| Age | Commit message (Collapse) | Author | Files | Lines |
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steal the (clever) algorithm from get_random_u32_below()
this fixes a bug where we were passing roundup_pow_of_two() a 64 bit
number - we're squaring device latencies now:
[ +1.681698] ------------[ cut here ]------------
[ +0.000010] UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13
[ +0.000011] shift exponent 64 is too large for 64-bit type 'long unsigned int'
[ +0.000011] CPU: 1 UID: 0 PID: 196 Comm: kworker/u32:13 Not tainted 6.14.0-rc6-dave+ #10
[ +0.000012] Hardware name: ASUS System Product Name/PRIME B460I-PLUS, BIOS 1301 07/13/2021
[ +0.000005] Workqueue: events_unbound __bch2_read_endio [bcachefs]
[ +0.000354] Call Trace:
[ +0.000005] <TASK>
[ +0.000007] dump_stack_lvl+0x5d/0x80
[ +0.000018] ubsan_epilogue+0x5/0x30
[ +0.000008] __ubsan_handle_shift_out_of_bounds.cold+0x61/0xe6
[ +0.000011] bch2_rand_range.cold+0x17/0x20 [bcachefs]
[ +0.000231] bch2_bkey_pick_read_device+0x547/0x920 [bcachefs]
[ +0.000229] __bch2_read_extent+0x1e4/0x18e0 [bcachefs]
[ +0.000241] ? bch2_btree_iter_peek_slot+0x3df/0x800 [bcachefs]
[ +0.000180] ? bch2_read_retry_nodecode+0x270/0x330 [bcachefs]
[ +0.000230] bch2_read_retry_nodecode+0x270/0x330 [bcachefs]
[ +0.000230] bch2_rbio_retry+0x1fa/0x600 [bcachefs]
[ +0.000224] ? bch2_printbuf_make_room+0x71/0xb0 [bcachefs]
[ +0.000243] ? bch2_read_csum_err+0x4a4/0x610 [bcachefs]
[ +0.000278] bch2_read_csum_err+0x4a4/0x610 [bcachefs]
[ +0.000227] ? __bch2_read_endio+0x58b/0x870 [bcachefs]
[ +0.000220] __bch2_read_endio+0x58b/0x870 [bcachefs]
[ +0.000268] ? try_to_wake_up+0x31c/0x7f0
[ +0.000011] ? process_one_work+0x176/0x330
[ +0.000008] process_one_work+0x176/0x330
[ +0.000008] worker_thread+0x252/0x390
[ +0.000008] ? __pfx_worker_thread+0x10/0x10
[ +0.000006] kthread+0xec/0x230
[ +0.000011] ? __pfx_kthread+0x10/0x10
[ +0.000009] ret_from_fork+0x31/0x50
[ +0.000009] ? __pfx_kthread+0x10/0x10
[ +0.000008] ret_from_fork_asm+0x1a/0x30
[ +0.000012] </TASK>
[ +0.000046] ---[ end trace ]---
Reported-by: Roland Vet <vet.roland@protonmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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get_random_u32_below() has a better algorithm than bch2_rand_range(),
it just didn't exist at the time.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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We were still using the trans after the unlock, leading to this bug in
the retry path:
00255 ------------[ cut here ]------------
00255 kernel BUG at fs/bcachefs/btree_iter.c:3348!
00255 Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
00255 bcachefs (0ca38fe8-0a26-41f9-9b5d-6a27796c7803): /fiotest offset 86048768: no device to read from:
00255 u64s 8 type extent 4098:168192:U32_MAX len 128 ver 0: durability: 0 crc: c_size 128 size 128 offset 0 nonce 0 csum crc32c 0:8040a368 compress none ec: idx 83 block 1 ptr: 0:302:128 gen 0
00255 bcachefs (0ca38fe8-0a26-41f9-9b5d-6a27796c7803): /fiotest offset 85983232: no device to read from:
00255 u64s 8 type extent 4098:168064:U32_MAX len 128 ver 0: durability: 0 crc: c_size 128 size 128 offset 0 nonce 0 csum crc32c 0:43311336 compress none ec: idx 83 block 1 ptr: 0:302:0 gen 0
00255 Modules linked in:
00255 CPU: 5 UID: 0 PID: 304 Comm: kworker/u70:2 Not tainted 6.14.0-rc6-ktest-g526aae23d67d #16040
00255 Hardware name: linux,dummy-virt (DT)
00255 Workqueue: events_unbound bch2_rbio_retry
00255 pstate: 60001005 (nZCv daif -PAN -UAO -TCO -DIT +SSBS BTYPE=--)
00255 pc : __bch2_trans_get+0x100/0x378
00255 lr : __bch2_trans_get+0xa0/0x378
00255 sp : ffffff80c865b760
00255 x29: ffffff80c865b760 x28: 0000000000000000 x27: ffffff80d76ed880
00255 x26: 0000000000000018 x25: 0000000000000000 x24: ffffff80f4ec3760
00255 x23: ffffff80f4010140 x22: 0000000000000056 x21: ffffff80f4ec0000
00255 x20: ffffff80f4ec3788 x19: ffffff80d75f8000 x18: 00000000ffffffff
00255 x17: 2065707974203820 x16: 7334367520200a3a x15: 0000000000000008
00255 x14: 0000000000000001 x13: 0000000000000100 x12: 0000000000000006
