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We triggered the following crash in syzkaller tests:
BUG: Bad page state in process syz.7.38 pfn:1eff3
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1eff3
flags: 0x3fffff00004004(referenced|reserved|node=0|zone=1|lastcpupid=0x1fffff)
raw: 003fffff00004004 ffffe6c6c07bfcc8 ffffe6c6c07bfcc8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000fffffffe 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x32/0x50
bad_page+0x69/0xf0
free_unref_page_prepare+0x401/0x500
free_unref_page+0x6d/0x1b0
uprobe_write_opcode+0x460/0x8e0
install_breakpoint.part.0+0x51/0x80
register_for_each_vma+0x1d9/0x2b0
__uprobe_register+0x245/0x300
bpf_uprobe_multi_link_attach+0x29b/0x4f0
link_create+0x1e2/0x280
__sys_bpf+0x75f/0xac0
__x64_sys_bpf+0x1a/0x30
do_syscall_64+0x56/0x100
entry_SYSCALL_64_after_hwframe+0x78/0xe2
BUG: Bad rss-counter state mm:00000000452453e0 type:MM_FILEPAGES val:-1
The following syzkaller test case can be used to reproduce:
r2 = creat(&(0x7f0000000000)='./file0\x00', 0x8)
write$nbd(r2, &(0x7f0000000580)=ANY=[], 0x10)
r4 = openat(0xffffffffffffff9c, &(0x7f0000000040)='./file0\x00', 0x42, 0x0)
mmap$IORING_OFF_SQ_RING(&(0x7f0000ffd000/0x3000)=nil, 0x3000, 0x0, 0x12, r4, 0x0)
r5 = userfaultfd(0x80801)
ioctl$UFFDIO_API(r5, 0xc018aa3f, &(0x7f0000000040)={0xaa, 0x20})
r6 = userfaultfd(0x80801)
ioctl$UFFDIO_API(r6, 0xc018aa3f, &(0x7f0000000140))
ioctl$UFFDIO_REGISTER(r6, 0xc020aa00, &(0x7f0000000100)={{&(0x7f0000ffc000/0x4000)=nil, 0x4000}, 0x2})
ioctl$UFFDIO_ZEROPAGE(r5, 0xc020aa04, &(0x7f0000000000)={{&(0x7f0000ffd000/0x1000)=nil, 0x1000}})
r7 = bpf$PROG_LOAD(0x5, &(0x7f0000000140)={0x2, 0x3, &(0x7f0000000200)=ANY=[@ANYBLOB="1800000000120000000000000000000095"], &(0x7f0000000000)='GPL\x00', 0x7, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, @fallback=0x30, 0xffffffffffffffff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x10, 0x0, @void, @value}, 0x94)
bpf$BPF_LINK_CREATE_XDP(0x1c, &(0x7f0000000040)={r7, 0x0, 0x30, 0x1e, @val=@uprobe_multi={&(0x7f0000000080)='./file0\x00', &(0x7f0000000100)=[0x2], 0x0, 0x0, 0x1}}, 0x40)
The cause is that zero pfn is set to the PTE without increasing the RSS
count in mfill_atomic_pte_zeropage() and the refcount of zero folio does
not increase accordingly. Then, the operation on the same pfn is performed
in uprobe_write_opcode()->__replace_page() to unconditional decrease the
RSS count and old_folio's refcount.
Therefore, two bugs are introduced:
1. The RSS count is incorrect, when process exit, the check_mm() report
error "Bad rss-count".
2. The reserved folio (zero folio) is freed when folio->refcount is zero,
then free_pages_prepare->free_page_is_bad() report error
"Bad page state".
There is more, the following warning could also theoretically be triggered:
__replace_page()
-> ...
-> folio_remove_rmap_pte()
-> VM_WARN_ON_FOLIO(is_zero_folio(folio), folio)
Considering that uprobe hit on the zero folio is a very rare case, just
reject zero old folio immediately after get_user_page_vma_remote().
[ mingo: Cleaned up the changelog ]
Fixes: 7396fa818d62 ("uprobes/core: Make background page replacement logic account for rss_stat counters")
Fixes: 2b1444983508 ("uprobes, mm, x86: Add the ability to install and remove uprobes breakpoints")
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20250224031149.1598949-1-tongtiangen@huawei.com
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Vast majority of threads don't have any seccomp filters, all while the
lock taken here is shared between all threads in given process and
frequently used.
Safety of the check relies on the following:
- seccomp_filter_release is only legally called for PF_EXITING threads
- SIGNAL_GROUP_EXIT is only ever set with the sighand lock held
- PF_EXITING is only ever set with the sighand lock held *or* after
SIGNAL_GROUP_EXIT is set *or* the process is single-threaded
- seccomp_sync_threads holds the sighand lock and skips all threads if
SIGNAL_GROUP_EXIT is set, PF_EXITING threads if not
Resulting reduction of contention gives me a 5% boost in a
microbenchmark spawning and killing threads within the same process.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250213170911.1140187-1-mjguzik@gmail.com
Signed-off-by: Kees Cook <kees@kernel.org>
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Syskaller triggers a warning due to prev_epc->pmu != next_epc->pmu in
perf_event_swap_task_ctx_data(). vmcore shows that two lists have the same
perf_event_pmu_context, but not in the same order.
The problem is that the order of pmu_ctx_list for the parent is impacted by
the time when an event/PMU is added. While the order for a child is
impacted by the event order in the pinned_groups and flexible_groups. So
the order of pmu_ctx_list in the parent and child may be different.
To fix this problem, insert the perf_event_pmu_context to its proper place
after iteration of the pmu_ctx_list.
The follow testcase can trigger above warning:
# perf record -e cycles --call-graph lbr -- taskset -c 3 ./a.out &
# perf stat -e cpu-clock,cs -p xxx // xxx is the pid of a.out
test.c
void main() {
int count = 0;
pid_t pid;
printf("%d running\n", getpid());
sleep(30);
printf("running\n");
pid = fork();
if (pid == -1) {
printf("fork error\n");
return;
}
if (pid == 0) {
while (1) {
count++;
}
} else {
while (1) {
count++;
}
}
}
The testcase first opens an LBR event, so it will allocate task_ctx_data,
and then open tracepoint and software events, so the parent context will
have 3 different perf_event_pmu_contexts. On inheritance, child ctx will
insert the perf_event_pmu_context in another order and the warning will
trigger.
