| Age | Commit message (Collapse) | Author | Lines |
|---|
|
Uprobe needs to fetch args into a percpu buffer, and then copy to ring
buffer to avoid non-atomic context problem.
Sometimes user-space strings, arrays can be very large, but the size of
percpu buffer is only page size. And store_trace_args() won't check
whether these data exceeds a single page or not, caused out-of-bounds
memory access.
It could be reproduced by following steps:
1. build kernel with CONFIG_KASAN enabled
2. save follow program as test.c
```
\#include <stdio.h>
\#include <stdlib.h>
\#include <string.h>
// If string length large than MAX_STRING_SIZE, the fetch_store_strlen()
// will return 0, cause __get_data_size() return shorter size, and
// store_trace_args() will not trigger out-of-bounds access.
// So make string length less than 4096.
\#define STRLEN 4093
void generate_string(char *str, int n)
{
int i;
for (i = 0; i < n; ++i)
{
char c = i % 26 + 'a';
str[i] = c;
}
str[n-1] = '\0';
}
void print_string(char *str)
{
printf("%s\n", str);
}
int main()
{
char tmp[STRLEN];
generate_string(tmp, STRLEN);
print_string(tmp);
return 0;
}
```
3. compile program
`gcc -o test test.c`
4. get the offset of `print_string()`
```
objdump -t test | grep -w print_string
0000000000401199 g F .text 000000000000001b print_string
```
5. configure uprobe with offset 0x1199
```
off=0x1199
cd /sys/kernel/debug/tracing/
echo "p /root/test:${off} arg1=+0(%di):ustring arg2=\$comm arg3=+0(%di):ustring"
> uprobe_events
echo 1 > events/uprobes/enable
echo 1 > tracing_on
```
6. run `test`, and kasan will report error.
==================================================================
BUG: KASAN: use-after-free in strncpy_from_user+0x1d6/0x1f0
Write of size 8 at addr ffff88812311c004 by task test/499CPU: 0 UID: 0 PID: 499 Comm: test Not tainted 6.12.0-rc3+ #18
Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x55/0x70
print_address_description.constprop.0+0x27/0x310
kasan_report+0x10f/0x120
? strncpy_from_user+0x1d6/0x1f0
strncpy_from_user+0x1d6/0x1f0
? rmqueue.constprop.0+0x70d/0x2ad0
process_fetch_insn+0xb26/0x1470
? __pfx_process_fetch_insn+0x10/0x10
? _raw_spin_lock+0x85/0xe0
? __pfx__raw_spin_lock+0x10/0x10
? __pte_offset_map+0x1f/0x2d0
? unwind_next_frame+0xc5f/0x1f80
? arch_stack_walk+0x68/0xf0
? is_bpf_text_address+0x23/0x30
? kernel_text_address.part.0+0xbb/0xd0
? __kernel_text_address+0x66/0xb0
? unwind_get_return_address+0x5e/0xa0
? __pfx_stack_trace_consume_entry+0x10/0x10
? arch_stack_walk+0xa2/0xf0
? _raw_spin_lock_irqsave+0x8b/0xf0
? __pfx__raw_spin_lock_irqsave+0x10/0x10
? depot_alloc_stack+0x4c/0x1f0
? _raw_spin_unlock_irqrestore+0xe/0x30
? stack_depot_save_flags+0x35d/0x4f0
? kasan_save_stack+0x34/0x50
? kasan_save_stack+0x24/0x50
? mutex_lock+0x91/0xe0
? __pfx_mutex_lock+0x10/0x10
prepare_uprobe_buffer.part.0+0x2cd/0x500
uprobe_dispatcher+0x2c3/0x6a0
? __pfx_uprobe_dispatcher+0x10/0x10
? __kasan_slab_alloc+0x4d/0x90
handler_chain+0xdd/0x3e0
handle_swbp+0x26e/0x3d0
? __pfx_handle_swbp+0x10/0x10
? uprobe_pre_sstep_notifier+0x151/0x1b0
irqentry_exit_to_user_mode+0xe2/0x1b0
asm_exc_int3+0x39/0x40
RIP: 0033:0x401199
Code: 01 c2 0f b6 45 fb 88 02 83 45 fc 01 8b 45 fc 3b 45 e4 7c b7 8b 45 e4 48 98 48 8d 50 ff 48 8b 45 e8 48 01 d0 ce
RSP: 002b:00007ffdf00576a8 EFLAGS: 00000206
RAX: 00007ffdf00576b0 RBX: 0000000000000000 RCX: 0000000000000ff2
RDX: 0000000000000ffc RSI: 0000000000000ffd RDI: 00007ffdf00576b0
RBP: 00007ffdf00586b0 R08: 00007feb2f9c0d20 R09: 00007feb2f9c0d20
R10: 0000000000000001 R11: 0000000000000202 R12: 0000000000401040
R13: 00007ffdf0058780 R14: 0000000000000000 R15: 0000000000000000
</TASK>
This commit enforces the buffer's maxlen less than a page-size to avoid
store_trace_args() out-of-memory access.
