Age | Commit message (Collapse) | Author | Files | Lines |
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Move the check if a jump_entry is valid to a function. No functional
change.
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris von Recklinghausen <crecklin@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Wood <swood@redhat.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/56b69bd3f8e644ed64f2dbde7c088030b8cbe76b.1560325897.git.bristot@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
"A set of small fixes:
- Repair the ktime_get_coarse() functions so they actually deliver
what they are supposed to: tick granular time stamps. The current
code missed to add the accumulated nanoseconds part of the
timekeeper so the resulting granularity was 1 second.
- Prevent the tracer from infinitely recursing into time getter
functions in the arm architectured timer by marking these functions
notrace
- Fix a trivial compiler warning caused by wrong qualifier ordering"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Repair ktime_get_coarse*() granularity
clocksource/drivers/arm_arch_timer: Don't trace count reader functions
clocksource/drivers/timer-ti-dm: Change to new style declaration
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
- Out of range read of stack trace output
- Fix for NULL pointer dereference in trace_uprobe_create()
- Fix to a livepatching / ftrace permission race in the module code
- Fix for NULL pointer dereference in free_ftrace_func_mapper()
- A couple of build warning clean ups
* tag 'trace-v5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Fix NULL pointer dereference in free_ftrace_func_mapper()
module: Fix livepatch/ftrace module text permissions race
tracing/uprobe: Fix obsolete comment on trace_uprobe_create()
tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create()
tracing: Make two symbols static
tracing: avoid build warning with HAVE_NOP_MCOUNT
tracing: Fix out-of-range read in trace_stack_print()
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
"This has an unusually high density of tricky fixes:
- task_get_css() could deadlock when it races against a dying cgroup.
- cgroup.procs didn't list thread group leaders with live threads.
This could mislead readers to think that a cgroup is empty when
it's not. Fixed by making PROCS iterator include dead tasks. I made
a couple mistakes making this change and this pull request contains
a couple follow-up patches.
- When cpusets run out of online cpus, it updates cpusmasks of member
tasks in bizarre ways. Joel improved the behavior significantly"
* 'for-5.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: restore sanity to cpuset_cpus_allowed_fallback()
cgroup: Fix css_task_iter_advance_css_set() cset skip condition
cgroup: css_task_iter_skip()'d iterators must be advanced before accessed
cgroup: Include dying leaders with live threads in PROCS iterations
cgroup: Implement css_task_iter_skip()
cgroup: Call cgroup_release() before __exit_signal()
docs cgroups: add another example size for hugetlb
cgroup: Use css_tryget() instead of css_tryget_online() in task_get_css()
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The mapper may be NULL when called from register_ftrace_function_probe()
with probe->data == NULL.
This issue can be reproduced as follow (it may be covered by compiler
optimization sometime):
/ # cat /sys/kernel/debug/tracing/set_ftrace_filter
#### all functions enabled ####
/ # echo foo_bar:dump > /sys/kernel/debug/tracing/set_ftrace_filter
[ 206.949100] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[ 206.952402] Mem abort info:
[ 206.952819] ESR = 0x96000006
[ 206.955326] Exception class = DABT (current EL), IL = 32 bits
[ 206.955844] SET = 0, FnV = 0
[ 206.956272] EA = 0, S1PTW = 0
[ 206.956652] Data abort info:
[ 206.957320] ISV = 0, ISS = 0x00000006
[ 206.959271] CM = 0, WnR = 0
[ 206.959938] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000419f3a000
[ 206.960483] [0000000000000000] pgd=0000000411a87003, pud=0000000411a83003, pmd=0000000000000000
[ 206.964953] Internal error: Oops: 96000006 [#1] SMP
[ 206.971122] Dumping ftrace buffer:
[ 206.973677] (ftrace buffer empty)
[ 206.975258] Modules linked in:
[ 206.976631] Process sh (pid: 281, stack limit = 0x(____ptrval____))
[ 206.978449] CPU: 10 PID: 281 Comm: sh Not tainted 5.2.0-rc1+ #17
[ 206.978955] Hardware name: linux,dummy-virt (DT)
[ 206.979883] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 206.980499] pc : free_ftrace_func_mapper+0x2c/0x118
[ 206.980874] lr : ftrace_count_free+0x68/0x80
[ 206.982539] sp : ffff0000182f3ab0