[ mingo: Tidied up the changelog. ]
Fixes: bd2756811766 ("perf: Rewrite core context handling")
Signed-off-by: Luo Gengkun <luogengkun@huaweicloud.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20250122073356.1824736-1-luogengkun@huaweicloud.com
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The perf_iterate_ctx() function performs RCU list traversal but
currently lacks RCU read lock protection. This causes lockdep warnings
when running perf probe with unshare(1) under CONFIG_PROVE_RCU_LIST=y:
WARNING: suspicious RCU usage
kernel/events/core.c:8168 RCU-list traversed in non-reader section!!
Call Trace:
lockdep_rcu_suspicious
? perf_event_addr_filters_apply
perf_iterate_ctx
perf_event_exec
begin_new_exec
? load_elf_phdrs
load_elf_binary
? lock_acquire
? find_held_lock
? bprm_execve
bprm_execve
do_execveat_common.isra.0
__x64_sys_execve
do_syscall_64
entry_SYSCALL_64_after_hwframe
This protection was previously present but was removed in commit
bd2756811766 ("perf: Rewrite core context handling"). Add back the
necessary rcu_read_lock()/rcu_read_unlock() pair around
perf_iterate_ctx() call in perf_event_exec().
[ mingo: Use scoped_guard() as suggested by Peter ]
Fixes: bd2756811766 ("perf: Rewrite core context handling")
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250117-fix_perf_rcu-v1-1-13cb9210fc6a@debian.org
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Similarly to scx_bpf_nr_cpu_ids(), introduce a new kfunc
scx_bpf_nr_node_ids() to expose the maximum number of NUMA nodes in the
system.
BPF schedulers can use this information together with the new node-aware
kfuncs, for example to create per-node DSQs, validate node IDs, etc.
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Reduce the variable passing madness surrounding check_ctx_access().
Currently, check_mem_access() passes many pointers to local variables to
check_ctx_access(). They are used to initialize "struct
bpf_insn_access_aux info" in check_ctx_access() and then passed to
is_valid_access(). Then, check_ctx_access() takes the data our from
info and write them back the pointers to pass them back. This can be
simpilified by moving info up to check_mem_access().
No functional change.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Link: https://lore.kernel.org/r/20250221175644.1822383-1-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull rseq fixes from Ingo Molnar:
- Fix overly spread-out RSEQ concurrency ID allocation pattern that
regressed certain workloads
- Fix RSEQ registration syscall behavior on -EFAULT errors when
CONFIG_DEBUG_RSEQ=y (This debug option is disabled on most
distributions)
* tag 'sched-urgent-2025-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rseq: Fix rseq registration with CONFIG_DEBUG_RSEQ
sched: Compact RSEQ concurrency IDs with reduced threads and affinity
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf event fixes from Ingo Molnar:
"Fix x86 Intel Lion Cove CPU event constraints, and fix uprobes
debug/error printk output pointer-value verbosity"
* tag 'perf-urgent-2025-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel: Fix event constraints for LNC
uprobes: Don't use %pK through printk
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
"Function graph accounting fixes:
- Fix the manage ops hashes
The function graph registers a "manager ops" and "sub-ops" to
ftrace. The manager ops does not have any callback but calls the
sub-ops callbacks. The manage ops hashes (what is used to tell
ftrace what functions to attach to) is built on the sub-ops it
manages.
There was an error in the way it built the hash. An empty hash
means to attach to all functions. When the manager ops had one
sub-ops it properly copied its hash. But when the manager ops had
more than one sub-ops, it went into a loop to make a set of all
functions it needed to add to the hash. If any of the subops hashes
was empty, that would mean to attach to all functions. The error
was that the first iteration of the loop passed in an empty hash to
start with in order to add the other hashes. That starting hash was
mistaken as to attach to all functions. This made the manage ops
attach to all functions whenever it had two or more sub-ops, even
if each sub-op was attached to only a single function.
- Do not add duplicate entries to the manager ops hash
If two or more subops hashes trace the same function, an entry for
that function will be added to the manager ops for each subops.
This causes waste and extra overhead.
Fprobe accounting fixes:
- Remove last function from fprobe hash
Fprobes has a ftrace hash to manage which functions an fprobe is
attached to. It also has a counter of how many fprobes are
attached. When the last fprobe is removed, it unregisters the
fprobe from ftrace but does not remove the functions the last
fprobe was attached to from the hash. This leaves the old functions
attached. When a new fprobe is added, the fprobe infrastructure
attaches to not only the functions of the new fprobe, but also to
the functions of the last fprobe.
- Fix accounting of the fprobe counter
When a fprobe is added, it updates a counter. If the counter goes
from zero to one, it attaches its ops to ftrace. When an fprobe is
removed, the counter is decremented. If the counter goes from 1 to
zero, it removes the fprobes ops from ftrace.
There was an issue where if two fprobes trace the same function,
the addition of each fprobe would increment the counter. But when
removing the first of the fprobes, it would notice that another
fprobe is still attached to one of its functions no it does not
remove the functions from the ftrace ops.
But it also did not decrement the counter, so when the last fprobe
is removed, the counter is still one. This leaves the fprobes
callback still registered with ftrace and it being called by the
functions defined by the fprobes ops hash. Worse yet, because all
the functions from the fprobe ops hash have been removed, that
tells ftrace that it wants to trace all functions.
Thus, this puts the state of the system where every function is
calling the fprobe callback handler (which does nothing as there
are no registered fprobes), but this causes a good 13% slow down of
the entire system.
Other updates:
- Add a selftest to test the above issues to prevent regressions.
- Fix preempt count accounting in function tracing
Better recursion protection was added to function tracing which
added another layer of preempt disable. As the preempt_count gets
traced in the event, it needs to subtract the amount of preempt
disabling the tracer does to record what the preempt_count was when
the trace was triggered.
- Fix memory leak in output of set_event
A variable is passed by the seq_file functions in the location that
is set by the return of the next() function. The start() function
allocates it and the stop() function frees it. But when the last
item is found, the next() returns NULL which leaks the data that
was allocated in start(). The m->private is used for something
else, so have next() free the data when it returns NULL, as stop()
will then just receive NULL in that case"
* tag 'ftrace-v6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Fix memory leak when reading set_event file
ftrace: Correct preemption accounting for function tracing.
selftests/ftrace: Update fprobe test to check enabled_functions file
fprobe: Fix accounting of when to unregister from function graph
fprobe: Always unregister fgraph function from ops
ftrace: Do not add duplicate entries in subops manager ops
ftrace: Fix accounting of adding subops to a manager ops
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https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Martin KaFai Lau says:
====================
pull-request: bpf-next 2025-02-20
We've added 19 non-merge commits during the last 8 day(s) which contain
a total of 35 files changed, 1126 insertions(+), 53 deletions(-).