Link: https://lore.kernel.org/all/20241015060148.1108331-1-mqaio@linux.alibaba.com/
Fixes: dcad1a204f72 ("tracing/uprobes: Fetch args before reserving a ring buffer")
Signed-off-by: Qiao Ma <mqaio@linux.alibaba.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduling fixes from Borislav Petkov:
- Add PREEMPT_RT maintainers
- Fix another aspect of delayed dequeued tasks wrt determining their
state, i.e., whether they're runnable or blocked
- Handle delayed dequeued tasks and their migration wrt PSI properly
- Fix the situation where a delayed dequeue task gets enqueued into a
new class, which should not happen
- Fix a case where memory allocation would happen while the runqueue
lock is held, which is a no-no
- Do not over-schedule when tasks with shorter slices preempt the
currently running task
- Make sure delayed to deque entities are properly handled before
unthrottling
- Other smaller cleanups and improvements
* tag 'sched_urgent_for_v6.12_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
MAINTAINERS: Add an entry for PREEMPT_RT.
sched/fair: Fix external p->on_rq users
sched/psi: Fix mistaken CPU pressure indication after corrupted task state bug
sched/core: Dequeue PSI signals for blocked tasks that are delayed
sched: Fix delayed_dequeue vs switched_from_fair()
sched/core: Disable page allocation in task_tick_mm_cid()
sched/deadline: Use hrtick_enabled_dl() before start_hrtick_dl()
sched/eevdf: Fix wakeup-preempt by checking cfs_rq->nr_running
sched: Fix sched_delayed vs cfs_bandwidth
|
|
Using commas to declare struct members makes adding new members to this
struct not as nice with patch management.
Test results linux-modules-kpd succeed [0].
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
[mcgrof: add automated test results from kdevops using KPD ]
Link: https://github.com/linux-kdevops/linux-modules-kpd/actions/runs/11420095343 # [0]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
Validate properties of the strtab that are depended on elsewhere, but
were previously unchecked:
* String table nonempty (offset 0 is valid)
* String table has a leading NUL (offset 0 corresponds to "")
* String table is NUL terminated (strfoo functions won't run out of the
table while reading).
* All symbols names are inbounds of the string table.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
This patch only moves the existing strtab population to a function.
Validation comes in a following patch, this is split out to make the new
validation checks more clearly separated.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
Group all the index detection together to make the parent function
easier to read.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
Pull out index validation for the symbol string section.
Note that this does not validate the *contents* of the string table,
only shape and presence of the section.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
Centralize symbol table detection and property validation.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
Centralize .gnu.linkonce.this_module detection and property validation.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
Centralize .modinfo detection and property validation.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
Factor out the validation of section names.
There are two behavioral changes:
1. Previously, we did not validate non-SHF_ALLOC sections.
This may have once been safe, as find_sec skips non-SHF_ALLOC
sections, but find_any_sec, which will be used to load BTF if that is
enabled, ignores the SHF_ALLOC flag. Since there's no need to support
invalid section names, validate all of them, not just SHF_ALLOC
sections.
2. Section names were validated *after* accessing them for the purposes
of detecting ".modinfo" and ".gnu.linkonce.this_module". They are now
checked prior to the access, which could avoid bad accesses with
malformed modules.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
Factor out and document the validation of section headers.
Because we now validate all section offsets and lengths before accessing
them, we can remove the ad-hoc checks.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
Factor out verification of the ELF header and document what is checked.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
`validate_section_offset` doesn't modify the info passed in. Make this
clear by adjusting the type signature.
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ftrace fixes from Steven Rostedt:
"A couple of fixes to function graph infrastructure:
- Fix allocation of idle shadow stack allocation during hotplug
If function graph tracing is started when a CPU is offline, if it
were come online during the trace then the idle task that
represents the CPU will not get a shadow stack allocated for it.
This means all function graph hooks that happen while that idle
task is running (including in interrupt mode) will have all its
events dropped.
Switch over to the CPU hotplug mechanism that will have any newly
brought on line CPU get a callback that can allocate the shadow
stack for its idle task.
- Fix allocation size of the ret_stack_list array
When function graph tracing converted over to allowing more than
one user at a time, it had to convert its shadow stack from an
array of ret_stack structures to an array of unsigned longs. The
shadow stacks are allocated in batches of 32 at a time and assigned
to every running task. The batch is held by the ret_stack_list
array.
But when the conversion happened, instead of allocating an array of
32 pointers, it was allocated as a ret_stack itself (PAGE_SIZE).
This ret_stack_list gets passed to a function that iterates over
what it believes is its size defined by the
FTRACE_RETSTACK_ALLOC_SIZE macro (which is 32).
Luckily (PAGE_SIZE) is greater than 32 * sizeof(long), otherwise
this would have been an array overflow. This still should be fixed
and the ret_stack_list should be allocated to the size it is
expected to be as someday it may end up being bigger than
SHADOW_STACK_SIZE"
* tag 'ftrace-v6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
fgraph: Allocate ret_stack_list with proper size
fgraph: Use CPU hotplug mechanism to initialize idle shadow stacks
|
|
Remove hard-coded strings by using the helper function str_low_high().
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241018110709.111707-2-thorsten.blum@linux.dev
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Reorganize kerneldoc parameter names to match the parameter
order in the function header.
Problems identified using Coccinelle.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20240930112121.95324-22-Julia.Lawall@inria.fr
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The function rb_check_pages() validates the integrity of a specified
per-CPU tracing ring buffer. It does so by traversing the underlying
linked list and checking its next and prev links.
