Pull EFI fixes from Ard Biesheuvel:
"A couple of fixes for EFI regressions introduced this cycle:
- Make EDID handling in the EFI stub mixed mode safe
- Ensure that efi_mm.user_ns has a sane value - this is needed now
that EFI runtime calls are preemptible on arm64"
* tag 'efi-fixes-for-v6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
kthread: Warn if mm_struct lacks user_ns in kthread_use_mm()
arm64: efi: Fix NULL pointer dereference by initializing user_ns
efi/libstub: gop: Fix EDID support in mixed-mode
Pull block fixes from Jens Axboe:
- Fix for a signedness issue introduced in this kernel release for rnbd
- Fix up user copy references for ublk when the server exits
* tag 'block-6.19-20251226' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
block: rnbd-clt: Fix signedness bug in init_dev()
ublk: clean up user copy references on ublk server exit
Pull io_uring fix from Jens Axboe:
"Just a single fix for a bug that can cause a leak of the filename with
IORING_OP_OPENAT, if direct descriptors are asked for and O_CLOEXEC
has been set in the request flags"
* tag 'io_uring-6.19-20251226' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
io_uring: fix filename leak in __io_openat_prep()
Pull virtio fixes from Michael Tsirkin:
"Just a bunch of fixes, mostly trivial ones in tools/virtio"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vhost/vsock: improve RCU read sections around vhost_vsock_get()
tools/virtio: add device, device_driver stubs
tools/virtio: fix up oot build
virtio_features: make it self-contained
tools/virtio: switch to kernel's virtio_config.h
tools/virtio: stub might_sleep and synchronize_rcu
tools/virtio: add struct cpumask to cpumask.h
tools/virtio: pass KCFLAGS to module build
tools/virtio: add ucopysize.h stub
tools/virtio: add dev_WARN_ONCE and is_vmalloc_addr stubs
tools/virtio: stub DMA mapping functions
tools/virtio: add struct module forward declaration
tools/virtio: use kernel's virtio.h
virtio: make it self-contained
tools/virtio: fix up compiler.h stub
Pull smb server fixes from Steve French:
- Fix parsing of SMB1 negotiate request by adjusting offsets affected
by the removal of the RFC1002 length field from the SMB header
- Update minimum PDU size macros for both SMB1 and SMB2
- Rename smb2_get_msg function to smb_get_msg to better reflect its
role in handling both SMB1 and SMB2 requests
* tag 'v6.19-rc2-smb3-server-fixes' of git://git.samba.org/ksmbd:
smb/server: fix minimum SMB2 PDU size
smb/server: fix minimum SMB1 PDU size
ksmbd: rename smb2_get_msg to smb_get_msg
ksmbd: Fix to handle removal of rfc1002 header from smb_hdr
__io_openat_prep() allocates a struct filename using getname(). However,
for the condition of the file being installed in the fixed file table as
well as having O_CLOEXEC flag set, the function returns early. At that
point, the request doesn't have REQ_F_NEED_CLEANUP flag set. Due to this,
the memory for the newly allocated struct filename is not cleaned up,
causing a memory leak.
Fix this by setting the REQ_F_NEED_CLEANUP for the request just after the
successful getname() call, so that when the request is torn down, the
filename will be cleaned up, along with other resources needing cleanup.
Reported-by: syzbot+00e61c43eb5e4740438f@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=00e61c43eb5e4740438f
Tested-by: syzbot+00e61c43eb5e4740438f@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
Fixes: b9445598d8 ("io_uring: openat directly into fixed fd table")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a WARN_ON_ONCE() check to detect mm_struct instances that are
missing user_ns initialization when passed to kthread_use_mm().
When a kthread adopts an mm via kthread_use_mm(), LSM hooks and
capability checks may access current->mm->user_ns for credential
validation. If user_ns is NULL, this leads to a NULL pointer
dereference crash.
This was observed with efi_mm on arm64, where commit a5baf582f4
("arm64/efi: Call EFI runtime services without disabling preemption")
introduced kthread_use_mm(&efi_mm), but efi_mm lacked user_ns
initialization, causing crashes during /proc access.
Adding this warning helps catch similar bugs early during development
rather than waiting for hard-to-debug NULL pointer crashes in
production.