The main changes are:
1) Add TCP_RTO_MAX_MS support to bpf_set/getsockopt, from Jason Xing
2) Add network TX timestamping support to BPF sock_ops, from Jason Xing
3) Add TX metadata Launch Time support, from Song Yoong Siang
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
igc: Add launch time support to XDP ZC
igc: Refactor empty frame insertion for launch time support
net: stmmac: Add launch time support to XDP ZC
selftests/bpf: Add launch time request to xdp_hw_metadata
xsk: Add launch time hardware offload support to XDP Tx metadata
selftests/bpf: Add simple bpf tests in the tx path for timestamping feature
bpf: Support selective sampling for bpf timestamping
bpf: Add BPF_SOCK_OPS_TSTAMP_SENDMSG_CB callback
bpf: Add BPF_SOCK_OPS_TSTAMP_ACK_CB callback
bpf: Add BPF_SOCK_OPS_TSTAMP_SND_HW_CB callback
bpf: Add BPF_SOCK_OPS_TSTAMP_SND_SW_CB callback
bpf: Add BPF_SOCK_OPS_TSTAMP_SCHED_CB callback
net-timestamp: Prepare for isolating two modes of SO_TIMESTAMPING
bpf: Disable unsafe helpers in TX timestamping callbacks
bpf: Prevent unsafe access to the sock fields in the BPF timestamping callback
bpf: Prepare the sock_ops ctx and call bpf prog for TX timestamping
bpf: Add networking timestamping support to bpf_get/setsockopt()
selftests/bpf: Add rto max for bpf_setsockopt test
bpf: Support TCP_RTO_MAX_MS for bpf_setsockopt
====================
Link: https://patch.msgid.link/20250221022104.386462-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Pull drm fixes from Dave Airlie:
"Weekly drm fixes pull request, lots of small things all over, msm has
a bunch of things but all very small, xe, i915, a fix for the cgroup
dmem controller.
core:
- remove MAINTAINERS entry
cgroup/dmem:
- use correct function for pool descendants
panel:
- fix signal polarity issue jd9365da-h3
nouveau:
- folio handling fix
- config fix
amdxdna:
- fix missing header
xe:
- Fix error handling in xe_irq_install
- Fix devcoredump format
i915:
- Use spin_lock_irqsave() in interruptible context on guc submission
- Fixes on DDI and TRANS programming
- Make sure all planes in use by the joiner have their crtc included
- Fix 128b/132b modeset issues
msm:
- More catalog fixes:
- to skip watchdog programming through top block if its not
present
- fix the setting of WB mask to ensure the WB input control is
programmed correctly through ping-pong
- drop lm_pair for sm6150 as that chipset does not have any
3dmerge block
- Fix the mode validation logic for DP/eDP to account for widebus
(2ppc) to allow high clock resolutions
- Fix to disable dither during encoder disable as otherwise this
was causing kms_writeback failure due to resource sharing
between WB and DSI paths as DSI uses dither but WB does not
- Fixes for virtual planes, namely to drop extraneous return and
fix uninitialized variables
- Fix to avoid spill-over of DSC encoder block bits when
programming the bits-per-component
- Fixes in the DSI PHY to protect against concurrent access of
PHY_CMN_CLK_CFG regs between clock and display drivers
- Core/GPU:
- Fix non-blocking fence wait incorrectly rounding up to 1 jiffy
timeout
- Only print GMU fw version once, instead of each time the GPU
resumes"
* tag 'drm-fixes-2025-02-22' of https://gitlab.freedesktop.org/drm/kernel: (28 commits)
drm/i915/dp: Fix disabling the transcoder function in 128b/132b mode
drm/i915/dp: Fix error handling during 128b/132b link training
accel/amdxdna: Add missing include linux/slab.h
MAINTAINERS: Remove myself
drm/nouveau/pmu: Fix gp10b firmware guard
cgroup/dmem: Don't open-code css_for_each_descendant_pre
drm/xe/guc: Fix size_t print format
drm/xe: Make GUC binaries dump consistent with other binaries in devcoredump
drm/i915: Make sure all planes in use by the joiner have their crtc included
drm/i915/ddi: Fix HDMI port width programming in DDI_BUF_CTL
drm/i915/dsi: Use TRANS_DDI_FUNC_CTL's own port width macro
drm/xe: Fix error handling in xe_irq_install()
drm/i915/gt: Use spin_lock_irqsave() in interruptible context
drm/msm/dsi/phy: Do not overwite PHY_CMN_CLK_CFG1 when choosing bitclk source
drm/msm/dsi/phy: Protect PHY_CMN_CLK_CFG1 against clock driver
drm/msm/dsi/phy: Protect PHY_CMN_CLK_CFG0 updated from driver side
drm/msm/dpu: Drop extraneous return in dpu_crtc_reassign_planes()
drm/msm/dpu: Don't leak bits_per_component into random DSC_ENC fields
drm/msm/dpu: Disable dither in phys encoder cleanup
drm/msm/dpu: Fix uninitialized variable
...
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Adding an unlikely() hint on early error return paths improves the
run-time performance of several sched related system calls.
Benchmarking on an i9-12900 shows the following per system call
performance improvements:
before after improvement
sched_getattr 182.4ns 170.6ns ~6.5%
sched_setattr 284.3ns 267.6ns ~5.9%
sched_getparam 161.6ns 148.1ns ~8.4%
sched_setparam 1265.4ns 1227.6ns ~3.0%
sched_getscheduler 129.4ns 118.2ns ~8.7%
sched_setscheduler 1237.3ns 1216.7ns ~1.7%
Results are based on running 20 tests with turbo disabled (to reduce
clock freq turbo changes), with 10 second run per test based on the
number of system calls per second. The % standard deviation of the
measurements for the 20 tests was 0.05% to 0.40%, so the results are
reliable.
Tested on kernel build with gcc 14.2.1
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250219142423.45516-1-colin.i.king@gmail.com
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The header file stats.h is included twice. Remove the redundant include
and the following make includecheck warning:
stats.h is included more than once
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250219111756.3070-2-thorsten.blum@linux.dev
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Scenario: In platform_device_register, the driver misuses struct
device as platform_data, making kmemdup duplicate a device. Accessing
the duplicate may cause list corruption due to its mutex magic or list
holding old content.
It recurs randomly as the first mutex - getting process skips the slow
path and mutex check. Adding MUTEX_WARN_ON(lock->magic!= lock) in
__mutex_trylock_fast() makes it always happen.
Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250126033243.53069-1-cuiyunhui@bytedance.com
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Currently, IRQ_MSI_IOMMU is selected if DMA_IOMMU is available to provide
an implementation for iommu_dma_prepare/compose_msi_msg(). However, it'll
make more sense for irqchips that call prepare/compose to select it, and
that will trigger all the additional code and data to be compiled into
the kernel.