00255 x11: ffffffc080b47a40 x10: 0000000000000000 x9 : ffffffc08038dea8
00255 x8 : ffffff80d75fc018 x7 : 0000000000000000 x6 : 0000000000003788
00255 x5 : 0000000000003760 x4 : ffffff80c922de80 x3 : ffffff80f18f0000
00255 x2 : ffffff80c922de80 x1 : 0000000000000130 x0 : 0000000000000006
00255 Call trace:
00255 __bch2_trans_get+0x100/0x378 (P)
00255 bch2_read_io_err+0x98/0x260
00255 bch2_read_endio+0xb8/0x2d0
00255 __bch2_read_extent+0xce8/0xfe0
00255 __bch2_read+0x2a8/0x978
00255 bch2_rbio_retry+0x188/0x318
00255 process_one_work+0x154/0x390
00255 worker_thread+0x20c/0x3b8
00255 kthread+0xf0/0x1b0
00255 ret_from_fork+0x10/0x20
00255 Code: 6b01001f 54ffff01 79408460 3617fec0 (d4210000)
00255 ---[ end trace 0000000000000000 ]---
00255 Kernel panic - not syncing: Oops - BUG: Fatal exception
00255 SMP: stopping secondary CPUs
00255 Kernel Offset: disabled
00255 CPU features: 0x000,00000070,00000010,8240500b
00255 Memory Limit: none
00255 ---[ end Kernel panic - not syncing: Oops - BUG: Fatal exception ]---
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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When there is no inode source, all "from_inode" members in the structure
bhc_io_opts should be set false.
Fixes: 7a7c43a0c1ecf ("bcachefs: Add bch_io_opts fields for indicating whether the opts came from the inode")
Reported-by: syzbot+c17ad4b4367b72a853cb@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c17ad4b4367b72a853cb
Signed-off-by: Roxana Nicolescu <nicolescu.roxana@protonmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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When bset past end of btree node, we should not add sectors to
b->written, which will overflow b->written.
Reported-by: syzbot+3cb3d9e8c3f197754825@syzkaller.appspotmail.com
Tested-by: syzbot+3cb3d9e8c3f197754825@syzkaller.appspotmail.com
Signed-off-by: Alan Huang <mmpgouride@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Add some more forgotten models to the SHA check.
Fixes: 50cef76d5cb0 ("x86/microcode/AMD: Load only SHA256-checksummed patches")
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Toralf Förster <toralf.foerster@gmx.de>
Link: https://lore.kernel.org/r/20250307220256.11816-1-bp@kernel.org
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Physical address space is 48 bit on Loongson-3A5000 physical machine,
however it is 47 bit for VM on Loongson-3A5000 system. Size of physical
address space of VM is the same with the size of virtual user space (a
half) of physical machine.
Variable cpu_vabits represents user address space, kernel address space
is not included (user space and kernel space are both a half of total).
Here cpu_vabits, rather than cpu_vabits - 1, is to represent the size of
guest physical address space.
Also there is strict checking about page fault GPA address, inject error
if it is larger than maximum GPA address of VM.
Cc: stable@vger.kernel.org
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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On host, the HW guest CSR registers are lost after suspend and resume
operation. Since last_vcpu of boot CPU still records latest vCPU pointer
so that the guest CSR register skips to reload when boot CPU resumes and
vCPU is scheduled.
Here last_vcpu is cleared so that guest CSR registers will reload from
scheduled vCPU context after suspend and resume.
Cc: stable@vger.kernel.org
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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There is a newly added macro INT_AVEC with CSR ESTAT register, which is
bit 14 used for LoongArch AVEC support. AVEC interrupt status bit 14 is
supported with macro CSR_ESTAT_IS, so here replace the hard-coded value
0x1fff with macro CSR_ESTAT_IS so that the AVEC interrupt status is also
supported by KVM.
Cc: stable@vger.kernel.org
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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With ltp test case "testcases/bin/hugefork02", there is a dmesg error
report message such as:
kernel BUG at mm/hugetlb.c:5550!