To guarantee that the list isn't modified during the check, a caller
typically needs to take cpu_buffer->reader_lock. This prevents the check
from running concurrently, for example, with a potential reader which
can make the list temporarily inconsistent when swapping its old reader
page into the buffer.
A problem with this approach is that the time when interrupts are
disabled is non-deterministic, dependent on the ring buffer size. This
particularly affects PREEMPT_RT because the reader_lock is a raw
spinlock which doesn't become sleepable on PREEMPT_RT kernels.
Modify the check so it still attempts to traverse the entire list, but
gives up the reader_lock between checking individual pages. Introduce
for this purpose a new variable ring_buffer_per_cpu.cnt which is bumped
any time the list is modified. The value is used by rb_check_pages() to
detect such a change and restart the check.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241015112810.27203-1-petr.pavlu@suse.com
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The ret_stack_list is an array of ret_stack shadow stacks for the function
graph usage. When the first function graph is enabled, all tasks in the
system get a shadow stack. The ret_stack_list is a 32 element array of
pointers to these shadow stacks. It allocates the shadow stack in batches
(32 stacks at a time), assigns them to running tasks, and continues until
all tasks are covered.
When the function graph shadow stack changed from an array of
ftrace_ret_stack structures to an array of longs, the allocation of
ret_stack_list went from allocating an array of 32 elements to just a
block defined by SHADOW_STACK_SIZE. Luckily, that's defined as PAGE_SIZE
and is much more than enough to hold 32 pointers. But it is way overkill
for the amount needed to allocate.
Change the allocation of ret_stack_list back to a kcalloc() of
FTRACE_RETSTACK_ALLOC_SIZE pointers.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241018215212.23f13f40@rorschach
Fixes: 42675b723b484 ("function_graph: Convert ret_stack to a series of longs")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
The function graph infrastructure allocates a shadow stack for every task
when enabled. This includes the idle tasks. The first time the function
graph is invoked, the shadow stacks are created and never freed until the
task exits. This includes the idle tasks.
Only the idle tasks that were for online CPUs had their shadow stacks
created when function graph tracing started. If function graph tracing is
enabled and a CPU comes online, the idle task representing that CPU will
not have its shadow stack created, and all function graph tracing for that
idle task will be silently dropped.
Instead, use the CPU hotplug mechanism to allocate the idle shadow stacks.
This will include idle tasks for CPUs that come online during tracing.
This issue can be reproduced by:
# cd /sys/kernel/tracing
# echo 0 > /sys/devices/system/cpu/cpu1/online
# echo 0 > set_ftrace_pid
# echo function_graph > current_tracer
# echo 1 > options/funcgraph-proc
# echo 1 > /sys/devices/system/cpu/cpu1
# grep '<idle>' per_cpu/cpu1/trace | head
Before, nothing would show up.
After:
1) <idle>-0 | 0.811 us | __enqueue_entity();
1) <idle>-0 | 5.626 us | } /* enqueue_entity */
1) <idle>-0 | | dl_server_update_idle_time() {
1) <idle>-0 | | dl_scaled_delta_exec() {
1) <idle>-0 | 0.450 us | arch_scale_cpu_capacity();
1) <idle>-0 | 1.242 us | }
1) <idle>-0 | 1.908 us | }
1) <idle>-0 | | dl_server_start() {
1) <idle>-0 | | enqueue_dl_entity() {
1) <idle>-0 | | task_contending() {
Note, if tracing stops and restarts, the old way would then initialize
the onlined CPUs.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20241018214300.6df82178@rorschach
Fixes: 868baf07b1a25 ("ftrace: Fix memory leak with function graph and cpu hotplug")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Pull bpf fixes from Daniel Borkmann:
- Fix BPF verifier to not affect subreg_def marks in its range
propagation (Eduard Zingerman)
- Fix a truncation bug in the BPF verifier's handling of
coerce_reg_to_size_sx (Dimitar Kanaliev)
- Fix the BPF verifier's delta propagation between linked registers
under 32-bit addition (Daniel Borkmann)
- Fix a NULL pointer dereference in BPF devmap due to missing rxq
information (Florian Kauer)
- Fix a memory leak in bpf_core_apply (Jiri Olsa)
- Fix an UBSAN-reported array-index-out-of-bounds in BTF parsing for
arrays of nested structs (Hou Tao)
- Fix build ID fetching where memory areas backing the file were
created with memfd_secret (Andrii Nakryiko)
- Fix BPF task iterator tid filtering which was incorrectly using pid
instead of tid (Jordan Rome)
- Several fixes for BPF sockmap and BPF sockhash redirection in
combination with vsocks (Michal Luczaj)
- Fix riscv BPF JIT and make BPF_CMPXCHG fully ordered (Andrea Parri)
- Fix riscv BPF JIT under CONFIG_CFI_CLANG to prevent the possibility
of an infinite BPF tailcall (Pu Lehui)
- Fix a build warning from resolve_btfids that bpf_lsm_key_free cannot
be resolved (Thomas Weißschuh)
- Fix a bug in kfunc BTF caching for modules where the wrong BTF object
was returned (Toke Høiland-Jørgensen)
- Fix a BPF selftest compilation error in cgroup-related tests with
musl libc (Tony Ambardar)
- Several fixes to BPF link info dumps to fill missing fields (Tyrone
Wu)
- Add BPF selftests for kfuncs from multiple modules, checking that the