If IRQ_MSI_IOMMU is selected with no IOMMU side implementation, then the
prepare/compose() will be NOP stubs.
If IRQ_MSI_IOMMU is not selected by an irqchip, then the related code on
the iommu side is compiled out.
Link: https://patch.msgid.link/r/a2620f67002c5cdf974e89ca3bf905f5c0817be6.1740014950.git.nicolinc@nvidia.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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kmemleak reports the following memory leak after reading set_event file:
# cat /sys/kernel/tracing/set_event
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xff110001234449e0 (size 16):
comm "cat", pid 13645, jiffies 4294981880
hex dump (first 16 bytes):
01 00 00 00 00 00 00 00 a8 71 e7 84 ff ff ff ff .........q......
backtrace (crc c43abbc):
__kmalloc_cache_noprof+0x3ca/0x4b0
s_start+0x72/0x2d0
seq_read_iter+0x265/0x1080
seq_read+0x2c9/0x420
vfs_read+0x166/0xc30
ksys_read+0xf4/0x1d0
do_syscall_64+0x79/0x150
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The issue can be reproduced regardless of whether set_event is empty or
not. Here is an example about the valid content of set_event.
# cat /sys/kernel/tracing/set_event
sched:sched_process_fork
sched:sched_switch
sched:sched_wakeup
*:*:mod:trace_events_sample
The root cause is that s_next() returns NULL when nothing is found.
This results in s_stop() attempting to free a NULL pointer because its
parameter is NULL.
Fix the issue by freeing the memory appropriately when s_next() fails
to find anything.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250220031528.7373-1-ahuang12@lenovo.com
Fixes: b355247df104 ("tracing: Cache ":mod:" events for modules not loaded yet")
Signed-off-by: Adrian Huang <ahuang12@lenovo.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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The function tracer should record the preemption level at the point when
the function is invoked. If the tracing subsystem decrement the
preemption counter it needs to correct this before feeding the data into
the trace buffer. This was broken in the commit cited below while
shifting the preempt-disabled section.
Use tracing_gen_ctx_dec() which properly subtracts one from the
preemption counter on a preemptible kernel.
Cc: stable@vger.kernel.org
Cc: Wander Lairson Costa <wander@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20250220140749.pfw8qoNZ@linutronix.de
Fixes: ce5e48036c9e7 ("ftrace: disable preemption when recursion locked")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
When adding a new fprobe, it will update the function hash to the
functions the fprobe is attached to and register with function graph to
have it call the registered functions. The fprobe_graph_active variable
keeps track of the number of fprobes that are using function graph.
If two fprobes attach to the same function, it increments the
fprobe_graph_active for each of them. But when they are removed, the first
fprobe to be removed will see that the function it is attached to is also
used by another fprobe and it will not remove that function from
function_graph. The logic will skip decrementing the fprobe_graph_active
variable.
This causes the fprobe_graph_active variable to not go to zero when all
fprobes are removed, and in doing so it does not unregister from
function graph. As the fgraph ops hash will now be empty, and an empty
filter hash means all functions are enabled, this triggers function graph
to add a callback to the fprobe infrastructure for every function!
# echo "f:myevent1 kernel_clone" >> /sys/kernel/tracing/dynamic_events
# echo "f:myevent2 kernel_clone%return" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc0024000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# > /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
trace_initcall_start_cb (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
run_init_process (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
try_to_run_init_process (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
x86_pmu_show_pmu_cap (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
cleanup_rapl_pmus (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
uncore_free_pcibus_map (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
uncore_types_exit (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
uncore_pci_exit.part.0 (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
kvm_shutdown (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
vmx_dump_msrs (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
[..]
# cat /sys/kernel/tracing/enabled_functions | wc -l
54702
If a fprobe is being removed and all its functions are also traced by
other fprobes, still decrement the fprobe_graph_active counter.
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.565129766@goodmis.org
Fixes: 4346ba1604093 ("fprobe: Rewrite fprobe on function-graph tracer")
Closes: https://lore.kernel.org/all/20250217114918.10397-A-hca@linux.ibm.com/
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
When the last fprobe is removed, it calls unregister_ftrace_graph() to
remove the graph_ops from function graph. The issue is when it does so, it
calls return before removing the function from its graph ops via
ftrace_set_filter_ips(). This leaves the last function lingering in the
fprobe's fgraph ops and if a probe is added it also enables that last
function (even though the callback will just drop it, it does add unneeded
overhead to make that call).
# echo "f:myevent1 kernel_clone" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc02f3000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# echo "f:myevent2 schedule_timeout" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc02f3000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
schedule_timeout (1) tramp: 0xffffffffc02f3000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# > /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
# echo "f:myevent3 kmem_cache_free" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kmem_cache_free (1) tramp: 0xffffffffc0219000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
schedule_timeout (1) tramp: 0xffffffffc0219000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
The above enabled a fprobe on kernel_clone, and then on schedule_timeout.
The content of the enabled_functions shows the functions that have a
callback attached to them. The fprobe attached to those functions
properly. Then the fprobes were cleared, and enabled_functions was empty
after that. But after adding a fprobe on kmem_cache_free, the
enabled_functions shows that the schedule_timeout was attached again. This
is because it was still left in the fprobe ops that is used to tell
function graph what functions it wants callbacks from.
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.393254452@goodmis.org
Fixes: 4346ba1604093 ("fprobe: Rewrite fprobe on function-graph tracer")
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Check if a function is already in the manager ops of a subops. A manager
ops contains multiple subops, and if two or more subops are tracing the
same function, the manager ops only needs a single entry in its hash.
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.226762894@goodmis.org
Fixes: 4f554e955614f ("ftrace: Add ftrace_set_filter_ips function")
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Function graph uses a subops and manager ops mechanism to attach to
ftrace. The manager ops connects to ftrace and the functions it connects
to is defined by a list of subops that it manages.
The function hash that defines what the above ops attaches to limits the
functions to attach if the hash has any content. If the hash is empty, it
means to trace all functions.
The creation of the manager ops hash is done by iterating over all the
subops hashes. If any of the subops hashes is empty, it means that the
manager ops hash must trace all functions as well.
The issue is in the creation of the manager ops. When a second subops is
attached, a new hash is created by starting it as NULL and adding the
subops one at a time. But the NULL ops is mistaken as an empty hash, and
once an empty hash is found, it stops the loop of subops and just enables
all functions.