[ 206.983102] x29: ffff0000182f3ab0 x28: ffff8003d0ec1700
[ 206.983632] x27: ffff000013054b40 x26: 0000000000000001
[ 206.984000] x25: ffff00001385f000 x24: 0000000000000000
[ 206.984394] x23: ffff000013453000 x22: ffff000013054000
[ 206.984775] x21: 0000000000000000 x20: ffff00001385fe28
[ 206.986575] x19: ffff000013872c30 x18: 0000000000000000
[ 206.987111] x17: 0000000000000000 x16: 0000000000000000
[ 206.987491] x15: ffffffffffffffb0 x14: 0000000000000000
[ 206.987850] x13: 000000000017430e x12: 0000000000000580
[ 206.988251] x11: 0000000000000000 x10: cccccccccccccccc
[ 206.988740] x9 : 0000000000000000 x8 : ffff000013917550
[ 206.990198] x7 : ffff000012fac2e8 x6 : ffff000012fac000
[ 206.991008] x5 : ffff0000103da588 x4 : 0000000000000001
[ 206.991395] x3 : 0000000000000001 x2 : ffff000013872a28
[ 206.991771] x1 : 0000000000000000 x0 : 0000000000000000
[ 206.992557] Call trace:
[ 206.993101] free_ftrace_func_mapper+0x2c/0x118
[ 206.994827] ftrace_count_free+0x68/0x80
[ 206.995238] release_probe+0xfc/0x1d0
[ 206.995555] register_ftrace_function_probe+0x4a8/0x868
[ 206.995923] ftrace_trace_probe_callback.isra.4+0xb8/0x180
[ 206.996330] ftrace_dump_callback+0x50/0x70
[ 206.996663] ftrace_regex_write.isra.29+0x290/0x3a8
[ 206.997157] ftrace_filter_write+0x44/0x60
[ 206.998971] __vfs_write+0x64/0xf0
[ 206.999285] vfs_write+0x14c/0x2f0
[ 206.999591] ksys_write+0xbc/0x1b0
[ 206.999888] __arm64_sys_write+0x3c/0x58
[ 207.000246] el0_svc_common.constprop.0+0x408/0x5f0
[ 207.000607] el0_svc_handler+0x144/0x1c8
[ 207.000916] el0_svc+0x8/0xc
[ 207.003699] Code: aa0003f8 a9025bf5 aa0103f5 f946ea80 (f9400303)
[ 207.008388] ---[ end trace 7b6d11b5f542bdf1 ]---
[ 207.010126] Kernel panic - not syncing: Fatal exception
[ 207.011322] SMP: stopping secondary CPUs
[ 207.013956] Dumping ftrace buffer:
[ 207.014595] (ftrace buffer empty)
[ 207.015632] Kernel Offset: disabled
[ 207.017187] CPU features: 0x002,20006008
[ 207.017985] Memory Limit: none
[ 207.019825] ---[ end Kernel panic - not syncing: Fatal exception ]---
Link: http://lkml.kernel.org/r/20190606031754.10798-1-liwei391@huawei.com
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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It's possible for livepatch and ftrace to be toggling a module's text
permissions at the same time, resulting in the following panic:
BUG: unable to handle page fault for address: ffffffffc005b1d9
#PF: supervisor write access in kernel mode
#PF: error_code(0x0003) - permissions violation
PGD 3ea0c067 P4D 3ea0c067 PUD 3ea0e067 PMD 3cc13067 PTE 3b8a1061
Oops: 0003 [#1] PREEMPT SMP PTI
CPU: 1 PID: 453 Comm: insmod Tainted: G O K 5.2.0-rc1-a188339ca5 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-20181126_142135-anatol 04/01/2014
RIP: 0010:apply_relocate_add+0xbe/0x14c
Code: fa 0b 74 21 48 83 fa 18 74 38 48 83 fa 0a 75 40 eb 08 48 83 38 00 74 33 eb 53 83 38 00 75 4e 89 08 89 c8 eb 0a 83 38 00 75 43 <89> 08 48 63 c1 48 39 c8 74 2e eb 48 83 38 00 75 32 48 29 c1 89 08
RSP: 0018:ffffb223c00dbb10 EFLAGS: 00010246
RAX: ffffffffc005b1d9 RBX: 0000000000000000 RCX: ffffffff8b200060
RDX: 000000000000000b RSI: 0000004b0000000b RDI: ffff96bdfcd33000
RBP: ffffb223c00dbb38 R08: ffffffffc005d040 R09: ffffffffc005c1f0
R10: ffff96bdfcd33c40 R11: ffff96bdfcd33b80 R12: 0000000000000018
R13: ffffffffc005c1f0 R14: ffffffffc005e708 R15: ffffffff8b2fbc74
FS: 00007f5f447beba8(0000) GS:ffff96bdff900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffc005b1d9 CR3: 000000003cedc002 CR4: 0000000000360ea0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
klp_init_object_loaded+0x10f/0x219
? preempt_latency_start+0x21/0x57
klp_enable_patch+0x662/0x809
? virt_to_head_page+0x3a/0x3c
? kfree+0x8c/0x126
patch_init+0x2ed/0x1000 [livepatch_test02]
? 0xffffffffc0060000
do_one_initcall+0x9f/0x1c5
? kmem_cache_alloc_trace+0xc4/0xd4
? do_init_module+0x27/0x210
do_init_module+0x5f/0x210
load_module+0x1c41/0x2290
? fsnotify_path+0x3b/0x42
? strstarts+0x2b/0x2b
? kernel_read+0x58/0x65
__do_sys_finit_module+0x9f/0xc3
? __do_sys_finit_module+0x9f/0xc3
__x64_sys_finit_module+0x1a/0x1c
do_syscall_64+0x52/0x61
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The above panic occurs when loading two modules at the same time with
ftrace enabled, where at least one of the modules is a livepatch module:
CPU0 CPU1
klp_enable_patch()
klp_init_object_loaded()
module_disable_ro()
ftrace_module_enable()
ftrace_arch_code_modify_post_process()
set_all_modules_text_ro()
klp_write_object_relocations()
apply_relocate_add()
*patches read-only code* - BOOM
A similar race exists when toggling ftrace while loading a livepatch
module.
