Now if the PTE/PMD is dirty with _PAGE_DIRTY but without _PAGE_MODIFIED,
after {pte,pmd}_modify() we lose _PAGE_DIRTY, then {pte,pmd}_dirty()
return false and lead to data loss. This can happen in certain scenarios
such as HW PTW doesn't set _PAGE_MODIFIED automatically, so here we need
_PAGE_MODIFIED to record the dirty status (_PAGE_DIRTY).
The new modification involves checking whether the original PTE/PMD has
the _PAGE_DIRTY flag. If it exists, the _PAGE_MODIFIED bit is also set,
ensuring that the {pte,pmd}_dirty() interface can always return accurate
information.
Cc: stable@vger.kernel.org
Co-developed-by: Liupu Wang <wangliupu@loongson.cn>
Signed-off-by: Liupu Wang <wangliupu@loongson.cn>
Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
1. Use phys_addr_t instead of u64, which can work for both 32/64 bits.
2. Check whether the input physical address is above TO_PHYS_MASK (and
return NULL if yes) for the DMW version.
Note: In theory early_ioremap() also need the TO_PHYS_MASK checking, but
the UEFI BIOS pass some DMW virtual addresses.
Cc: stable@vger.kernel.org
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Now we use virtual addresses to fill CSR_MERRENTRY/CSR_TLBRENTRY, but
hardware hope physical addresses. Now it works well because the high
bits are ignored above PA_BITS (48 bits), but explicitly use physical
addresses can avoid potential bugs. So fix it.
Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
LoongArch's MSG interrupt features are used across multiple subsystems.
Clarify these features to avoid misuse, existing users will be adjusted
if necessary.
MSGINT: Infrastructure, means the CPU core supports message interupts.
Indicated by CPUCFG1.MSGINT.
AVECINT: AVEC interrupt controller based on MSGINT, means the CPU chip
supports direct message interrupts. Indicated by IOCSR.FEATURES.DMSI.
REDIRECTINT: REDIRECT interrupt controller based on MSGINT and AVECINT,
means the CPU chip supports redirect message interrupts. Indicated by
IOCSR.FEATURES.RMSI.
For example:
Loongson-3A5000/3C5000 doesn't support MSGINT/AVECINT/REDIRECTINT;
Loongson-3A6000 supports MSGINT but doesn't support AVECINT/REDIRECTINT;
Loongson-3C6000 supports MSGINT/AVECINT/REDIRECTINT.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
It's used to work around an objtool issue since commit abb2a5572264
("LoongArch: Add cflag -fno-isolate-erroneous-paths-dereference"), but
it's then passed to bindgen and cause an error because Clang does not
have this option.
Fixes: abb2a5572264 ("LoongArch: Add cflag -fno-isolate-erroneous-paths-dereference")
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Mingcong Bai <jeffbai@aosc.io>
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
The HD-audio codec driver configs have been updated again the drivers
got split with different kconfigs.
Enable all Realtek HD-audio codecs and HDMI codecs (except for
NVIDIA_MCP and TEGRA) per request.
Fixes: 1d8dd982c409 ("ALSA: hda/realtek: Enable drivers as default")
Fixes: 81231ad173d8 ("ALSA: hda/hdmi: Enable drivers as default")
Cc: loongarch@lists.linux.dev
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250731091109.16901-3-tiwai@suse.de
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
When attach fentry/fexit BPF programs, __arch_prepare_bpf_trampoline()
is called twice with different `struct bpf_tramp_image *im`:
bpf_trampoline_update()
-> arch_bpf_trampoline_size()
-> __arch_prepare_bpf_trampoline()
-> arch_prepare_bpf_trampoline()
-> __arch_prepare_bpf_trampoline()
Use move_imm() will emit unstable instruction sequences, so let's use
move_addr() instead to prevent subtle bugs.
(I observed this while debugging other issues with printk.)
Cc: stable@vger.kernel.org
Tested-by: Vincent Li <vincent.mc.li@gmail.com>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
The current implementation of bpf_arch_text_poke() requires 5 nops
at patch site which is not applicable for kernel/module functions.