# echo "f:myevent1 kernel_clone" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# echo "f:myevent2 schedule_timeout" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
trace_initcall_start_cb (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
run_init_process (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
try_to_run_init_process (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
x86_pmu_show_pmu_cap (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
cleanup_rapl_pmus (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_free_pcibus_map (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_types_exit (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_pci_exit.part.0 (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
kvm_shutdown (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
vmx_dump_msrs (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
vmx_cleanup_l1d_flush (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
[..]
Fix this by initializing the new hash to NULL and if the hash is NULL do
not treat it as an empty hash but instead allocate by copying the content
of the first sub ops. Then on subsequent iterations, the new hash will not
be NULL, but the content of the previous subops. If that first subops
attached to all functions, then new hash may assume that the manager ops
also needs to attach to all functions.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.060300046@goodmis.org
Fixes: 5fccc7552ccbc ("ftrace: Add subops logic to allow one ops to manage many")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
x86 version of arch_memremap_wb() needs the flags to decide if the mapping
has to be encrypted or decrypted.
Pass down the flag to arch_memremap_wb(). All current implementations
ignore the argument.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20250217163822.343400-2-kirill.shutemov@linux.intel.com
|
|
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Move ctl tables to two files:
- perf_event_{paranoid,mlock_kb,max_sample_rate} and
perf_cpu_time_max_percent into kernel/events/core.c
- perf_event_max_{stack,context_per_stack} into
kernel/events/callchain.c
Make static variables and functions that are fully contained in core.c
and callchain.cand remove them from include/linux/perf_event.h.
Additionally six_hundred_forty_kb is moved to callchain.c.
Two new sysctl tables are added ({callchain,events_core}_sysctl_table)
with their respective sysctl registration functions.
This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kerenel/sysctl.c.
Signed-off-by: Joel Granados <joel.granados@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250218-jag-mv_ctltables-v1-5-cd3698ab8d29@kernel.org
|
|
new patches
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
With CONFIG_DEBUG_RSEQ=y, at rseq registration the read-only fields are
copied from user-space, if this copy fails the syscall returns -EFAULT
and the registration should not be activated - but it erroneously is.
Move the activation of the registration after the copy of the fields to
fix this bug.
Fixes: 7d5265ffcd8b ("rseq: Validate read-only fields under DEBUG_RSEQ config")
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/20250219205330.324770-1-mjeanson@efficios.com
|
|
Adding an unlikely() hint on task comparisons on an unlikely error
return path improves run-time performance of the kcmp system call.
Benchmarking on an i9-12900 shows an improvement of ~5.5% on kcmp().
Results based on running 20 tests with turbo disabled (to reduce
clock freq turbo changes), with 10 second run per test and comparing
the number of kcmp calls per second. The % Standard deviation of 20
tests was ~0.25%, results are reliable.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20250213163916.709392-1-colin.i.king@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
All users of the time releated parts of the vDSO are now using the generic
storage implementation. Remove the therefore unnecessary compatibility
accessor functions and symbols.
Co-developed-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-18-13a4669dfc8c@linutronix.de
|
|
Historically each architecture defined their own way to store the vDSO
data page. Add a generic mechanism to provide storage for that page.
Furthermore this generic storage will be extended to also provide
uniform storage for *non*-time-related data, like the random state or
architecture-specific data. These will have their own pages and data
structures, so rename 'vdso_data' into 'vdso_time_data' to make that
split clear from the name.
Also introduce a new consistent naming scheme for the symbols related to
the vDSO, which makes it clear if the symbol is accessible from
userspace or kernel space and the type of data behind the symbol.
The generic fault handler contains an optimization to prefault the vvar
page when the timens page is accessed. This was lifted from s390 and x86.
Co-developed-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-5-13a4669dfc8c@linutronix.de
|
|
HZ_250 config description contains alternative choice for NTSC
media users (HZ_300), which is written as "selected 300Hz". This is
incorrect, as it implies that HZ_300 is automatically selected
whereas the user has chosen HZ_250 instead.
Fix the wording to "select 300Hz".
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20250203025000.17953-1-bagasdotme@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Reject struct_ops programs with refcounted kptr arguments (arguments
tagged with __ref suffix) that tail call. Once a refcounted kptr is
passed to a struct_ops program from the kernel, it can be freed or
xchged into maps. As there is no guarantee a callee can get the same
valid refcounted kptr in the ctx, we cannot allow such usage.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250220221532.1079331-1-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
bpf_send_signal_common() uses preemptible() to check whether or not the
current context is preemptible. If it is preemptible, it will use
irq_work to send the signal asynchronously instead of trying to hold a
spin-lock, because spin-lock is sleepable under PREEMPT_RT.
However, preemptible() depends on CONFIG_PREEMPT_COUNT. When
CONFIG_PREEMPT_COUNT is turned off (e.g., CONFIG_PREEMPT_VOLUNTARY=y),
!preemptible() will be evaluated as 1 and bpf_send_signal_common() will
use irq_work unconditionally.
Fix it by unfolding "!preemptible()" and using "preempt_count() != 0 ||
irqs_disabled()" instead.
Fixes: 87c544108b61 ("bpf: Send signals asynchronously if !preemptible")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250220042259.1583319-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Cross-merge bpf fixes after downstream PR (bpf-6.14-rc4).
Minor conflict:
kernel/bpf/btf.c
Adjacent changes:
kernel/bpf/arena.c
kernel/bpf/btf.c
kernel/bpf/syscall.c
kernel/bpf/verifier.c
mm/memory.c
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Pull BPF fixes from Daniel Borkmann:
- Fix a soft-lockup in BPF arena_map_free on 64k page size kernels
(Alan Maguire)
- Fix a missing allocation failure check in BPF verifier's
acquire_lock_state (Kumar Kartikeya Dwivedi)
- Fix a NULL-pointer dereference in trace_kfree_skb by adding kfree_skb
to the raw_tp_null_args set (Kuniyuki Iwashima)
- Fix a deadlock when freeing BPF cgroup storage (Abel Wu)
- Fix a syzbot-reported deadlock when holding BPF map's freeze_mutex
(Andrii Nakryiko)
- Fix a use-after-free issue in bpf_test_init when eth_skb_pkt_type is
accessing skb data not containing an Ethernet header (Shigeru
Yoshida)
- Fix skipping non-existing keys in generic_map_lookup_batch (Yan Zhai)
- Several BPF sockmap fixes to address incorrect TCP copied_seq
calculations, which prevented correct data reads from recv(2) in user
space (Jiayuan Chen)
- Two fixes for BPF map lookup nullness elision (Daniel Xu)
- Fix a NULL-pointer dereference from vmlinux BTF lookup in
bpf_sk_storage_tracing_allowed (Jared Kangas)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
selftests: bpf: test batch lookup on array of maps with holes
bpf: skip non exist keys in generic_map_lookup_batch
bpf: Handle allocation failure in acquire_lock_state
bpf: verifier: Disambiguate get_constant_map_key() errors
bpf: selftests: Test constant key extraction on irrelevant maps
bpf: verifier: Do not extract constant map keys for irrelevant maps
bpf: Fix softlockup in arena_map_free on 64k page kernel
net: Add rx_skb of kfree_skb to raw_tp_null_args[].