Oops - BUG[#1]:
CPU: 0 UID: 0 PID: 1517 Comm: hugefork02 Not tainted 6.14.0-rc2+ #241
Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022
pc 90000000004eaf1c ra 9000000000485538 tp 900000010edbc000 sp 900000010edbf940
a0 900000010edbfb00 a1 9000000108d20280 a2 00007fffe9474000 a3 00007ffff3474000
a4 0000000000000000 a5 0000000000000003 a6 00000000003cadd3 a7 0000000000000000
t0 0000000001ffffff t1 0000000001474000 t2 900000010ecd7900 t3 00007fffe9474000
t4 00007fffe9474000 t5 0000000000000040 t6 900000010edbfb00 t7 0000000000000001
t8 0000000000000005 u0 90000000004849d0 s9 900000010edbfa00 s0 9000000108d20280
s1 00007fffe9474000 s2 0000000002000000 s3 9000000108d20280 s4 9000000002b38b10
s5 900000010edbfb00 s6 00007ffff3474000 s7 0000000000000406 s8 900000010edbfa08
ra: 9000000000485538 unmap_vmas+0x130/0x218
ERA: 90000000004eaf1c __unmap_hugepage_range+0x6f4/0x7d0
PRMD: 00000004 (PPLV0 +PIE -PWE)
EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0)
PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
Process hugefork02 (pid: 1517, threadinfo=00000000a670eaf4, task=000000007a95fc64)
Call Trace:
[<90000000004eaf1c>] __unmap_hugepage_range+0x6f4/0x7d0
[<9000000000485534>] unmap_vmas+0x12c/0x218
[<9000000000494068>] exit_mmap+0xe0/0x308
[<900000000025fdc4>] mmput+0x74/0x180
[<900000000026a284>] do_exit+0x294/0x898
[<900000000026aa30>] do_group_exit+0x30/0x98
[<900000000027bed4>] get_signal+0x83c/0x868
[<90000000002457b4>] arch_do_signal_or_restart+0x54/0xfa0
[<90000000015795e8>] irqentry_exit_to_user_mode+0xb8/0x138
[<90000000002572d0>] tlb_do_page_fault_1+0x114/0x1b4
The problem is that base address allocated from hugetlbfs is not aligned
with pmd size. Here add a checking for hugetlbfs and align base address
with pmd size. After this patch the test case "testcases/bin/hugefork02"
passes to run.
This is similar to the commit 7f24cbc9c4d42db8a3c8484d1 ("mm/mmap: teach
generic_get_unmapped_area{_topdown} to handle hugetlb mappings").
Cc: stable@vger.kernel.org # 6.13+
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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The current max_pfn equals to zero. In this case, it causes user cannot
get some page information through /proc filesystem such as kpagecount.
The following message is displayed by stress-ng test suite with command
"stress-ng --verbose --physpage 1 -t 1".
# stress-ng --verbose --physpage 1 -t 1
stress-ng: error: [1691] physpage: cannot read page count for address 0x134ac000 in /proc/kpagecount, errno=22 (Invalid argument)
stress-ng: error: [1691] physpage: cannot read page count for address 0x7ffff207c3a8 in /proc/kpagecount, errno=22 (Invalid argument)
stress-ng: error: [1691] physpage: cannot read page count for address 0x134b0000 in /proc/kpagecount, errno=22 (Invalid argument)
...
After applying this patch, the kernel can pass the test.
# stress-ng --verbose --physpage 1 -t 1
stress-ng: debug: [1701] physpage: [1701] started (instance 0 on CPU 3)
stress-ng: debug: [1701] physpage: [1701] exited (instance 0 on CPU 3)
stress-ng: debug: [1700] physpage: [1701] terminated (success)
Cc: stable@vger.kernel.org # 6.8+
Fixes: ff6c3d81f2e8 ("NUMA: optimize detection of memory with no node id assigned by firmware")
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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When CONFIG_RANDOM_KMALLOC_CACHES or other randomization infrastructrue
enabled, the idle_task's stack may different between the booting kernel
and target kernel. So when resuming from hibernation, an ACTION_BOOT_CPU
IPI wakeup the idle instruction in arch_cpu_idle_dead() and jump to the
interrupt handler. But since the stack pointer is changed, the interrupt
handler cannot restore correct context.
So rename the current arch_cpu_idle_dead() to idle_play_dead(), make it
as the default version of play_dead(), and the new arch_cpu_idle_dead()
call play_dead() directly. For hibernation, implement an arch-specific
hibernate_resume_nonboot_cpu_disable() to use the polling version (idle
instruction is replace by nop, and irq is disabled) of play_dead(), i.e.
poll_play_dead(), to avoid IPI handler corrupting the idle_task's stack
when resuming from hibernation.
This solution is a little similar to commit 406f992e4a372dafbe3c ("x86 /
hibernate: Use hlt_play_dead() when resuming from hibernation").
Cc: stable@vger.kernel.org
Tested-by: Erpeng Xu <xuerpeng@uniontech.com>
Tested-by: Yuli Wang <wangyuli@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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In LoongArch, get_numa_distances_cnt() isn't in use, resulting in a
compiler warning.
Fix follow errors with clang-18 when W=1e:
arch/loongarch/kernel/acpi.c:259:28: error: unused function 'get_numa_distances_cnt' [-Werror,-Wunused-function]
259 | static inline unsigned int get_numa_distances_cnt(struct acpi_table_slit *slit)
| ^~~~~~~~~~~~~~~~~~~~~~
1 error generated.
Link: https://lore.kernel.org/all/Z7bHPVUH4lAezk0E@kernel.org/
Signed-off-by: Yuli Wang <wangyuli@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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When compiling on LoongArch, there exists the following objtool warning
in arch/loongarch/kernel/machine_kexec.o:
kexec_reboot() falls through to next function crash_shutdown_secondary()
Avoid using unreachable() as it can (and will in the absence of UBSAN)
generate fall-through code. Use BUG() so we get a "break BRK_BUG" trap
(with unreachable annotation).