Because LoongArch reserves ONLY 2 nops at the function entry. With
CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS=y, this can be done by ftrace
instead.
See the following commit for details:
* commit b91e014f078e ("bpf: Make BPF trampoline use register_ftrace_direct() API")
* commit 9cdc3b6a299c ("LoongArch: ftrace: Add direct call support")
Cc: stable@vger.kernel.org
Tested-by: Vincent Li <vincent.mc.li@gmail.com>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
In __arch_prepare_bpf_trampoline(), retval_off is meaningful only when
save_ret is not 0, so the current logic is correct. But it may cause a
build warning:
arch/loongarch/net/bpf_jit.c:1547 __arch_prepare_bpf_trampoline() error: uninitialized symbol 'retval_off'.
So initialize retval_off unconditionally to fix it.
Cc: stable@vger.kernel.org
Fixes: f9b6b41f0cf3 ("LoongArch: BPF: Add basic bpf trampoline support")
Closes: https://lore.kernel.org/r/202508191020.PBBh07cK-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
The atomic instructions sc.q, llacq.{w/d}, screl.{w/d} were newly added
in the LoongArch Reference Manual v1.10, it is necessary to handle them
in insns_not_supported() to avoid putting a breakpoint in the middle of
a ll/sc atomic sequence, otherwise it will loop forever for kprobes and
uprobes.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Attempt VMA lock-based page fault handling first, and fall back to the
existing mmap_lock-based handling if that fails.
The "ebizzy -mTRp" test on Loongson-3A6000 shows that PER_VMA_LOCK can
improve the benchmark by about 17.9% (97837.7 to 115430.8).
This is the LoongArch variant of "x86/mm: try VMA lock-based page fault
handling first".
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Automatically disable kaslr when the kernel loads from kexec_file.
kexec_file loads the secondary kernel image to a non-linked address,
inherently providing KASLR-like randomization.
However, on LoongArch where System RAM may be non-contiguous, enabling
KASLR for the second kernel may relocate it to an invalid memory region
and cause a boot failure. Thus, we disable KASLR when "kexec_file" is
detected in the command line.
To ensure compatibility with older kernels loaded via kexec_file, this
patch should be backported to stable branches.
Cc: stable@vger.kernel.org
Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Enabling crash dump (kdump) includes:
- Prepare contents of ELF header of a core dump file, /proc/vmcore,
using crash_prepare_elf64_headers().
- Add "mem=size@start" parameter to the command line and pass it to the
capture kernel. Limit the runtime memory area of the captured kernel
to avoid disrupting the production kernel's runtime state.
- Add "elfcorehdr=size@start" parameter to the cmdline.
The basic usage for kdump (add the cmdline parameter crashkernel=512M
to grub.cfg for production kernel):
1) Load capture kernel image (vmlinux.efi or vmlinux can both be used):
# kexec -s -p vmlinuz.efi --initrd=initrd.img --reuse-cmdline
2) Do something to crash, like:
# echo c > /proc/sysrq-trigger
Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
This patch creates kexec_elf_ops to load ELF binary file for
kexec_file_load() syscall.
However, for `kbuf->memsz` and `kbuf->buf_min`, special handling is
required, and the generic `kexec_elf_load()` cannot be used directly.
$ readelf -l vmlinux
...
Type Offset VirtAddr PhysAddr
FileSiz MemSiz Flags Align
LOAD 0x0000000000010000 0x9000000000200000 0x9000000000200000
0x0000000002747a00 0x000000000287a0d8 RWE 0x10000
NOTE 0x0000000000000000 0x0000000000000000 0x0000000000000000
0x0000000000000000 0x0000000000000000 R 0x8
phdr->p_paddr should have been a physical address, but it is a virtual
address on the current LoongArch. This will cause kexec_file to fail
when loading the kernel and need to be converted to a physical address.
From the above MemSiz, it can be seen that 0x287a0d8 isn't page aligned.
Although kexec_add_buffer() will perform PAGE_SIZE alignment on kbuf->
memsz, there is still a stampeding in the loaded kernel space and initrd
space. The initrd resolution failed when starting the second kernel.
