Optimize copy functions by reducing misalign access and pipeline stall - #17
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Optimize copy functions by reducing misalign access and pipeline stall#17mcd500 wants to merge 3 commits into
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mcd500
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Jun 1, 2021
This reverts commit 8a87800.
04091d6 introduces an assembly version of memmove but it does take misalignment into account (it checks if length is a multiple of machine word size but pointers need also be aligned). As a result it will generate misaligned load/store for the majority of cases and causes significant performance regression on hardware that traps misaligned load/store and emulate them using firmware. The current behaviour of memcpy is that it checks if both src and dest pointers are co-aligned (aka congruent modular SZ_REG). If aligned, it will copy data word-by-word after first aligning pointers to word boundary. If src and dst are not co-aligned, however, byte-wise copy will be performed. This patch fixes the memmove and optimises memcpy for misaligned cases. It will first align destination pointer to word-boundary regardless whether src and dest are co-aligned or not. If they indeed are, then wordwise copy is performed. If they are not co-aligned, then it will load two adjacent words from src and use shifts to assemble a full machine word. Some additional assembly level micro-optimisation is also performed to ensure more instructions can be compressed (e.g. prefer a0 to t6). In my testing this speeds up memcpy 4~5x when src and dest are not co-aligned (which is quite common in networking), and speeds up memmove 1000+x by avoiding trapping to firmware. Signed-off-by: Gary Guo <gary@garyguo.net>
…pipeline stall This patch will reduce cpu usage dramatically in kernel space especially for user apps which use sys-call with large buffer size, such as network applications. The main reason behind this is that every unaligned memory access will raise exceptions and switch between s-mode and m-mode causing large overhead. First copy in bytes until reaches the first word aligned boundary in destination memory address. This is the preparation before the bulk aligned word copy. The destination address is aligned now, but oftentimes the source address is not in an aligned boundary. To reduce the unaligned memory access, it reads the data from source in aligned boundaries, which will cause the data to have an offset, and then combines the data in the next iteration by fixing offset with shifting before writing to destination. The majority of the improving copy speed comes from this shift copy. In the lucky situation that the both source and destination address are on the aligned boundary, perform load and store with register size to copy the data. Without the unrolling, it will reduce the speed since the next store instruction for the same register using from the load will stall the pipeline. At last, copying the remainder in one byte at a time. Signed-off-by: Akira Tsukamoto <akira.tsukamoto@gmail.com>
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This is superseded by Matteo's libstring series and #28 |
esmil pushed a commit
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Sep 20, 2021
It's later supposed to be either a correct address or NULL. Without the initialization, it may contain an undefined value which results in the following segmentation fault: # perf top --sort comm -g --ignore-callees=do_idle terminates with: #0 0x00007ffff56b7685 in __strlen_avx2 () from /lib64/libc.so.6 #1 0x00007ffff55e3802 in strdup () from /lib64/libc.so.6 #2 0x00005555558cb139 in hist_entry__init (callchain_size=<optimized out>, sample_self=true, template=0x7fffde7fb110, he=0x7fffd801c250) at util/hist.c:489 #3 hist_entry__new (template=template@entry=0x7fffde7fb110, sample_self=sample_self@entry=true) at util/hist.c:564 #4 0x00005555558cb4ba in hists__findnew_entry (hists=hists@entry=0x5555561d9e38, entry=entry@entry=0x7fffde7fb110, al=al@entry=0x7fffde7fb420, sample_self=sample_self@entry=true) at util/hist.c:657 #5 0x00005555558cba1b in __hists__add_entry (hists=hists@entry=0x5555561d9e38, al=0x7fffde7fb420, sym_parent=<optimized out>, bi=bi@entry=0x0, mi=mi@entry=0x0, sample=sample@entry=0x7fffde7fb4b0, sample_self=true, ops=0x0, block_info=0x0) at util/hist.c:288 #6 0x00005555558cbb70 in hists__add_entry (sample_self=true, sample=0x7fffde7fb4b0, mi=0x0, bi=0x0, sym_parent=<optimized out>, al=<optimized out>, hists=0x5555561d9e38) at util/hist.c:1056 #7 iter_add_single_cumulative_entry (iter=0x7fffde7fb460, al=<optimized out>) at util/hist.c:1056 #8 0x00005555558cc8a4 in hist_entry_iter__add (iter=iter@entry=0x7fffde7fb460, al=al@entry=0x7fffde7fb420, max_stack_depth=<optimized out>, arg=arg@entry=0x7fffffff7db0) at util/hist.c:1231 #9 0x00005555557cdc9a in perf_event__process_sample (machine=<optimized out>, sample=0x7fffde7fb4b0, evsel=<optimized out>, event=<optimized out>, tool=0x7fffffff7db0) at builtin-top.c:842 #10 deliver_event (qe=<optimized out>, qevent=<optimized out>) at builtin-top.c:1202 #11 0x00005555558a9318 in do_flush (show_progress=false, oe=0x7fffffff80e0) at util/ordered-events.c:244 #12 __ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP, timestamp=timestamp@entry=0) at util/ordered-events.c:323 #13 0x00005555558a9789 in __ordered_events__flush (timestamp=<optimized out>, how=<optimized out>, oe=<optimized out>) at util/ordered-events.c:339 #14 ordered_events__flush (how=OE_FLUSH__TOP, oe=0x7fffffff80e0) at util/ordered-events.c:341 #15 ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP) at util/ordered-events.c:339 #16 0x00005555557cd631 in process_thread (arg=0x7fffffff7db0) at builtin-top.c:1114 #17 0x00007ffff7bb817a in start_thread () from /lib64/libpthread.so.0 #18 0x00007ffff5656dc3 in clone () from /lib64/libc.so.6 If you look at the frame #2, the code is: 488 if (he->srcline) { 489 he->srcline = strdup(he->srcline); 490 if (he->srcline == NULL) 491 goto err_rawdata; 492 } If he->srcline is not NULL (it is not NULL if it is uninitialized rubbish), it gets strdupped and strdupping a rubbish random string causes the problem. Also, if you look at the commit 1fb7d06, it adds the srcline property into the struct, but not initializing it everywhere needed. Committer notes: Now I see, when using --ignore-callees=do_idle we end up here at line 2189 in add_callchain_ip(): 2181 if (al.sym != NULL) { 2182 if (perf_hpp_list.parent && !