Age | Commit message (Collapse) | Author |
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I've been focusing on networking BPF bits lately, add myself as a
reviewer.
Signed-off-by: Stanislav Fomichev <stfomichev@gmail.com>
Acked-by: KP Singh <kpsingh@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20250610175442.2138504-1-stfomichev@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Two 'static inline' TDX helper functions (sc_retry() and
sc_retry_prerr()) take function pointer arguments which refer to
assembly functions. Normally, the compiler inlines the TDX helper,
realizes that the function pointer targets are completely static --
thus can be resolved at compile time -- and generates direct call
instructions.
But, other times (like when CONFIG_CC_OPTIMIZE_FOR_SIZE=y), the
compiler declines to inline the helpers and will instead generate
indirect call instructions.
Indirect calls to assembly functions require special annotation (for
various Control Flow Integrity mechanisms). But TDX assembly
functions lack the special annotations and can only be called
directly.
Annotate both the helpers as '__always_inline' to prod the compiler
into maintaining the direct calls. There is no guarantee here, but
Peter has volunteered to report the compiler bug if this assumption
ever breaks[1].
Fixes: 1e66a7e27539 ("x86/virt/tdx: Handle SEAMCALL no entropy error in common code")
Fixes: df01f5ae07dd ("x86/virt/tdx: Add SEAMCALL error printing for module initialization")
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/20250605145914.GW39944@noisy.programming.kicks-ass.net/ [1]
Link: https://lore.kernel.org/all/20250606130737.30713-1-kai.huang%40intel.com
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Commit a17b37a3f416 ("x86/idle: Change arguments of mwait_idle_with_hints()
to u32") changed the type of arguments of mwait_idle_with_hints() from
unsigned long to u32.
Change the type of variables in the call to mwait_idle_with_hints() to
unsigned int to follow the change.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Reviewed-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/20250609063528.48715-1-ubizjak@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Use ACPI IRQ override on MACHENIKE laptop to make the internal
keyboard work.
Add a new entry to the irq1_edge_low_force_override structure, similar
to the existing ones.
Link: https://bbs.deepin.org.cn/zh/post/287628
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Link: https://patch.msgid.link/20250603122059.1072790-1-guanwentao@uniontech.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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On the MSI Modern 14 C5M the ECDT table contains invalid data:
UID : 00000000
GPE Number : 00 /* Invalid, 03 would be correct */
Namepath : "" /* Invalid, "\_SB.PCI0.SBRG.EC" would
* be correct
*/
This slows down the EC access as the wrong GPE event is used for
communication. Additionally the ID string is invalid.
Ignore such faulty ECDT tables by verifying that the ID string has
a valid format.
Tested-by: glpnk@proton.me
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://patch.msgid.link/20250529235310.540530-1-W_Armin@gmx.de
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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With nosmp in cmdline, other CPUs are not brought up, leaving
their cpc_desc_ptr NULL. CPU0's iteration via for_each_possible_cpu()
dereferences these NULL pointers, causing panic.
Panic backtrace:
[ 0.401123] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b8
...
[ 0.403255] [<ffffffff809a5818>] cppc_allow_fast_switch+0x6a/0xd4
...
Kernel panic - not syncing: Attempted to kill init!
Fixes: 3cc30dd00a58 ("cpufreq: CPPC: Enable fast_switch")
Reported-by: Xu Lu <luxu.kernel@bytedance.com>
Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Link: https://patch.msgid.link/20250604023036.99553-1-cuiyunhui@bytedance.com
[ rjw: New subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Commit a17b37a3f416 ("x86/idle: Change arguments of mwait_idle_with_hints()
to u32") changed the type of arguments of mwait_idle_with_hints() from
unsigned long to u32.
Change the type of variables in the call to mwait_idle_with_hints() to
unsigned int to follow the change.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Link: https://patch.msgid.link/20250609064235.49146-1-ubizjak@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Fix a compile error in the `impl_has_hr_timer!` macro as follows:
error[E0599]: no method named cast_mut found for raw pointer *mut Foo in the current scope
The `container_of!` macro already returns a mutable pointer when used
in a `*mut T` context so the `.cast_mut()` method is not available.
[ We missed this one because there is no caller yet and it is
a macro. - Miguel ]
Fixes: 74d6a606c2b3 ("rust: retain pointer mut-ness in `container_of!`")
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250606020505.3186533-1-fujita.tomonori@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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CXL has a symbol dependency on einj_core.ko, so if einj_init() fails then
cxl_core.ko fails to load. Prior to the faux_device_create() conversion,
einj_probe() failures were tracked by the einj_initialized flag without
failing einj_init().
Revert to that behavior and always succeed einj_init() given there is no
way, and no pressing need, to discern faux device-create vs device-probe
failures.
This situation arose because CXL knows proper kernel named objects to
trigger errors against, but acpi-einj knows how to perform the error
injection. The injection mechanism is shared with non-CXL use cases. The
result is CXL now has a module dependency on einj-core.ko, and init/probe
failures are handled at runtime.
Fixes: 6cb9441bfe8d ("ACPI: APEI: EINJ: Transition to the faux device interface")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Ben Cheatham <benjamin.cheatham@amd.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20250607033228.1475625-4-dan.j.williams@intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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The acpi-einj conversion to faux_device_create() leads to a noisy error
message when the error injection facility is disabled. Quiet the error as
CXL error injection via ACPI expects the module to stay loaded even if the
error injection facility is disabled.
This situation arose because CXL knows proper kernel named objects to
trigger errors against, but acpi-einj knows how to perform the error
injection. The injection mechanism is shared with non-CXL use cases. The
result is CXL now has a module dependency on einj-core.ko, and init/probe
failures are handled at runtime.