It can be known from the link script vmlinux.lds.S that,
BSS_SECTION(0, SZ_64K, 8)
. = ALIGN(PECOFF_SEGMENT_ALIGN);
It needs to be aligned according to SZ_64K, so that after alignment, its
size is consistent with _kernel_asize.
The basic usage (vmlinux):
1) Load second kernel image:
# kexec -s -l vmlinux --initrd=initrd.img --reuse-cmdline
2) Startup second kernel:
# kexec -e
Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
This patch creates kexec_efi_ops to load EFI binary file for
kexec_file_load() syscall.
The efi_kexec_load() as two parts:
- the first part loads the kernel image (vmlinuz.efi or vmlinux.efi)
- the second part loads other segments (e.g: initrd, cmdline, etc)
Currently, pez (vmlinuz.efi) and pei (vmlinux.efi) format images are
supported.
The basic usage (vmlinuz.efi or vmlinux.efi):
1) Load second kernel image:
# kexec -s -l vmlinuz.efi --initrd=initrd.img --reuse-cmdline
2) Startup second kernel:
# kexec -e
Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Add some preparatory infrastructure:
- Add command line processing.
- Add support for loading other segments.
- Other minor modifications.
This initrd will be passed to the second kernel via the command line
'initrd=start,size'.
The 'kexec_file' command line parameter indicates that the kernel is
loaded via kexec_file.
Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Define a dedicated image header structure for LoongArch architecture to
standardize kernel loading in bootloaders (primarily for kexec_file).
This header includes critical metadata, such as PE/DOS signature, kernel
entry points, kernel image size and load address offset, etc.
Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
For power saving or debugging purpose, we usually want to limit the SIMD
(LSX/LASX) usage on a rich feature platform. So allow specify SIMD width
via kernel parameters "simd=".
Allowed values of "simd=" are any integers, and recommended values are:
0: Disable all SIMD features;
128: Enable at most 128bit SIMD features;
256: Enable at most 256bit SIMD features;
-1(default): Enable as many as possible SIMD features automatically.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Commit b15212824a01 ("LoongArch: Make LTO case independent in Makefile")
moves "KBUILD_LDFLAGS += -mllvm --loongarch-annotate-tablejump" out of
CONFIG_CC_HAS_ANNOTATE_TABLEJUMP, which breaks the build for LLVM-18, as
'--loongarch-annotate-tablejump' is unimplemented there:
ld.lld: error: -mllvm: ld.lld: Unknown command line argument '--loongarch-annotate-tablejump'.
Call ld-option to detect '--loongarch-annotate-tablejump' before use, so
as to fix the build error.
Fixes: b15212824a01 ("LoongArch: Make LTO case independent in Makefile")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org> # build
Suggested-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Currently, when compiling with GCC, there is no "break 7" instruction
for zero division due to using the option -mno-check-zero-division, but
the compiler still generates "break 0" instruction for zero division.
Here is a simple example:
$ cat test.c
int div(int a)
{
return a / 0;
}
$ gcc -O2 -S test.c -o test.s
GCC generates "break 0" on LoongArch and "ud2" on x86, objtool decodes
"ud2" as INSN_BUG for x86, so decode "break 0" as INSN_BUG can fix the
objtool warnings for LoongArch, but this is not the intention.
When decoding "break 0" as INSN_TRAP in the previous commit, the aim is
to handle "break 0" as a trap. The generated "break 0" for zero division
by GCC is not proper, it should generate a break instruction with proper
bug type, so add the GCC option -fno-isolate-erroneous-paths-dereference
to avoid generating the unexpected "break 0" instruction for now.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202509200413.7uihAxJ5-lkp@intel.com/
Fixes: baad7830ee9a ("objtool/LoongArch: Mark types based on break immediate code")
Suggested-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Add a NULL-pointer check after the kcalloc() call in init_vdso(). If
allocation fails, return -ENOMEM to prevent a possible dereference of
vdso_info.code_mapping.pages when it is NULL.