Fix it by ensuring that the livepatch and ftrace code patching
operations -- and their respective permissions changes -- are protected
by the text_mutex.
Link: http://lkml.kernel.org/r/ab43d56ab909469ac5d2520c5d944ad6d4abd476.1560474114.git.jpoimboe@redhat.com
Reported-by: Johannes Erdfelt <johannes@erdfelt.com>
Fixes: 444d13ff10fb ("modules: add ro_after_init support")
Acked-by: Jessica Yu <jeyu@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Commit 0597c49c69d5 ("tracing/uprobes: Use dyn_event framework for
uprobe events") cleaned up the usage of trace_uprobe_create(), and the
function has been no longer used for removing uprobe/uretprobe.
Link: http://lkml.kernel.org/r/20190614074026.8045-2-devel@etsukata.com
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Just like the case of commit 8b05a3a7503c ("tracing/kprobes: Fix NULL
pointer dereference in trace_kprobe_create()"), writing an incorrectly
formatted string to uprobe_events can trigger NULL pointer dereference.
Reporeducer:
# echo r > /sys/kernel/debug/tracing/uprobe_events
dmesg:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 8000000079d12067 P4D 8000000079d12067 PUD 7b7ab067 PMD 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 1903 Comm: bash Not tainted 5.2.0-rc3+ #15
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
RIP: 0010:strchr+0x0/0x30
Code: c0 eb 0d 84 c9 74 18 48 83 c0 01 48 39 d0 74 0f 0f b6 0c 07 3a 0c 06 74 ea 19 c0 83 c8 01 c3 31 c0 c3 0f 1f 84 00 00 00 00 00 <0f> b6 07 89 f2 40 38 f0 75 0e eb 13 0f b6 47 01 48 83 c
RSP: 0018:ffffb55fc0403d10 EFLAGS: 00010293
RAX: ffff993ffb793400 RBX: 0000000000000000 RCX: ffffffffa4852625
RDX: 0000000000000000 RSI: 000000000000002f RDI: 0000000000000000
RBP: ffffb55fc0403dd0 R08: ffff993ffb793400 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff993ff9cc1668 R14: 0000000000000001 R15: 0000000000000000
FS: 00007f30c5147700(0000) GS:ffff993ffda00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000007b628000 CR4: 00000000000006f0
Call Trace:
trace_uprobe_create+0xe6/0xb10
? __kmalloc_track_caller+0xe6/0x1c0
? __kmalloc+0xf0/0x1d0
? trace_uprobe_create+0xb10/0xb10
create_or_delete_trace_uprobe+0x35/0x90
? trace_uprobe_create+0xb10/0xb10
trace_run_command+0x9c/0xb0
trace_parse_run_command+0xf9/0x1eb
? probes_open+0x80/0x80
__vfs_write+0x43/0x90
vfs_write+0x14a/0x2a0
ksys_write+0xa2/0x170
do_syscall_64+0x7f/0x200
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Link: http://lkml.kernel.org/r/20190614074026.8045-1-devel@etsukata.com
Cc: stable@vger.kernel.org
Fixes: 0597c49c69d5 ("tracing/uprobes: Use dyn_event framework for uprobe events")
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Fix sparse warnings:
kernel/trace/trace.c:6927:24: warning:
symbol 'get_tracing_log_err' was not declared. Should it be static?
kernel/trace/trace.c:8196:15: warning:
symbol 'trace_instance_dir' was not declared. Should it be static?
Link: http://lkml.kernel.org/r/20190614153210.24424-1-yuehaibing@huawei.com
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Selecting HAVE_NOP_MCOUNT enables -mnop-mcount (if gcc supports it)
and sets CC_USING_NOP_MCOUNT. Reuse __is_defined (which is suitable for
testing CC_USING_* defines) to avoid conditional compilation and fix
the following gcc 9 warning on s390:
kernel/trace/ftrace.c:2514:1: warning: ‘ftrace_code_disable’ defined
but not used [-Wunused-function]
Link: http://lkml.kernel.org/r/patch.git-1a82d13f33ac.your-ad-here.call-01559732716-ext-6629@work.hours
Fixes: 2f4df0017baed ("tracing: Add -mcount-nop option support")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Puts range check before dereferencing the pointer.