correct kfuncs are called (Simon Sundberg)
- Ensure that internal and user-facing bpf_redirect flags don't overlap
(Toke Høiland-Jørgensen)
- Switch to use kvzmalloc to allocate BPF verifier environment (Rik van
Riel)
- Use raw_spinlock_t in BPF ringbuf to fix a sleep in atomic splat
under RT (Wander Lairson Costa)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (38 commits)
lib/buildid: Handle memfd_secret() files in build_id_parse()
selftests/bpf: Add test case for delta propagation
bpf: Fix print_reg_state's constant scalar dump
bpf: Fix incorrect delta propagation between linked registers
bpf: Properly test iter/task tid filtering
bpf: Fix iter/task tid filtering
riscv, bpf: Make BPF_CMPXCHG fully ordered
bpf, vsock: Drop static vsock_bpf_prot initialization
vsock: Update msg_count on read_skb()
vsock: Update rx_bytes on read_skb()
bpf, sockmap: SK_DROP on attempted redirects of unsupported af_vsock
selftests/bpf: Add asserts for netfilter link info
bpf: Fix link info netfilter flags to populate defrag flag
selftests/bpf: Add test for sign extension in coerce_subreg_to_size_sx()
selftests/bpf: Add test for truncation after sign extension in coerce_reg_to_size_sx()
bpf: Fix truncation bug in coerce_reg_to_size_sx()
selftests/bpf: Assert link info uprobe_multi count & path_size if unset
bpf: Fix unpopulated path_size when uprobe_multi fields unset
selftests/bpf: Fix cross-compiling urandom_read
selftests/bpf: Add test for kfunc module order
...
|
|
In the sched_ext built-in idle CPU selection logic, when handling a
WF_SYNC wakeup, we always attempt to migrate the task to the waker's
CPU, as the waker is expected to yield the CPU after waking the task.
However, it may be preferable to keep the task on its previous CPU if
the waker's CPU is cache-affine.
The same approach is also used by the fair class and in other scx
schedulers, like scx_rusty and scx_bpfland.
Therefore, apply the same logic to the built-in idle CPU selection
policy as well.
Signed-off-by: Andrea Righi <andrea.righi@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
Convert the fields of 'enum vcpu_state' to uppercase for better
readability. No functional changes intended.
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20240809014802.15320-1-qiuxu.zhuo@intel.com
|
|
All those:
Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar
... MAX_LOCKDEP_SUBCLASSES: 8
... MAX_LOCK_DEPTH: 48
... MAX_LOCKDEP_KEYS: 8192
and so on are dumped with the KERN_WARNING level. It is due to missing
KERN_* annotation.
Use pr_info() instead of bare printk() to dump the info with the info
level.
Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20241007065457.20128-1-jirislaby@kernel.org
|
|
Add a function to check that an offline CPU has left the tracing
infrastructure in a sane state.
Commit 9bb69ba4c177 ("ACPI: processor_idle: use raw_safe_halt() in
acpi_idle_play_dead()") fixed an issue where the acpi_idle_play_dead()
function called safe_halt() instead of raw_safe_halt(), which had the
side-effect of setting the hardirqs_enabled flag for the offline CPU.
On x86 this triggered warnings from lockdep_assert_irqs_disabled() when
the CPU was brought back online again later. These warnings were too
early for the exception to be handled correctly, leading to a
triple-fault.
Add lockdep_cleanup_dead_cpu() to check for this kind of failure mode,
print the events leading up to it, and correct it so that the CPU can
come online again correctly. Re-introducing the original bug now merely
results in this warning instead:
[ 61.556652] smpboot: CPU 1 is now offline
[ 61.556769] CPU 1 left hardirqs enabled!
[ 61.556915] irq event stamp: 128149
[ 61.556965] hardirqs last enabled at (128149): [<ffffffff81720a36>] acpi_idle_play_dead+0x46/0x70
[ 61.557055] hardirqs last disabled at (128148): [<ffffffff81124d50>] do_idle+0x90/0xe0
[ 61.557117] softirqs last enabled at (128078): [<ffffffff81cec74c>] __do_softirq+0x31c/0x423
[ 61.557199] softirqs last disabled at (128065): [<ffffffff810baae1>] __irq_exit_rcu+0x91/0x100
[boqun: Capitalize the title and reword the message a bit]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/f7bd2b3b999051bb3ef4be34526a9262008285f5.camel@infradead.org
|
|
Optimize get_inode_sequence_number() to use simpler and faster:
!atomic64_try_cmpxchg_relaxed(*ptr, &old, new)
instead of:
atomic64_cmpxchg relaxed(*ptr, old, new) != old
The x86 CMPXCHG instruction returns success in ZF flag, so
this change saves a compare after cmpxchg. The generated
code improves from:
3da: 31 c0 xor %eax,%eax
3dc: f0 48 0f b1 8a 38 01 lock cmpxchg %rcx,0x138(%rdx)
3e3: 00 00
3e5: 48 85 c0 test %rax,%rax
3e8: 48 0f 44 c1 cmove %rcx,%rax
to:
3da: 31 c0 xor %eax,%eax
3dc: f0 48 0f b1 8a 38 01 lock cmpxchg %rcx,0x138(%rdx)
3e3: 00 00
3e5: 48 0f 44 c1 cmove %rcx,%rax
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/all/20241010071023.21913-2-ubizjak@gmail.com
|
|
Use atomic64_inc_return(&ref) instead of atomic64_add_return(1, &ref)
to use optimized implementation and ease register pressure around
the primitive for targets that implement optimized variant.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/all/20241010071023.21913-1-ubizjak@gmail.com
|
|
print_reg_state() should not consider adding reg->off to reg->var_off.value
when dumping scalars. Scalars can be produced with reg->off != 0 through
BPF_ADD_CONST, and thus as-is this can skew the register log dump.