Fixes: 6cb9441bfe8d ("ACPI: APEI: EINJ: Transition to the faux device interface")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20250607033228.1475625-3-dan.j.williams@intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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faux_device_create() is almost a suitable candidate to replace
platform_driver_probe() if not for the fact that faux_device_create()
supports dynamic attach/detach of the driver.
Drop the bind attributes with the expectation that simple faux devices can
always assume that the device is permanently bound at create, and only
unbound at 'destroy'.
The acpi-einj driver depends on static bind.
Fixes: 6cb9441bfe8d ("ACPI: APEI: EINJ: Transition to the faux device interface")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20250607033228.1475625-2-dan.j.williams@intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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This reverts commit 28615e6eed152f2fda5486680090b74aeed7b554.
No, we don't make random features default to being on.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: SeongJae Park <sj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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syzbot reports:
BUG: KASAN: slab-use-after-free in getrusage+0x1109/0x1a60
Read of size 8 at addr ffff88810de2d2c8 by task a.out/304
CPU: 0 UID: 0 PID: 304 Comm: a.out Not tainted 6.16.0-rc1 #1 PREEMPT(voluntary)
Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x53/0x70
print_report+0xd0/0x670
? __pfx__raw_spin_lock_irqsave+0x10/0x10
? getrusage+0x1109/0x1a60
kasan_report+0xce/0x100
? getrusage+0x1109/0x1a60
getrusage+0x1109/0x1a60
? __pfx_getrusage+0x10/0x10
__io_uring_show_fdinfo+0x9fe/0x1790
? ksys_read+0xf7/0x1c0
? do_syscall_64+0xa4/0x260
? vsnprintf+0x591/0x1100
? __pfx___io_uring_show_fdinfo+0x10/0x10
? __pfx_vsnprintf+0x10/0x10
? mutex_trylock+0xcf/0x130
? __pfx_mutex_trylock+0x10/0x10
? __pfx_show_fd_locks+0x10/0x10
? io_uring_show_fdinfo+0x57/0x80
io_uring_show_fdinfo+0x57/0x80
seq_show+0x38c/0x690
seq_read_iter+0x3f7/0x1180
? inode_set_ctime_current+0x160/0x4b0
seq_read+0x271/0x3e0
? __pfx_seq_read+0x10/0x10
? __pfx__raw_spin_lock+0x10/0x10
? __mark_inode_dirty+0x402/0x810
? selinux_file_permission+0x368/0x500
? file_update_time+0x10f/0x160
vfs_read+0x177/0xa40
? __pfx___handle_mm_fault+0x10/0x10
? __pfx_vfs_read+0x10/0x10
? mutex_lock+0x81/0xe0
? __pfx_mutex_lock+0x10/0x10
? fdget_pos+0x24d/0x4b0
ksys_read+0xf7/0x1c0
? __pfx_ksys_read+0x10/0x10
? do_user_addr_fault+0x43b/0x9c0
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0f74170fc9
Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 8
RSP: 002b:00007fffece049e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0f74170fc9
RDX: 0000000000001000 RSI: 00007fffece049f0 RDI: 0000000000000004
RBP: 00007fffece05ad0 R08: 0000000000000000 R09: 00007fffece04d90
R10: 0000000000000000 R11: 0000000000000206 R12: 00005651720a1100
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Allocated by task 298:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_slab_alloc+0x6e/0x70
kmem_cache_alloc_node_noprof+0xe8/0x330
copy_process+0x376/0x5e00
create_io_thread+0xab/0xf0
io_sq_offload_create+0x9ed/0xf20
io_uring_setup+0x12b0/0x1cc0
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 22:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x37/0x50
kmem_cache_free+0xc4/0x360
rcu_core+0x5ff/0x19f0
handle_softirqs+0x18c/0x530
run_ksoftirqd+0x20/0x30
smpboot_thread_fn+0x287/0x6c0
kthread+0x30d/0x630
ret_from_fork+0xef/0x1a0
ret_from_fork_asm+0x1a/0x30
Last potentially related work creation:
kasan_save_stack+0x33/0x60
kasan_record_aux_stack+0x8c/0xa0
__call_rcu_common.constprop.0+0x68/0x940
__schedule+0xff2/0x2930
__cond_resched+0x4c/0x80
mutex_lock+0x5c/0xe0
io_uring_del_tctx_node+0xe1/0x2b0
io_uring_clean_tctx+0xb7/0x160
io_uring_cancel_generic+0x34e/0x760
do_exit+0x240/0x2350
do_group_exit+0xab/0x220
__x64_sys_exit_group+0x39/0x40
x64_sys_call+0x1243/0x1840
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88810de2cb00
which belongs to the cache task_struct of size 3712
The buggy address is located 1992 bytes inside of
freed 3712-byte region [ffff88810de2cb00, ffff88810de2d980)
which is caused by the task_struct pointed to by sq->thread being
released while it is being used in the function
__io_uring_show_fdinfo(). Holding ctx->uring_lock does not prevent ehre
relase or exit of sq->thread.
Fix this by assigning and looking up ->thread under RCU, and grabbing a
reference to the task_struct. This ensures that it cannot get released
while fdinfo is using it.