Reproducer:
# echo stacktrace > trace_options
# echo 1 > events/enable
# cat trace > /dev/null
KASAN report:
==================================================================
BUG: KASAN: use-after-free in trace_stack_print+0x26b/0x2c0
Read of size 8 at addr ffff888069d20000 by task cat/1953
CPU: 0 PID: 1953 Comm: cat Not tainted 5.2.0-rc3+ #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
Call Trace:
dump_stack+0x8a/0xce
print_address_description+0x60/0x224
? trace_stack_print+0x26b/0x2c0
? trace_stack_print+0x26b/0x2c0
__kasan_report.cold+0x1a/0x3e
? trace_stack_print+0x26b/0x2c0
kasan_report+0xe/0x20
trace_stack_print+0x26b/0x2c0
print_trace_line+0x6ea/0x14d0
? tracing_buffers_read+0x700/0x700
? trace_find_next_entry_inc+0x158/0x1d0
s_show+0xea/0x310
seq_read+0xaa7/0x10e0
? seq_escape+0x230/0x230
__vfs_read+0x7c/0x100
vfs_read+0x16c/0x3a0
ksys_read+0x121/0x240
? kernel_write+0x110/0x110
? perf_trace_sys_enter+0x8a0/0x8a0
? syscall_slow_exit_work+0xa9/0x410
do_syscall_64+0xb7/0x390
? prepare_exit_to_usermode+0x165/0x200
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f867681f910
Code: b6 fe ff ff 48 8d 3d 0f be 08 00 48 83 ec 08 e8 06 db 01 00 66 0f 1f 44 00 00 83 3d f9 2d 2c 00 00 75 10 b8 00 00 00 00 04
RSP: 002b:00007ffdabf23488 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f867681f910
RDX: 0000000000020000 RSI: 00007f8676cde000 RDI: 0000000000000003
RBP: 00007f8676cde000 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000871 R11: 0000000000000246 R12: 00007f8676cde000
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000000ec0
Allocated by task 1214:
save_stack+0x1b/0x80
__kasan_kmalloc.constprop.0+0xc2/0xd0
kmem_cache_alloc+0xaf/0x1a0
getname_flags+0xd2/0x5b0
do_sys_open+0x277/0x5a0
do_syscall_64+0xb7/0x390
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Freed by task 1214:
save_stack+0x1b/0x80
__kasan_slab_free+0x12c/0x170
kmem_cache_free+0x8a/0x1c0
putname+0xe1/0x120
do_sys_open+0x2c5/0x5a0
do_syscall_64+0xb7/0x390
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The buggy address belongs to the object at ffff888069d20000
which belongs to the cache names_cache of size 4096
The buggy address is located 0 bytes inside of
4096-byte region [ffff888069d20000, ffff888069d21000)
The buggy address belongs to the page:
page:ffffea0001a74800 refcount:1 mapcount:0 mapping:ffff88806ccd1380 index:0x0 compound_mapcount: 0
flags: 0x100000000010200(slab|head)
raw: 0100000000010200 dead000000000100 dead000000000200 ffff88806ccd1380
raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888069d1ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888069d1ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888069d20000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888069d20080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888069d20100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Link: http://lkml.kernel.org/r/20190610040016.5598-1-devel@etsukata.com
Fixes: 4285f2fcef80 ("tracing: Remove the ULONG_MAX stack trace hackery")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Jason reported that the coarse ktime based time getters advance only once
per second and not once per tick as advertised.
The code reads only the monotonic base time, which advances once per
second. The nanoseconds are accumulated on every tick in xtime_nsec up to
a second and the regular time getters take this nanoseconds offset into
account, but the ktime_get_coarse*() implementation fails to do so.
Add the accumulated xtime_nsec value to the monotonic base time to get the
proper per tick advancing coarse tinme.
Fixes: b9ff604cff11 ("timekeeping: Add ktime_get_coarse_with_offset")
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Sultan Alsawaf <sultan@kerneltoast.com>
Cc: Waiman Long <longman@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1906132136280.1791@nanos.tec.linutronix.de
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Logan noticed that devm_memremap_pages_release() kills the percpu_ref
drops all the page references that were acquired at init and then
immediately proceeds to unplug, arch_remove_memory(), the backing pages
for the pagemap. If for some reason device shutdown actually collides
with a busy / elevated-ref-count page then arch_remove_memory() should
be deferred until after that reference is dropped.
As it stands the "wait for last page ref drop" happens *after*
devm_memremap_pages_release() returns, which is obviously too late and
can lead to crashes.
Fix this situation by assigning the responsibility to wait for the
percpu_ref to go idle to devm_memremap_pages() with a new ->cleanup()
callback. Implement the new cleanup callback for all
devm_memremap_pages() users: pmem, devdax, hmm, and p2pdma.
Link: http://lkml.kernel.org/r/155727339156.292046.5432007428235387859.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: 41e94a851304 ("add devm_memremap_pages")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Use the new devm_release_action() facility to allow
devm_memremap_pages_release() to be manually triggered.
Link: http://lkml.kernel.org/r/155727337088.292046.5774214552136776763.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
In the case that a process is constrained by taskset(1) (i.e.
sched_setaffinity(2)) to a subset of available cpus, and all of those are
subsequently offlined, the scheduler will set tsk->cpus_allowed to
the current value of task_cs(tsk)->effective_cpus.