Cc: stable@vger.kernel.org
Fixes: 2ed119aef60d ("LoongArch: Set correct size for vDSO code mapping")
Signed-off-by: Guangshuo Li <202321181@mail.sdu.edu.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
When testing the kernel live patching with "modprobe livepatch-sample",
there is a timeout over 15 seconds from "starting patching transition"
to "patching complete". The dmesg command shows "unreliable stack" for
user tasks in debug mode, here is one of the messages:
livepatch: klp_try_switch_task: bash:1193 has an unreliable stack
The "unreliable stack" is because it can not unwind from do_syscall()
to its previous frame handle_syscall(). It should use fp to find the
original stack top due to secondary stack in do_syscall(), but fp is
not used for some other functions, then fp can not be restored by the
next frame of do_syscall(), so it is necessary to save fp if task is
not current, in order to get the stack top of do_syscall().
Here are the call chains:
klp_enable_patch()
klp_try_complete_transition()
klp_try_switch_task()
klp_check_and_switch_task()
klp_check_stack()
stack_trace_save_tsk_reliable()
arch_stack_walk_reliable()
When executing "rmmod livepatch-sample", there exists a similar issue.
With this patch, it takes a short time for patching and unpatching.
Before:
# modprobe livepatch-sample
# dmesg -T | tail -3
[Sat Sep 6 11:00:20 2025] livepatch: 'livepatch_sample': starting patching transition
[Sat Sep 6 11:00:35 2025] livepatch: signaling remaining tasks
[Sat Sep 6 11:00:36 2025] livepatch: 'livepatch_sample': patching complete
# echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled
# rmmod livepatch_sample
rmmod: ERROR: Module livepatch_sample is in use
# rmmod livepatch_sample
# dmesg -T | tail -3
[Sat Sep 6 11:06:05 2025] livepatch: 'livepatch_sample': starting unpatching transition
[Sat Sep 6 11:06:20 2025] livepatch: signaling remaining tasks
[Sat Sep 6 11:06:21 2025] livepatch: 'livepatch_sample': unpatching complete
After:
# modprobe livepatch-sample
# dmesg -T | tail -2
[Tue Sep 16 16:19:30 2025] livepatch: 'livepatch_sample': starting patching transition
[Tue Sep 16 16:19:31 2025] livepatch: 'livepatch_sample': patching complete
# echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled
# rmmod livepatch_sample
# dmesg -T | tail -2
[Tue Sep 16 16:19:36 2025] livepatch: 'livepatch_sample': starting unpatching transition
[Tue Sep 16 16:19:37 2025] livepatch: 'livepatch_sample': unpatching complete
Cc: stable@vger.kernel.org # v6.9+
Fixes: 199cc14cb4f1 ("LoongArch: Add kernel livepatching support")
Reported-by: Xi Zhang <zhangxi@kylinos.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
As Documentation/filesystems/sysfs.rst suggested, show() should only use
sysfs_emit() or sysfs_emit_at() when formatting the value to be returned
to user space.
No functional change intended.
Cc: stable@vger.kernel.org
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
ARCH_STRICT_ALIGN is used for hardware without UAL, now it only control
the -mstrict-align flag. However, ACPI structures are packed by default
so will cause unaligned accesses.
To avoid this, define ACPI_MISALIGNMENT_NOT_SUPPORTED in asm/acenv.h to
align ACPI structures if ARCH_STRICT_ALIGN enabled.
Cc: stable@vger.kernel.org
Reported-by: Binbin Zhou <zhoubinbin@loongson.cn>
Suggested-by: Xi Ruoyao <xry111@xry111.site>
Suggested-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Loongson-3A6000 and 3C6000 CPUs also support unaligned memory access, so
the current description is out of date to some extent.
Actually, all of Loongson-3 series processors based on LoongArch support
unaligned memory access, this hardware capability is indicated by the bit
20 (UAL) of CPUCFG1 register, update the help info to reflect the reality.