Cc: stable@vger.kernel.org # 6.12+
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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Andy reported the following build warning from head_32.S:
In file included from arch/x86/kernel/head_32.S:29:
arch/x86/include/asm/pgtable_32.h:59:5: error: "PTRS_PER_PMD" is not defined, evaluates to 0 [-Werror=undef]
59 | #if PTRS_PER_PMD > 1
The reason is that on 2-level i386 paging the folded in PMD's
PTRS_PER_PMD constant is not defined in assembly headers,
only in generic MM C headers.
Instead of trying to fish out the definition from the generic
headers, just define it - it even has a comment for it already...
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/Z8oa8AUVyi2HWfo9@gmail.com
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Compared to the SNP Guest Request, the "Extended" version adds data pages for
receiving certificates. If not enough pages provided, the HV can report to the
VM how much is needed so the VM can reallocate and repeat.
Commit
ae596615d93d ("virt: sev-guest: Reduce the scope of SNP command mutex")
moved handling of the allocated/desired pages number out of scope of said
mutex and create a possibility for a race (multiple instances trying to
trigger Extended request in a VM) as there is just one instance of
snp_msg_desc per /dev/sev-guest and no locking other than snp_cmd_mutex.
Fix the issue by moving the data blob/size and the GHCB input struct
(snp_req_data) into snp_guest_req which is allocated on stack now and accessed
by the GHCB caller under that mutex.
Stop allocating SEV_FW_BLOB_MAX_SIZE in snp_msg_alloc() as only one of four
callers needs it. Free the received blob in get_ext_report() right after it is
copied to the userspace. Possible future users of snp_send_guest_request() are
likely to have different ideas about the buffer size anyways.
Fixes: ae596615d93d ("virt: sev-guest: Reduce the scope of SNP command mutex")
Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nikunj A Dadhania <nikunj@amd.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250307013700.437505-3-aik@amd.com
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Commit
ae596615d93d ("virt: sev-guest: Reduce the scope of SNP command mutex")
narrowed the command mutex scope to snp_send_guest_request(). However,
GET_REPORT, GET_DERIVED_KEY, and GET_EXT_REPORT share the req structure in
snp_guest_dev. Without the mutex protection, concurrent requests can overwrite
each other's data. Fix it by dynamically allocating the request structure.
Fixes: ae596615d93d ("virt: sev-guest: Reduce the scope of SNP command mutex")
Closes: https://github.com/AMDESE/AMDSEV/issues/265
Reported-by: andreas.stuehrk@yaxi.tech
Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250307013700.437505-2-aik@amd.com
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Xen doesn't offer MSR_FAM10H_MMIO_CONF_BASE to all guests. This results
in the following warning:
unchecked MSR access error: RDMSR from 0xc0010058 at rIP: 0xffffffff8101d19f (xen_do_read_msr+0x7f/0xa0)
Call Trace:
xen_read_msr+0x1e/0x30
amd_get_mmconfig_range+0x2b/0x80
quirk_amd_mmconfig_area+0x28/0x100
pnp_fixup_device+0x39/0x50
__pnp_add_device+0xf/0x150
pnp_add_device+0x3d/0x100
pnpacpi_add_device_handler+0x1f9/0x280
acpi_ns_get_device_callback+0x104/0x1c0
acpi_ns_walk_namespace+0x1d0/0x260
acpi_get_devices+0x8a/0xb0
pnpacpi_init+0x50/0x80
do_one_initcall+0x46/0x2e0
kernel_init_freeable+0x1da/0x2f0
kernel_init+0x16/0x1b0
ret_from_fork+0x30/0x50
ret_from_fork_asm+0x1b/0x30
based on quirks for a "PNP0c01" device. Treating MMCFG as disabled is the
right course of action, so no change is needed there.
This was most likely exposed by fixing the Xen MSR accessors to not be
silently-safe.
Fixes: 3fac3734c43a ("xen/pv: support selecting safe/unsafe msr accesses")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250307002846.3026685-1-andrew.cooper3@citrix.com
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The fix to atomically read the pipe head and tail state when not holding
the pipe mutex has caused a number of headaches due to the size change
of the involved types.
It turns out that we don't have _that_ many places that access these
fields directly and were affected, but we have more than we strictly
should have, because our low-level helper functions have been designed
to have intimate knowledge of how the pipes work.
And as a result, that random noise of direct 'pipe->head' and
'pipe->tail' accesses makes it harder to pinpoint any actual potential
problem spots remaining.
For example, we didn't have a "is the pipe full" helper function, but
instead had a "given these pipe buffer indexes and this pipe size, is
the pipe full". That's because some low-level pipe code does actually
want that much more complicated interface.
But most other places literally just want a "is the pipe full" helper,
and not having it meant that those places ended up being unnecessarily
much too aware of this all.
It would have been much better if only the very core pipe code that
cared had been the one aware of this all.