*parent && 2183 symbol__match_regex(al.sym, &parent_regex)) 2184 *parent = al.sym; 2185 else if (have_ignore_callees && root_al && 2186 symbol__match_regex(al.sym, &ignore_callees_regex)) { 2187 /* Treat this symbol as the root, 2188 forgetting its callees. */ 2189 *root_al = al; 2190 callchain_cursor_reset(cursor); 2191 } 2192 } And the al that doesn't have the ->srcline field initialized will be copied to the root_al, so then, back to: 1211 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al, 1212 int max_stack_depth, void *arg) 1213 { 1214 int err, err2; 1215 struct map *alm = NULL; 1216 1217 if (al) 1218 alm = map__get(al->map); 1219 1220 err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent, 1221 iter->evsel, al, max_stack_depth); 1222 if (err) { 1223 map__put(alm); 1224 return err; 1225 } 1226 1227 err = iter->ops->prepare_entry(iter, al); 1228 if (err) 1229 goto out; 1230 1231 err = iter->ops->add_single_entry(iter, al); 1232 if (err) 1233 goto out; 1234 That al at line 1221 is what hist_entry_iter__add() (called from sample__resolve_callchain()) saw as 'root_al', and then: iter->ops->add_single_entry(iter, al); will go on with al->srcline with a bogus value, I'll add the above sequence to the cset and apply, thanks! Signed-off-by: Michael Petlan <mpetlan@redhat.com> CC: Milian Wolff <milian.wolff@kdab.com> Cc: Jiri Olsa <jolsa@redhat.com> Fixes: 1fb7d06 ("perf report Use srcline from callchain for hist entries") Link: https //lore.kernel.org/r/20210719145332.29747-1-mpetlan@redhat.com Reported-by: Juri Lelli <jlelli@redhat.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
esmil pushed a commit
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Sep 24, 2021
commit 57f0ff0 upstream. It's later supposed to be either a correct address or NULL. Without the initialization, it may contain an undefined value which results in the following segmentation fault: # perf top --sort comm -g --ignore-callees=do_idle terminates with: #0 0x00007ffff56b7685 in __strlen_avx2 () from /lib64/libc.so.6 #1 0x00007ffff55e3802 in strdup () from /lib64/libc.so.6 #2 0x00005555558cb139 in hist_entry__init (callchain_size=<optimized out>, sample_self=true, template=0x7fffde7fb110, he=0x7fffd801c250) at util/hist.c:489 #3 hist_entry__new (template=template@entry=0x7fffde7fb110, sample_self=sample_self@entry=true) at util/hist.c:564 #4 0x00005555558cb4ba in hists__findnew_entry (hists=hists@entry=0x5555561d9e38, entry=entry@entry=0x7fffde7fb110, al=al@entry=0x7fffde7fb420, sample_self=sample_self@entry=true) at util/hist.c:657 #5 0x00005555558cba1b in __hists__add_entry (hists=hists@entry=0x5555561d9e38, al=0x7fffde7fb420, sym_parent=<optimized out>, bi=bi@entry=0x0, mi=mi@entry=0x0, sample=sample@entry=0x7fffde7fb4b0, sample_self=true, ops=0x0, block_info=0x0) at util/hist.c:288 #6 0x00005555558cbb70 in hists__add_entry (sample_self=true, sample=0x7fffde7fb4b0, mi=0x0, bi=0x0, sym_parent=<optimized out>, al=<optimized out>, hists=0x5555561d9e38) at util/hist.c:1056 #7 iter_add_single_cumulative_entry (iter=0x7fffde7fb460, al=<optimized out>) at util/hist.c:1056 #8 0x00005555558cc8a4 in hist_entry_iter__add (iter=iter@entry=0x7fffde7fb460, al=al@entry=0x7fffde7fb420, max_stack_depth=<optimized out>, arg=arg@entry=0x7fffffff7db0) at util/hist.c:1231 #9 0x00005555557cdc9a in perf_event__process_sample (machine=<optimized out>, sample=0x7fffde7fb4b0, evsel=<optimized out>, event=<optimized out>, tool=0x7fffffff7db0) at builtin-top.c:842 #10 deliver_event (qe=<optimized out>, qevent=<optimized out>) at builtin-top.c:1202 #11 0x00005555558a9318 in do_flush (show_progress=false, oe=0x7fffffff80e0) at util/ordered-events.c:244 #12 __ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP, timestamp=timestamp@entry=0) at util/ordered-events.c:323 #13 0x00005555558a9789 in __ordered_events__flush (timestamp=<optimized out>, how=<optimized out>, oe=<optimized out>) at util/ordered-events.c:339 #14 ordered_events__flush (how=OE_FLUSH__TOP, oe=0x7fffffff80e0) at util/ordered-events.c:341 #15 ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP) at util/ordered-events.c:339 #16 0x00005555557cd631 in process_thread (arg=0x7fffffff7db0) at builtin-top.c:1114 #17 0x00007ffff7bb817a in start_thread () from /lib64/libpthread.so.0 #18 0x00007ffff5656dc3 in clone () from /lib64/libc.so.6 If you look at the frame #2, the code is: 488 if (he->srcline) { 489 he->srcline = strdup(he->srcline); 490 if (he->srcline == NULL) 491 goto err_rawdata; 492 } If he->srcline is not NULL (it is not NULL if it is uninitialized rubbish), it gets strdupped and strdupping a rubbish random string causes the problem. Also, if you look at the commit 1fb7d06, it adds the srcline property into the struct, but not initializing it everywhere needed. Committer notes: Now I see, when using --ignore-callees=do_idle we end up here at line 2189 in add_callchain_ip(): 2181 if (al.sym != NULL) { 2182 if (perf_hpp_list.parent && !*parent && 2183 symbol__match_regex(al.sym, &parent_regex)) 2184 *parent = al.sym; 2185 else if (have_ignore_callees && root_al && 2186 symbol__match_regex(al.sym, &ignore_callees_regex)) { 2187 /* Treat this symbol as the root, 2188 forgetting its callees. */ 2189 *root_al = al; 2190 callchain_cursor_reset(cursor); 2191 } 2192 } And the al that doesn't have the ->srcline field initialized will be copied to the root_al, so then, back to: 1211 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al, 1212 int max_stack_depth, void *arg) 1213 { 1214 int err, err2; 1215 struct map *alm = NULL; 1216 1217 if (al) 1218 alm = map__get(al->map); 1219 1220 err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent, 1221 iter->evsel, al, max_stack_depth); 1222 if (err) { 1223 map__put(alm); 1224 return err; 1225 } 1226 1227 err = iter->ops->prepare_entry(iter, al); 1228 if (err) 1229 goto out; 1230 1231 err = iter->ops->add_single_entry(iter, al); 1232 if (err) 1233 goto out; 1234 That al at line 1221 is what hist_entry_iter__add() (called from sample__resolve_callchain()) saw as 'root_al', and then: iter->ops->add_single_entry(iter, al); will go on with al->srcline with a bogus value, I'll add the above sequence to the cset and apply, thanks! Signed-off-by: Michael Petlan <mpetlan@redhat.com> CC: Milian Wolff <milian.wolff@kdab.com> Cc: Jiri Olsa <jolsa@redhat.com> Fixes: 1fb7d06 ("perf report Use srcline from callchain for hist entries") Link: https //lore.kernel.org/r/20210719145332.29747-1-mpetlan@redhat.com Reported-by: Juri Lelli <jlelli@redhat.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
esmil pushed a commit
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Mar 7, 2022