This is done via a call to do_set_cpus_allowed() in the context of
cpuset_cpus_allowed_fallback() made by the scheduler when this case is
detected. This is the only call made to cpuset_cpus_allowed_fallback()
in the latest mainline kernel.
However, this is not sane behavior.
I will demonstrate this on a system running the latest upstream kernel
with the following initial configuration:
# grep -i cpu /proc/$$/status
Cpus_allowed: ffffffff,fffffff
Cpus_allowed_list: 0-63
(Where cpus 32-63 are provided via smt.)
If we limit our current shell process to cpu2 only and then offline it
and reonline it:
# taskset -p 4 $$
pid 2272's current affinity mask: ffffffffffffffff
pid 2272's new affinity mask: 4
# echo off > /sys/devices/system/cpu/cpu2/online
# dmesg | tail -3
[ 2195.866089] process 2272 (bash) no longer affine to cpu2
[ 2195.872700] IRQ 114: no longer affine to CPU2
[ 2195.879128] smpboot: CPU 2 is now offline
# echo on > /sys/devices/system/cpu/cpu2/online
# dmesg | tail -1
[ 2617.043572] smpboot: Booting Node 0 Processor 2 APIC 0x4
We see that our current process now has an affinity mask containing
every cpu available on the system _except_ the one we originally
constrained it to:
# grep -i cpu /proc/$$/status
Cpus_allowed: ffffffff,fffffffb
Cpus_allowed_list: 0-1,3-63
This is not sane behavior, as the scheduler can now not only place the
process on previously forbidden cpus, it can't even schedule it on
the cpu it was originally constrained to!
Other cases result in even more exotic affinity masks. Take for instance
a process with an affinity mask containing only cpus provided by smt at
the moment that smt is toggled, in a configuration such as the following:
# taskset -p f000000000 $$
# grep -i cpu /proc/$$/status
Cpus_allowed: 000000f0,00000000
Cpus_allowed_list: 36-39
A double toggle of smt results in the following behavior:
# echo off > /sys/devices/system/cpu/smt/control
# echo on > /sys/devices/system/cpu/smt/control
# grep -i cpus /proc/$$/status
Cpus_allowed: ffffff00,ffffffff
Cpus_allowed_list: 0-31,40-63
This is even less sane than the previous case, as the new affinity mask
excludes all smt-provided cpus with ids less than those that were
previously in the affinity mask, as well as those that were actually in
the mask.
With this patch applied, both of these cases end in the following state:
# grep -i cpu /proc/$$/status
Cpus_allowed: ffffffff,ffffffff
Cpus_allowed_list: 0-63
The original policy is discarded. Though not ideal, it is the simplest way
to restore sanity to this fallback case without reinventing the cpuset
wheel that rolls down the kernel just fine in cgroup v2. A user who wishes
for the previous affinity mask to be restored in this fallback case can use
that mechanism instead.
This patch modifies scheduler behavior by instead resetting the mask to
task_cs(tsk)->cpus_allowed by default, and cpu_possible mask in legacy
mode. I tested the cases above on both modes.
Note that the scheduler uses this fallback mechanism if and only if
_every_ other valid avenue has been traveled, and it is the last resort
before calling BUG().
Suggested-by: Waiman Long <longman@redhat.com>
Suggested-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Acked-by: Phil Auld <pauld@redhat.com>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ptrace fixes from Eric Biederman:
"This is just two very minor fixes:
- prevent ptrace from reading unitialized kernel memory found twice
by syzkaller
- restore a missing smp_rmb in ptrace_may_access and add comment tp
it so it is not removed by accident again.
Apologies for being a little slow about getting this to you, I am
still figuring out how to develop with a little baby in the house"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ptrace: restore smp_rmb() in __ptrace_may_access()
signal/ptrace: Don't leak unitialized kernel memory with PTRACE_PEEK_SIGINFO
|
|
Restore the read memory barrier in __ptrace_may_access() that was deleted
a couple years ago. Also add comments on this barrier and the one it pairs
with to explain why they're there (as far as I understand).
Fixes: bfedb589252c ("mm: Add a user_ns owner to mm_struct and fix ptrace permission checks")
Cc: stable@vger.kernel.org
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
While adding handling for dying task group leaders c03cd7738a83
("cgroup: Include dying leaders with live threads in PROCS
iterations") added an inverted cset skip condition to
css_task_iter_advance_css_set(). It should skip cset if it's
completely empty but was incorrectly testing for the inverse condition
for the dying_tasks list. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: c03cd7738a83 ("cgroup: Include dying leaders with live threads in PROCS iterations")
Reported-by: syzbot+d4bba5ccd4f9a2a68681@syzkaller.appspotmail.com
|
|
There's some discussion on how to do this the best, and Tejun prefers
that BFQ just create the file itself instead of having cgroups support
a symlink feature.