So let's fix it - better late than never. This just introduces the
trivial wrappers for "is this pipe full or empty" and to get how many
pipe buffers are used, so that instead of writing
if (pipe_full(pipe->head, pipe->tail, pipe->max_usage))
the places that literally just want to know if a pipe is full can just
say
if (pipe_is_full(pipe))
instead. The existing trivial cases were converted with a 'sed' script.
This cuts down on the places that access pipe->head and pipe->tail
directly outside of the pipe code (and core splice code) quite a lot.
The splice code in particular still revels in doing the direct low-level
accesses, and the fuse fuse_dev_splice_write() code also seems a bit
unnecessarily eager to go very low-level, but it's at least a bit better
than it used to be.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Commit 5f89154e8e9e3445f9b59 ("block: Use enum to define RQF_x bit
indexes") converted the RQF flags to an anonymous enum, which was
a beneficial change. This patch goes one step further by naming the enum
as "rqf_flags".
This naming enables exporting these flags to BPF clients, eliminating
the need to duplicate these flags in BPF code. Instead, BPF clients can
now access the same kernel-side values through CO:RE (Compile Once, Run
Everywhere), as shown in this example:
rqf_stats = bpf_core_enum_value(enum rqf_flags, __RQF_STATS)
Suggested-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20250306-rqf_flags-v1-1-bbd64918b406@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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|
There's no point in doing copygc on non-rw devices: the fragmentation
doesn't matter if we're not writing to them, and we may not have
anywhere to put the data on our other devices.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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|
Previously, we fixed journal resize spuriousl failing with
-BCH_ERR_open_buckets_empty, but initial journal allocation was missed
because it didn't invoke the "block on allocator" loop at all.
Factor out the "loop on allocator" code to fix that.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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The 5-level paging code parses the command line to look for the 'no5lvl'
string, and does so very early, before sanitize_boot_params() has been
called and has been given the opportunity to wipe bogus data from the
fields in boot_params that are not covered by struct setup_header, and
are therefore supposed to be initialized to zero by the bootloader.
This triggers an early boot crash when using syslinux-efi to boot a
recent kernel built with CONFIG_X86_5LEVEL=y and CONFIG_EFI_STUB=n, as
the 0xff padding that now fills the unused PE/COFF header is copied into
boot_params by the bootloader, and interpreted as the top half of the
command line pointer.
Fix this by sanitizing the boot_params before use. Note that there is no
harm in calling this more than once; subsequent invocations are able to
spot that the boot_params have already been cleaned up.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org> # v6.1+
Link: https://lore.kernel.org/r/20250306155915.342465-2-ardb+git@google.com
Closes: https://lore.kernel.org/all/202503041549.35913.ulrich.gemkow@ikr.uni-stuttgart.de
|
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This was another case that Rasmus pointed out where the direct access to
the pipe head and tail pointers broke on 32-bit configurations due to
the type changes.
As with the pipe FIONREAD case, fix it by using the appropriate helper
functions that deal with the right pipe index sizing.
Reported-by: Rasmus Villemoes <ravi@prevas.dk>
Link: https://lore.kernel.org/all/878qpi5wz4.fsf@prevas.dk/
Fixes: 3d252160b818 ("fs/pipe: Read pipe->{head,tail} atomically outside pipe->mutex")Cc: Oleg >
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Swapnil Sapkal <swapnil.sapkal@amd.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Rasmus points out that we do indeed have other cases of breakage from
the type changes that were introduced on 32-bit targets in order to read
the pipe head and tail values atomically (commit 3d252160b818: "fs/pipe:
Read pipe->{head,tail} atomically outside pipe->mutex").
Fix it up by using the proper helper functions that now deal with the
pipe buffer index types properly. This makes the code simpler and more
obvious.
The compiler does the CSE and loop hoisting of the pipe ring size
masking that we used to do manually, so open-coding this was never a
good idea.
Reported-by: Rasmus Villemoes <ravi@prevas.dk>
Link: https://lore.kernel.org/all/87cyeu5zgk.fsf@prevas.dk/
Fixes: 3d252160b818 ("fs/pipe: Read pipe->{head,tail} atomically outside pipe->mutex")Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Swapnil Sapkal <swapnil.sapkal@amd.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
That's what 'pipe_full()' does, so it's more consistent. But more
importantly it gets the type limits right when the pipe head and tail
are no longer necessarily 'unsigned int'.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Resources should be released only after all threads that utilize them
have been destroyed.
This commit ensures that resources are not released prematurely by waiting
for the associated workqueue to complete before deallocating them.
Cc: stable <stable@kernel.org>
Fixes: b9aa02ca39a4 ("usb: typec: ucsi: Add polling mechanism for partner tasks like alt mode checking")
Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20250305111739.1489003-2-akuchynski@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
When used on Huawei hisi platforms, Prolific Mass Storage Card Reader
which the VID:PID is in 067b:2731 might fail to enumerate at boot time
and doesn't work well with LPM enabled, combination quirks:
USB_QUIRK_DELAY_INIT + USB_QUIRK_NO_LPM
fixed the problems.