When bringing down the netdevice or system shutdown, a panic can be triggered while accessing the sysfs path because the device is already removed. [ 755.549084] mlx5_core 0000:12:00.1: Shutdown was called [ 756.404455] mlx5_core 0000:12:00.0: Shutdown was called ... [ 757.937260] BUG: unable to handle kernel NULL pointer dereference at (null) [ 758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280 crash> bt ... PID: 12649 TASK: ffff8924108f2100 CPU: 1 COMMAND: "amsd" ... #9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778 [exception RIP: dma_pool_alloc+0x1ab] RIP: ffffffff8ee11acb RSP: ffff89240e1a3968 RFLAGS: 00010046 RAX: 0000000000000246 RBX: ffff89243d874100 RCX: 0000000000001000 RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffff89243d874090 RBP: ffff89240e1a39c0 R8: 000000000001f080 R9: ffff8905ffc03c00 R10: ffffffffc04680d4 R11: ffffffff8edde9fd R12: 00000000000080d0 R13: ffff89243d874090 R14: ffff89243d874080 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core] #11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core] #12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core] #13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core] #14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core] #15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core] #16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core] #17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46 #18 [ffff89240e1a3d48] speed_show at ffffffff8f277208 #19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3 #20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf #21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596 #22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10 #23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5 #24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff #25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f #26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92 crash> net_device.state ffff89443b0c0000 state = 0x5 (__LINK_STATE_START| __LINK_STATE_NOCARRIER) To prevent this scenario, we also make sure that the netdevice is present. Signed-off-by: suresh kumar <suresh2514@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
esmil pushed a commit
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Mar 16, 2022
[ Upstream commit 4224cfd ] When bringing down the netdevice or system shutdown, a panic can be triggered while accessing the sysfs path because the device is already removed. [ 755.549084] mlx5_core 0000:12:00.1: Shutdown was called [ 756.404455] mlx5_core 0000:12:00.0: Shutdown was called ... [ 757.937260] BUG: unable to handle kernel NULL pointer dereference at (null) [ 758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280 crash> bt ... PID: 12649 TASK: ffff8924108f2100 CPU: 1 COMMAND: "amsd" ... #9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778 [exception RIP: dma_pool_alloc+0x1ab] RIP: ffffffff8ee11acb RSP: ffff89240e1a3968 RFLAGS: 00010046 RAX: 0000000000000246 RBX: ffff89243d874100 RCX: 0000000000001000 RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffff89243d874090 RBP: ffff89240e1a39c0 R8: 000000000001f080 R9: ffff8905ffc03c00 R10: ffffffffc04680d4 R11: ffffffff8edde9fd R12: 00000000000080d0 R13: ffff89243d874090 R14: ffff89243d874080 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core] #11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core] #12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core] #13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core] #14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core] #15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core] #16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core] #17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46 #18 [ffff89240e1a3d48] speed_show at ffffffff8f277208 #19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3 #20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf #21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596 #22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10 #23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5 #24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff #25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f #26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92 crash> net_device.state ffff89443b0c0000 state = 0x5 (__LINK_STATE_START| __LINK_STATE_NOCARRIER) To prevent this scenario, we also make sure that the netdevice is present. Signed-off-by: suresh kumar <suresh2514@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
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Apr 19, 2022
[ Upstream commit f22881d ] In calipso_map_cat_ntoh(), in the for loop, if the return value of netlbl_bitmap_walk() is equal to (net_clen_bits - 1), when netlbl_bitmap_walk() is called next time, out-of-bounds memory accesses of bitmap[byte_offset] occurs. The bug was found during fuzzing. The following is the fuzzing report BUG: KASAN: slab-out-of-bounds in netlbl_bitmap_walk+0x3c/0xd0 Read of size 1 at addr ffffff8107bf6f70 by task err_OH/252 CPU: 7 PID: 252 Comm: err_OH Not tainted 5.17.0-rc7+ #17 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x21c/0x230 show_stack+0x1c/0x60 dump_stack_lvl+0x64/0x7c print_address_description.constprop.0+0x70/0x2d0 __kasan_report+0x158/0x16c kasan_report+0x74/0x120 __asan_load1+0x80/0xa0 netlbl_bitmap_walk+0x3c/0xd0 calipso_opt_getattr+0x1a8/0x230 calipso_sock_getattr+0x218/0x340 calipso_sock_getattr+0x44/0x60 netlbl_sock_getattr+0x44/0x80 selinux_netlbl_socket_setsockopt+0x138/0x170 selinux_socket_setsockopt+0x4c/0x60 security_socket_setsockopt+0x4c/0x90 __sys_setsockopt+0xbc/0x2b0 __arm64_sys_setsockopt+0x6c/0x84 invoke_syscall+0x64/0x190 el0_svc_common.constprop.0+0x88/0x200 do_el0_svc+0x88/0xa0 el0_svc+0x128/0x1b0 el0t_64_sync_handler+0x9c/0x120 el0t_64_sync+0x16c/0x170 Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Wang Yufen <wangyufen@huawei.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
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Sep 14, 2022