Reported-by: syzbot+531502bbbe51d2f769f4@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/682b06a5.a70a0220.3849cf.00b3.GAE@google.com
Fixes: 3fcb9d17206e ("io_uring/sqpoll: statistics of the true utilization of sq threads")
Signed-off-by: Penglei Jiang <superman.xpt@gmail.com>
Link: https://lore.kernel.org/r/20250610171801.70960-1-superman.xpt@gmail.com
[axboe: massage commit message]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux
Merge an urgent cpupower utility fix for 6.16-rc1 from Shuah Khan:
"Add unitdir variable for specifying the location to install systemd
service units instead of installing under ${libdir}/systemd/system
which doesn't work on some distributions."
* tag 'linux-cpupower-6.16-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux:
cpupower: split unitdir from libdir in Makefile
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Previously, e1000_down called cancel_work_sync for the e1000 reset task
(via e1000_down_and_stop), which takes RTNL.
As reported by users and syzbot, a deadlock is possible in the following
scenario:
CPU 0:
- RTNL is held
- e1000_close
- e1000_down
- cancel_work_sync (cancel / wait for e1000_reset_task())
CPU 1:
- process_one_work
- e1000_reset_task
- take RTNL
To remedy this, avoid calling cancel_work_sync from e1000_down
(e1000_reset_task does nothing if the device is down anyway). Instead,
call cancel_work_sync for e1000_reset_task when the device is being
removed.
Fixes: e400c7444d84 ("e1000: Hold RTNL when e1000_down can be called")
Reported-by: syzbot+846bb38dc67fe62cc733@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/683837bf.a00a0220.52848.0003.GAE@google.com/
Reported-by: John <john.cs.hey@gmail.com>
Closes: https://lore.kernel.org/netdev/CAP=Rh=OEsn4y_2LvkO3UtDWurKcGPnZ_NPSXK=FbgygNXL37Sw@mail.gmail.com/
Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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Set use_nsecs=true as timestamp is reported in ns. Lack of this result
in smaller timestamp error window which cause error during phc2sys
execution on E825 NICs:
phc2sys[1768.256]: ioctl PTP_SYS_OFFSET_PRECISE: Invalid argument
This problem was introduced in the cited commit which omitted setting
use_nsecs to true when converting the ice driver to use
convert_base_to_cs().
Testing hints (ethX is PF netdev):
phc2sys -s ethX -c CLOCK_REALTIME -O 37 -m
phc2sys[1769.256]: CLOCK_REALTIME phc offset -5 s0 freq -0 delay 0
Fixes: d4bea547ebb57 ("ice/ptp: Remove convert_art_to_tsc()")
Signed-off-by: Anton Nadezhdin <anton.nadezhdin@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Tested-by: Rinitha S <sx.rinitha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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If a reset event is received from the PF early in the init cycle, the
state machine hangs for about 25 seconds.
Reproducer:
echo 1 > /sys/class/net/$PF0/device/sriov_numvfs
ip link set dev $PF0 vf 0 mac $NEW_MAC
The log shows:
[792.620416] ice 0000:5e:00.0: Enabling 1 VFs
[792.738812] iavf 0000:5e:01.0: enabling device (0000 -> 0002)
[792.744182] ice 0000:5e:00.0: Enabling 1 VFs with 17 vectors and 16 queues per VF
[792.839964] ice 0000:5e:00.0: Setting MAC 52:54:00:00:00:11 on VF 0. VF driver will be reinitialized
[813.389684] iavf 0000:5e:01.0: Failed to communicate with PF; waiting before retry
[818.635918] iavf 0000:5e:01.0: Hardware came out of reset. Attempting reinit.
[818.766273] iavf 0000:5e:01.0: Multiqueue Enabled: Queue pair count = 16
Fix it by scheduling the reset task and making the reset task capable of
resetting early in the init cycle.
Fixes: ef8693eb90ae3 ("i40evf: refactor reset handling")
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Tested-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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When a VFLR interrupt is received during a VF reset initiated from a
different source, the VFLR may be not fully handled. This can
leave the VF in an undefined state.
To address this, set the I40E_VFLR_EVENT_PENDING bit again during VFLR
handling if the reset is not yet complete. This ensures the driver
will properly complete the VF reset in such scenarios.
Fixes: 52424f974bc5 ("i40e: Fix VF hang when reset is triggered on another VF")
Signed-off-by: Robert Malz <robert.malz@canonical.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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The function i40e_vc_reset_vf attempts, up to 20 times, to handle a
VF reset request, using the return value of i40e_reset_vf as an indicator
of whether the reset was successfully triggered. Currently, i40e_reset_vf
always returns true, which causes new reset requests to be ignored if a
different VF reset is already in progress.
This patch updates the return value of i40e_reset_vf to reflect when
another VF reset is in progress, allowing the caller to properly use
the retry mechanism.
Fixes: 52424f974bc5 ("i40e: Fix VF hang when reset is triggered on another VF")
Signed-off-by: Robert Malz <robert.malz@canonical.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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When cross compiling the kernel with clang, we need to override
CLANG_CROSS_FLAGS when preparing the step libraries.
Prior to commit d1d096312176 ("tools: fix annoying "mkdir -p ..." logs
when building tools in parallel"), MAKEFLAGS would have been set to a
value that wouldn't set a value for CLANG_CROSS_FLAGS, hiding the
fact that we weren't properly overriding it.