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Linux 6.19-rc2 (9448598b22 ("Linux 6.19-rc2")) is crashing with a NULL
pointer dereference on arm64 hosts:
Unable to handle kernel NULL pointer dereference at virtual address 00000000000000c8
pc : cap_capable (security/commoncap.c:82 security/commoncap.c:128)
Call trace:
cap_capable (security/commoncap.c:82 security/commoncap.c:128) (P)
security_capable (security/security.c:?)
ns_capable_noaudit (kernel/capability.c:342 kernel/capability.c:381)
__ptrace_may_access (./include/linux/rcupdate.h:895 kernel/ptrace.c:326)
ptrace_may_access (kernel/ptrace.c:353)
do_task_stat (fs/proc/array.c:467)
proc_tgid_stat (fs/proc/array.c:673)
proc_single_show (fs/proc/base.c:803)
I've bissected the problem to commit a5baf582f4 ("arm64/efi: Call EFI
runtime services without disabling preemption").
>From my analyzes, the crash occurs because efi_mm lacks a user_ns field
initialization. This was previously harmless, but commit a5baf582f4
("arm64/efi: Call EFI runtime services without disabling preemption")
changed the EFI runtime call path to use kthread_use_mm(&efi_mm), which
temporarily adopts efi_mm as the current mm for the calling kthread.
When a thread has an active mm, LSM hooks like cap_capable() expect
mm->user_ns to be valid for credential checks. With efi_mm.user_ns being
NULL, capability checks during possible /proc access dereference the
NULL pointer and crash.
Fix by initializing efi_mm.user_ns to &init_user_ns.
Fixes: a5baf582f4 ("arm64/efi: Call EFI runtime services without disabling preemption")
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
The efi_edid_discovered_protocol and efi_edid_active_protocol have mixed
mode fields. So all their attributes should be accessed through
the efi_table_attr() helper.
Doing so fixes the upper 32 bits of the 64 bit gop_edid pointer getting
set to random values (followed by a crash at boot) when booting a x86_64
kernel on a machine with 32 bit UEFI like the Asus T100TA.
Fixes: 17029cdd8f ("efi/libstub: gop: Add support for reading EDID")
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Pull nfsd fixes from Chuck Lever:
"A set of NFSD fixes that arrived just a bit late for the 6.19 merge
window.
Regression fixes:
- Mark variable __maybe_unused to avoid W=1 build break
Stable fixes:
- NFSv4 file creation neglects setting ACL
- Clear TIME_DELEG in the suppattr_exclcreat bitmap
- Clear SECLABEL in the suppattr_exclcreat bitmap
- Fix memory leak in nfsd_create_serv error paths
- Bound check rq_pages index in inline path
- Return 0 on success from svc_rdma_copy_inline_range
- Use rc_pageoff for memcpy byte offset
- Avoid NULL deref on zero length gss_token in gss_read_proxy_verf"
* tag 'nfsd-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
NFSD: NFSv4 file creation neglects setting ACL
NFSD: Clear TIME_DELEG in the suppattr_exclcreat bitmap
NFSD: Clear SECLABEL in the suppattr_exclcreat bitmap
nfsd: fix memory leak in nfsd_create_serv error paths
nfsd: Mark variable __maybe_unused to avoid W=1 build break
svcrdma: bound check rq_pages index in inline path
svcrdma: return 0 on success from svc_rdma_copy_inline_range
svcrdma: use rc_pageoff for memcpy byte offset
SUNRPC: svcauth_gss: avoid NULL deref on zero length gss_token in gss_read_proxy_verf
Pull erofs fix from Gao Xiang:
"Junbeom reported that synchronous reads could hit unintended EIOs
under memory pressure due to incorrect error propagation in
z_erofs_decompress_queue(), where earlier physical clusters in the
same decompression queue may be served for another readahead.
This addresses the issue by decompressing each physical cluster
independently as long as disk I/Os succeed, rather than being impacted
by the error status of previous physical clusters in the same queue.
Summary:
- Fix unexpected EIOs under memory pressure caused by recent
incorrect error propagation logic"
* tag 'erofs-for-6.19-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
erofs: fix unexpected EIO under memory pressure
vhost_vsock_get() uses hash_for_each_possible_rcu() to find the
`vhost_vsock` associated with the `guest_cid`. hash_for_each_possible_rcu()
should only be called within an RCU read section, as mentioned in the
following comment in include/linux/rculist.h:
/**
* hlist_for_each_entry_rcu - iterate over rcu list of given type
* @pos: the type * to use as a loop cursor.