[ Upstream commit 67d7d8a ] Hulk Robot reported a issue: ================================================================== BUG: KASAN: use-after-free in ext4_xattr_set_entry+0x18ab/0x3500 Write of size 4105 at addr ffff8881675ef5f4 by task syz-executor.0/7092 CPU: 1 PID: 7092 Comm: syz-executor.0 Not tainted 4.19.90-dirty #17 Call Trace: [...] memcpy+0x34/0x50 mm/kasan/kasan.c:303 ext4_xattr_set_entry+0x18ab/0x3500 fs/ext4/xattr.c:1747 ext4_xattr_ibody_inline_set+0x86/0x2a0 fs/ext4/xattr.c:2205 ext4_xattr_set_handle+0x940/0x1300 fs/ext4/xattr.c:2386 ext4_xattr_set+0x1da/0x300 fs/ext4/xattr.c:2498 __vfs_setxattr+0x112/0x170 fs/xattr.c:149 __vfs_setxattr_noperm+0x11b/0x2a0 fs/xattr.c:180 __vfs_setxattr_locked+0x17b/0x250 fs/xattr.c:238 vfs_setxattr+0xed/0x270 fs/xattr.c:255 setxattr+0x235/0x330 fs/xattr.c:520 path_setxattr+0x176/0x190 fs/xattr.c:539 __do_sys_lsetxattr fs/xattr.c:561 [inline] __se_sys_lsetxattr fs/xattr.c:557 [inline] __x64_sys_lsetxattr+0xc2/0x160 fs/xattr.c:557 do_syscall_64+0xdf/0x530 arch/x86/entry/common.c:298 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x459fe9 RSP: 002b:00007fa5e54b4c08 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd RAX: ffffffffffffffda RBX: 000000000051bf60 RCX: 0000000000459fe9 RDX: 00000000200003c0 RSI: 0000000020000180 RDI: 0000000020000140 RBP: 000000000051bf60 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000001009 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc73c93fc0 R14: 000000000051bf60 R15: 00007fa5e54b4d80 [...] ================================================================== Above issue may happen as follows: ------------------------------------- ext4_xattr_set ext4_xattr_set_handle ext4_xattr_ibody_find >> s->end < s->base >> no EXT4_STATE_XATTR >> xattr_check_inode is not executed ext4_xattr_ibody_set ext4_xattr_set_entry >> size_t min_offs = s->end - s->base >> UAF in memcpy we can easily reproduce this problem with the following commands: mkfs.ext4 -F /dev/sda mount -o debug_want_extra_isize=128 /dev/sda /mnt touch /mnt/file setfattr -n user.cat -v `seq -s z 4096|tr -d '[:digit:]'` /mnt/file In ext4_xattr_ibody_find, we have the following assignment logic: header = IHDR(inode, raw_inode) = raw_inode + EXT4_GOOD_OLD_INODE_SIZE + i_extra_isize is->s.base = IFIRST(header) = header + sizeof(struct ext4_xattr_ibody_header) is->s.end = raw_inode + s_inode_size In ext4_xattr_set_entry min_offs = s->end - s->base = s_inode_size - EXT4_GOOD_OLD_INODE_SIZE - i_extra_isize - sizeof(struct ext4_xattr_ibody_header) last = s->first free = min_offs - ((void *)last - s->base) - sizeof(__u32) = s_inode_size - EXT4_GOOD_OLD_INODE_SIZE - i_extra_isize - sizeof(struct ext4_xattr_ibody_header) - sizeof(__u32) In the calculation formula, all values except s_inode_size and i_extra_size are fixed values. When i_extra_size is the maximum value s_inode_size - EXT4_GOOD_OLD_INODE_SIZE, min_offs is -4 and free is -8. The value overflows. As a result, the preceding issue is triggered when memcpy is executed. Therefore, when finding xattr or setting xattr, check whether there is space for storing xattr in the inode to resolve this issue. Cc: stable@kernel.org Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220616021358.2504451-3-libaokun1@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
esmil pushed a commit
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Sep 29, 2022
[ Upstream commit d71608a ] When doing slub_debug test, kfence's 'test_memcache_typesafe_by_rcu' kunit test case cause a use-after-free error: BUG: KASAN: use-after-free in kobject_del+0x14/0x30 Read of size 8 at addr ffff888007679090 by task kunit_try_catch/261 CPU: 1 PID: 261 Comm: kunit_try_catch Tainted: G B N 6.0.0-rc5-next-20220916 #17 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x34/0x48 print_address_description.constprop.0+0x87/0x2a5 print_report+0x103/0x1ed kasan_report+0xb7/0x140 kobject_del+0x14/0x30 kmem_cache_destroy+0x130/0x170 test_exit+0x1a/0x30 kunit_try_run_case+0xad/0xc0 kunit_generic_run_threadfn_adapter+0x26/0x50 kthread+0x17b/0x1b0 </TASK> The cause is inside kmem_cache_destroy(): kmem_cache_destroy acquire lock/mutex shutdown_cache schedule_work(kmem_cache_release) (if RCU flag set) release lock/mutex kmem_cache_release (if RCU flag not set) In some certain timing, the scheduled work could be run before the next RCU flag checking, which can then get a wrong value and lead to double kmem_cache_release(). Fix it by caching the RCU flag inside protected area, just like 'refcnt' Fixes: 0495e33 ("mm/slab_common: Deleting kobject in kmem_cache_destroy() without holding slab_mutex/cpu_hotplug_lock") Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Waiman Long <longman@redhat.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
esmil pushed a commit
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Oct 5, 2022
When doing slub_debug test, kfence's 'test_memcache_typesafe_by_rcu' kunit test case cause a use-after-free error: BUG: KASAN: use-after-free in kobject_del+0x14/0x30 Read of size 8 at addr ffff888007679090 by task kunit_try_catch/261 CPU: 1 PID: 261 Comm: kunit_try_catch Tainted: G B N 6.0.0-rc5-next-20220916 #17 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x34/0x48 print_address_description.constprop.0+0x87/0x2a5 print_report+0x103/0x1ed kasan_report+0xb7/0x140 kobject_del+0x14/0x30 kmem_cache_destroy+0x130/0x170 test_exit+0x1a/0x30 kunit_try_run_case+0xad/0xc0 kunit_generic_run_threadfn_adapter+0x26/0x50 kthread+0x17b/0x1b0 </TASK> The cause is inside kmem_cache_destroy(): kmem_cache_destroy acquire lock/mutex shutdown_cache schedule_work(kmem_cache_release) (if RCU flag set) release lock/mutex kmem_cache_release (if RCU flag not set) In some certain timing, the scheduled work could be run before the next RCU flag checking, which can then get a wrong value and lead to double kmem_cache_release(). Fix it by caching the RCU flag inside protected area, just like 'refcnt' Fixes: 0495e33 ("mm/slab_common: Deleting kobject in kmem_cache_destroy() without holding slab_mutex/cpu_hotplug_lock") Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Waiman Long <longman@redhat.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
esmil pushed a commit
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Jun 20, 2023