Hence revert commit 54b7b868e826 and 19e9da9e86c4 for 5.2, and this
can be done properly for 5.3.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull yet more SPDX updates from Greg KH:
"Another round of SPDX header file fixes for 5.2-rc4
These are all more "GPL-2.0-or-later" or "GPL-2.0-only" tags being
added, based on the text in the files. We are slowly chipping away at
the 700+ different ways people tried to write the license text. All of
these were reviewed on the spdx mailing list by a number of different
people.
We now have over 60% of the kernel files covered with SPDX tags:
$ ./scripts/spdxcheck.py -v 2>&1 | grep Files
Files checked: 64533
Files with SPDX: 40392
Files with errors: 0
I think the majority of the "easy" fixups are now done, it's now the
start of the longer-tail of crazy variants to wade through"
* tag 'spdx-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (159 commits)
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 450
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 449
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 448
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 446
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 445
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 444
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 443
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 442
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 440
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 438
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 437
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 436
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 435
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 434
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 433
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 432
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 431
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 430
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 429
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH:
"Here are some small char and misc driver fixes for 5.2-rc4 to resolve
a number of reported issues.
The most "notable" one here is the kernel headers in proc^Wsysfs
fixes. Those changes move the header file info into sysfs and fixes
the build issues that you reported.
Other than that, a bunch of small habanalabs driver fixes, some fpga
driver fixes, and a few other tiny driver fixes.
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
habanalabs: Read upper bits of trace buffer from RWPHI
habanalabs: Fix virtual address access via debugfs for 2MB pages
fpga: zynqmp-fpga: Correctly handle error pointer
habanalabs: fix bug in checking huge page optimization
habanalabs: Avoid using a non-initialized MMU cache mutex
habanalabs: fix debugfs code
uapi/habanalabs: add opcode for enable/disable device debug mode
habanalabs: halt debug engines on user process close
test_firmware: Use correct snprintf() limit
genwqe: Prevent an integer overflow in the ioctl
parport: Fix mem leak in parport_register_dev_model
fpga: dfl: expand minor range when registering chrdev region
fpga: dfl: Add lockdep classes for pdata->lock
fpga: dfl: afu: Pass the correct device to dma_mapping_error()
fpga: stratix10-soc: fix use-after-free on s10_init()
w1: ds2408: Fix typo after 49695ac46861 (reset on output_write retry with readback)
kheaders: Do not regenerate archive if config is not changed
kheaders: Move from proc to sysfs
lkdtm/bugs: Adjust recursion test to avoid elision
lkdtm/usercopy: Moves the KERNEL_DS test to non-canonical
|
|
Pull block fixes from Jens Axboe:
- Allow symlink from the bfq.weight cgroup parameter to the general
weight (Angelo)
- Damien is new skd maintainer (Bart)
- NVMe pull request from Sagi, with a few small fixes.
- Ensure we set DMA segment size properly, dma-debug is now tripping on
these (Christoph)
- Remove useless debugfs_create() return check (Greg)
- Remove redundant unlikely() check on IS_ERR() (Kefeng)
- Fixup request freeing on exit (Ming)
* tag 'for-linus-20190608' of git://git.kernel.dk/linux-block:
block, bfq: add weight symlink to the bfq.weight cgroup parameter
cgroup: let a symlink too be created with a cftype file
block: free sched's request pool in blk_cleanup_queue
nvme-rdma: use dynamic dma mapping per command
nvme: Fix u32 overflow in the number of namespace list calculation
mmc: also set max_segment_size in the device
mtip32xx: also set max_segment_size in the device
rsxx: don't call dma_set_max_seg_size
nvme-pci: don't limit DMA segement size
block: Drop unlikely before IS_ERR(_OR_NULL)
block: aoe: no need to check return value of debugfs_create functions
nvmet: fix data_len to 0 for bdev-backed write_zeroes
MAINTAINERS: Hand over skd maintainership
nvme-tcp: fix queue mapping when queue count is limited
nvme-rdma: fix queue mapping when queue count is limited
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These fix a crash during resume from hibernation introduced during the
4.19 cycle, cause the new Performance and Energy Bias Hint (EPB) code
to be built only if CONFIG_PM is set and add a few missing kerneldoc
comments.
Specifics:
- Fix a crash that occurs when a kernel with 'nosmt' in the command
line is used to resume the system from hibernation (as the
"restore" kernel), because memory mapping differences between the
restore and image kernels cause SMT siblings to be woken up from
idle states and subsequently they try to fetch instructions from
incorrect memory locations (Jiri Kosina).
- Cause the new Performance and Energy Bias Hint (EPB) code to be
built only if CONFIG_PM is set, because that code is not really
necessary otherwise (Rafael Wysocki).
- Add kerneldoc comments to documents some helper functions related
to system-wide suspend to avoid possible confusion regarding their
purpose (Rafael Wysocki)"
* tag 'pm-5.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
x86/power: Fix 'nosmt' vs hibernation triple fault during resume
PM: sleep: Add kerneldoc comments to some functions
x86: intel_epb: Do not build when CONFIG_PM is unset
|
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* pm-x86:
x86/power: Fix 'nosmt' vs hibernation triple fault during resume
x86: intel_epb: Do not build when CONFIG_PM is unset
|
|
This commit enables a cftype to have a symlink (of any name) that
points to the file associated with the cftype.