Cc: stable@vger.kernel.org
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
When compiling with LLVM and CONFIG_RUST is set, there exist objtool
warnings in rust/core.o and rust/kernel.o, like this:
rust/core.o: warning: objtool:
_RNvXs1_NtNtCs5QSdWC790r4_4core5ascii10ascii_charNtB5_9AsciiCharNtNtB9_3fmt5Debug3fmt+0x54:
sibling call from callable instruction with modified stack frame
For this special case, the related object file shows that there is no
generated relocation section '.rela.discard.tablejump_annotate' for the
table jump instruction jirl, thus objtool can not know that what is the
actual destination address.
If rustc has the option "-Cllvm-args=--loongarch-annotate-tablejump",
pass the option to enable jump tables for objtool, otherwise it should
pass "-Zno-jump-tables" to keep compatibility with older rustc.
How to test:
$ rustup component add rust-src
$ make LLVM=1 rustavailable
$ make ARCH=loongarch LLVM=1 clean defconfig
$ scripts/config -d MODVERSIONS \
-e RUST -e SAMPLES -e SAMPLES_RUST \
-e SAMPLE_RUST_CONFIGFS -e SAMPLE_RUST_MINIMAL \
-e SAMPLE_RUST_MISC_DEVICE -e SAMPLE_RUST_PRINT \
-e SAMPLE_RUST_DMA -e SAMPLE_RUST_DRIVER_PCI \
-e SAMPLE_RUST_DRIVER_PLATFORM -e SAMPLE_RUST_DRIVER_FAUX \
-e SAMPLE_RUST_DRIVER_AUXILIARY -e SAMPLE_RUST_HOSTPROGS
$ make ARCH=loongarch LLVM=1 olddefconfig all
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
When compiling with LLVM and CONFIG_RUST is set, there exists the
following objtool warning:
rust/compiler_builtins.o: warning: objtool: __rust__unordsf2(): unexpected end of section .text.unlikely.
objdump shows that the end of section .text.unlikely is an atomic
instruction:
amswap.w $zero, $ra, $zero
According to the LoongArch Reference Manual, if the amswap.w atomic
memory access instruction has the same register number as rd and rj,
the execution will trigger an Instruction Non-defined Exception, so
mark the above instruction as INSN_BUG type to fix the warning.
Cc: stable@vger.kernel.org
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
If the break immediate code is 0, it should mark the type as
INSN_TRAP. If the break immediate code is 1, it should mark the
type as INSN_BUG.
While at it, format the code style and add the code comment for nop.
Cc: stable@vger.kernel.org
Suggested-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
When compiling with LLVM and CONFIG_LTO_CLANG is set, there exist many
objtool warnings "sibling call from callable instruction with modified
stack frame".
For this special case, the related object file shows that there is no
generated relocation section '.rela.discard.tablejump_annotate' for the
table jump instruction jirl, thus objtool can not know that what is the
actual destination address.
It needs to do something on the LLVM side to make sure that there is the
relocation section '.rela.discard.tablejump_annotate' if LTO is enabled,
but in order to maintain compatibility for the current LLVM compiler,
this can be done in the kernel Makefile for now. Ensure it is aware of
linker with LTO, '--loongarch-annotate-tablejump' needs to be passed via
'-mllvm' to ld.lld.
Note that it should also pass the compiler option -mannotate-tablejump
rather than only pass '-mllvm --loongarch-annotate-tablejump' to ld.lld
if LTO is enabled, otherwise there are no jump info for some table jump
instructions.
Fixes: e20ab7d454ee ("LoongArch: Enable jump table for objtool")
Closes: https://lore.kernel.org/loongarch/20250731175655.GA1455142@ax162/
Reported-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Co-developed-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Commit 57fbad15c2eee772 ("stackleak: Rename STACKLEAK to KSTACK_ERASE")
misses the stackframe.h part for LoongArch, so fix it.
Fixes: 57fbad15c2eee772 ("stackleak: Rename STACKLEAK to KSTACK_ERASE")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Now if preemption happens between protected_save_fpu_context() and
protected_save_lbt_context(), FTOP context is lost. Because FTOP is
saved by protected_save_lbt_context() but protected_save_fpu_context()
disables TM before that. So save LBT before FPU in setup_sigcontext()
to avoid this potential risk.