The cited commit adds a compeletion to remove dependency on rtnl lock. But it causes a deadlock for multiple encapsulations: crash> bt ffff8aece8a64000 PID: 1514557 TASK: ffff8aece8a64000 CPU: 3 COMMAND: "tc" #0 [ffffa6d14183f368] __schedule at ffffffffb8ba7f45 #1 [ffffa6d14183f3f8] schedule at ffffffffb8ba8418 #2 [ffffa6d14183f418] schedule_preempt_disabled at ffffffffb8ba8898 #3 [ffffa6d14183f428] __mutex_lock at ffffffffb8baa7f8 #4 [ffffa6d14183f4d0] mutex_lock_nested at ffffffffb8baabeb #5 [ffffa6d14183f4e0] mlx5e_attach_encap at ffffffffc0f48c17 [mlx5_core] #6 [ffffa6d14183f628] mlx5e_tc_add_fdb_flow at ffffffffc0f39680 [mlx5_core] #7 [ffffa6d14183f688] __mlx5e_add_fdb_flow at ffffffffc0f3b636 [mlx5_core] #8 [ffffa6d14183f6f0] mlx5e_tc_add_flow at ffffffffc0f3bcdf [mlx5_core] #9 [ffffa6d14183f728] mlx5e_configure_flower at ffffffffc0f3c1d1 [mlx5_core] #10 [ffffa6d14183f790] mlx5e_rep_setup_tc_cls_flower at ffffffffc0f3d529 [mlx5_core] #11 [ffffa6d14183f7a0] mlx5e_rep_setup_tc_cb at ffffffffc0f3d714 [mlx5_core] #12 [ffffa6d14183f7b0] tc_setup_cb_add at ffffffffb8931bb8 #13 [ffffa6d14183f810] fl_hw_replace_filter at ffffffffc0dae901 [cls_flower] #14 [ffffa6d14183f8d8] fl_change at ffffffffc0db5c57 [cls_flower] #15 [ffffa6d14183f970] tc_new_tfilter at ffffffffb8936047 #16 [ffffa6d14183fac8] rtnetlink_rcv_msg at ffffffffb88c7c31 #17 [ffffa6d14183fb50] netlink_rcv_skb at ffffffffb8942853 #18 [ffffa6d14183fbc0] rtnetlink_rcv at ffffffffb88c1835 #19 [ffffa6d14183fbd0] netlink_unicast at ffffffffb8941f27 #20 [ffffa6d14183fc18] netlink_sendmsg at ffffffffb8942245 #21 [ffffa6d14183fc98] sock_sendmsg at ffffffffb887d482 #22 [ffffa6d14183fcb8] ____sys_sendmsg at ffffffffb887d81a #23 [ffffa6d14183fd38] ___sys_sendmsg at ffffffffb88806e2 #24 [ffffa6d14183fe90] __sys_sendmsg at ffffffffb88807a2 #25 [ffffa6d14183ff28] __x64_sys_sendmsg at ffffffffb888080f #26 [ffffa6d14183ff38] do_syscall_64 at ffffffffb8b9b6a8 #27 [ffffa6d14183ff50] entry_SYSCALL_64_after_hwframe at ffffffffb8c0007c crash> bt 0xffff8aeb07544000 PID: 1110766 TASK: ffff8aeb07544000 CPU: 0 COMMAND: "kworker/u20:9" #0 [ffffa6d14e6b7bd8] __schedule at ffffffffb8ba7f45 #1 [ffffa6d14e6b7c68] schedule at ffffffffb8ba8418 #2 [ffffa6d14e6b7c88] schedule_timeout at ffffffffb8baef88 #3 [ffffa6d14e6b7d10] wait_for_completion at ffffffffb8ba968b #4 [ffffa6d14e6b7d60] mlx5e_take_all_encap_flows at ffffffffc0f47ec4 [mlx5_core] #5 [ffffa6d14e6b7da0] mlx5e_rep_update_flows at ffffffffc0f3e734 [mlx5_core] #6 [ffffa6d14e6b7df8] mlx5e_rep_neigh_update at ffffffffc0f400bb [mlx5_core] #7 [ffffa6d14e6b7e50] process_one_work at ffffffffb80acc9c #8 [ffffa6d14e6b7ed0] worker_thread at ffffffffb80ad012 #9 [ffffa6d14e6b7f10] kthread at ffffffffb80b615d #10 [ffffa6d14e6b7f50] ret_from_fork at ffffffffb8001b2f After the first encap is attached, flow will be added to encap entry's flows list. If neigh update is running at this time, the following encaps of the flow can't hold the encap_tbl_lock and sleep. If neigh update thread is waiting for that flow's init_done, deadlock happens. Fix it by holding lock outside of the for loop. If neigh update is running, prevent encap flows from offloading. Since the lock is held outside of the for loop, concurrent creation of encap entries is not allowed. So remove unnecessary wait_for_completion call for res_ready. Fixes: 95435ad ("net/mlx5e: Only access fully initialized flows in neigh update") Signed-off-by: Chris Mi <cmi@nvidia.com> Reviewed-by: Roi Dayan <roid@nvidia.com> Reviewed-by: Vlad Buslov <vladbu@nvidia.com> Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
esmil pushed a commit
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Jun 20, 2023
Currently, the per cpu upcall counters are allocated after the vport is created and inserted into the system. This could lead to the datapath accessing the counters before they are allocated resulting in a kernel Oops. Here is an example: PID: 59693 TASK: ffff0005f4f51500 CPU: 0 COMMAND: "ovs-vswitchd" #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4 #1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc #2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60 #3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58 #4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388 #5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c #6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68 #7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch] ... PID: 58682 TASK: ffff0005b2f0bf00 CPU: 0 COMMAND: "kworker/0:3" #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758 #1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994 #2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8 #3 [ffff80000a5d3120] die at ffffb70f0628234c #4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8 #5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4 #6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4 #7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710 #8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74 #9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac #10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24 #11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc #12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch] #13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch] #14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch] #15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch] #16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch] #17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90 We moved the per cpu upcall counter allocation to the existing vport alloc and free functions to solve this. Fixes: 95637d9 ("net: openvswitch: release vport resources on failure") Fixes: 1933ea3 ("net: openvswitch: Add support to count upcall packets") Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Aaron Conole <aconole@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
esmil pushed a commit
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Sep 20, 2023
[ Upstream commit 17e8e5d ] Alexei reported: After fast forwarding bpf-next today bpf_nf test started to fail when run twice: $ ./test_progs -t bpf_nf #17 bpf_nf:OK Summary: 1/10 PASSED, 0 SKIPPED, 0 FAILED $ ./test_progs -t bpf_nf All error logs: test_bpf_nf_ct:PASS:test_bpf_nf__open_and_load 0 nsec test_bpf_nf_ct:PASS:iptables-legacy -t raw -A PREROUTING -j CONNMARK --set-mark 42/0 0 nsec (network_helpers.c:102: errno: Address already in use) Failed to bind socket test_bpf_nf_ct:FAIL:start_server unexpected start_server: actual -1 < expected 0 #17/1 bpf_nf/xdp-ct:FAIL test_bpf_nf_ct:PASS:test_bpf_nf__open_and_load 0 nsec test_bpf_nf_ct:PASS:iptables-legacy -t raw -A PREROUTING -j CONNMARK --set-mark 42/0 0 nsec (network_helpers.c:102: errno: Address already in use) Failed to bind socket test_bpf_nf_ct:FAIL:start_server unexpected start_server: actual -1 < expected 0 #17/2 bpf_nf/tc-bpf-ct:FAIL #17 bpf_nf:FAIL Summary: 0/8 PASSED, 0 SKIPPED, 1 FAILED I was able to locally reproduce as well. Rearrange the connection teardown so that the client closes its connection first so that we don't need to linger in TCP time-wait. Fixes: e81fbd4 ("selftests/bpf: Add existing connection bpf_*_ct_lookup() test") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/CAADnVQ+0dnDq_v_vH1EfkacbfGnHANaon7zsw10pMb-D9FS0Pw@mail.gmail.com Link: https://lore.kernel.org/bpf/20230626131942.5100-1-daniel@iogearbox.net Signed-off-by: Sasha Levin <sashal@kernel.org>