* @head: the head for your list.
* @member: the name of the hlist_node within the struct.
* @cond: optional lockdep expression if called from non-RCU protection.
*
* This list-traversal primitive may safely run concurrently with
* the _rcu list-mutation primitives such as hlist_add_head_rcu()
* as long as the traversal is guarded by rcu_read_lock().
*/
Currently, all calls to vhost_vsock_get() are between rcu_read_lock()
and rcu_read_unlock() except for calls in vhost_vsock_set_cid() and
vhost_vsock_reset_orphans(). In both cases, the current code is safe,
but we can make improvements to make it more robust.
About vhost_vsock_set_cid(), when building the kernel with
CONFIG_PROVE_RCU_LIST enabled, we get the following RCU warning when the
user space issues `ioctl(dev, VHOST_VSOCK_SET_GUEST_CID, ...)` :
WARNING: suspicious RCU usage
6.18.0-rc7 #62 Not tainted
-----------------------------
drivers/vhost/vsock.c:74 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by rpc-libvirtd/3443:
#0: ffffffffc05032a8 (vhost_vsock_mutex){+.+.}-{4:4}, at: vhost_vsock_dev_ioctl+0x2ff/0x530 [vhost_vsock]
stack backtrace:
CPU: 2 UID: 0 PID: 3443 Comm: rpc-libvirtd Not tainted 6.18.0-rc7 #62 PREEMPT(none)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-7.fc42 06/10/2025
Call Trace:
<TASK>
dump_stack_lvl+0x75/0xb0
dump_stack+0x14/0x1a
lockdep_rcu_suspicious.cold+0x4e/0x97
vhost_vsock_get+0x8f/0xa0 [vhost_vsock]
vhost_vsock_dev_ioctl+0x307/0x530 [vhost_vsock]
__x64_sys_ioctl+0x4f2/0xa00
x64_sys_call+0xed0/0x1da0
do_syscall_64+0x73/0xfa0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
...
</TASK>
This is not a real problem, because the vhost_vsock_get() caller, i.e.
vhost_vsock_set_cid(), holds the `vhost_vsock_mutex` used by the hash
table writers. Anyway, to prevent that warning, add lockdep_is_held()
condition to hash_for_each_possible_rcu() to verify that either the
caller is in an RCU read section or `vhost_vsock_mutex` is held when
CONFIG_PROVE_RCU_LIST is enabled; and also clarify the comment for
vhost_vsock_get() to better describe the locking requirements and the
scope of the returned pointer validity.
About vhost_vsock_reset_orphans(), currently this function is only
called via vsock_for_each_connected_socket(), which holds the
`vsock_table_lock` spinlock (which is also an RCU read-side critical
section). However, add an explicit RCU read lock there to make the code
more robust and explicit about the RCU requirements, and to prevent
issues if the calling context changes in the future or if
vhost_vsock_reset_orphans() is called from other contexts.
Fixes: 834e772c8d ("vhost/vsock: fix use-after-free in network stack callers")
Cc: stefanha@redhat.com
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20251126133826.142496-1-sgarzare@redhat.com>
Message-ID: <20251126210313.GA499503@fedora>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Add #undef __user before and after including compiler_types.h to avoid
redefinition warnings when compiling with system headers that also
define __user. This allows tools/virtio to build without warnings.
Additionally, stub out __must_check
Created using Cursor CLI.
