user/sven/linux.git/kernel, branch v6.1.23

tracing: Fix wrong return in kprobe_event_gen_test.c

2023-04-06T10:10:41Z

[ Upstream commit bc4f359b3b607daac0290d0038561237a86b38cb ] Overwriting the error code with the deletion result may cause the function to return 0 despite encountering an error. Commit b111545d26c0 ("tracing: Remove the useless value assignment in test_create_synth_event()") solves a similar issue by returning the original error code, so this patch does the same. Found by Linux Verification Center (linuxtesting.org) with SVACE. Link: https://lore.kernel.org/linux-trace-kernel/20230131075818.5322-1-aagusev@ispras.ru Signed-off-by: Anton Gusev Reviewed-by: Steven Rostedt (Google) Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin

sched_getaffinity: don't assume 'cpumask_size()' is fully initialized

2023-04-06T10:10:40Z

[ Upstream commit 6015b1aca1a233379625385feb01dd014aca60b5 ] The getaffinity() system call uses 'cpumask_size()' to decide how big the CPU mask is - so far so good. It is indeed the allocation size of a cpumask. But the code also assumes that the whole allocation is initialized without actually doing so itself. That's wrong, because we might have fixed-size allocations (making copying and clearing more efficient), but not all of it is then necessarily used if 'nr_cpu_ids' is smaller. Having checked other users of 'cpumask_size()', they all seem to be ok, either using it purely for the allocation size, or explicitly zeroing the cpumask before using the size in bytes to copy it. See for example the ublk_ctrl_get_queue_affinity() function that uses the proper 'zalloc_cpumask_var()' to make sure that the whole mask is cleared, whether the storage is on the stack or if it was an external allocation. Fix this by just zeroing the allocation before using it. Do the same for the compat version of sched_getaffinity(), which had the same logic. Also, for consistency, make sched_getaffinity() use 'cpumask_bits()' to access the bits. For a cpumask_var_t, it ends up being a pointer to the same data either way, but it's just a good idea to treat it like you would a 'cpumask_t'. The compat case already did that. Reported-by: Ryan Roberts Link: https://lore.kernel.org/lkml/7d026744-6bd6-6827-0471-b5e8eae0be3f@arm.com/ Cc: Yury Norov Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

tracing: Do not let histogram values have some modifiers

2023-04-06T10:10:36Z

[ Upstream commit e0213434fe3e4a0d118923dc98d31e7ff1cd9e45 ] Histogram values can not be strings, stacktraces, graphs, symbols, syscalls, or grouped in buckets or log. Give an error if a value is set to do so. Note, the histogram code was not prepared to handle these modifiers for histograms and caused a bug. Mark Rutland reported: # echo 'p:copy_to_user __arch_copy_to_user n=$arg2' >> /sys/kernel/tracing/kprobe_events # echo 'hist:keys=n:vals=hitcount.buckets=8:sort=hitcount' > /sys/kernel/tracing/events/kprobes/copy_to_user/trigger # cat /sys/kernel/tracing/events/kprobes/copy_to_user/hist [ 143.694628] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 143.695190] Mem abort info: [ 143.695362] ESR = 0x0000000096000004 [ 143.695604] EC = 0x25: DABT (current EL), IL = 32 bits [ 143.695889] SET = 0, FnV = 0 [ 143.696077] EA = 0, S1PTW = 0 [ 143.696302] FSC = 0x04: level 0 translation fault [ 143.702381] Data abort info: [ 143.702614] ISV = 0, ISS = 0x00000004 [ 143.702832] CM = 0, WnR = 0 [ 143.703087] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000448f9000 [ 143.703407] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 [ 143.704137] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 143.704714] Modules linked in: [ 143.705273] CPU: 0 PID: 133 Comm: cat Not tainted 6.2.0-00003-g6fc512c10a7c #3 [ 143.706138] Hardware name: linux,dummy-virt (DT) [ 143.706723] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 143.707120] pc : hist_field_name.part.0+0x14/0x140 [ 143.707504] lr : hist_field_name.part.0+0x104/0x140 [ 143.707774] sp : ffff800008333a30 [ 143.707952] x29: ffff800008333a30 x28: 0000000000000001 x27: 0000000000400cc0 [ 143.708429] x26: ffffd7a653b20260 x25: 0000000000000000 x24: ffff10d303ee5800 [ 143.708776] x23: ffffd7a6539b27b0 x22: ffff10d303fb8c00 x21: 0000000000000001 [ 143.709127] x20: ffff10d303ec2000 x19: 0000000000000000 x18: 0000000000000000 [ 143.709478] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 143.709824] x14: 0000000000000000 x13: 203a6f666e692072 x12: 6567676972742023 [ 143.710179] x11: 0a230a6d6172676f x10: 000000000000002c x9 : ffffd7a6521e018c [ 143.710584] x8 : 000000000000002c x7 : 7f7f7f7f7f7f7f7f x6 : 000000000000002c [ 143.710915] x5 : ffff10d303b0103e x4 : ffffd7a653b20261 x3 : 000000000000003d [ 143.711239] x2 : 0000000000020001 x1 : 0000000000000001 x0 : 0000000000000000 [ 143.711746] Call trace: [ 143.712115] hist_field_name.part.0+0x14/0x140 [ 143.712642] hist_field_name.part.0+0x104/0x140 [ 143.712925] hist_field_print+0x28/0x140 [ 143.713125] event_hist_trigger_print+0x174/0x4d0 [ 143.713348] hist_show+0xf8/0x980 [ 143.713521] seq_read_iter+0x1bc/0x4b0 [ 143.713711] seq_read+0x8c/0xc4 [ 143.713876] vfs_read+0xc8/0x2a4 [ 143.714043] ksys_read+0x70/0xfc [ 143.714218] __arm64_sys_read+0x24/0x30 [ 143.714400] invoke_syscall+0x50/0x120 [ 143.714587] el0_svc_common.constprop.0+0x4c/0x100 [ 143.714807] do_el0_svc+0x44/0xd0 [ 143.714970] el0_svc+0x2c/0x84 [ 143.715134] el0t_64_sync_handler+0xbc/0x140 [ 143.715334] el0t_64_sync+0x190/0x194 [ 143.715742] Code: a9bd7bfd 910003fd a90153f3 aa0003f3 (f9400000) [ 143.716510] ---[ end trace 0000000000000000 ]--- Segmentation fault Link: https://lkml.kernel.org/r/20230302020810.559462599@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Andrew Morton Fixes: c6afad49d127f ("tracing: Add hist trigger 'sym' and 'sym-offset' modifiers") Reported-by: Mark Rutland Tested-by: Mark Rutland Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin

tracing: Add .graph suffix option to histogram value

2023-04-06T10:10:36Z

[ Upstream commit a2c54256dec7510477e2b4f4db187e638f7cac37 ] Add the .graph suffix which shows the bar graph of the histogram value. For example, the below example shows that the bar graph of the histogram of the runtime for each tasks. ------ # cd /sys/kernel/debug/tracing/ # echo hist:keys=pid:vals=runtime.graph:sort=pid > \ events/sched/sched_stat_runtime/trigger # sleep 10 # cat events/sched/sched_stat_runtime/hist # event histogram # # trigger info: hist:keys=pid:vals=hitcount,runtime.graph:sort=pid:size=2048 [active] # { pid: 14 } hitcount: 2 runtime: { pid: 16 } hitcount: 8 runtime: { pid: 26 } hitcount: 1 runtime: { pid: 57 } hitcount: 3 runtime: { pid: 61 } hitcount: 20 runtime: ### { pid: 66 } hitcount: 2 runtime: { pid: 70 } hitcount: 3 runtime: { pid: 72 } hitcount: 2 runtime: { pid: 145 } hitcount: 14 runtime: #################### { pid: 152 } hitcount: 5 runtime: ####### { pid: 153 } hitcount: 2 runtime: #### Totals: Hits: 62 Entries: 11 Dropped: 0 ------- Link: https://lore.kernel.org/linux-trace-kernel/166610813953.56030.10944148382315789485.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Tom Zanussi Tested-by: Tom Zanussi Stable-dep-of: e0213434fe3e ("tracing: Do not let histogram values have some modifiers") Signed-off-by: Sasha Levin

tracing: Add .percent suffix option to histogram values

2023-04-06T10:10:36Z

[ Upstream commit abaa5258ce5e5887a9de049f50a85dc023391a1c ] Add .percent suffix option to show the histogram values in percentage. This feature is useful when we need yo undersntand the overall trend for the histograms of large values. E.g. this shows the runtime percentage for each tasks. ------ # cd /sys/kernel/debug/tracing/ # echo hist:keys=pid:vals=hitcount,runtime.percent:sort=pid > \ events/sched/sched_stat_runtime/trigger # sleep 10 # cat events/sched/sched_stat_runtime/hist # event histogram # # trigger info: hist:keys=pid:vals=hitcount,runtime.percent:sort=pid:size=2048 [active] # { pid: 8 } hitcount: 7 runtime (%): 4.14 { pid: 14 } hitcount: 5 runtime (%): 3.69 { pid: 16 } hitcount: 11 runtime (%): 3.41 { pid: 61 } hitcount: 41 runtime (%): 19.75 { pid: 65 } hitcount: 4 runtime (%): 1.48 { pid: 70 } hitcount: 6 runtime (%): 3.60 { pid: 72 } hitcount: 2 runtime (%): 1.10 { pid: 144 } hitcount: 10 runtime (%): 32.01 { pid: 151 } hitcount: 8 runtime (%): 22.66 { pid: 152 } hitcount: 2 runtime (%): 8.10 Totals: Hits: 96 Entries: 10 Dropped: 0 ----- Link: https://lore.kernel.org/linux-trace-kernel/166610813077.56030.4238090506973562347.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) Reviewed-by: Tom Zanussi Tested-by: Tom Zanussi Stable-dep-of: e0213434fe3e ("tracing: Do not let histogram values have some modifiers") Signed-off-by: Sasha Levin