Fixes: 56a2df7615fa ("tools/resolve_btfids: Compile resolve_btfids as host program")
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20250606074538.1608546-1-suleiman@google.com
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The sample file was renamed from trace_output_kern.c to
trace_output.bpf.c in commit d4fffba4d04b ("samples/bpf: Change _kern
suffix to .bpf with syscall tracing program"). Adjust the path in the
documentation comment for bpf_perf_event_output.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Link: https://lore.kernel.org/r/20250610140756.16332-1-tklauser@distanz.ch
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This conversion moved the folio_unlock() to inside __write_node_folio(),
but missed one caller so we had a double-unlock on this path.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chao Yu <chao@kernel.org>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Reported-by: syzbot+c0dc46208750f063d0e0@syzkaller.appspotmail.com
Fixes: 80f31d2a7e5f (f2fs: return bool from __write_node_folio)
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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The variable "head" is allocated and initialized as a list before
allocating the first "item" for the list. If the allocation of "item"
fails, it frees "head" and then jumps to the label "free_now" which will
process head and free it.
This will cause a UAF of "head", and it doesn't need to free it before
jumping to the "free_now" label as that code will free it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250610093348.33c5643a@gandalf.local.home
Fixes: a9d0aab5eb33 ("tracing: Fix regression of filter waiting a long time on RCU synchronization")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202506070424.lCiNreTI-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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In prepare_function_table() when the pinctrl function table IRQ entries
are generated, the pin bank is calculated from the absolute pin number;
however the IRQ bank mux array is indexed from the first pin bank of the
controller. For R_PIO controllers, this means the absolute pin bank is
way off from the relative pin bank used for array indexing.
Correct this by taking into account the pin base of the controller.
Fixes: f5e2cd34b12f ("pinctrl: sunxi: allow reading mux values from DT")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/20250607135203.2085226-1-wens@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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On 32-bit ARCH=um, CONFIG_X86_32 is still defined, so it
doesn't indicate building on real X86 machines. There's
no MSR on UML though, so add a check for CONFIG_X86.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20250606090110.15784-2-johannes@sipsolutions.net
Signed-off-by: Niklas Cassel <cassel@kernel.org>
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Commit 1017560164b6 ("drm/meson: use unsigned long long / Hz for
frequency types") attempts to resolve video playback using 59.94Hz.
using YUV420 by changing the clock calculation to use
Hz instead of kHz (thus yielding more precision).
The basic calculation itself is correct, however the comparisions in
meson_vclk_vic_supported_freq() and meson_vclk_setup() don't work
anymore for 59.94Hz modes (using the freq * 1000 / 1001 logic). For
example, drm/edid specifies a 593407kHz clock for 3840x2160@59.94Hz.
With the mentioend commit we convert this to Hz. Then meson_vclk
tries to find a matchig "params" entry (as the clock setup code
currently only supports specific frequencies) by taking the venc_freq
from the params and calculating the "alt frequency" (used for the
59.94Hz modes) from it, which is:
(594000000Hz * 1000) / 1001 = 593406593Hz
Similar calculation is applied to the phy_freq (TMDS clock), which is 10
times the pixel clock.
Implement a new meson_vclk_freqs_are_matching_param() function whose
purpose is to compare if the requested and calculated frequencies. They
may not match exactly (for the reasons mentioned above). Allow the
clocks to deviate slightly to make the 59.94Hz modes again.
Fixes: 1017560164b6 ("drm/meson: use unsigned long long / Hz for frequency types")
Reported-by: Christian Hewitt <christianshewitt@gmail.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250609202751.962208-1-martin.blumenstingl@googlemail.com
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meson_vclk_vic_supported_freq() has a debug print which includes the
pixel freq. However, within the whole function the pixel freq is
irrelevant, other than checking the end of the params array. Switch to
printing the vclk_freq which is being compared / matched against the
inputs to the function to avoid confusion when analyzing error reports
from users.
Fixes: e5fab2ec9ca4 ("drm/meson: vclk: add support for YUV420 setup")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250606221031.3419353-1-martin.blumenstingl@googlemail.com
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The "phy" and "vclk" frequency labels were swapped, making it more
difficult to debug driver errors. Swap the label order to make them
match with the actual frequencies printed to correct this.
Fixes: e5fab2ec9ca4 ("drm/meson: vclk: add support for YUV420 setup")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250606203729.3311592-1-martin.blumenstingl@googlemail.com
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On at least an ASRock 990FX Extreme 4 with a VIA VT6330, the devices
have not yet been enabled by the first time ata_acpi_cbl_80wire() is
called. This means that the ata_for_each_dev loop is never entered,
and a 40 wire cable is assumed.
The VIA controller on this board does not report the cable in the PCI
config space, thus having to fall back to ACPI even though no SATA
bridge is present.
The _GTM values are correctly reported by the firmware through ACPI,
which has already set up faster transfer modes, but due to the above
the controller is forced down to a maximum of UDMA/33.
Resolve this by modifying ata_acpi_cbl_80wire() to directly return the
cable type. First, an unknown cable is assumed which preserves the mode
set by the firmware, and then on subsequent calls when the devices have
been enabled, an 80 wire cable is correctly detected.
Since the function now directly returns the cable type, it is renamed
to ata_acpi_cbl_pata_type().
Signed-off-by: Tasos Sahanidis <tasos@tasossah.com>
Link: https://lore.kernel.org/r/20250519085945.1399466-1-tasos@tasossah.com
Signed-off-by: Niklas Cassel <cassel@kernel.org>
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The controller has a hardware bug that can hard hang the system when
doing ATAPI DMAs without any trace of what happened. Depending on the
device attached, it can also prevent the system from booting.
In this case, the system hangs when reading the ATIP from optical media
with cdrecord -vvv -atip on an _NEC DVD_RW ND-4571A 1-01 and an
Optiarc DVD RW AD-7200A 1.06 attached to an ASRock 990FX Extreme 4,
running at UDMA/33.
