulich 2013-10-21 728 return n;
7a3d9b0f Jan Beulich 2013-10-21 729 }
7a3d9b0f Jan Beulich 2013-10-21 730
:::::: The code at line 722 was first introduced by commit
:::::: 7a3d9b0f3abbea957b829cdfff8169872c575642 x86: Unify copy_to_user() and add size checking to it
:::::: TO: Jan Beulich <JBeulich@suse.com>
:::::: CC: Ingo Molnar <mingo@kernel.org>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
Hi Stanislaw,
[auto build test WARNING on net-next/master]
[also build test WARNING on v4.10-rc6 next-20170202]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Stanislaw-Gruszka/ethtool-do-not-vzalloc-0-on-registers-dump/20170202-194352
config: cris-etrax-100lx_v2_defconfig (attached as .config)
compiler: cris-linux-gcc (GCC) 6.2.0
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=cris
Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
All warnings (new ones prefixed by >>):
net/core/ethtool.c: In function 'ethtool_get_feature_mask':
net/core/ethtool.c:311:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
In file included from include/linux/uaccess.h:5:0,
from include/net/checksum.h:25,
from include/linux/skbuff.h:31,
from include/linux/if_ether.h:23,
from include/uapi/linux/ethtool.h:18,
from include/linux/ethtool.h:17,
from net/core/ethtool.c:18:
net/core/ethtool.c: In function 'ethtool_get_regs':
>> arch/cris/include/asm/uaccess.h:380:10: warning: 'regbuf' may be used uninitialized in this function [-Wmaybe-uninitialized]
return __copy_user(to, from, n);
^~~~~~~~~~~~~~~~~~~~~~~~
net/core/ethtool.c:1395:8: note: 'regbuf' was declared here
void *regbuf;
^~~~~~
vim +/regbuf +380 arch/cris/include/asm/uaccess.h
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 364 memset(to, 0, n);
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 365 return n;
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 366 }
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 367 if (__builtin_constant_p(n))
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 368 return __constant_copy_from_user(to, from, n);
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 369 else
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 370 return __copy_user_zeroing(to, from, n);
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 371 }
^1da177e4 include/asm-cris/uaccess.h Linus Torvalds 2005-04-16 372
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 373 static inline size_t copy_to_user(void __user *to, const void *from, size_t n)
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 374 {
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 375 if (unlikely(!access_ok(VERIFY_WRITE, to, n)))
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 376 return n;
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 377 if (__builtin_constant_p(n))
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 378 return __constant_copy_to_user(to, from, n);
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 379 else
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 @380 return __copy_user(to, from, n);
eb47e0293 arch/cris/include/asm/uaccess.h Al Viro 2016-08-18 381 }
^1da177e4 include/asm-cris/uaccess.h Linus Torvalds 2005-04-16 382
^1da177e4 include/asm-cris/uaccess.h Linus Torvalds 2005-04-16 383 /* We let the __ versions of copy_from/to_user inline, because they're often
^1da177e4 include/asm-cris/uaccess.h Linus Torvalds 2005-04-16 384 * used in fast paths and have only a small space overhead.
^1da177e4 include/asm-cris/uaccess.h Linus Torvalds 2005-04-16 385 */
^1da177e4 include/asm-cris/uaccess.h Linus Torvalds 2005-04-16 386
d9b5444ee include/asm-cris/uaccess.h Adrian Bunk 2005-11-07 387 static inline unsigned long
07f2402b4 include/asm-cris/uaccess.h Jesper Nilsson 2008-03-04 388 __generic_copy_from_user_nocheck(void *to, const void __user *from,
:::::: The code at line 380 was first introduced by commit
:::::: eb47e0293baaa3044022059f1fa9ff474bfe35cb cris: buggered copy_from_user/copy_to_user/clear_user
:::::: TO: Al Viro <viro@zeniv.linux.org.uk>
:::::: CC: Al Viro <viro@zeniv.linux.org.uk>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/net/core/ethtool.c b/net/core/ethtool.c index 6b3eee0..3ec897f 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -1405,9 +1405,11 @@ static int ethtool_get_regs(struct net_device *dev, char __user *useraddr) if (regs.len > reglen) regs.len = reglen; - regbuf = vzalloc(reglen); - if (reglen && !regbuf) - return -ENOMEM; + if (reglen) { + regbuf = vzalloc(reglen); + if (!regbuf) + return -ENOMEM; + } ops->get_regs(dev, ®s, regbuf);
If ->get_regs_len() callback return 0, we allocate 0 bytes of memory, what print ugly warning in dmesg, which can be found further below. This happen on mac80211 devices where ieee80211_get_regs_len() just return 0 and driver only fills ethtool_regs structure and actually do not provide any dump. However I assume this can happen on other drivers i.e. when for some devices driver provide regs dump and for others do not. Hence preventing to to print warning in ethtool code seems to be reasonable. ethtool: vmalloc: allocation failure: 0 bytes, mode:0x24080c2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_ZERO) <snip> Call Trace: [<ffffffff813bde47>] dump_stack+0x63/0x8c [<ffffffff811b0a1f>] warn_alloc+0x13f/0x170 [<ffffffff811f0476>] __vmalloc_node_range+0x1e6/0x2c0 [<ffffffff811f0874>] vzalloc+0x54/0x60 [<ffffffff8169986c>] dev_ethtool+0xb4c/0x1b30 [<ffffffff816adbb1>] dev_ioctl+0x181/0x520 [<ffffffff816714d2>] sock_do_ioctl+0x42/0x50 <snip> Mem-Info: active_anon:435809 inactive_anon:173951 isolated_anon:0 active_file:835822 inactive_file:196932 isolated_file:0 unevictable:0 dirty:8 writeback:0 unstable:0 slab_reclaimable:157732 slab_unreclaimable:10022 mapped:83042 shmem:306356 pagetables:9507 bounce:0 free:130041 free_pcp:1080 free_cma:0 Node 0 active_anon:1743236kB inactive_anon:695804kB active_file:3343288kB inactive_file:787728kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:332168kB dirty:32kB writeback:0kB shmem:0kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 1225424kB writeback_tmp:0kB unstable:0kB pages_scanned:0 all_unreclaimable? no Node 0 DMA free:15900kB min:136kB low:168kB high:200kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15984kB managed:15900kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 3187 7643 7643 Node 0 DMA32 free:419732kB min:28124kB low:35152kB high:42180kB active_anon:541180kB inactive_anon:248988kB active_file:1466388kB inactive_file:389632kB unevictable:0kB writepending:0kB present:3370280kB managed:3290932kB mlocked:0kB slab_reclaimable:217184kB slab_unreclaimable:4180kB kernel_stack:160kB pagetables:984kB bounce:0kB free_pcp:2236kB local_pcp:660kB free_cma:0kB lowmem_reserve[]: 0 0 4456 4456 Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> --- net/core/ethtool.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)