Message-ID: <56424ce95c72cb4957070a7cd3c3c40ad5addaee.1764873799.git.mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Pull sound fixes from Takashi Iwai:
"Likely the last pull request in 2025, again a collection of lots of
small fixes. Most of them are various device-specific small fixes:
- An ASoC core fix for correcting the clamping behavior of *_SX mixer
elements
- Various fixes for ASoC fsl, SOF, etc
- Usual HD- and USB-audio quirks / fix-ups
- A couple of error-handling fixes for legacy PCMCIA drivers"
* tag 'sound-6.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (35 commits)
ALSA: hda/realtek: fix PCI SSID for one of the HP 200 G2i laptop
ASoC: ops: fix snd_soc_get_volsw for sx controls
ALSA: hda/realtek: Add Asus quirk for TAS amplifiers
ASoC: Intel: soc-acpi-intel-mtl-match: Add 6 amp CS35L63 with feedback
ASoC: Intel: soc-acpi-intel-mtl-match: Add 6 amp CS35L56 with feedback
ASoC: fsl-asoc-card: Use of_property_present() for non-boolean properties
ASoC: rt1320: update VC blind write settings
ASoC: fsl_xcvr: provide regmap names
ASoC: fsl_sai: Add missing registers to cache default
ASoC: ak4458: remove the reset operation in probe and remove
ASoC: fsl_asrc_dma: fix duplicate debugfs directory error
ASoC: fsl_easrc: fix duplicate debugfs directory error
ALSA: hda/realtek: fix micmute LED reversed on HP Abe and Bantie
ALSA: hda/realtek: Add support for HP Clipper Laptop
ALSA: hda/realtek: Add support for HP Trekker Laptop
ALSA: usb-mixer: us16x08: validate meter packet indices
ASoC: Intel: soc-acpi-intel-nvl-match: Drop rt722 l3 from the match table
ASoC: soc-acpi / SOF: Add best_effort flag to get_function_tplg_files op
ASoC: SOF: Intel: pci-mtl: Change the topology path to intel/sof-ipc4-tplg
ASoC: SOF: ipc4-topology: set playback channel mask
...
Pull dma-mapping fix from Marek Szyprowski:
- fix boot failure of parisc systems after recent rework of the DMA API
infrastructure (Leon Romanovsky)
* tag 'dma-mapping-6.19-2025-12-22' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
parisc: Set valid bit in high byte of 64‑bit physical address
With the removal of the RFC1002 length field from the SMB header,
smb2_get_msg is now used to get the smb1 request from the request buffer.
Since this function is no longer exclusive to smb2 and now supports smb1
as well, This patch rename it to smb_get_msg to better reflect its usage.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Pull Coccinelle fixes from Julia Lawall:
"These fix a typo and make the coccicheck script more robust by
ensuring that only compatible semantic patches are executed for the
chosen mode"
* tag 'coccinelle-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux:
Coccinelle: pm_runtime: Fix typo in report message
scripts: coccicheck: filter *.cocci files by MODE
Pull input fixes from Dmitry Torokhov:
- a quirk for i8042 to better handle another TUXEDO model
- a quirk to atkbd to handle incorcet behavior of HONOR FMB-P internal
keyboard
- a definition for a new ABS_SND_PROFILE event
- fixes to alps and lkkbd drivers to reliably shut down pending work on
removal
- a fix to apple_z2 driver tightening input report parsing
- a fix for "off-by-one" error when validating config in ti_am335x_tsc
driver
- addition of CRKD Guitars device IDs to xpad driver.
* tag 'input-for-v6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: ti_am335x_tsc - fix off-by-one error in wire_order validation
Input: xpad - add support for CRKD Guitars
Input: add ABS_SND_PROFILE
Input: apple_z2 - fix reading incorrect reports after exiting sleep
Input: alps - fix use-after-free bugs caused by dev3_register_work
Input: i8042 - add TUXEDO InfinityBook Max Gen10 AMD to i8042 quirk table
Input: atkbd - skip deactivate for HONOR FMB-P's internal keyboard
Input: lkkbd - disable pending work before freeing device
Pull x86 fixes from Ingo Molnar:
- Fix FPU core dumps on certain CPU models
- Fix htmldocs build warning
- Export TLB tracing event name via header
- Remove unused constant from <linux/mm_types.h>
- Fix comments
- Fix whitespace noise in documentation
- Fix variadic structure's definition to un-confuse UBSAN
- Fix posted MSI interrupts irq_retrigger() bug
- Fix asm build failure with older GCC builds
* tag 'x86-urgent-2025-12-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/bug: Fix old GCC compile fails
x86/msi: Make irq_retrigger() functional for posted MSI
x86/platform/uv: Fix UBSAN array-index-out-of-bounds
mm: Remove tlb_flush_reason::NR_TLB_FLUSH_REASONS from <linux/mm_types.h>
x86/mm/tlb/trace: Export the TLB_REMOTE_WRONG_CPU enum in <trace/events/tlb.h>
x86/sgx: Remove unmatched quote in __sgx_encl_extend function comment
x86/boot/Documentation: Fix whitespace noise in boot.rst
x86/fpu: Fix FPU state core dump truncation on CPUs with no extended xfeatures
x86/boot/Documentation: Fix htmldocs build warning due to malformed table in boot.rst
Enhance the coccicheck script to filter *.cocci files based on the
specified MODE (e.g., report, patch). This ensures that only compatible
semantic patch files are executed, preventing errors such as:
"virtual rule report not supported"
This error occurs when a .cocci file does not define a 'virtual <MODE>'
rule, yet is executed in that mode.
