tjh.dev
Linux kernel
============
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In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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Pull tracing fixes from Steven Rostedt:
- Fix timerlat with use of FORTIFY_SOURCE
FORTIFY_SOURCE was added to the stack tracer where it compares the
entry->caller array to having entry->size elements.
timerlat has the following:
memcpy(&entry->caller, fstack->calls, size);
entry->size = size;
Which triggers FORTIFY_SOURCE as the caller is populated before the
entry->size is initialized.
Swap the order to satisfy FORTIFY_SOURCE logic.
- Add down_write(trace_event_sem) when adding trace events in modules
Trace events being added to the ftrace_events array are protected by
the trace_event_sem semaphore. But when loading modules that have
trace events, the addition of the events are not protected by the
semaphore and loading two modules that have events at the same time
can corrupt the list.
Also add a lockdep_assert_held(trace_event_sem) to
_trace_add_event_dirs() to confirm it is held when iterating the
list.
* tag 'trace-v6.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Add down_write(trace_event_sem) when adding trace event
tracing/osnoise: Fix crash in timerlat_dump_stack()
Pull i2c fixes from Wolfram Sang:
"omap:
- add missing error check
- fix PM disable in probe error path
stm32:
- unmap DMA buffer on transfer failure
- use correct device when mapping and unmapping during transfers"
* tag 'i2c-for-6.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: stm32f7: unmap DMA mapped buffer
i2c: stm32: fix the device used for the DMA map
i2c: omap: Fix an error handling path in omap_i2c_probe()
i2c: omap: Handle omap_i2c_init() errors in omap_i2c_probe()
When a module is loaded, it adds trace events defined by the module. It
may also need to modify the modules trace printk formats to replace enum
names with their values.
If two modules are loaded at the same time, the adding of the event to the
ftrace_events list can corrupt the walking of the list in the code that is
modifying the printk format strings and crash the kernel.
The addition of the event should take the trace_event_sem for write while
it adds the new event.
Also add a lockdep_assert_held() on that semaphore in
__trace_add_event_dirs() as it iterates the list.
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/20250718223158.799bfc0c@batman.local.home
Reported-by: Fusheng Huang(黄富生) <Fusheng.Huang@luxshare-ict.com>
Closes: https://lore.kernel.org/all/20250717105007.46ccd18f@batman.local.home/
Fixes: 110bf2b764eb6 ("tracing: add protection around module events unload")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Pull x86 bug fix from Thomas Gleixner:
"A single fix for a GCC wreckage, which emits a KCSAN instrumentation
call in __sev_es_nmi_complete() despite the function being annotated
with 'noinstr'.
As all functions in that source file are noinstr, exclude the whole
file from KCSAN in the Makefile to cure it"
* tag 'x86-urgent-2025-07-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sev: Work around broken noinstr on GCC
i2c-host-fixes for v6.16-rc6
omap: add missing error check and fix PM disable in probe error
path.
stm32: unmap DMA buffer on transfer failure and use correct
device when mapping and unmapping during transfers.
We have observed kernel panics when using timerlat with stack saving,
with the following dmesg output:
memcpy: detected buffer overflow: 88 byte write of buffer size 0
WARNING: CPU: 2 PID: 8153 at lib/string_helpers.c:1032 __fortify_report+0x55/0xa0
CPU: 2 UID: 0 PID: 8153 Comm: timerlatu/2 Kdump: loaded Not tainted 6.15.3-200.fc42.x86_64 #1 PREEMPT(lazy)
Call Trace:
<TASK>
? trace_buffer_lock_reserve+0x2a/0x60
__fortify_panic+0xd/0xf
__timerlat_dump_stack.cold+0xd/0xd
timerlat_dump_stack.part.0+0x47/0x80
timerlat_fd_read+0x36d/0x390
vfs_read+0xe2/0x390
? syscall_exit_to_user_mode+0x1d5/0x210
ksys_read+0x73/0xe0
do_syscall_64+0x7b/0x160
? exc_page_fault+0x7e/0x1a0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
__timerlat_dump_stack() constructs the ftrace stack entry like this:
struct stack_entry *entry;
...
memcpy(&entry->caller, fstack->calls, size);
entry->size = fstack->nr_entries;
Since commit e7186af7fb26 ("tracing: Add back FORTIFY_SOURCE logic to
kernel_stack event structure"), struct stack_entry marks its caller
field with __counted_by(size). At the time of the memcpy, entry->size
contains garbage from the ringbuffer, which under some circumstances is
zero, triggering a kernel panic by buffer overflow.
Populate the size field before the memcpy so that the out-of-bounds
check knows the correct size. This is analogous to
__ftrace_trace_stack().
Cc: stable@vger.kernel.org
Cc: John Kacur <jkacur@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Cc: Attila Fazekas <afazekas@redhat.com>
Link: https://lore.kernel.org/20250716143601.7313-1-tglozar@redhat.com
Fixes: e7186af7fb26 ("tracing: Add back FORTIFY_SOURCE logic to kernel_stack event structure")
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Pull locking fix from Thomas Gleixner:
"A single fix for the futex selftest code to make 32-bit user space
work correctly on 64-bit kernels.
sys_futex_wait() expects a struct __kernel_timespec for the timeout,
but the selftest uses struct timespec, which is the original 32-bit
non 2038 compliant variant.