The issue can be reproduced by running the same command with a cygwin
build of cdrecord on WinXP, although it requires more attempts to cause
it. The hang in that case is also resolved by forcing PIO. It doesn't
appear that VIA has produced any drivers for that OS, thus no known
workaround exists.
HDDs attached to the controller do not suffer from any DMA issues.
Cc: stable@vger.kernel.org
Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/916677
Signed-off-by: Tasos Sahanidis <tasos@tasossah.com>
Link: https://lore.kernel.org/r/20250519085508.1398701-1-tasos@tasossah.com
Signed-off-by: Niklas Cassel <cassel@kernel.org>
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Check the return value of kzalloc() and exit early to avoid a potential
NULL pointer dereference.
Cc: stable@vger.kernel.org
Fixes: 4f8ef33dd44a ("ASoC: soc_sdw_utils: skip the endpoint that doesn't present")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://patch.msgid.link/20250610103225.1475-2-thorsten.blum@linux.dev
Signed-off-by: Mark Brown <broonie@kernel.org>
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Replace `/// SAFETY` comments in doc comments with proper `# Safety`
sections, as per rustdoc conventions.
Also mark the C FFI callbacks as `unsafe` to correctly reflect their
safety requirements.
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Closes: https://github.com/Rust-for-Linux/linux/issues/1169
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
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`vc4_hdmi_audio_init` calls `devm_snd_dmaengine_pcm_register` which may
return EPROBE_DEFER. Calling `drm_connector_hdmi_audio_init` adds a
child device. The driver model docs[1] state that adding a child device
prior to returning EPROBE_DEFER may result in an infinite loop.
[1] https://www.kernel.org/doc/html/v6.14/driver-api/driver-model/driver.html
Fixes: 9640f1437a88 ("drm/vc4: hdmi: switch to using generic HDMI Codec infrastructure")
Signed-off-by: Gabriel Dalimonte <gabriel.dalimonte@gmail.com>
Link: https://lore.kernel.org/r/20250601-vc4-audio-inf-probe-v2-1-9ad43c7b6147@gmail.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
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Add Yang Shen as the maintainer of the HiSilicon GPIO driver,
replacing Jay Fang.
Signed-off-by: Yang Shen <shenyang39@huawei.com>
Reviewed-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/20250529034023.3780376-1-shenyang39@huawei.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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I'm moving all my kernel work over to using my kernel.org email address.
Update .mailmap and MAINTAINER entries still using hdegoede@redhat.com.
Signed-off-by: Hans de Goede <hansg@kernel.org>
Link: https://lore.kernel.org/r/20250609143558.42941-2-hansg@kernel.org
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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Bump the module version.
Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Link: https://lore.kernel.org/r/20250609184659.7210-6-stuart.w.hayes@gmail.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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The dell_rbu driver will use memset() to clear the data held by each
packet when it is no longer needed (when the driver is unloaded, the
packet size is changed, etc).
The amount of memory that is cleared (before this patch) is the normal
packet size. However, the last packet in the list may be smaller.
Fix this to only clear the memory actually used by each packet, to prevent
it from writing past the end of data buffer.
Because the packet data buffers are allocated with __get_free_pages() (in
page-sized increments), this bug could only result in a buffer being
overwritten when a packet size larger than one page is used. The only user
of the dell_rbu module should be the Dell BIOS update program, which uses
a packet size of 4096, so no issues should be seen without the patch, it
just blocks the possiblity.
Fixes: 6c54c28e69f2 ("[PATCH] dell_rbu: new Dell BIOS update driver")
Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Link: https://lore.kernel.org/r/20250609184659.7210-5-stuart.w.hayes@gmail.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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Pass the correct list head to list_for_each_entry*() when looping through
the packet list.
Without this patch, reading the packet data via sysfs will show the data
incorrectly (because it starts at the wrong packet), and clearing the
packet list will result in a NULL pointer dereference.
Fixes: d19f359fbdc6 ("platform/x86: dell_rbu: don't open code list_for_each_entry*()")
Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Link: https://lore.kernel.org/r/20250609184659.7210-3-stuart.w.hayes@gmail.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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Fix a sparse lock context warning.
Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Link: https://lore.kernel.org/r/20250609184659.7210-2-stuart.w.hayes@gmail.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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commit 5b1122fc4995f ("platform/x86/amd/pmf: fix cleanup in
amd_pmf_init_smart_pc()") adjusted the error handling flow to use a ladder
but this isn't actually needed because work is only scheduled in
amd_pmf_start_policy_engine() and with device managed cleanups pointers
for allocations don't need to be freed.
Adjust the error flow to a single call to amd_pmf_deinit_smart_pc() for
the cases that need to clean up.
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20250512211154.2510397-4-superm1@kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20250522003457.1516679-4-superm1@kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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If any of the tee init fails, pass up the errors and clear the tee_ctx
pointer. This will prevent cleaning up multiple times.
Fixes: ac052d8c08f9d ("platform/x86/amd/pmf: Add PMF TEE interface")
Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20250512211154.2510397-3-superm1@kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20250522003457.1516679-3-superm1@kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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If setting up smart PC fails for any reason then this can lead to
a double free when unloading amd-pmf. This is because dev->buf was
freed but never set to NULL and is again freed in amd_pmf_remove().
To avoid subtle allocation bugs in failures leading to a double free
change all allocations into device managed allocations.