Fixes: 98d7ca374ba4 ("bpf: Track delta between "linked" registers.")
Reported-by: Nathaniel Theis <nathaniel.theis@nccgroup.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241016134913.32249-2-daniel@iogearbox.net
|
|
Nathaniel reported a bug in the linked scalar delta tracking, which can lead
to accepting a program with OOB access. The specific code is related to the
sync_linked_regs() function and the BPF_ADD_CONST flag, which signifies a
constant offset between two scalar registers tracked by the same register id.
The verifier attempts to track "similar" scalars in order to propagate bounds
information learned about one scalar to others. For instance, if r1 and r2
are known to contain the same value, then upon encountering 'if (r1 != 0x1234)
goto xyz', not only does it know that r1 is equal to 0x1234 on the path where
that conditional jump is not taken, it also knows that r2 is.
Additionally, with env->bpf_capable set, the verifier will track scalars
which should be a constant delta apart (if r1 is known to be one greater than
r2, then if r1 is known to be equal to 0x1234, r2 must be equal to 0x1233.)
The code path for the latter in adjust_reg_min_max_vals() is reached when
processing both 32 and 64-bit addition operations. While adjust_reg_min_max_vals()
knows whether dst_reg was produced by a 32 or a 64-bit addition (based on the
alu32 bool), the only information saved in dst_reg is the id of the source
register (reg->id, or'ed by BPF_ADD_CONST) and the value of the constant
offset (reg->off).
Later, the function sync_linked_regs() will attempt to use this information
to propagate bounds information from one register (known_reg) to others,
meaning, for all R in linked_regs, it copies known_reg range (and possibly
adjusting delta) into R for the case of R->id == known_reg->id.
For the delta adjustment, meaning, matching reg->id with BPF_ADD_CONST, the
verifier adjusts the register as reg = known_reg; reg += delta where delta
is computed as (s32)reg->off - (s32)known_reg->off and placed as a scalar
into a fake_reg to then simulate the addition of reg += fake_reg. This is
only correct, however, if the value in reg was created by a 64-bit addition.
When reg contains the result of a 32-bit addition operation, its upper 32
bits will always be zero. sync_linked_regs() on the other hand, may cause
the verifier to believe that the addition between fake_reg and reg overflows
into those upper bits. For example, if reg was generated by adding the
constant 1 to known_reg using a 32-bit alu operation, then reg->off is 1
and known_reg->off is 0. If known_reg is known to be the constant 0xFFFFFFFF,
sync_linked_regs() will tell the verifier that reg is equal to the constant
0x100000000. This is incorrect as the actual value of reg will be 0, as the
32-bit addition will wrap around.
Example:
0: (b7) r0 = 0; R0_w=0
1: (18) r1 = 0x80000001; R1_w=0x80000001
3: (37) r1 /= 1; R1_w=scalar()
4: (bf) r2 = r1; R1_w=scalar(id=1) R2_w=scalar(id=1)
5: (bf) r4 = r1; R1_w=scalar(id=1) R4_w=scalar(id=1)
6: (04) w2 += 2147483647; R2_w=scalar(id=1+2147483647,smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
7: (04) w4 += 0 ; R4_w=scalar(id=1+0,smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
8: (15) if r2 == 0x0 goto pc+1
10: R0=0 R1=0xffffffff80000001 R2=0x7fffffff R4=0xffffffff80000001 R10=fp0
What can be seen here is that r1 is copied to r2 and r4, such that {r1,r2,r4}.id
are all the same which later lets sync_linked_regs() to be invoked. Then, in
a next step constants are added with alu32 to r2 and r4, setting their ->off,
as well as id |= BPF_ADD_CONST. Next, the conditional will bind r2 and
propagate ranges to its linked registers. The verifier now believes the upper
32 bits of r4 are r4=0xffffffff80000001, while actually r4=r1=0x80000001.
One approach for a simple fix suitable also for stable is to limit the constant
delta tracking to only 64-bit alu addition. If necessary at some later point,
BPF_ADD_CONST could be split into BPF_ADD_CONST64 and BPF_ADD_CONST32 to avoid
mixing the two under the tradeoff to further complicate sync_linked_regs().
However, none of the added tests from dedf56d775c0 ("selftests/bpf: Add tests
for add_const") make this necessary at this point, meaning, BPF CI also passes
with just limiting tracking to 64-bit alu addition.
Fixes: 98d7ca374ba4 ("bpf: Track delta between "linked" registers.")
Reported-by: Nathaniel Theis <nathaniel.theis@nccgroup.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20241016134913.32249-1-daniel@iogearbox.net
|
|
In userspace, you can add a tid filter by setting
the "task.tid" field for "bpf_iter_link_info".
However, `get_pid_task` when called for the
`BPF_TASK_ITER_TID` type should have been using
`PIDTYPE_PID` (tid) instead of `PIDTYPE_TGID` (pid).