esmil pushed a commit
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Sep 26, 2023
commit 0b0747d upstream. The following processes run into a deadlock. CPU 41 was waiting for CPU 29 to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29 was hung by that spinlock with IRQs disabled. PID: 17360 TASK: ffff95c1090c5c40 CPU: 41 COMMAND: "mrdiagd" !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0 !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0 !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0 # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0 # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0 # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0 # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0 # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0 # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0 # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0 #10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0 #11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0 #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0 #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0 #14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0 #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0 #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0 #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0 #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0 #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0 #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0 #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0 #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0 #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0 #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0 #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0 #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0 #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0 PID: 17355 TASK: ffff95c1090c3d80 CPU: 29 COMMAND: "mrdiagd" !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0 !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0 # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0 # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0 # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0 # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0 # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0 # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0 # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0 # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0 #10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0 #11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0 #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0 #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0 #14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0 #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0 #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0 #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0 The lock is used to synchronize different sysfs operations, it doesn't protect any resource that will be touched by an interrupt. Consequently it's not required to disable IRQs. Replace the spinlock with a mutex to fix the deadlock. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Link: https://lore.kernel.org/r/20230828221018.19471-1-junxiao.bi@oracle.com Reviewed-by: Mike Christie <michael.christie@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
esmil pushed a commit
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Oct 13, 2023
Fix an error detected by memory sanitizer: ``` ==4033==WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x55fb0fbedfc7 in read_alias_info tools/perf/util/pmu.c:457:6 #1 0x55fb0fbea339 in check_info_data tools/perf/util/pmu.c:1434:2 #2 0x55fb0fbea339 in perf_pmu__check_alias tools/perf/util/pmu.c:1504:9 #3 0x55fb0fbdca85 in parse_events_add_pmu tools/perf/util/parse-events.c:1429:32 #4 0x55fb0f965230 in parse_events_parse tools/perf/util/parse-events.y:299:6 #5 0x55fb0fbdf6b2 in parse_events__scanner tools/perf/util/parse-events.c:1822:8 #6 0x55fb0fbdf8c1 in __parse_events tools/perf/util/parse-events.c:2094:8 #7 0x55fb0fa8ffa9 in parse_events tools/perf/util/parse-events.h:41:9 #8 0x55fb0fa8ffa9 in test_event tools/perf/tests/parse-events.c:2393:8 #9 0x55fb0fa8f458 in test__pmu_events tools/perf/tests/parse-events.c:2551:15 #10 0x55fb0fa6d93f in run_test tools/perf/tests/builtin-test.c:242:9 #11 0x55fb0fa6d93f in test_and_print tools/perf/tests/builtin-test.c:271:8 #12 0x55fb0fa6d082 in __cmd_test tools/perf/tests/builtin-test.c:442:5 #13 0x55fb0fa6d082 in cmd_test tools/perf/tests/builtin-test.c:564:9 #14 0x55fb0f942720 in run_builtin tools/perf/perf.c:322:11 #15 0x55fb0f942486 in handle_internal_command tools/perf/perf.c:375:8 #16 0x55fb0f941dab in run_argv tools/perf/perf.c:419:2 #17 0x55fb0f941dab in main tools/perf/perf.c:535:3 ``` Fixes: 7b723db ("perf pmu: Be lazy about loading event info files from sysfs") Signed-off-by: Ian Rogers <irogers@google.com> Cc: James Clark <james.clark@arm.com> Cc: Kan Liang <kan.liang@linux.intel.com> Link: https://lore.kernel.org/r/20230914022425.1489035-1-irogers@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org>
esmil pushed a commit
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Oct 13, 2023
The following call trace shows a deadlock issue due to recursive locking of mutex "device_mutex". First lock acquire is in target_for_each_device() and second in target_free_device(). PID: 148266 TASK: ffff8be21ffb5d00 CPU: 10 COMMAND: "iscsi_ttx" #0 [ffffa2bfc9ec3b18] __schedule at ffffffffa8060e7f #1 [ffffa2bfc9ec3ba0] schedule at ffffffffa8061224 #2 [ffffa2bfc9ec3bb8] schedule_preempt_disabled at ffffffffa80615ee #3 [ffffa2bfc9ec3bc8] __mutex_lock at ffffffffa8062fd7 #4 [ffffa2bfc9ec3c40] __mutex_lock_slowpath at ffffffffa80631d3 #5 [ffffa2bfc9ec3c50] mutex_lock at ffffffffa806320c #6 [ffffa2bfc9ec3c68] target_free_device at ffffffffc0935998 [target_core_mod] #7 [ffffa2bfc9ec3c90] target_core_dev_release at ffffffffc092f975 [target_core_mod] #8 [ffffa2bfc9ec3ca0] config_item_put at ffffffffa79d250f #9 [ffffa2bfc9ec3cd0] config_item_put at ffffffffa79d2583 #10 [ffffa2bfc9ec3ce0] target_devices_idr_iter at ffffffffc0933f3a [target_core_mod] #11 [ffffa2bfc9ec3d00] idr_for_each at ffffffffa803f6fc #12 [ffffa2bfc9ec3d60] target_for_each_device at ffffffffc0935670 [target_core_mod] #13 [ffffa2bfc9ec3d98] transport_deregister_session at ffffffffc0946408 [target_core_mod] #14 [ffffa2bfc9ec3dc8] iscsit_close_session at ffffffffc09a44a6 [iscsi_target_mod] #15 [ffffa2bfc9ec3df0] iscsit_close_connection at ffffffffc09a4a88 [iscsi_target_mod] #16 [ffffa2bfc9ec3df8] finish_task_switch at ffffffffa76e5d07 #17 [ffffa2bfc9ec3e78] iscsit_take_action_for_connection_exit at ffffffffc0991c23 [iscsi_target_mod] #18 [ffffa2bfc9ec3ea0] iscsi_target_tx_thread at ffffffffc09a403b [iscsi_target_mod] #19 [ffffa2bfc9ec3f08] kthread at ffffffffa76d8080 #20 [ffffa2bfc9ec3f50] ret_from_fork at ffffffffa8200364 Fixes: 36d4cb4 ("scsi: target: Avoid that EXTENDED COPY commands trigger lock inversion") Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Link: https://lore.kernel.org/r/20230918225848.66463-1-junxiao.bi@oracle.com Reviewed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