Fixes: 5b1122fc4995f ("platform/x86/amd/pmf: fix cleanup in amd_pmf_init_smart_pc()")
Link: https://lore.kernel.org/r/20250512211154.2510397-2-superm1@kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20250522003457.1516679-2-superm1@kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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When the DMA mode is changed on the (still real!) SB AWE32 after
playing a stream and closing, the previous DMA setup was still
silently kept, and it can confuse the hardware, resulting in the
unexpected noises. As a workaround, enforce the disablement of DMA
setups when the DMA setup is changed by the kcontrol.
https://bugzilla.kernel.org/show_bug.cgi?id=218185
Link: https://patch.msgid.link/20250610064322.26787-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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When a PCM stream is already running, one shouldn't change the DMA
mode via kcontrol, which may screw up the hardware. Return -EBUSY
instead.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218185
Link: https://patch.msgid.link/20250610064322.26787-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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The GU605C has similar audio hardware to the GU605M so apply the
same quirk.
Note that in the linked bugzilla there are two separate problems
with the GU605C. This patch fixes one of the problems, so I haven't
added a Closes: tag.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reported-by: Nick Karaolidis <nick@karaolidis.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=220152
Cc: <stable@vger.kernel.org>
Link: https://patch.msgid.link/20250609102125.63196-1-rf@opensource.cirrus.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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The built-in mic of ASUS VivoBook X513EA is broken recently by the
fix of the pin sort. The fixup ALC256_FIXUP_ASUS_MIC_NO_PRESENCE
is working for addressing the regression, too.
Fixes: 3b4309546b48 ("ALSA: hda: Fix headset detection failure due to unstable sort")
Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
Cc: <stable@vger.kernel.org>
Link: https://patch.msgid.link/20250610035607.690771-1-chris.chiu@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Luis Gerhorst says:
====================
This improves the expressiveness of unprivileged BPF by inserting
speculation barriers instead of rejecting the programs.
The approach was previously presented at LPC'24 [1] and RAID'24 [2].
To mitigate the Spectre v1 (PHT) vulnerability, the kernel rejects
potentially-dangerous unprivileged BPF programs as of
commit 9183671af6db ("bpf: Fix leakage under speculation on mispredicted
branches"). In [2], we have analyzed 364 object files from open source
projects (Linux Samples and Selftests, BCC, Loxilb, Cilium, libbpf
Examples, Parca, and Prevail) and found that this affects 31% to 54% of
programs.
To resolve this in the majority of cases this patchset adds a fall-back
for mitigating Spectre v1 using speculation barriers. The kernel still
optimistically attempts to verify all speculative paths but uses
speculation barriers against v1 when unsafe behavior is detected. This
allows for more programs to be accepted without disabling the BPF
Spectre mitigations (e.g., by setting cpu_mitigations_off()).
For this, it relies on the fact that speculation barriers generally
prevent all later instructions from executing if the speculation was not
correct (not only loads). See patch 7 ("bpf: Fall back to nospec for
Spectre v1") for a detailed description and references to the relevant
vendor documentation (AMD and Intel x86-64, ARM64, and PowerPC).
In [1] we have measured the overhead of this approach relative to having
mitigations off and including the upstream Spectre v4 mitigations. For
event tracing and stack-sampling profilers, we found that mitigations
increase BPF program execution time by 0% to 62%. For the Loxilb network
load balancer, we have measured a 14% slowdown in SCTP performance but
no significant slowdown for TCP. This overhead only applies to programs
that were previously rejected.
I reran the expressiveness-evaluation with v6.14 and made sure the main
results still match those from [1] and [2] (which used v6.5).
Main design decisions are:
* Do not use separate bytecode insns for v1 and v4 barriers (inspired by
Daniel Borkmann's question at LPC). This simplifies the verifier
significantly and has the only downside that performance on PowerPC is
not as high as it could be.
* Allow archs to still disable v1/v4 mitigations separately by setting
bpf_jit_bypass_spec_v1/v4(). This has the benefit that archs can
benefit from improved BPF expressiveness / performance if they are not
vulnerable (e.g., ARM64 for v4 in the kernel).
* Do not remove the empty BPF_NOSPEC implementation for backends for
which it is unknown whether they are vulnerable to Spectre v1.
[1] https://lpc.events/event/18/contributions/1954/ ("Mitigating
Spectre-PHT using Speculation Barriers in Linux eBPF")
[2] https://arxiv.org/pdf/2405.00078 ("VeriFence: Lightweight and
Precise Spectre Defenses for Untrusted Linux Kernel Extensions")
Changes:
* v3 -> v4:
- Remove insn parameter from do_check_insn() and extract
process_bpf_exit_full as a function as requested by Eduard
- Investigate apparent sanitize_check_bounds() bug reported by
Kartikeya (does appear to not be a bug but only confusing code),
sent separate patch to document it and add an assert
- Remove already-merged commit 1 ("selftests/bpf: Fix caps for
__xlated/jited_unpriv")
- Drop former commit 10 ("bpf: Allow nospec-protected var-offset stack
access") as it did not include a test and there are other places
where var-off is rejected. Also, none of the tested real-world
programs used var-off in the paper. Therefore keep the old behavior
for now and potentially prepare a patch that converts all cases
later if required.
- Add link to AMD lfence and PowerPC speculation barrier (ori 31,31,0)
documentation
- Move detailed barrier documentation to commit 7 ("bpf: Fall back to
nospec for Spectre v1")
- Link to v3: https://lore.kernel.org/all/20250501073603.1402960-1-luis.gerhorst@fau.de/
* v2 -> v3:
- Fix
https://lore.kernel.org/oe-kbuild-all/202504212030.IF1SLhz6-lkp@intel.com/
and similar by moving the bpf_jit_bypass_spec_v1/v4() prototypes out
of the #ifdef CONFIG_BPF_SYSCALL. Decided not to move them to
filter.h (where similar bpf_jit_*() prototypes live) as they would
still have to be duplicated in bpf.h to be usable to
bpf_bypass_spec_v1/v4() (unless including filter.h in bpf.h is an
option).