Signed-off-by: Hanlu Li <lihanlu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
When enabling CONFIG_KASAN, CONFIG_PREEMPT_VOLUNTARY_BUILD and
CONFIG_PREEMPT_VOLUNTARY at the same time, there will be soft deadlock,
the relevant logs are as follows:
rcu: INFO: rcu_sched self-detected stall on CPU
...
Call Trace:
[<900000000024f9e4>] show_stack+0x5c/0x180
[<90000000002482f4>] dump_stack_lvl+0x94/0xbc
[<9000000000224544>] rcu_dump_cpu_stacks+0x1fc/0x280
[<900000000037ac80>] rcu_sched_clock_irq+0x720/0xf88
[<9000000000396c34>] update_process_times+0xb4/0x150
[<90000000003b2474>] tick_nohz_handler+0xf4/0x250
[<9000000000397e28>] __hrtimer_run_queues+0x1d0/0x428
[<9000000000399b2c>] hrtimer_interrupt+0x214/0x538
[<9000000000253634>] constant_timer_interrupt+0x64/0x80
[<9000000000349938>] __handle_irq_event_percpu+0x78/0x1a0
[<9000000000349a78>] handle_irq_event_percpu+0x18/0x88
[<9000000000354c00>] handle_percpu_irq+0x90/0xf0
[<9000000000348c74>] handle_irq_desc+0x94/0xb8
[<9000000001012b28>] handle_cpu_irq+0x68/0xa0
[<9000000001def8c0>] handle_loongarch_irq+0x30/0x48
[<9000000001def958>] do_vint+0x80/0xd0
[<9000000000268a0c>] kasan_mem_to_shadow.part.0+0x2c/0x2a0
[<90000000006344f4>] __asan_load8+0x4c/0x120
[<900000000025c0d0>] module_frob_arch_sections+0x5c8/0x6b8
[<90000000003895f0>] load_module+0x9e0/0x2958
[<900000000038b770>] __do_sys_init_module+0x208/0x2d0
[<9000000001df0c34>] do_syscall+0x94/0x190
[<900000000024d6fc>] handle_syscall+0xbc/0x158
After analysis, this is because the slow speed of loading the amdgpu
module leads to the long time occupation of the cpu and then the soft
deadlock.
When loading a module, module_frob_arch_sections() tries to figure out
the number of PLTs/GOTs that will be needed to handle all the RELAs. It
will call the count_max_entries() to find in an out-of-order date which
counting algorithm has O(n^2) complexity.
To make it faster, we sort the relocation list by info and addend. That
way, to check for a duplicate relocation, it just needs to compare with
the previous entry. This reduces the complexity of the algorithm to O(n
log n), as done in commit d4e0340919fb ("arm64/module: Optimize module
load time by optimizing PLT counting"). This gives sinificant reduction
in module load time for modules with large number of relocations.
After applying this patch, the soft deadlock problem has been solved,
and the kernel starts normally without "Call Trace".
Using the default configuration to test some modules, the results are as
follows:
Module Size
ip_tables 36K
fat 143K
radeon 2.5MB
amdgpu 16MB
Without this patch:
Module Module load time (ms) Count(PLTs/GOTs)
ip_tables 18 59/6
fat 0 162/14
radeon 54 1221/84
amdgpu 1411 4525/1098
With this patch:
Module Module load time (ms) Count(PLTs/GOTs)
ip_tables 18 59/6
fat 0 162/14
radeon 22 1221/84
amdgpu 45 4525/1098
Fixes: fcdfe9d22bed ("LoongArch: Add ELF and module support")
Signed-off-by: Kanglong Wang <wangkanglong@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
When the CPU is offline, the timer of LoongArch is not correctly closed.
This is harmless for real machines, but resulting in an excessively high
cpu usage rate of the offline vCPU thread in the virtual machines.
To correctly close the timer, we have made the following modifications:
Register the cpu hotplug event (CPUHP_AP_LOONGARCH_ARCH_TIMER_STARTING)
for LoongArch. This event's hooks will be called to close the timer when
the CPU is offline.