esmil pushed a commit
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Dec 11, 2023
When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be dereferenced as wrong struct in irdma_free_pending_cqp_request(). PID: 3669 TASK: ffff88aef892c000 CPU: 28 COMMAND: "kworker/28:0" #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34 #1 [fffffe0000549e40] nmi_handle at ffffffff810788b2 #2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f #3 [fffffe0000549eb8] do_nmi at ffffffff81079582 #4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4 [exception RIP: native_queued_spin_lock_slowpath+1291] RIP: ffffffff8127e72b RSP: ffff88aa841ef778 RFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88b01f849700 RCX: ffffffff8127e47e RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff83857ec0 RBP: ffff88afe3e4efc8 R8: ffffed15fc7c9dfa R9: ffffed15fc7c9dfa R10: 0000000000000001 R11: ffffed15fc7c9df9 R12: 0000000000740000 R13: ffff88b01f849708 R14: 0000000000000003 R15: ffffed1603f092e1 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0000 -- <NMI exception stack> -- #5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b #6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4 #7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363 #8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma] #9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma] #10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma] #11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma] #12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb #13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6 #14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278 #15 [ffff88aa841efb88] device_del at ffffffff82179d23 #16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice] #17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice] #18 [ffff88aa841efde8] process_one_work at ffffffff811c589a #19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff #20 [ffff88aa841eff10] kthread at ffffffff811d87a0 #21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions") Link: https://lore.kernel.org/r/20231130081415.891006-1-lishifeng@sangfor.com.cn Suggested-by: "Ismail, Mustafa" <mustafa.ismail@intel.com> Signed-off-by: Shifeng Li <lishifeng@sangfor.com.cn> Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
esmil pushed a commit
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Feb 21, 2024
Test runners on debug kernels occasionally fail with: # # RUN tls_err.13_aes_gcm.poll_partial_rec_async ... # # tls.c:1883:poll_partial_rec_async:Expected poll(&pfd, 1, 5) (0) == 1 (1) # # tls.c:1870:poll_partial_rec_async:Expected status (256) == 0 (0) # # poll_partial_rec_async: Test failed at step #17 # # FAIL tls_err.13_aes_gcm.poll_partial_rec_async # not ok 699 tls_err.13_aes_gcm.poll_partial_rec_async # # FAILED: 698 / 699 tests passed. This points to the second poll() in the test which is expected to wait for the sender to send the rest of the data. Apparently under some conditions that doesn't happen within 5ms, bump the timeout to 20ms. Fixes: 23fcb62 ("selftests: tls: add tests for poll behavior") Link: https://lore.kernel.org/r/20240213142055.395564-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
esmil pushed a commit
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Sep 25, 2024
A sysfs reader can race with a device reset or removal, attempting to read device state when the device is not actually present. eg: [exception RIP: qed_get_current_link+17] #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede] #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb crash> struct net_device.state ffff9a9d21336000 state = 5, state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100). The device is not present, note lack of __LINK_STATE_PRESENT (0b10). This is the same sort of panic as observed in commit 4224cfd ("net-sysfs: add check for netdevice being present to speed_show"). There are many other callers of __ethtool_get_link_ksettings() which don't have a device presence check. Move this check into ethtool to protect all callers. Fixes: d519e17 ("net: export device speed and duplex via sysfs") Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show") Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com> Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
esmil pushed a commit
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Feb 17, 2025
…O write After commit ac325fc ("btrfs: do not hold the extent lock for entire read") we can now trigger a race between a task doing a direct IO write and readahead. When this race is triggered it results in tasks getting stale data when they attempt do a buffered read (including the task that did the direct IO write). This race can be sporadically triggered with test case generic/418, failing like this: $ ./check generic/418 FSTYP -- btrfs PLATFORM -- Linux/x86_64 debian0 6.13.0-rc7-btrfs-next-185+ #17 SMP PREEMPT_DYNAMIC Mon Feb 3 12:28:46 WET 2025 MKFS_OPTIONS -- /dev/sdc MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1 generic/418 14s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//generic/418.out.bad) --- tests/generic/418.out 2020-06-10 19:29:03.850519863 +0100 +++ /home/fdmanana/git/hub/xfstests/results//generic/418.out.bad 2025-02-03 15:42:36.974609476 +0000 @@ -1,2 +1,5 @@ QA output created by 418 +cmpbuf: offset 0: Expected: 0x1, got 0x0 +[6:0] FAIL - comparison failed, offset 24576 +diotest -wp -b 4096 -n 8 -i 4 failed at loop 3 Silence is golden ... (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/generic/418.out /home/fdmanana/git/hub/xfstests/results//generic/418.out.bad' to see the entire diff) Ran: generic/418 Failures: generic/418 Failed 1 of 1 tests The race happens like this: 1) A file has a prealloc extent for the range [16K, 28K); 2) Task A starts a direct IO write against file range [24K, 