- Fix
https://lore.kernel.org/oe-kbuild-all/202504220035.SoGveGpj-lkp@intel.com/
by moving the variable declarations out of the switch-case.
- Build touched C files with W=2 and bpf config on x86 to check that
there are no other warnings introduced.
- Found 3 more checkpatch warnings that can be fixed without degrading
readability.
- Rebase to bpf-next 2025-05-01
- Link to v2: https://lore.kernel.org/bpf/20250421091802.3234859-1-luis.gerhorst@fau.de/
* v1 -> v2:
- Drop former commits 9 ("bpf: Return PTR_ERR from push_stack()") and 11
("bpf: Fall back to nospec for spec path verification") as suggested
by Alexei. This series therefore no longer changes push_stack() to
return PTR_ERR.
- Add detailed explanation of how lfence works internally and how it
affects the algorithm.
- Add tests checking that nospec instructions are inserted in expected
locations using __xlated_unpriv as suggested by Eduard (also,
include a fix for __xlated_unpriv)
- Add a test for the mitigations from the description of
commit 9183671af6db ("bpf: Fix leakage under speculation on
mispredicted branches")
- Remove unused variables from do_check[_insn]() as suggested by
Eduard.
- Remove INSN_IDX_MODIFIED to improve readability as suggested by
Eduard. This also causes the nospec_result-check to run (and fail)
for jumping-ops. Add a warning to assert that this check must never
succeed in that case.
- Add details on the safety of patch 10 ("bpf: Allow nospec-protected
var-offset stack access") based on the feedback on v1.
- Rebase to bpf-next-250420
- Link to v1: https://lore.kernel.org/all/20250313172127.1098195-1-luis.gerhorst@fau.de/
* RFC -> v1:
- rebase to bpf-next-250313
- tests: mark expected successes/new errors
- add bpt_jit_bypass_spec_v1/v4() to avoid #ifdef in
bpf_bypass_spec_v1/v4()
- ensure that nospec with v1-support is implemented for archs for
which GCC supports speculation barriers, except for MIPS
- arm64: emit speculation barrier
- powerpc: change nospec to include v1 barrier
- discuss potential security (archs that do not impl. BPF nospec) and
performance (only PowerPC) regressions
- Link to RFC: https://lore.kernel.org/bpf/20250224203619.594724-1-luis.gerhorst@fau.de/
====================
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://patch.msgid.link/20250603205800.334980-1-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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|
This is based on the gadget from the description of commit 9183671af6db
("bpf: Fix leakage under speculation on mispredicted branches").
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250603212814.338867-1-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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|
This implements the core of the series and causes the verifier to fall
back to mitigating Spectre v1 using speculation barriers. The approach
was presented at LPC'24 [1] and RAID'24 [2].
If we find any forbidden behavior on a speculative path, we insert a
nospec (e.g., lfence speculation barrier on x86) before the instruction
and stop verifying the path. While verifying a speculative path, we can
furthermore stop verification of that path whenever we encounter a
nospec instruction.
A minimal example program would look as follows:
A = true
B = true
if A goto e
f()
if B goto e
unsafe()
e: exit
There are the following speculative and non-speculative paths
(`cur->speculative` and `speculative` referring to the value of the
push_stack() parameters):
- A = true
- B = true
- if A goto e
- A && !cur->speculative && !speculative
- exit
- !A && !cur->speculative && speculative
- f()
- if B goto e
- B && cur->speculative && !speculative
- exit
- !B && cur->speculative && speculative
- unsafe()
If f() contains any unsafe behavior under Spectre v1 and the unsafe
behavior matches `state->speculative &&
error_recoverable_with_nospec(err)`, do_check() will now add a nospec
before f() instead of rejecting the program:
A = true
B = true
if A goto e
nospec
f()
if B goto e
unsafe()
e: exit
Alternatively, the algorithm also takes advantage of nospec instructions
inserted for other reasons (e.g., Spectre v4). Taking the program above
as an example, speculative path exploration can stop before f() if a
nospec was inserted there because of Spectre v4 sanitization.
In this example, all instructions after the nospec are dead code (and
with the nospec they are also dead code speculatively).
For this, it relies on the fact that speculation barriers generally
prevent all later instructions from executing if the speculation was not
correct:
* On Intel x86_64, lfence acts as full speculation barrier, not only as
a load fence [3]:
An LFENCE instruction or a serializing instruction will ensure that
no later instructions execute, even speculatively, until all prior
instructions complete locally. [...] Inserting an LFENCE instruction
after a bounds check prevents later operations from executing before
the bound check completes.
This was experimentally confirmed in [4].
* On AMD x86_64, lfence is dispatch-serializing [5] (requires MSR
C001_1029[1] to be set if the MSR is supported, this happens in
init_amd()). AMD further specifies "A dispatch serializing instruction
forces the processor to retire the serializing instruction and all
previous instructions before the next instruction is executed" [8]. As
dispatch is not specific to memory loads or branches, lfence therefore
also affects all instructions there. Also, if retiring a branch means
it's PC change becomes architectural (should be), this means any
"wrong" speculation is aborted as required for this series.
* ARM's SB speculation barrier instruction also affects "any instruction
that appears later in the program order than the barrier" [6].