Signed-off-by: Angelo Ruocco <angeloruocco90@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
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b636fd38dc40 ("cgroup: Implement css_task_iter_skip()") introduced
css_task_iter_skip() which is used to fix task iterations skipping
dying threadgroup leaders with live threads. Skipping is implemented
as a subportion of full advancing but css_task_iter_next() forgot to
fully advance a skipped iterator before determining the next task to
visit causing it to return invalid task pointers.
Fix it by making css_task_iter_next() fully advance the iterator if it
has been skipped since the previous iteration.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: syzbot
Link: http://lkml.kernel.org/r/00000000000097025d058a7fd785@google.com
Fixes: b636fd38dc40 ("cgroup: Implement css_task_iter_skip()")
|
|
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 315 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Based on 1 normalized pattern(s):
distributed under the terms of the gnu gpl version 2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 2 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.032570679@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Based on 1 normalized pattern(s):
distribute under gplv2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 8 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.475576622@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Based on 1 normalized pattern(s):
this file is released under the gplv2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 68 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Based on 1 normalized pattern(s):
released under terms in gpl version 2 see copying
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 5 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081035.689962394@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 59 temple place suite 330 boston ma 02111
1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 136 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.384967451@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of version 2 of the gnu general public license as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 64 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.894819585@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Based on 1 normalized pattern(s):
this software is licensed under the terms of the gnu general public
license version 2 as published by the free software foundation and
may be copied distributed and modified under those terms this
program is distributed in the hope that it will be useful but
without any warranty without even the implied warranty of
merchantability or fitness for a particular purpose see the gnu
general public license for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 285 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Improve the comments for pidfd_send_signal().
First, the comment still referred to a file descriptor for a process as a
"task file descriptor" which stems from way back at the beginning of the
discussion. Replace this with "pidfd" for consistency.
Second, the wording for the explanation of the arguments to the syscall
was a bit inconsistent, e.g. some used the past tense some used present
tense. Make the wording more consistent.
Signed-off-by: Christian Brauner <christian@brauner.io>
|
|
Instead of playing silly games with CONFIG_DEBUG_PREEMPT toggling
between this_cpu_*() and __this_cpu_*() use raw_cpu_*(), which is
exactly what we want here.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Link: https://lkml.kernel.org/r/20190527082326.GP2623@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
The sequence
static DEFINE_WW_CLASS(test_ww_class);
struct ww_acquire_ctx ww_ctx;
struct ww_mutex ww_lock_a;
struct ww_mutex ww_lock_b;
struct ww_mutex ww_lock_c;
struct mutex lock_c;
ww_acquire_init(&ww_ctx, &test_ww_class);
ww_mutex_init(&ww_lock_a, &test_ww_class);
ww_mutex_init(&ww_lock_b, &test_ww_class);
ww_mutex_init(&ww_lock_c, &test_ww_class);
mutex_init(&lock_c);
ww_mutex_lock(&ww_lock_a, &ww_ctx);
mutex_lock(&lock_c);
ww_mutex_lock(&ww_lock_b, &ww_ctx);
ww_mutex_lock(&ww_lock_c, &ww_ctx);
mutex_unlock(&lock_c); (*)
ww_mutex_unlock(&ww_lock_c);
ww_mutex_unlock(&ww_lock_b);
ww_mutex_unlock(&ww_lock_a);
ww_acquire_fini(&ww_ctx); (**)
will trigger the following error in __lock_release() when calling
mutex_release() at **:
DEBUG_LOCKS_WARN_ON(depth <= 0)
The problem is that the hlock merging happening at * updates the
references for test_ww_class incorrectly to 3 whereas it should've
updated it to 4 (representing all the instances for ww_ctx and
ww_lock_[abc]).
Fix this by updating the references during merging correctly taking into
account that we can have non-zero references (both for the hlock that we
merge into another hlock or for the hlock we are merging into).
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/20190524201509.9199-2-imre.deak@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The sequence
static DEFINE_WW_CLASS(test_ww_class);
struct ww_acquire_ctx ww_ctx;
struct ww_mutex ww_lock_a;
struct ww_mutex ww_lock_b;
struct mutex lock_c;
struct mutex lock_d;
ww_acquire_init(&ww_ctx, &test_ww_class);
ww_mutex_init(&ww_lock_a, &test_ww_class);
ww_mutex_init(&ww_lock_b, &test_ww_class);
mutex_init(&lock_c);
ww_mutex_lock(&ww_lock_a, &ww_ctx);
mutex_lock(&lock_c);
ww_mutex_lock(&ww_lock_b, &ww_ctx);
mutex_unlock(&lock_c); (*)
ww_mutex_unlock(&ww_lock_b);
ww_mutex_unlock(&ww_lock_a);
ww_acquire_fini(&ww_ctx);
triggers the following WARN in __lock_release() when doing the unlock at *:
DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth - 1);
The problem is that the WARN check doesn't take into account the merging
of ww_lock_a and ww_lock_b which results in decreasing curr->lockdep_depth
by 2 not only 1.