28K). At the start of the direct IO write it invalidates the page cache at __iomap_dio_rw() with kiocb_invalidate_pages() for the 4K page at file offset 24K; 3) Task A enters btrfs_dio_iomap_begin() and locks the extent range [24K, 28K); 4) Task B starts a readahead for file range [16K, 28K), entering btrfs_readahead(). First it attempts to read the page at offset 16K by entering btrfs_do_readpage(), where it calls get_extent_map(), locks the range [16K, 20K) and gets the extent map for the range [16K, 28K), caching it into the 'em_cached' variable declared in the local stack of btrfs_readahead(), and then unlocks the range [16K, 20K). Since the extent map has the prealloc flag, at btrfs_do_readpage() we zero out the page's content and don't submit any bio to read the page from the extent. Then it attempts to read the page at offset 20K entering btrfs_do_readpage() where we reuse the previously cached extent map (decided by get_extent_map()) since it spans the page's range and it's still in the inode's extent map tree. Just like for the previous page, we zero out the page's content since the extent map has the prealloc flag set. Then it attempts to read the page at offset 24K entering btrfs_do_readpage() where we reuse the previously cached extent map (decided by get_extent_map()) since it spans the page's range and it's still in the inode's extent map tree. Just like for the previous pages, we zero out the page's content since the extent map has the prealloc flag set. Note that we didn't lock the extent range [24K, 28K), so we didn't synchronize with the ongoing direct IO write being performed by task A; 5) Task A enters btrfs_create_dio_extent() and creates an ordered extent for the range [24K, 28K), with the flags BTRFS_ORDERED_DIRECT and BTRFS_ORDERED_PREALLOC set; 6) Task A unlocks the range [24K, 28K) at btrfs_dio_iomap_begin(); 7) The ordered extent enters btrfs_finish_one_ordered() and locks the range [24K, 28K); 8) Task A enters fs/iomap/direct-io.c:iomap_dio_complete() and it tries to invalidate the page at offset 24K by calling kiocb_invalidate_post_direct_write(), resulting in a call chain that ends up at btrfs_release_folio(). The btrfs_release_folio() call ends up returning false because the range for the page at file offset 24K is currently locked by the task doing the ordered extent completion in the previous step (7), so we have: btrfs_release_folio() -> __btrfs_release_folio() -> try_release_extent_mapping() -> try_release_extent_state() This last function checking that the range is locked and returning false and propagating it up to btrfs_release_folio(). So this results in a failure to invalidate the page and kiocb_invalidate_post_direct_write() triggers this message logged in dmesg: Page cache invalidation failure on direct I/O. Possible data corruption due to collision with buffered I/O! After this we leave the page cache with stale data for the file range [24K, 28K), filled with zeroes instead of the data written by direct IO write (all bytes with a 0x01 value), so any task attempting to read with buffered IO, including the task that did the direct IO write, will get all bytes in the range with a 0x00 value instead of the written data. Fix this by locking the range, with btrfs_lock_and_flush_ordered_range(), at the two callers of btrfs_do_readpage() instead of doing it at get_extent_map(), just like we did before commit ac325fc ("btrfs: do not hold the extent lock for entire read"), and unlocking the range after all the calls to btrfs_do_readpage(). This way we never reuse a cached extent map without flushing any pending ordered extents from a concurrent direct IO write. Fixes: ac325fc ("btrfs: do not hold the extent lock for entire read") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
esmil pushed a commit
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Feb 17, 2025
At btrfs_write_check() if our file's i_size is not sector size aligned and
we have a write that starts at an offset larger than the i_size that falls
within the same page of the i_size, then we end up not zeroing the file
range [i_size, write_offset).
The code is this:
start_pos = round_down(pos, fs_info->sectorsize);
oldsize = i_size_read(inode);
if (start_pos > oldsize) {
/* Expand hole size to cover write data, preventing empty gap */
loff_t end_pos = round_up(pos + count, fs_info->sectorsize);
ret = btrfs_cont_expand(BTRFS_I(inode), oldsize, end_pos);
if (ret)
return ret;
}
So if our file's i_size is 90269 bytes and a write at offset 90365 bytes
comes in, we get 'start_pos' set to 90112 bytes, which is less than the
i_size and therefore we don't zero out the range [90269, 90365) by
calling btrfs_cont_expand().
This is an old bug introduced in commit 9036c10 ("Btrfs: update hole
handling v2"), from 2008, and the buggy code got moved around over the
years.
Fix this by discarding 'start_pos' and comparing against the write offset
('pos') without any alignment.
This bug was recently exposed by test case generic/363 which tests this
scenario by polluting ranges beyond EOF with an mmap write and than verify
that after a file increases we get zeroes for the range which is supposed
to be a hole and not what we wrote with the previous mmaped write.
We're only seeing this exposed now because generic/363 used to run only
on xfs until last Sunday's fstests update.
The test was failing like this:
$ ./check generic/363
FSTYP -- btrfs
PLATFORM -- Linux/x86_64 debian0 6.13.0-rc7-btrfs-next-185+ #17 SMP PREEMPT_DYNAMIC Mon Feb 3 12:28:46 WET 2025
MKFS_OPTIONS -- /dev/sdc
MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1
generic/363 0s ... [failed, exit status 1]- output mismatch (see /home/fdmanana/git/hub/xfstests/results//generic/363.out.bad)
--- tests/generic/363.out 2025-02-05 15:31:14.013646509 +0000
+++ /home/fdmanana/git/hub/xfstests/results//generic/363.out.bad 2025-02-05 17:25:33.112630781 +0000
@@ -1 +1,46 @@
QA output created by 363
+READ BAD DATA: offset = 0xdcad, size = 0xd921, fname = /home/fdmanana/btrfs-tests/dev/junk
+OFFSET GOOD BAD RANGE
+0x1609d 0x0000 0x3104 0x0
+operation# (mod 256) for the bad data may be 4
+0x1609e 0x0000 0x0472 0x1
+operation# (mod 256) for the bad data may be 4
...
(Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/generic/363.out /home/fdmanana/git/hub/xfstests/results//generic/363.out.bad' to see the entire diff)
Ran: generic/363
Failures: generic/363
Failed 1 of 1 tests
Fixes: 9036c10 ("Btrfs: update hole handling v2")
CC: stable@vger.kernel.org
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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