Fix it up by converting the callsite supplied timespec to a
__kernel_timespec and hand that into the syscall"
* tag 'locking-urgent-2025-07-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
selftests/futex: Convert 32-bit timespec to 64-bit version for 32-bit compatibility mode
Forcibly disable KCSAN for the sev-nmi.c source file, which only
contains functions annotated as 'noinstr' but is emitted with calls to
KCSAN instrumentation nonetheless. E.g.,
vmlinux.o: error: objtool: __sev_es_nmi_complete+0x58: call to __kcsan_check_access() leaves .noinstr.text section
make[2]: *** [/usr/local/google/home/ardb/linux/scripts/Makefile.vmlinux_o:72: vmlinux.o] Error 1
Fixes: a3cbbb4717e1 ("x86/boot: Move SEV startup code into startup/")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/20250714073402.4107091-2-ardb+git@google.com
Before each I2C transfer using DMA, the I2C buffer is DMA'pped to make
sure the memory buffer is DMA'able. This is handle in the function
`stm32_i2c_prep_dma_xfer()`.
If the transfer fails for any reason the I2C buffer must be unmap.
Use the dma_callback to factorize the code and fix this issue.
Note that the `stm32f7_i2c_dma_callback()` is now called in case of DMA
transfer success and error and that the `complete()` on the dma_complete
completion structure is done inconditionnally in case of transfer
success or error as well as the `dmaengine_terminate_async()`.
This is allowed as a `complete()` in case transfer error has no effect
as well as a `dmaengine_terminate_async()` on a transfer success.
Also fix the unneeded cast and remove not more needed variables.
Fixes: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support")
Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Cc: <stable@vger.kernel.org> # v4.18+
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20250704-i2c-upstream-v4-2-84a095a2c728@foss.st.com
Pull scheduler fix from Thomas Gleixner:
"A single fix for the scheduler.
A recent commit changed the runqueue counter nr_uninterruptible to an
unsigned int. Due to the fact that the counters are not updated on
migration of a uninterruptble task to a different CPU, these counters
can exceed INT_MAX.
The counter is cast to long in the load average calculation, which
means that the cast expands into negative space resulting in bogus
load average values.
Convert it back to unsigned long to fix this.
* tag 'sched-urgent-2025-07-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Change nr_uninterruptible type to unsigned long
sys_futex_wait() expects a struct __kernel_timespec pointer for the
timeout, but the provided struct timespec pointer is of type struct
old_timespec32 when compiled for 32-bit architectures, unless they use
64-bit timespecs already.
Make it work for all variants by converting the provided timespec value
into a local struct __kernel_timespec and provide a pointer to it to the
syscall. This is a pointless operation for 64-bit, but this is not a
hotpath operation, so keep it simple.
This fix is based off [1]
Originally-by: Wei Gao <wegao@suse.com>
Signed-off-by: Terry Tritton <terry.tritton@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250704190234.14230-1-terry.tritton@linaro.org
Link: https://lore.kernel.org/all/20231203235117.29677-1-wegao@suse.com/ [1]
Pull /proc/sys dcache lookup fix from Al Viro:
"Fix for the breakage spotted by Neil in the interplay between
/proc/sys ->d_compare() weirdness and parallel lookups"
* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fix proc_sys_compare() handling of in-lookup dentries
If the DMA mapping failed, it produced an error log with the wrong
device name:
"stm32-dma3 40400000.dma-controller: rejecting DMA map of vmalloc memory"
Fix this issue by replacing the dev with the I2C dev.
Fixes: bb8822cbbc53 ("i2c: i2c-stm32: Add generic DMA API")
Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Cc: <stable@vger.kernel.org> # v4.18+
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20250704-i2c-upstream-v4-1-84a095a2c728@foss.st.com
Pull hyperv fixes from Wei Liu:
- Select use CONFIG_SYSFB only if EFI is enabled (Michael Kelley)
- An assorted set of fixes to remove warnings for missing export.h
header inclusion (Naman Jain)
- An assorted set of fixes for when Linux run as the root partition
for Microsoft Hypervisor (Mukesh Rathor, Nuno Das Neves, Stanislav
Kinsburskii)
- Fix the check for HYPERVISOR_CALLBACK_VECTOR (Naman Jain)
- Fix fcopy tool to handle irregularities with size of ring buffer
(Naman Jain)
- Fix incorrect file path conversion in fcopy tool (Yasumasa Suenaga)
* tag 'hyperv-fixes-signed-20250718' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
tools/hv: fcopy: Fix irregularities with size of ring buffer
PCI: hv: Use the correct hypercall for unmasking interrupts on nested
x86/hyperv: Expose hv_map_msi_interrupt()
Drivers: hv: Use nested hypercall for post message and signal event
x86/hyperv: Clean up hv_map/unmap_interrupt() return values
x86/hyperv: Fix usage of cpu_online_mask to get valid cpu
PCI: hv: Don't load the driver for baremetal root partition
net: mana: Fix warnings for missing export.h header inclusion
PCI: hv: Fix warnings for missing export.h header inclusion
clocksource: hyper-v: Fix warnings for missing export.h header inclusion
x86/hyperv: Fix warnings for missing export.h header inclusion
Drivers: hv: Fix warnings for missing export.h header inclusion
Drivers: hv: Fix the check for HYPERVISOR_CALLBACK_VECTOR
tools/hv: fcopy: Fix incorrect file path conversion
Drivers: hv: Select CONFIG_SYSFB only if EFI is enabled
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