For example:
make coccicheck M=drivers/hwtracing/coresight/ MODE=report
In this case, running "secs_to_jiffies.cocci" would trigger the error
because it lacks support for 'report' mode. With this change, such files
are skipped automatically, improving robustness and developer
experience.
Signed-off-by: Songwei Chai <quic_songchai@quicinc.com>
Reviewed-by: Julia Lawall <Julia.Lawall@inria.fr>
erofs readahead could fail with ENOMEM under the memory pressure because
it tries to alloc_page with GFP_NOWAIT | GFP_NORETRY, while GFP_KERNEL
for a regular read. And if readahead fails (with non-uptodate folios),
the original request will then fall back to synchronous read, and
`.read_folio()` should return appropriate errnos.
However, in scenarios where readahead and read operations compete,
read operation could return an unintended EIO because of an incorrect
error propagation.
To resolve this, this patch modifies the behavior so that, when the
PCL is for read(which means pcl.besteffort is true), it attempts actual
decompression instead of propagating the privios error except initial EIO.
- Page size: 4K
- The original size of FileA: 16K
- Compress-ratio per PCL: 50% (Uncompressed 8K -> Compressed 4K)
[page0, page1] [page2, page3]
[PCL0]---------[PCL1]
- functions declaration:
. pread(fd, buf, count, offset)
. readahead(fd, offset, count)
- Thread A tries to read the last 4K
- Thread B tries to do readahead 8K from 4K
- RA, besteffort == false
- R, besteffort == true
<process A> <process B>
pread(FileA, buf, 4K, 12K)
do readahead(page3) // failed with ENOMEM
wait_lock(page3)
if (!uptodate(page3))
goto do_read
readahead(FileA, 4K, 8K)
// Here create PCL-chain like below:
// [null, page1] [page2, null]
// [PCL0:RA]-----[PCL1:RA]
...
do read(page3) // found [PCL1:RA] and add page3 into it,
// and then, change PCL1 from RA to R
...
// Now, PCL-chain is as below:
// [null, page1] [page2, page3]
// [PCL0:RA]-----[PCL1:R]
// try to decompress PCL-chain...
z_erofs_decompress_queue
err = 0;
// failed with ENOMEM, so page 1
// only for RA will not be uptodated.
// it's okay.
err = decompress([PCL0:RA], err)
// However, ENOMEM propagated to next
// PCL, even though PCL is not only
// for RA but also for R. As a result,
// it just failed with ENOMEM without
// trying any decompression, so page2
// and page3 will not be uptodated.
** BUG HERE ** --> err = decompress([PCL1:R], err)
return err as ENOMEM
...
wait_lock(page3)
if (!uptodate(page3))
return EIO <-- Return an unexpected EIO!
...
Fixes: 2349d2fa02 ("erofs: sunset unneeded NOFAILs")
Cc: stable@vger.kernel.org
Reviewed-by: Jaewook Kim <jw5454.kim@samsung.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Junbeom Yeom <junbeom.yeom@samsung.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
ASoC: Fixes for v6.19
We've been quite busy with fixes since the merge window, though not in
any particularly exciting ways - the standout thing is the fix for _SX
controls which were broken by a change to how we do clamping, otherwise
it's all fairly run of the mill fixes and quirks.
Pull ata fix from Damien Le Moal:
- Disable link power management (LPM) for a Seagate drive that is
misbehaving when LPM is enabled
* tag 'ata-6.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
ata: libata-core: Disable LPM on ST2000DM008-2FR102
Pull spi fixes from Mark Brown:
"A small collection of fixes for various SPI drivers, plus a relaxation
of constraints in the DT for the DesignWare controller to reflect
hardware that's been seen.