Signed-off-by: Miao Li <limiao@kylinos.cn>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20250304070757.139473-1-limiao870622@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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|
of_parse_phandle_with_fixed_args() requires its caller to
call into of_node_put() on the node pointer from the output
structure, but such a call is currently missing.
Call into of_node_put() to rectify that.
Fixes: 159f8a0209af ("gpio-rcar: Add DT support")
Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20250305163753.34913-2-fabrizio.castro.jz@renesas.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
|
|
Add btrfs_free_chunk_map() to free the memory allocated
by btrfs_alloc_chunk_map() if btrfs_add_chunk_map() fails.
Fixes: 7dc66abb5a47 ("btrfs: use a dedicated data structure for chunk maps")
CC: stable@vger.kernel.org
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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|
Since commit 5f73e7d0386d ("kbuild: refactor cross-compiling
linux-headers package"), the linux-headers pacman package fails
to build when "O=" is set. The build system complains:
/mnt/chroot/linux/scripts/Makefile.build:41: mnt/chroots/linux-mainline/pacman/linux-upstream/pkg/linux-upstream-headers/usr//lib/modules/6.14.0-rc3-00350-g771dba31fffc/build/scripts/Makefile: No such file or directory
This is because the "srcroot" variable is set to "." and the
"build" variable is set to the absolute path. This makes the
"src" variables point to wrong directory.
Change the "build" variable to a relative path to "." to
fix build.
Fixes: 5f73e7d0386d ("kbuild: refactor cross-compiling linux-headers package")
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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Add missing skb_dst_drop() to drop reference to the old dst before
adding the new dst to the skb.
Fixes: 79ff2fc31e0f ("ila: Cache a route to translated address")
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Link: https://patch.msgid.link/20250305081655.19032-1-justin.iurman@uliege.be
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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This patch follows commit 92191dd10730 ("net: ipv6: fix dst ref loops in
rpl, seg6 and ioam6 lwtunnels") and, on a second thought, the same patch
is also needed for ila (even though the config that triggered the issue
was pathological, but still, we don't want that to happen).
Fixes: 79ff2fc31e0f ("ila: Cache a route to translated address")
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Link: https://patch.msgid.link/20250304181039.35951-1-justin.iurman@uliege.be
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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daddr can be NULL if there is no neighbour table entry present,
in that case the tx packet should be dropped.
saddr will usually be set by MCTP core, but check for NULL in case a
packet is transmitted by a different protocol.
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Fixes: c8755b29b58e ("mctp i3c: MCTP I3C driver")
Link: https://patch.msgid.link/20250304-mctp-i3c-null-v1-1-4416bbd56540@codeconstruct.com.au
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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|
By default fair_server dl_server allocates 5% of the bandwidth to the root
domain. Due to this writing any value less than 5% fails due to -EBUSY:
$ cat /proc/sys/kernel/sched_rt_period_us
1000000
$ echo 49999 > /proc/sys/kernel/sched_rt_runtime_us
-bash: echo: write error: Device or resource busy
$ echo 50000 > /proc/sys/kernel/sched_rt_runtime_us
$
Since the sched_rt_runtime_us allows -1 as the minimum, put this
restriction in the documentation.
One should check average of runtime/period in
/sys/kernel/debug/sched/fair_server/cpuX/* for exact value.
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/r/20250306052954.452005-3-sshegde@linux.ibm.com
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The ftrace selftest reported a failure because writing -1 to
sched_rt_runtime_us returns -EBUSY. This happens when the possible
CPUs are different from active CPUs.
Active CPUs are part of one root domain, while remaining CPUs are part
of def_root_domain. Since active cpumask is being used, this results in
cpus=0 when a non active CPUs is used in the loop.
Fix it by looping over the online CPUs instead for validating the
bandwidth calculations.
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/r/20250306052954.452005-2-sshegde@linux.ibm.com
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|
It is already difficult for users to troubleshoot which of multiple pid
limits restricts their workload. The per-(hierarchical-)NS pid_max would
contribute to the confusion.
Also, the implementation copies the limit upon creation from
parent, this pattern showed cumbersome with some attributes in legacy
cgroup controllers -- it's subject to race condition between parent's
limit modification and children creation and once copied it must be
changed in the descendant.
Let's do what other places do (ucounts or cgroup limits) -- create new
pid namespaces without any limit at all. The global limit (actually any
ancestor's limit) is still effectively in place, we avoid the
set/unshare race and bumps of global (ancestral) limit have the desired
effect on pid namespace that do not care.
Link: https://lore.kernel.org/r/20240408145819.8787-1-mkoutny@suse.com/
Link: https://lore.kernel.org/r/20250221170249.890014-1-mkoutny@suse.com/
Fixes: 7863dcc72d0f4 ("pid: allow pid_max to be set per pid namespace")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Link: https://lore.kernel.org/r/20250305145849.55491-1-mkoutny@suse.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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|
The recent rewrite with the use of regular atomic helpers broke the
DPMS unblanking on X11. Fix it by moving the call of
bochs_hw_blank(false) from CRTC mode_set_nofb() to atomic_enable().