Fixes: f0d74c4da1f0 ("bpf: Parameterize task iterators.")
Signed-off-by: Jordan Rome <linux@jordanrome.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241016210048.1213935-1-linux@jordanrome.com
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Current release - new code bugs:
- eth: mlx5: HWS, don't destroy more bwc queue locks than allocated
Previous releases - regressions:
- ipv4: give an IPv4 dev to blackhole_netdev
- udp: compute L4 checksum as usual when not segmenting the skb
- tcp/dccp: don't use timer_pending() in reqsk_queue_unlink().
- eth: mlx5e: don't call cleanup on profile rollback failure
- eth: microchip: vcap api: fix memory leaks in
vcap_api_encode_rule_test()
- eth: enetc: disable Tx BD rings after they are empty
- eth: macb: avoid 20s boot delay by skipping MDIO bus registration
for fixed-link PHY
Previous releases - always broken:
- posix-clock: fix missing timespec64 check in pc_clock_settime()
- genetlink: hold RCU in genlmsg_mcast()
- mptcp: prevent MPC handshake on port-based signal endpoints
- eth: vmxnet3: fix packet corruption in vmxnet3_xdp_xmit_frame
- eth: stmmac: dwmac-tegra: fix link bring-up sequence
- eth: bcmasp: fix potential memory leak in bcmasp_xmit()
Misc:
- add Andrew Lunn as a co-maintainer of all networking drivers"
* tag 'net-6.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (47 commits)
net/mlx5e: Don't call cleanup on profile rollback failure
net/mlx5: Unregister notifier on eswitch init failure
net/mlx5: Fix command bitmask initialization
net/mlx5: Check for invalid vector index on EQ creation
net/mlx5: HWS, use lock classes for bwc locks
net/mlx5: HWS, don't destroy more bwc queue locks than allocated
net/mlx5: HWS, fixed double free in error flow of definer layout
net/mlx5: HWS, removed wrong access to a number of rules variable
mptcp: pm: fix UaF read in mptcp_pm_nl_rm_addr_or_subflow
net: ethernet: mtk_eth_soc: fix memory corruption during fq dma init
vmxnet3: Fix packet corruption in vmxnet3_xdp_xmit_frame
net: dsa: vsc73xx: fix reception from VLAN-unaware bridges
net: ravb: Only advertise Rx/Tx timestamps if hardware supports it
net: microchip: vcap api: Fix memory leaks in vcap_api_encode_rule_test()
net: phy: mdio-bcm-unimac: Add BCM6846 support
dt-bindings: net: brcm,unimac-mdio: Add bcm6846-mdio
udp: Compute L4 checksum as usual when not segmenting the skb
genetlink: hold RCU in genlmsg_mcast()
net: dsa: mv88e6xxx: Fix the max_vid definition for the MV88E6361
tcp/dccp: Don't use timer_pending() in reqsk_queue_unlink().
...
|
|
Save the searching time during bpf_scx_init.
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
Conflicts:
kernel/sched/ext.c
There's a context conflict between this upstream commit:
3fdb9ebcec10 sched_ext: Start schedulers with consistent p->scx.slice values
... and this fix in sched/urgent:
98442f0ccd82 sched: Fix delayed_dequeue vs switched_from_fair()
Resolve it.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Unexport nr_irqs and declare it static now that all code that reads or
modifies nr_irqs has been converted to number_of_interrupts() /
set_number_of_interrupts(). Change the type of 'nr_irqs' from 'int' into
'unsigned int' to match the return type and argument type of the
irq_get_nr_iqs() / irq_set_nr_irqs() functions.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241015190953.1266194-23-bvanassche@acm.org
|
|
Use the irq_get_nr_irqs() function instead of the global variable
'nr_irqs'. Cache the result of this function in a local variable in
order not to rely on CSE (common subexpression elimination). Prepare
for changing 'nr_irqs' from an exported global variable into a variable
with file scope.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241015190953.1266194-22-bvanassche@acm.org
|
|
Prepare for changing 'nr_irqs' from an exported global variable into a
variable with file scope.
This will prevent accidental changes of assignments to a local variable
'nr_irqs' into assignments to the global 'nr_irqs' variable.
Suppose that a patch would be submitted for review that removes a
declaration of a local variable with the name 'nr_irqs' and that that patch
does not remove all assignments to that local variable. Such a patch
converts an assignment to a local variable into an assignment into a global
variable. If the 'nr_irqs' assignment is more than three lines away from
other changes, the assignment won't be included in the diff context lines
and hence won't be visible without inspecting the modified file.
With these abstraction series applied, such accidental conversions from
assignments to a local variable into an assignment to a global variable are
converted into a compilation error.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241015190953.1266194-2-bvanassche@acm.org
|
|
There is a potential infinite loop issue that can occur when using a
combination of tail calls and freplace.
In an upcoming selftest, the attach target for entry_freplace of
tailcall_freplace.c is subprog_tc of tc_bpf2bpf.c, while the tail call in
entry_freplace leads to entry_tc. This results in an infinite loop:
entry_tc -> subprog_tc -> entry_freplace --tailcall-> entry_tc.
The problem arises because the tail_call_cnt in entry_freplace resets to
zero each time entry_freplace is executed, causing the tail call mechanism
to never terminate, eventually leading to a kernel panic.