Note that the following sequence doesn't trigger the WARN, since there
won't be any hlock merging.
ww_acquire_init(&ww_ctx, &test_ww_class);
ww_mutex_init(&ww_lock_a, &test_ww_class);
ww_mutex_init(&ww_lock_b, &test_ww_class);
mutex_init(&lock_c);
mutex_init(&lock_d);
ww_mutex_lock(&ww_lock_a, &ww_ctx);
mutex_lock(&lock_c);
mutex_lock(&lock_d);
ww_mutex_lock(&ww_lock_b, &ww_ctx);
mutex_unlock(&lock_d);
ww_mutex_unlock(&ww_lock_b);
ww_mutex_unlock(&ww_lock_a);
mutex_unlock(&lock_c);
ww_acquire_fini(&ww_ctx);
In general both of the above two sequences are valid and shouldn't
trigger any lockdep warning.
Fix this by taking the decrement due to the hlock merging into account
during lock release and hlock class re-setting. Merging can't happen
during lock downgrading since there won't be a new possibility to merge
hlocks in that case, so add a WARN if merging still happens then.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: ville.syrjala@linux.intel.com
Link: https://lkml.kernel.org/r/20190524201509.9199-1-imre.deak@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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As explained in
0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once")
we always, no matter what, have to bring up x86 HT siblings during boot at
least once in order to avoid first MCE bringing the system to its knees.
That means that whenever 'nosmt' is supplied on the kernel command-line,
all the HT siblings are as a result sitting in mwait or cpudile after
going through the online-offline cycle at least once.
This causes a serious issue though when a kernel, which saw 'nosmt' on its
commandline, is going to perform resume from hibernation: if the resume
from the hibernated image is successful, cr3 is flipped in order to point
to the address space of the kernel that is being resumed, which in turn
means that all the HT siblings are all of a sudden mwaiting on address
which is no longer valid.
That results in triple fault shortly after cr3 is switched, and machine
reboots.
Fix this by always waking up all the SMT siblings before initiating the
'restore from hibernation' process; this guarantees that all the HT
siblings will be properly carried over to the resumed kernel waiting in
resume_play_dead(), and acted upon accordingly afterwards, based on the
target kernel configuration.
Symmetricaly, the resumed kernel has to push the SMT siblings to mwait
again in case it has SMT disabled; this means it has to online all
the siblings when resuming (so that they come out of hlt) and offline
them again to let them reach mwait.
Cc: 4.19+ <stable@vger.kernel.org> # v4.19+
Debugged-by: Thomas Gleixner <tglx@linutronix.de>
Fixes: 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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In mark_lock_irq(), the following checks are performed:
----------------------------------
| -> | unsafe | read unsafe |
|----------------------------------|
| safe | F B | F* B* |
|----------------------------------|
| read safe | F? B* | - |
----------------------------------
Where:
F: check_usage_forwards
B: check_usage_backwards
*: check enabled by STRICT_READ_CHECKS
?: check enabled by the !dir condition
From checking point of view, the special F? case does not make sense,
whereas it perhaps is made for peroformance concern. As later patch will
address this issue, remove this exception, which makes the checks
consistent later.
With STRICT_READ_CHECKS = 1 which is default, there is no functional
change.
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-24-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The new bit can be any possible lock usage except it is garbage, so the
cases in switch can be made simpler. Warn early on if wrong usage bit is
passed without taking locks. No functional change.
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-23-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Lock usage bit initialization is consolidated into one function
mark_usage(). Trivial readability improvement. No functional change.
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-22-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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As Peter has put it all sound and complete for the cause, I simply quote:
"It (check_redundant) was added for cross-release (which has since been
reverted) which would generate a lot of redundant links (IIRC) but
having it makes the reports more convoluted -- basically, if we had an
A-B-C relation, then A-C will not be added to the graph because it is
already covered. This then means any report will include B, even though
a shorter cycle might have been possible."
This would increase the number of direct dependencies. For a simple workload
(make clean; reboot; make vmlinux -j8), the data looks like this:
CONFIG_LOCKDEP_SMALL: direct dependencies: 6926
!CONFIG_LOCKDEP_SMALL: direct dependencies: 9052 (+30.7%)
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-21-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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These two functions now handle different check results themselves. A new
check_path function is added to check whether there is a path in the
dependency graph. No functional change.
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-20-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The @nested is not used in __release_lock so remove it despite that it
is not used in lock_release in the first place.
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-19-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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In check_deadlock(), the third argument read comes from the second
argument hlock so that it can be removed. No functional change.
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-18-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The breadth-first search is implemented as flat-out non-recursive now, but
the comments are still describing it as recursive, update the comments in
that regard.
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-16-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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In search of a dependency in the lock graph, there is contant checks for
forward or backward search. Directly reference the field offset of the
struct that differentiates the type of search to avoid those checks.
No functional change.
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-15-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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With the change, we can slightly adjust the code to iterate the queue in BFS
search, which simplifies the code. No functional change.
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-14-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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