Fixes: 2037174993c8 ("drm/bochs: Use regular atomic helpers")
Link: https://bugzilla.suse.com/show_bug.cgi?id=1238209
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20250304134203.20534-1-tiwai@suse.de
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The variable "compact_result" is not initialized in function
__alloc_pages_slowpath(). It causes should_compact_retry() to use an
uninitialized value.
Initialize variable "compact_result" with the value COMPACT_SKIPPED.
BUG: KMSAN: uninit-value in __alloc_pages_slowpath+0xee8/0x16c0 mm/page_alloc.c:4416
__alloc_pages_slowpath+0xee8/0x16c0 mm/page_alloc.c:4416
__alloc_frozen_pages_noprof+0xa4c/0xe00 mm/page_alloc.c:4752
alloc_pages_mpol+0x4cd/0x890 mm/mempolicy.c:2270
alloc_frozen_pages_noprof mm/mempolicy.c:2341 [inline]
alloc_pages_noprof mm/mempolicy.c:2361 [inline]
folio_alloc_noprof+0x1dc/0x350 mm/mempolicy.c:2371
filemap_alloc_folio_noprof+0xa6/0x440 mm/filemap.c:1019
__filemap_get_folio+0xb9a/0x1840 mm/filemap.c:1970
grow_dev_folio fs/buffer.c:1039 [inline]
grow_buffers fs/buffer.c:1105 [inline]
__getblk_slow fs/buffer.c:1131 [inline]
bdev_getblk+0x2c9/0xab0 fs/buffer.c:1431
getblk_unmovable include/linux/buffer_head.h:369 [inline]
ext4_getblk+0x3b7/0xe50 fs/ext4/inode.c:864
ext4_bread_batch+0x9f/0x7d0 fs/ext4/inode.c:933
__ext4_find_entry+0x1ebb/0x36c0 fs/ext4/namei.c:1627
ext4_lookup_entry fs/ext4/namei.c:1729 [inline]
ext4_lookup+0x189/0xb40 fs/ext4/namei.c:1797
__lookup_slow+0x538/0x710 fs/namei.c:1793
lookup_slow+0x6a/0xd0 fs/namei.c:1810
walk_component fs/namei.c:2114 [inline]
link_path_walk+0xf29/0x1420 fs/namei.c:2479
path_openat+0x30f/0x6250 fs/namei.c:3985
do_filp_open+0x268/0x600 fs/namei.c:4016
do_sys_openat2+0x1bf/0x2f0 fs/open.c:1428
do_sys_open fs/open.c:1443 [inline]
__do_sys_openat fs/open.c:1459 [inline]
__se_sys_openat fs/open.c:1454 [inline]
__x64_sys_openat+0x2a1/0x310 fs/open.c:1454
x64_sys_call+0x36f5/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:258
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Local variable compact_result created at:
__alloc_pages_slowpath+0x66/0x16c0 mm/page_alloc.c:4218
__alloc_frozen_pages_noprof+0xa4c/0xe00 mm/page_alloc.c:4752
Link: https://lkml.kernel.org/r/tencent_ED1032321D6510B145CDBA8CBA0093178E09@qq.com
Reported-by: syzbot+0cfd5e38e96a5596f2b6@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0cfd5e38e96a5596f2b6
Signed-off-by: Hao Zhang <zhanghao1@kylinos.cn>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The return value of rio_add_net() should be checked. If it fails,
put_device() should be called to free the memory and give up the reference
initialized in rio_add_net().
Link: https://lkml.kernel.org/r/20250227041131.3680761-1-haoxiang_li2024@163.com
Fixes: e6b585ca6e81 ("rapidio: move net allocation into core code")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
rio_add_net() calls device_register() and fails when device_register()
fails. Thus, put_device() should be used rather than kfree(). Add
"mport->net = NULL;" to avoid a use after free issue.
Link: https://lkml.kernel.org/r/20250227073409.3696854-1-haoxiang_li2024@163.com
Fixes: e8de370188d0 ("rapidio: add mport char device driver")
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Update Sumit Garg's email address to @kernel.org.
Link: https://lkml.kernel.org/r/20250227113228.1809449-1-sumit.garg@linaro.org
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit 96a5c186efff ("mm/page_alloc.c: don't show protection in zone's
->lowmem_reserve[] for empty zone") removes the protection of lower zones
from allocations targeting memory-less high zones. This had an unintended
impact on the pattern of reclaims because it makes the high-zone-targeted
allocation more likely to succeed in lower zones, which adds pressure to
said zones. I.e, the following corresponding checks in
zone_watermark_ok/zone_watermark_fast are less likely to trigger:
if (free_pages <= min + z->lowmem_reserve[highest_zoneidx])
return false;
As a result, we are observing an increase in reclaim and kswapd scans, due
to the increased pressure. This was initially observed as increased
latency in filesystem operations when benchmarking with fio on a machine
with some memory-less zones, but it has since been associated with
increased contention in locks related to memory reclaim. By reverting
this patch, the original performance was recovered on that machine.
The original commit was introduced as a clarification of the
/proc/zoneinfo output, so it doesn't seem there are usecases depending on
it, making the revert a simple solution.