bpf: Fix deadlock when freeing cgroup storage
selftests/bpf: Add strparser test for bpf
selftests/bpf: Fix invalid flag of recv()
bpf: Disable non stream socket for strparser
bpf: Fix wrong copied_seq calculation
strparser: Add read_sock callback
bpf: avoid holding freeze_mutex during mmap operation
bpf: unify VM_WRITE vs VM_MAYWRITE use in BPF map mmaping logic
selftests/bpf: Adjust data size to have ETH_HLEN
bpf, test_run: Fix use-after-free issue in eth_skb_pkt_type()
bpf: Remove unnecessary BTF lookups in bpf_sk_storage_tracing_allowed
|
|
https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes
An reset signal polarity fix for the jd9365da-h3 panel, a folio handling
fix and config fix in nouveau, a dmem cgroup descendant pool handling
fix, and a missing header for amdxdna.
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maxime Ripard <mripard@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250220-glorious-cockle-of-might-5b35f7@houat
|
|
Add the bpf_sock_ops_enable_tx_tstamp kfunc to allow BPF programs to
selectively enable TX timestamping on a skb during tcp_sendmsg().
For example, BPF program will limit tracking X numbers of packets
and then will stop there instead of tracing all the sendmsgs of
matched flow all along. It would be helpful for users who cannot
afford to calculate latencies from every sendmsg call probably
due to the performance or storage space consideration.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250220072940.99994-12-kerneljasonxing@gmail.com
|
|
The callback function of call_rcu() just calls kfree(), so use
kfree_rcu() instead of call_rcu() + callback function.
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20250218082021.2766-1-lirongqing@baidu.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
Interrupt controller drivers which enable CONFIG_GENERIC_PENDING_IRQ
require to know whether an interrupt can be moved in process context or not
to decide whether they need to invoke the work around for non-atomic MSI
updates or not.
This information can be retrieved via irq_can_move_pcntxt(). That helper
requires access to the top-most interrupt domain data, but the driver which
requires this is usually further down in the hierarchy.
Introduce irq_can_move_in_process_context() which retrieves that
information from the top-most interrupt domain data.
[ tglx: Massaged change log ]
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250217085657.789309-6-apatel@ventanamicro.com
|
|
CONFIG_GENERIC_PENDING_IRQ requires an architecture specific implementation
of irq_force_complete_move() for CPU hotplug. At the moment, only x86
implements this unconditionally, but for RISC-V irq_force_complete_move()
is only needed when the RISC-V IMSIC driver is in use and not needed
otherwise.
To allow runtime configuration of this mechanism, introduce a common
irq_force_complete_move() implementation in the interrupt core code, which
only invokes the completion function, when a interrupt chip in the
hierarchy implements it.
Switch X86 over to the new mechanism. No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250217085657.789309-5-apatel@ventanamicro.com
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This new kfunc will be able to copy a zero-terminated C strings from
another task's address space. This is similar to `bpf_copy_from_user_str()`
but reads memory of specified task.
Signed-off-by: Jordan Rome <linux@jordanrome.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250213152125.1837400-2-linux@jordanrome.com
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negative dentry
No callers of kern_path_locked() or user_path_locked_at() want a
negative dentry. So change them to return -ENOENT instead. This
simplifies callers.
This results in a subtle change to bcachefs in that an ioctl will now
return -ENOENT in preference to -EXDEV. I believe this restores the
behaviour to what it was prior to
Commit bbe6a7c899e7 ("bch2_ioctl_subvolume_destroy(): fix locking")
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250217003020.3170652-2-neilb@suse.de
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The current implementation has a bug: If the current css doesn't
contain any pool that is a descendant of the "pool" (i.e. when
found_descendant == false), then "pool" will point to some unrelated
pool. If the current css has a child, we'll overwrite parent_pool with
this unrelated pool on the next iteration.
Since we can just check whether a pool refers to the same region to
determine whether or not it's related, all the additional pool tracking
is unnecessary, so just switch to using css_for_each_descendant_pre for
traversal.
Fixes: b168ed458dde ("kernel/cgroup: Add "dmem" memory accounting cgroup")
Signed-off-by: Friedrich Vock <friedrich.vock@gmx.de>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250127152754.21325-1-friedrich.vock@gmx.de
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
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Compute env->peak_states as a maximum value of sum of
env->explored_states and env->free_list size.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250215110411.3236773-11-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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When fixes from patches 1 and 3 are applied, Patrick Somaru reported
an increase in memory consumption for sched_ext iterator-based
programs hitting 1M instructions limit. For example, 2Gb VMs ran out
of memory while verifying a program. Similar behaviour could be
reproduced on current bpf-next master.
Here is an example of such program:
/* verification completes if given 16G or RAM,
* final env->free_list size is 369,960 entries.
*/
SEC("raw_tp")
__flag(BPF_F_TEST_STATE_FREQ)
__success
int free_list_bomb(const void *ctx)
{
volatile char buf[48] = {};
unsigned i, j;
j = 0;
bpf_for(i, 0, 10) {
/* this forks verifier state:
* - verification of current path continues and
* creates a checkpoint after 'if';
* - verification of forked path hits the
* checkpoint and marks it as loop_entry.
*/
if (bpf_get_prandom_u32())
asm volatile ("");
/* this marks 'j' as precise, thus any checkpoint
* created on current iteration would not be matched
* on the next iteration.
*/
buf[j++] = 42;
j %= ARRAY_SIZE(buf);
}
asm volatile (""::"r"(buf));
return 0;
}
Memory consumption increased due to more states being marked as loop
entries and eventually added to env->free_list.
This commit introduces logic to free states from env->free_list during
verification. A state in env->free_list can be freed if:
- it has no child states;
- it is not used as a loop_entry.