To fix this issue, the solution is twofold:
1. Prevent updating a program extended by an freplace program to a
prog_array map.
2. Prevent extending a program that is already part of a prog_array map
with an freplace program.
This ensures that:
* If a program or its subprogram has been extended by an freplace program,
it can no longer be updated to a prog_array map.
* If a program has been added to a prog_array map, neither it nor its
subprograms can be extended by an freplace program.
Moreover, an extension program should not be tailcalled. As such, return
-EINVAL if the program has a type of BPF_PROG_TYPE_EXT when adding it to a
prog_array map.
Additionally, fix a minor code style issue by replacing eight spaces with a
tab for proper formatting.
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20241015150207.70264-2-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
bpf_task_from_pid() that currently exists looks up the
struct task_struct corresponding to the pid in the root pid
namespace (init_pid_ns).
This patch adds bpf_task_from_vpid() which looks up the
struct task_struct corresponding to vpid in the pid namespace
of the current process.
This is useful for getting information about other processes
in the same pid namespace.
Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Link: https://lore.kernel.org/r/AM6PR03MB5848E50DA58F79CDE65433C399442@AM6PR03MB5848.eurprd03.prod.outlook.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
The bpf_get_kmem_cache() is to get a slab cache information from a
virtual address like virt_to_cache(). If the address is a pointer
to a slab object, it'd return a valid kmem_cache pointer, otherwise
NULL is returned.
It doesn't grab a reference count of the kmem_cache so the caller is
responsible to manage the access. The returned point is marked as
PTR_UNTRUSTED.
The intended use case for now is to symbolize locks in slab objects
from the lock contention tracepoints.
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev> (mm/*)
Acked-by: Vlastimil Babka <vbabka@suse.cz> #mm/slab
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241010232505.1339892-3-namhyung@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
When the initial printk ring buffer size is updated, setup_log_buf()
allocates a new ring buffer, as well as a set of meta-data structures
for the new ring buffer. The function also emits the new size of the
ring buffer, but not the size of the meta-data structures.
This makes it difficult to assess how changing the log buffer size
impacts memory usage during boot.
For instance, increasing the ring buffer size from 512 KB to 1 MB
through the command line yields an increase of 2304 KB in reserved
memory at boot, while the only obvious change is the 512 KB
difference in the ring buffer sizes:
log_buf_len=512K:
printk: log_buf_len: 524288 bytes
Memory: ... (... 733252K reserved ...)
log_buf_len=1M:
printk: log_buf_len: 1048576 bytes
Memory: ... (... 735556K reserved ...)
This is because of how the size of the meta-data structures scale with
the size of the ring buffer.
Even when there aren't changes to the printk ring buffer size (i.e. the
initial size == 1 << CONFIG_LOG_BUF_SHIFT), it is impossible to tell
how much memory is consumed by the printk ring buffer during boot.
Therefore, unconditionally log the sizes of the printk ring buffer
and its meta-data structures, so that it's easier to understand
how changing the log buffer size (either through the command line or
by changing CONFIG_LOG_BUF_SHIFT) affects boot time memory usage.
With the new logs, it is much easier to see exactly why the memory
increased by 2304 KB:
log_buf_len=512K:
printk: log buffer data + meta data: 524288 + 1835008 = 2359296 bytes
Memory: ... (... 733252K reserved ...)
log_buf_len=1M:
printk: log buffer data + meta data: 1048576 + 3670016 = 4718592 bytes
Memory: ... (... 735556K reserved ...)
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20240930184826.3595221-1-isaacmanjarres@google.com
[pmladek@suse.com: Updated the examples in the commit message, simplified comment for default buffer.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext fixes from Tejun Heo:
- More issues reported in the enable/disable paths on large machines
with many tasks due to scx_tasks_lock being held too long. Break up
the task iterations
- Remove ops.select_cpu() dependency in bypass mode so that a
misbehaving implementation can't live-lock the machine by pushing all
tasks to few CPUs in bypass mode
- Other misc fixes
* tag 'sched_ext-for-6.12-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
sched_ext: Remove unnecessary cpu_relax()
sched_ext: Don't hold scx_tasks_lock for too long
sched_ext: Move scx_tasks_lock handling into scx_task_iter helpers
sched_ext: bypass mode shouldn't depend on ops.select_cpu()
sched_ext: Move scx_buildin_idle_enabled check to scx_bpf_select_cpu_dfl()
sched_ext: Start schedulers with consistent p->scx.slice values
Revert "sched_ext: Use shorter slice while bypassing"
sched_ext: use correct function name in pick_task_scx() warning message
selftests: sched_ext: Add sched_ext as proper selftest target
|
|
There is a warning in checkpatch script that triggers, when min and max
arguments of usleep_range_state() are in reverse order. This check does
only cover callsites which uses constants. Add this check into the code as
a WARN_ON_ONCE() to also cover callsites not using constants and fix the
mis-usage by resetting the delta to 0.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-9-dc8b907cb62f@linutronix.de
|
|
A lot of commonly used functions for inserting a sleep or delay lack a
proper function description. Add function descriptions to all of them to
have important information in a central place close to the code.
No functional change.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-5-dc8b907cb62f@linutronix.de
|
|
schedule_timeout*() functions do not have proper kernel-doc formatted
function descriptions. schedule_hrtimeout() and schedule_hrtimeout_range()
have a almost identical description.