For reference, I collected vmstat with and without this patch on a freshly
booted system running intensive randread io from an nvme for 5 minutes. I
got:
rpm-6.12.0-slfo.1.2 -> pgscan_kswapd 5629543865
Patched -> pgscan_kswapd 33580844
33M scans is similar to what we had in kernels predating this patch.
These numbers is fairly representative of the workload on this machine, as
measured in several runs. So we are talking about a 2-order of magnitude
increase.
Link: https://lkml.kernel.org/r/20250226032258.234099-1-krisman@suse.de
Fixes: 96a5c186efff ("mm/page_alloc.c: don't show protection in zone's ->lowmem_reserve[] for empty zone")
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When handling faults for anon shmem finish_fault() will attempt to install
ptes for the entire folio. Unfortunately if it encounters a single
non-pte_none entry in that range it will bail, even if the pte that
triggered the fault is still pte_none. When this situation happens the
fault will be retried endlessly never making forward progress.
This patch fixes this behavior and if it detects that a pte in the range
is not pte_none it will fall back to setting a single pte.
[bgeffon@google.com: tweak whitespace]
Link: https://lkml.kernel.org/r/20250227133236.1296853-1-bgeffon@google.com
Link: https://lkml.kernel.org/r/20250226162341.915535-1-bgeffon@google.com
Fixes: 43e027e41423 ("mm: memory: extend finish_fault() to support large folio")
Signed-off-by: Brian Geffon <bgeffon@google.com>
Suggested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reported-by: Marek Maslanka <mmaslanka@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickens <hughd@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Fix callers that previously skipped calling arch_sync_kernel_mappings() if
an error occurred during a pgtable update. The call is still required to
sync any pgtable updates that may have occurred prior to hitting the error
condition.
These are theoretical bugs discovered during code review.
Link: https://lkml.kernel.org/r/20250226121610.2401743-1-ryan.roberts@arm.com
Fixes: 2ba3e6947aed ("mm/vmalloc: track which page-table levels were modified")
Fixes: 0c95cba49255 ("mm: apply_to_pte_range warn and fail if a large pte is encountered")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christop Hellwig <hch@infradead.org>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Although the scenario where shmem_writepage() is called with info->flags &
VM_LOCKED is unlikely to happen, it's still possible, as evidenced by
syzbot [1]. However, the warning in this case isn't necessary because the
situation is already handled correctly [2].
[2] https://lore.kernel.org/lkml/8afe1f7f-31a2-4fc0-1fbd-f9ba8a116fe3@google.com/
Link: https://lkml.kernel.org/r/20250226-20250221-warning-in-shmem_writepage-v1-1-5ad19420e17e@igalia.com
Fixes: 9a976f0c847b ("shmem: skip page split if we're not reclaiming")
Signed-off-by: Ricardo Cañuelo Navarro <rcn@igalia.com>
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Closes: https://lore.kernel.org/lkml/ZZ9PShXjKJkVelNm@xpf.sh.intel.com/ [1]
Suggested-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Florent Revest <revest@chromium.org>
Cc: Luis Chamberalin <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Current implementation of move_pages_pte() copies source and destination
PTEs in order to detect concurrent changes to PTEs involved in the move.
However these copies are also used to unmap the PTEs, which will fail if
CONFIG_HIGHPTE is enabled because the copies are allocated on the stack.
Fix this by using the actual PTEs which were kmap()ed.
Link: https://lkml.kernel.org/r/20250226185510.2732648-3-surenb@google.com
Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Lokesh recently raised an issue about UFFDIO_MOVE getting into a deadlock
state when it goes into split_folio() with raised folio refcount.
split_folio() expects the reference count to be exactly mapcount +
num_pages_in_folio + 1 (see can_split_folio()) and fails with EAGAIN
otherwise.
If multiple processes are trying to move the same large folio, they raise
the refcount (all tasks succeed in that) then one of them succeeds in
locking the folio, while others will block in folio_lock() while keeping
the refcount raised. The winner of this race will proceed with calling
split_folio() and will fail returning EAGAIN to the caller and unlocking
the folio. The next competing process will get the folio locked and will
go through the same flow. In the meantime the original winner will be
retried and will block in folio_lock(), getting into the queue of waiting
processes only to repeat the same path. All this results in a livelock.
An easy fix would be to avoid waiting for the folio lock while holding
folio refcount, similar to madvise_free_huge_pmd() where folio lock is
acquired before raising the folio refcount. Since we lock and take a
refcount of the folio while holding the PTE lock, changing the order of
these operations should not break anything.
Modify move_pages_pte() to try locking the folio first and if that fails
and the folio is large then return EAGAIN without touching the folio
refcount. If the folio is single-page then split_folio() is not called,
so we don't have this issue. Lokesh has a reproducer [1] and I verified
that this change fixes the issue.
[1] https://github.com/lokeshgidra/uffd_move_ioctl_deadlock
[akpm@linux-foundation.org: reflow comment to 80 cols, s/end/end up/]
Link: https://lkml.kernel.org/r/20250226185510.2732648-2-surenb@google.com
Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: Lokesh Gidra <lokeshgidra@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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