There's several fixes for the Cadence QuadSPI driver since a fix
during the last release made some existing issues with error handling
during probe more readily visible"
* tag 'spi-fix-v6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: mt65xx: Use IRQF_ONESHOT with threaded IRQ
spi: dt-bindings: snps,dw-abp-ssi: Allow up to 16 chip-selects
spi: cadence-quadspi: Fix clock disable on probe failure path
spi: cadence-quadspi: Add error logging for DMA request failure
spi: fsl-cpm: Check length parity before switching to 16 bit mode
spi: mpfs: Fix an error handling path in mpfs_spi_probe()
clang is generating very inefficient code for native_save_fl() which is
used for local_irq_save() in critical spots.
Allowing the "pop %0" to use memory:
1) forces the compiler to add annoying stack canaries when
CONFIG_STACKPROTECTOR_STRONG=y in many places.
2) Almost always is followed by an immediate "move memory,register"
One good example is _raw_spin_lock_irqsave, with 8 extra instructions
ffffffff82067a30 <_raw_spin_lock_irqsave>:
ffffffff82067a30: ...
ffffffff82067a39: 53 push %rbx
// Three instructions to ajust the stack, read the per-cpu canary
// and copy it to 8(%rsp)
ffffffff82067a3a: 48 83 ec 10 sub $0x10,%rsp
ffffffff82067a3e: 65 48 8b 05 da 15 45 02 mov %gs:0x24515da(%rip),%rax # <__stack_chk_guard>
ffffffff82067a46: 48 89 44 24 08 mov %rax,0x8(%rsp)
ffffffff82067a4b: 9c pushf
// instead of pop %rbx, compiler uses 2 instructions.
ffffffff82067a4c: 8f 04 24 pop (%rsp)
ffffffff82067a4f: 48 8b 1c 24 mov (%rsp),%rbx
ffffffff82067a53: fa cli
ffffffff82067a54: b9 01 00 00 00 mov $0x1,%ecx
ffffffff82067a59: 31 c0 xor %eax,%eax
ffffffff82067a5b: f0 0f b1 0f lock cmpxchg %ecx,(%rdi)
ffffffff82067a5f: 75 1d jne ffffffff82067a7e <_raw_spin_lock_irqsave+0x4e>
// three instructions to check the stack canary
ffffffff82067a61: 65 48 8b 05 b7 15 45 02 mov %gs:0x24515b7(%rip),%rax # <__stack_chk_guard>
ffffffff82067a69: 48 3b 44 24 08 cmp 0x8(%rsp),%rax
ffffffff82067a6e: 75 17 jne ffffffff82067a87
...
// One extra instruction to adjust the stack.
ffffffff82067a73: 48 83 c4 10 add $0x10,%rsp
...
// One more instruction in case the stack was mangled.
ffffffff82067a87: e8 a4 35 ff ff call ffffffff8205b030 <__stack_chk_fail>
This patch changes nothing for gcc, but for clang saves ~20000 bytes of text
even though more functions are inlined.
$ size vmlinux.gcc.before vmlinux.gcc.after vmlinux.clang.before vmlinux.clang.after
text data bss dec hex filename
45565821 25005462 4704800 75276083 47c9f33 vmlinux.gcc.before
45565821 25005462 4704800 75276083 47c9f33 vmlinux.gcc.after
45121072 24638617 5533040 75292729 47ce039 vmlinux.clang.before
45093887 24638633 5536808 75269328 47c84d0 vmlinux.clang.after
$ scripts/bloat-o-meter -t vmlinux.clang.before vmlinux.clang.after
add/remove: 1/2 grow/shrink: 21/533 up/down: 2250/-22112 (-19862)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Work around clang problems with "=rm" asm constraint.
clang seems to always chose the memory output, while it is almost
always the worst choice.
Add ASM_OUTPUT_RM so that we can replace "=rm" constraint
where it matters for clang, while not penalizing gcc.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull xfs fixes from Carlos Maiolino:
"This contains a few fixes for zoned devices support, an UAF and a
compiler warning, and some cleaning up"
* tag 'xfs-fixes-6.19-rc2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: fix the zoned RT growfs check for zone alignment
xfs: validate that zoned RT devices are zone aligned
xfs: fix XFS_ERRTAG_FORCE_ZERO_RANGE for zoned file system
xfs: fix a memory leak in xfs_buf_item_init()
xfs: fix stupid compiler warning
xfs: fix a UAF problem in xattr repair
xfs: ignore discard return value