* PowerPC's barrier also affects all subsequent instructions [7]:
[...] executing an ori R31,R31,0 instruction ensures that all
instructions preceding the ori R31,R31,0 instruction have completed
before the ori R31,R31,0 instruction completes, and that no
subsequent instructions are initiated, even out-of-order, until
after the ori R31,R31,0 instruction completes. The ori R31,R31,0
instruction may complete before storage accesses associated with
instructions preceding the ori R31,R31,0 instruction have been
performed
Regarding the example, this implies that `if B goto e` will not execute
before `if A goto e` completes. Once `if A goto e` completes, the CPU
should find that the speculation was wrong and continue with `exit`.
If there is any other path that leads to `if B goto e` (and therefore
`unsafe()`) without going through `if A goto e`, then a nospec will
still be needed there. However, this patch assumes this other path will
be explored separately and therefore be discovered by the verifier even
if the exploration discussed here stops at the nospec.
This patch furthermore has the unfortunate consequence that Spectre v1
mitigations now only support architectures which implement BPF_NOSPEC.
Before this commit, Spectre v1 mitigations prevented exploits by
rejecting the programs on all architectures. Because some JITs do not
implement BPF_NOSPEC, this patch therefore may regress unpriv BPF's
security to a limited extent:
* The regression is limited to systems vulnerable to Spectre v1, have
unprivileged BPF enabled, and do NOT emit insns for BPF_NOSPEC. The
latter is not the case for x86 64- and 32-bit, arm64, and powerpc
64-bit and they are therefore not affected by the regression.
According to commit a6f6a95f2580 ("LoongArch, bpf: Fix jit to skip
speculation barrier opcode"), LoongArch is not vulnerable to Spectre
v1 and therefore also not affected by the regression.
* To the best of my knowledge this regression may therefore only affect
MIPS. This is deemed acceptable because unpriv BPF is still disabled
there by default. As stated in a previous commit, BPF_NOSPEC could be
implemented for MIPS based on GCC's speculation_barrier
implementation.
* It is unclear which other architectures (besides x86 64- and 32-bit,
ARM64, PowerPC 64-bit, LoongArch, and MIPS) supported by the kernel
are vulnerable to Spectre v1. Also, it is not clear if barriers are
available on these architectures. Implementing BPF_NOSPEC on these
architectures therefore is non-trivial. Searching GCC and the kernel
for speculation barrier implementations for these architectures
yielded no result.
* If any of those regressed systems is also vulnerable to Spectre v4,
the system was already vulnerable to Spectre v4 attacks based on
unpriv BPF before this patch and the impact is therefore further
limited.
As an alternative to regressing security, one could still reject
programs if the architecture does not emit BPF_NOSPEC (e.g., by removing
the empty BPF_NOSPEC-case from all JITs except for LoongArch where it
appears justified). However, this will cause rejections on these archs
that are likely unfounded in the vast majority of cases.
In the tests, some are now successful where we previously had a
false-positive (i.e., rejection). Change them to reflect where the
nospec should be inserted (using __xlated_unpriv) and modify the error
message if the nospec is able to mitigate a problem that previously
shadowed another problem (in that case __xlated_unpriv does not work,
therefore just add a comment).
Define SPEC_V1 to avoid duplicating this ifdef whenever we check for
nospec insns using __xlated_unpriv, define it here once. This also
improves readability. PowerPC can probably also be added here. However,
omit it for now because the BPF CI currently does not include a test.
Limit it to EPERM, EACCES, and EINVAL (and not everything except for
EFAULT and ENOMEM) as it already has the desired effect for most
real-world programs. Briefly went through all the occurrences of EPERM,
EINVAL, and EACCESS in verifier.c to validate that catching them like
this makes sense.
Thanks to Dustin for their help in checking the vendor documentation.
[1] https://lpc.events/event/18/contributions/1954/ ("Mitigating
Spectre-PHT using Speculation Barriers in Linux eBPF")
[2] https://arxiv.org/pdf/2405.00078 ("VeriFence: Lightweight and
Precise Spectre Defenses for Untrusted Linux Kernel Extensions")
[3] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/runtime-speculative-side-channel-mitigations.html
("Managed Runtime Speculative Execution Side Channel Mitigations")
[4] https://dl.acm.org/doi/pdf/10.1145/3359789.3359837 ("Speculator: a
tool to analyze speculative execution attacks and mitigations" -
Section 4.6 "Stopping Speculative Execution")
[5] https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/programmer-references/software-techniques-for-managing-speculation.pdf
("White Paper - SOFTWARE TECHNIQUES FOR MANAGING SPECULATION ON AMD
PROCESSORS - REVISION 5.09.23")
[6] https://developer.arm.com/documentation/ddi0597/2020-12/Base-Instructions/SB--Speculation-Barrier-
("SB - Speculation Barrier - Arm Armv8-A A32/T32 Instruction Set
Architecture (2020-12)")
[7] https://wiki.raptorcs.com/w/images/5/5f/OPF_PowerISA_v3.1C.pdf
("Power ISA™ - Version 3.1C - May 26, 2024 - Section 9.2.1 of Book
III")
[8] https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/programmer-references/40332.pdf
("AMD64 Architecture Programmer’s Manual Volumes 1–5 - Revision 4.08
- April 2024 - 7.6.4 Serializing Instructions")
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Henriette Herzog <henriette.herzog@rub.de>
Cc: Dustin Nguyen <nguyen@cs.fau.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
Link: https://lore.kernel.org/r/20250603212428.338473-1-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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This is made to clarify that this flag will cause a nospec to be added
after this insn and can therefore be relied upon to reduce speculative
path analysis.
Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: Henriette Herzog <henriette.herzog@rub.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
Link: https://lore.kernel.org/r/20250603212024.338154-1-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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