Clear the timer interrupt when the timer is turned off. Since before the
timer is turned off, there may be a timer interrupt that has already been
in the pending state due to the interruption of the disabled, which also
affects the halt state of the offline vCPU.
Signed-off-by: Xianglai Li <lixianglai@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
JITs can set bpf_jit_bypass_spec_v1/v4() if they want the verifier to
skip analysis/patching for the respective vulnerability, it is safe to
set both bpf_jit_bypass_spec_v1/v4(), because there is no speculation
barrier instruction for LoongArch.
Suggested-by: Luis Gerhorst <luis.gerhorst@fau.de>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
In specific use cases combining tailcalls and BPF-to-BPF calls，
MAX_TAIL_CALL_CNT won't work because of missing tail_call_cnt
back-propagation from callee to caller. This patch fixes this
tailcall issue caused by abusing the tailcall in bpf2bpf feature
on LoongArch like the way of "bpf, x64: Fix tailcall hierarchy".
Push tail_call_cnt_ptr and tail_call_cnt into the stack,
tail_call_cnt_ptr is passed between tailcall and bpf2bpf,
uses tail_call_cnt_ptr to increment tail_call_cnt.
Fixes: bb035ef0cc91 ("LoongArch: BPF: Support mixing bpf2bpf and tailcalls")
Reviewed-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Haoran Jiang <jianghaoran@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Use BPF_TRAMP_F_INDIRECT flag to detect struct ops and emit proper
prologue and epilogue for this case.
With this patch, all of the struct_ops related testcases (except
struct_ops_multi_pages) passed on LoongArch.
The testcase struct_ops_multi_pages failed is because the actual
image_pages_cnt is 40 which is bigger than MAX_TRAMP_IMAGE_PAGES.
Before:
$ sudo ./test_progs -t struct_ops -d struct_ops_multi_pages
...
WATCHDOG: test case struct_ops_module/struct_ops_load executes for 10 seconds...
After:
$ sudo ./test_progs -t struct_ops -d struct_ops_multi_pages
...
#15 bad_struct_ops:OK
...
#399 struct_ops_autocreate:OK
...
#400 struct_ops_kptr_return:OK
...
#401 struct_ops_maybe_null:OK
...
#402 struct_ops_module:OK
...
#404 struct_ops_no_cfi:OK
...
#405 struct_ops_private_stack:SKIP
...
#406 struct_ops_refcounted:OK
Summary: 8/25 PASSED, 3 SKIPPED, 0 FAILED
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
BPF trampoline is the critical infrastructure of the BPF subsystem,
acting as a mediator between kernel functions and BPF programs. Numerous
important features, such as using BPF program for zero overhead kernel
introspection, rely on this key component.
The related tests have passed, including the following technical points:
1. fentry
2. fmod_ret
3. fexit
The following related testcases passed on LoongArch:
sudo ./test_progs -a fentry_test/fentry
sudo ./test_progs -a fexit_test/fexit
sudo ./test_progs -a fentry_fexit
sudo ./test_progs -a modify_return
sudo ./test_progs -a fexit_sleep
sudo ./test_progs -a test_overhead
sudo ./test_progs -a trampoline_count
This issue was first reported by Geliang Tang in June 2024 while
debugging MPTCP BPF selftests on a LoongArch machine (see commit
eef0532e900c "selftests/bpf: Null checks for links in bpf_tcp_ca").
Geliang, Huacai, and Tiezhu then worked together to drive the
implementation of this feature, encouraging broader collaboration among
Chinese kernel engineers.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202507100034.wXofj6VX-lkp@intel.com/
Reported-by: Geliang Tang <geliang@kernel.org>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Tested-by: Vincent Li <vincent.mc.li@gmail.com>
Co-developed-by: George Guo <guodongtai@kylinos.cn>
Signed-off-by: George Guo <guodongtai@kylinos.cn>
Signed-off-by: Chenghao Duan <duanchenghao@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: maoxiaochuan <maoxiaochuan@loongson.cn>
Tianyang Zhang