Add missing function descriptions. Remove copy of function description and
add a pointer to the existing description instead.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-3-dc8b907cb62f@linutronix.de
|
|
All schedule_timeout() and *sleep*() related functions are interfaces on
top of timer list timers and hrtimers to add a sleep to the code. As they
are built on top of the timer list timers and hrtimers, the [hr]timer
interfaces are already used except when queuing the timer in
schedule_timeout(). But there exists the appropriate interface add_timer()
which does the same job with an extra check for an already pending timer.
Split all those functions as they are into a separate file and use
add_timer() instead of __mod_timer() in schedule_timeout().
While at it fix minor formatting issues and a multi line printk function
call in schedule_timeout().
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-2-dc8b907cb62f@linutronix.de
|
|
Change %0 to 0 in kernel-doc comments. %0 is not valid.
Signed-off-by: Wang Jinchao <wangjinchao@xfusion.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241009022135.92400-2-wangjinchao@xfusion.com
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring-buffer fixes from Steven Rostedt:
- Fix ref counter of buffers assigned at boot up
A tracing instance can be created from the kernel command line. If it
maps to memory, it is considered permanent and should not be deleted,
or bad things can happen. If it is not mapped to memory, then the
user is fine to delete it via rmdir from the instances directory. But
the ref counts assumed 0 was free to remove and greater than zero was
not. But this was not the case. When an instance is created, it
should have the reference of 1, and if it should not be removed, it
must be greater than 1. The boot up code set normal instances with a
ref count of 0, which could get removed if something accessed it and
then released it. And memory mapped instances had a ref count of 1
which meant it could be deleted, and bad things happen. Keep normal
instances ref count as 1, and set memory mapped instances ref count
to 2.
- Protect sub buffer size (order) updates from other modifications
When a ring buffer is changing the size of its sub-buffers, no other
operations should be performed on the ring buffer. That includes
reading it. But the locking only grabbed the buffer->mutex that keeps
some operations from touching the ring buffer. It also must hold the
cpu_buffer->reader_lock as well when updates happen as other paths
use that to do some operations on the ring buffer.
* tag 'trace-ringbuffer-v6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Fix reader locking when changing the sub buffer order
ring-buffer: Fix refcount setting of boot mapped buffers
|
|
coerce_reg_to_size_sx() updates the register state after a sign-extension
operation. However, there's a bug in the assignment order of the unsigned
min/max values, leading to incorrect truncation:
0: (85) call bpf_get_prandom_u32#7 ; R0_w=scalar()
1: (57) r0 &= 1 ; R0_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=1,var_off=(0x0; 0x1))
2: (07) r0 += 254 ; R0_w=scalar(smin=umin=smin32=umin32=254,smax=umax=smax32=umax32=255,var_off=(0xfe; 0x1))
3: (bf) r0 = (s8)r0 ; R0_w=scalar(smin=smin32=-2,smax=smax32=-1,umin=umin32=0xfffffffe,umax=0xffffffff,var_off=(0xfffffffffffffffe; 0x1))
In the current implementation, the unsigned 32-bit min/max values
(u32_min_value and u32_max_value) are assigned directly from the 64-bit
signed min/max values (s64_min and s64_max):
reg->umin_value = reg->u32_min_value = s64_min;
reg->umax_value = reg->u32_max_value = s64_max;
Due to the chain assigmnent, this is equivalent to:
reg->u32_min_value = s64_min; // Unintended truncation
reg->umin_value = reg->u32_min_value;
reg->u32_max_value = s64_max; // Unintended truncation
reg->umax_value = reg->u32_max_value;
Fixes: 1f9a1ea821ff ("bpf: Support new sign-extension load insns")
Reported-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Reported-by: Zac Ecob <zacecob@protonmail.com>
Signed-off-by: Dimitar Kanaliev <dimitar.kanaliev@siteground.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Reviewed-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Link: https://lore.kernel.org/r/20241014121155.92887-2-dimitar.kanaliev@siteground.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
No implementation of this hook uses the passed in timekeeper anymore.
This avoids including a non-VDSO header while building the VDSO, which can
lead to compilation errors.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/all/20241010-vdso-generic-arch_update_vsyscall-v1-1-7fe5a3ea4382@linutronix.de
|
|
The function ring_buffer_subbuf_order_set() updates each
ring_buffer_per_cpu and installs new sub buffers that match the requested
page order. This operation may be invoked concurrently with readers that
rely on some of the modified data, such as the head bit (RB_PAGE_HEAD), or
the ring_buffer_per_cpu.pages and reader_page pointers. However, no
exclusive access is acquired by ring_buffer_subbuf_order_set(). Modifying
the mentioned data while a reader also operates on them can then result in
incorrect memory access and various crashes.
Fix the problem by taking the reader_lock when updating a specific
ring_buffer_per_cpu in ring_buffer_subbuf_order_set().
Link: https://lore.kernel.org/linux-trace-kernel/20240715145141.5528-1-petr.pavlu@suse.com/
Link: https://lore.kernel.org/linux-trace-kernel/20241010195849.2f77cc3f@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20241011112850.17212b25@gandalf.local.home/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241015112440.26987-1-petr.pavlu@suse.com
Fixes: 8e7b58c27b3c ("ring-buffer: Just update the subbuffers when changing their allocation order")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