kcsan: avoid passing -g for test

2023-04-06T10:10:35Z

[ Upstream commit 5eb39cde1e2487ba5ec1802dc5e58a77e700d99e ] Nathan reported that when building with GNU as and a version of clang that defaults to DWARF5, the assembler will complain with: Error: non-constant .uleb128 is not supported This is because `-g` defaults to the compiler debug info default. If the assembler does not support some of the directives used, the above errors occur. To fix, remove the explicit passing of `-g`. All the test wants is that stack traces print valid function names, and debug info is not required for that. (I currently cannot recall why I added the explicit `-g`.) Link: https://lkml.kernel.org/r/20230316224705.709984-2-elver@google.com Fixes: 1fe84fd4a402 ("kcsan: Add test suite") Signed-off-by: Marco Elver Reported-by: Nathan Chancellor Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

kernel: kcsan: kcsan_test: build without structleak plugin

2023-04-06T10:10:34Z

[ Upstream commit 6fcd4267a840d0536b8e5334ad5f31e4105fce85 ] Building kcsan_test with structleak plugin enabled makes the stack frame size to grow. kernel/kcsan/kcsan_test.c:704:1: error: the frame size of 3296 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] Turn off the structleak plugin checks for kcsan_test. Link: https://lkml.kernel.org/r/20221128104358.2660634-1-anders.roxell@linaro.org Signed-off-by: Anders Roxell Suggested-by: Arnd Bergmann Acked-by: Marco Elver Cc: Arnd Bergmann Cc: David Gow Cc: Jason A. Donenfeld Cc: Kees Cook Signed-off-by: Andrew Morton Stable-dep-of: 5eb39cde1e24 ("kcsan: avoid passing -g for test") Signed-off-by: Sasha Levin

sched/fair: Sanitize vruntime of entity being migrated

2023-03-30T10:49:30Z

commit a53ce18cacb477dd0513c607f187d16f0fa96f71 upstream. Commit 829c1651e9c4 ("sched/fair: sanitize vruntime of entity being placed") fixes an overflowing bug, but ignore a case that se->exec_start is reset after a migration. For fixing this case, we delay the reset of se->exec_start after placing the entity which se->exec_start to detect long sleeping task. In order to take into account a possible divergence between the clock_task of 2 rqs, we increase the threshold to around 104 days. Fixes: 829c1651e9c4 ("sched/fair: sanitize vruntime of entity being placed") Originally-by: Zhang Qiao Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Tested-by: Zhang Qiao Link: https://lore.kernel.org/r/20230317160810.107988-1-vincent.guittot@linaro.org Signed-off-by: Greg Kroah-Hartman

sched/fair: sanitize vruntime of entity being placed

2023-03-30T10:49:30Z

commit 829c1651e9c4a6f78398d3e67651cef9bb6b42cc upstream. When a scheduling entity is placed onto cfs_rq, its vruntime is pulled to the base level (around cfs_rq->min_vruntime), so that the entity doesn't gain extra boost when placed backwards. However, if the entity being placed wasn't executed for a long time, its vruntime may get too far behind (e.g. while cfs_rq was executing a low-weight hog), which can inverse the vruntime comparison due to s64 overflow. This results in the entity being placed with its original vruntime way forwards, so that it will effectively never get to the cpu. To prevent that, ignore the vruntime of the entity being placed if it didn't execute for much longer than the characteristic sheduler time scale. [rkagan: formatted, adjusted commit log, comments, cutoff value] Signed-off-by: Zhang Qiao Co-developed-by: Roman Kagan Signed-off-by: Roman Kagan Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20230130122216.3555094-1-rkagan@amazon.de Signed-off-by: Greg Kroah-Hartman

entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-up

2023-03-30T10:49:13Z

[ Upstream commit b416514054810cf2d2cc348ae477cea619b64da7 ] RCU sometimes needs to perform a delayed wake up for specific kthreads handling offloaded callbacks (RCU_NOCB). These wakeups are performed by timers and upon entry to idle (also to guest and to user on nohz_full). However the delayed wake-up on kernel exit is actually performed after the thread flags are fetched towards the fast path check for work to do on exit to user. As a result, and if there is no other pending work to do upon that kernel exit, the current task will resume to userspace with TIF_RESCHED set and the pending wake up ignored. Fix this with fetching the thread flags _after_ the delayed RCU-nocb kthread wake-up. Fixes: 47b8ff194c1f ("entry: Explicitly flush pending rcuog wakeup before last rescheduling point") Signed-off-by: Frederic Weisbecker Signed-off-by: Paul E. McKenney Signed-off-by: Joel Fernandes (Google) Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20230315194349.10798-3-joel@joelfernandes.org Signed-off-by: Sasha Levin