This commit:
- updates bpf_verifier_state->used_as_loop_entry to be a counter
that tracks how many states use this one as a loop entry;
- adds a function maybe_free_verifier_state(), which:
- frees a state if its ->branches and ->used_as_loop_entry counters
are both zero;
- if the state is freed, state->loop_entry->used_as_loop_entry is
decremented, and an attempt is made to free state->loop_entry.
In the example above, this approach reduces the maximum number of
states in the free list from 369,960 to 16,223.
However, this approach has its limitations. If the buf size in the
example above is modified to 64, state caching overflows: the state
for j=0 is evicted from the cache before it can be used to stop
traversal. As a result, states in the free list accumulate because
their branch counters do not reach zero.
The effect of this patch on the selftests looks as follows:
File Program Max free list (A) Max free list (B) Max free list (DIFF)
-------------------------------- ------------------------------------ ----------------- ----------------- --------------------
arena_list.bpf.o arena_list_add 17 3 -14 (-82.35%)
bpf_iter_task_stack.bpf.o dump_task_stack 39 9 -30 (-76.92%)
iters.bpf.o checkpoint_states_deletion 265 89 -176 (-66.42%)
iters.bpf.o clean_live_states 19 0 -19 (-100.00%)
profiler2.bpf.o tracepoint__syscalls__sys_enter_kill 102 1 -101 (-99.02%)
profiler3.bpf.o tracepoint__syscalls__sys_enter_kill 144 0 -144 (-100.00%)
pyperf600_iter.bpf.o on_event 15 0 -15 (-100.00%)
pyperf600_nounroll.bpf.o on_event 1170 1158 -12 (-1.03%)
setget_sockopt.bpf.o skops_sockopt 18 0 -18 (-100.00%)
strobemeta_nounroll1.bpf.o on_event 147 83 -64 (-43.54%)
strobemeta_nounroll2.bpf.o on_event 312 209 -103 (-33.01%)
strobemeta_subprogs.bpf.o on_event 124 86 -38 (-30.65%)
test_cls_redirect_subprogs.bpf.o cls_redirect 15 0 -15 (-100.00%)
timer.bpf.o test1 30 15 -15 (-50.00%)
Measured using "do-not-submit" patches from here:
https://github.com/eddyz87/bpf/tree/get-loop-entry-hungup
Reported-by: Patrick Somaru <patsomaru@meta.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250215110411.3236773-10-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The next patch in the set needs the ability to remove individual
states from env->free_list while only holding a pointer to the state.
Which requires env->free_list to be a doubly linked list.
This patch converts env->free_list and struct bpf_verifier_state_list
to use struct list_head for this purpose. The change to
env->explored_states is collateral.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250215110411.3236773-9-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The patch 9 is simpler if less places modify loop_entry field.
The loop deleted by this patch does not affect correctness, but is a
performance optimization. However, measurements on selftests and
sched_ext programs show that this optimization is unnecessary:
- at most 2 steps are done in get_loop_entry();
- most of the time 0 or 1 steps are done in get_loop_entry().
Measured using "do-not-submit" patches from here:
https://github.com/eddyz87/bpf/tree/get-loop-entry-hungup
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250215110411.3236773-8-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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For a generic loop detection algorithm a graph node can be a loop
header for itself. However, state loop entries are computed for use in
is_state_visited(), where get_loop_entry(state)->branches is checked.
is_state_visited() also checks state->branches, thus the case when
state == state->loop_entry is not interesting for is_state_visited().
This change does not affect correctness, but simplifies
get_loop_entry() a bit and also simplifies change to
update_loop_entry() in patch 9.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250215110411.3236773-7-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Tejun Heo reported an infinite loop in get_loop_entry(),
when verifying a sched_ext program layered_dispatch in [1].
After some investigation I'm sure that root cause is fixed by patches
1,3 in this patch-set.
To err on the safe side, this commit modifies get_loop_entry() to
detect infinite loops and abort verification in such cases.
The number of steps get_loop_entry(S) can make while moving along the
bpf_verifier_state->loop_entry chain is bounded by the DFS depth of
state S. This fact is exploited to implement the check.
To avoid dealing with the potential error code returned from
get_loop_entry() in update_loop_entry(), remove the get_loop_entry()
calls there:
- This change does not affect correctness. Loop entries would still be
updated during the backward DFS move in update_branch_counts().
- This change does not affect performance. Measurements show that
get_loop_entry() performs at most 1 step on selftests and at most 2
steps on sched_ext programs (1 step in 17 cases, 2 steps in 3
cases, measured using "do-not-submit" patches from [2]).
[1] https://github.com/sched-ext/scx/
commit f0b27038ea10 ("XXX - kernel stall")
[2] https://github.com/eddyz87/bpf/tree/get-loop-entry-hungup
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250215110411.3236773-6-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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verifier.c:is_state_visited() uses RANGE_WITHIN states comparison rules
for cached states that have loop_entry with non-zero branches count
(meaning that loop_entry's verification is not yet done).
The RANGE_WITHIN rules in regsafe()/stacksafe() require register and
stack objects types to be identical in current and old states.
verifier.c:clean_live_states() replaces registers and stack spills
with NOT_INIT/STACK_INVALID marks, if these registers/stack spills are
not read in any child state. This means that clean_live_states() works
against loop convergence logic under some conditions. See selftest in
the next patch for a specific example.
Mitigate this by prohibiting clean_verifier_state() when
state->loop_entry->branches > 0.
This undoes negative verification performance impact of the
copy_verifier_state() fix from the previous patch.
Below is comparison between master and current patch.
selftests:
File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
---------------------------------- ---------------------------- --------- --------- --------------- ---------- ---------- --------------
arena_htab.bpf.o arena_htab_llvm 717 423 -294 (-41.00%) 57 37 -20 (-35.09%)
arena_htab_asm.bpf.o arena_htab_asm 597 445 -152 (-25.46%) 47 37 -10 (-21.28%)
arena_list.bpf.o arena_list_add 1493 1822 +329 (+22.04%) 30 37 +7 (+23.33%)
arena_list.bpf.o arena_list_del 309 261 -48 (-15.53%) 23 15 -8 (-34.78%)
iters.bpf.o checkpoint_states_deletion 18125 22154 +4029 (+22.23%) 818 918 +100 (+12.22%)
iters.bpf.o iter_nested_deeply_iters 593 367 -226 (-38.11%) 67 43 -24 (-35.82%)
iters.bpf.o iter_nested_iters 813 772 -41 (-5.04%) 79 72 -7 (-8.86%)
iters.bpf.o iter_subprog_check_stacksafe 155 135 -20 (-12.90%) 15 14 -1 (-6.67%)
iters.bpf.o iter_subprog_iters 1094 808 -286 (-26.14%) 88 68 -20 (-22.73%)
iters.bpf.o loop_state_deps2 479 356 -123 (-25.68%) 46 35 -11 (-23.91%)
iters.bpf.o triple_continue 35 31 -4 (-11.43%) 3 3 +0 (+0.00%)
kmem_cache_iter.bpf.o open_coded_iter 63 59 -4 (-6.35%) 7 6 -1 (-14.29%)
mptcp_subflow.bpf.o _getsockopt_subflow 501 446 -55 (-10.98%) 25 23 -2 (-8.00%)
pyperf600_iter.bpf.o on_event 12339 6379 -5960 (-48.30%) 441 286 -155 (-35.15%)
verifier_bits_iter.bpf.o max_words 92 84 -8 (-8.70%) 8 7 -1 (-12.50%)
verifier_iterating_callbacks.bpf.o cond_break2 113 192 +79 (+69.91%) 12 21 +9 (+75.00%)
sched_ext:
File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
----------------- ---------------------- --------- --------- ----------------- ---------- ---------- ----------------
bpf.bpf.o layered_dispatch 11485 9039 -2446 (-21.30%) 848 662 -186 (-21.93%)
bpf.bpf.o layered_dump 7422 5022 -2400 (-32.34%) 681 298 -383 (-56.24%)
bpf.bpf.o layered_enqueue 16854 13753 -3101 (-18.40%) 1611 1308 -303 (-18.81%)
bpf.bpf.o layered_init 1000001 5549 -994452 (-99.45%) 84672 523 -84149 (-99.38%)
bpf.bpf.o layered_runnable 3149 1899 -1250 (-39.70%) 288 151 -137 (-47.57%)
bpf.bpf.o p2dq_init 2343 1936 -407 (-17.37%) 201 170 -31 (-15.42%)
bpf.bpf.o refresh_layer_cpumasks 16487 1285 -15202 (-92.21%) 1770 120 -1650 (-93.22%)
bpf.bpf.o rusty_select_cpu 1937 1386 -551 (-28.45%) 177 125 -52 (-29.38%)
scx_central.bpf.o central_dispatch 636 600 -36 (-5.66%) 63 59 -4 (-6.35%)
scx_central.bpf.o central_init 913 632 -281 (-30.78%) 48 39 -9 (-18.75%)
scx_nest.bpf.o nest_init 636 601 -35 (-5.50%) 60 58 -2 (-3.33%)
scx_pair.bpf.o pair_dispatch 1000001 1914 -998087 (-99.81%) 58169 142 -58027 (-99.76%)
scx_qmap.bpf.o qmap_dispatch 2393 2187 -206 (-8.61%) 196 174 -22 (-11.22%)
scx_qmap.bpf.o qmap_init 16367 22777 +6410 (+39.16%) 603 768 +165 (+27.36%)
'layered_init' and 'pair_dispatch' hit 1M on master, but are verified
ok with this patch.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250215110411.3236773-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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The bpf_verifier_state.loop_entry state should be copied by
copy_verifier_state(). Otherwise, .loop_entry values from unrelated
states would poison env->cur_state.
Additionally, env->stack should not contain any states with
.loop_entry != NULL. The states in env->stack are yet to be verified,
while .loop_entry is set for states that reached an equivalent state.
This means that env->cur_state->loop_entry should always be NULL after
pop_stack().
See the selftest in the next commit for an example of the program that
is not safe yet is accepted by verifier w/o this fix.
This change has some verification performance impact for selftests:
File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
---------------------------------- ---------------------------- --------- --------- -------------- ---------- ---------- -------------
arena_htab.bpf.o arena_htab_llvm 717 426 -291 (-40.59%) 57 37 -20 (-35.09%)
arena_htab_asm.bpf.o arena_htab_asm 597 445 -152 (-25.46%) 47 37 -10 (-21.28%)
arena_list.bpf.o arena_list_del 309 279 -30 (-9.71%) 23 14 -9 (-39.13%)
iters.bpf.o iter_subprog_check_stacksafe 155 141 -14 (-9.03%) 15 14 -1 (-6.67%)
iters.bpf.o iter_subprog_iters 1094 1003 -91 (-8.32%) 88 83 -5 (-5.68%)
iters.bpf.o loop_state_deps2 479 725 +246 (+51.36%) 46 63 +17 (+36.96%)
kmem_cache_iter.bpf.o open_coded_iter 63 59 -4 (-6.35%) 7 6 -1 (-14.29%)
verifier_bits_iter.bpf.o max_words 92 84 -8 (-8.70%) 8 7 -1 (-12.50%)
verifier_iterating_callbacks.bpf.o cond_break2 113 107 -6 (-5.31%) 12 12 +0 (+0.00%)
And significant negative impact for sched_ext:
File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
----------------- ---------------------- --------- --------- -------------------- ---------- ---------- ------------------
bpf.bpf.o lavd_init 7039 14723 +7684 (+109.16%) 490 1139 +649 (+132.45%)
bpf.bpf.o layered_dispatch 11485 10548 -937 (-8.16%) 848 762 -86 (-10.14%)
bpf.bpf.o layered_dump 7422 1000001 +992579 (+13373.47%) 681 31178 +30497 (+4478.27%)
bpf.bpf.o layered_enqueue 16854 71127 +54273 (+322.02%) 1611 6450 +4839 (+300.37%)
bpf.bpf.o p2dq_dispatch 665 791 +126 (+18.95%) 68 78 +10 (+14.71%)
bpf.bpf.o p2dq_init 2343 2980 +637 (+27.19%) 201 237 +36 (+17.91%)
bpf.bpf.o refresh_layer_cpumasks 16487 674760 +658273 (+3992.68%) 1770 65370 +63600 (+3593.22%)
bpf.bpf.o rusty_select_cpu 1937 40872 +38935 (+2010.07%) 177 3210 +3033 (+1713.56%)
scx_central.bpf.o central_dispatch 636 2687 +2051 (+322.48%) 63 227 +164 (+260.32%)
scx_nest.bpf.o nest_init 636 815 +179 (+28.14%) 60 73 +13 (+21.67%)
scx_qmap.bpf.o qmap_dispatch 2393 3580 +1187 (+49.60%) 196 253 +57 (+29.08%)
scx_qmap.bpf.o qmap_dump 233 318 +85 (+36.48%) 22 30 +8 (+36.36%)
scx_qmap.bpf.o qmap_init 16367 17436 +1069 (+6.53%) 603 669 +66 (+10.95%)
Note 'layered_dump' program, which now hits 1M instructions limit.
This impact would be mitigated in the next patch.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250215110411.3236773-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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