Linux kernel stable tree (mirror) https://git.radix-linux.su/kernel/linux.git/atom?h=v6.18.21 2026-04-02T11:23:24+00:00 2026-04-02T11:23:24+00:00 Xi Ruoyao xry111@xry111.site 2026-03-26T06:29:09+00:00 urn:sha1:53a27c09850be4f5fcb225bfcb19eab7202e6933 commit e4878c37f6679fdea91b27a0f4e60a871f0b7bad upstream. With -fno-asynchronous-unwind-tables and --no-eh-frame-hdr (the default of the linker), the GNU_EH_FRAME segment (specified by vdso.lds.S) is empty. This is not valid, as the current DWARF specification mandates the first byte of the EH frame to be the version number 1. It causes some unwinders to complain, for example the ClickHouse query profiler spams the log with messages: clickhouse-server[365854]: libunwind: unsupported .eh_frame_hdr version: 127 at 7ffffffb0000 Here "127" is just the byte located at the p_vaddr (0, i.e. the beginning of the vDSO) of the empty GNU_EH_FRAME segment. Cross- checking with /proc/365854/maps has also proven 7ffffffb0000 is the start of vDSO in the process VM image. In LoongArch the -fno-asynchronous-unwind-tables option seems just a MIPS legacy, and MIPS only uses this option to satisfy the MIPS-specific "genvdso" program, per the commit cfd75c2db17e ("MIPS: VDSO: Explicitly use -fno-asynchronous-unwind-tables"). IIRC it indicates some inherent limitation of the MIPS ELF ABI and has nothing to do with LoongArch. So we can simply flip it over to -fasynchronous-unwind-tables and pass --eh-frame-hdr for linking the vDSO, allowing the profilers to unwind the stack for statistics even if the sample point is taken when the PC is in the vDSO. However simply adjusting the options above would exploit an issue: when the libgcc unwinder saw the invalid GNU_EH_FRAME segment, it silently falled back to a machine-specific routine to match the code pattern of rt_sigreturn() and extract the registers saved in the sigframe if the code pattern is matched. As unwinding from signal handlers is vital for libgcc to support pthread cancellation etc., the fall-back routine had been silently keeping the LoongArch Linux systems functioning since Linux 5.19. But when we start to emit GNU_EH_FRAME with the correct format, fall-back routine will no longer be used and libgcc will fail to unwind the sigframe, and unwinding from signal handlers will no longer work, causing dozens of glibc test failures. To make it possible to unwind from signal handlers again, it's necessary to code the unwind info in __vdso_rt_sigreturn via .cfi_* directives. The offsets in the .cfi_* directives depend on the layout of struct sigframe, notably the offset of sigcontext in the sigframe. To use the offset in the assembly file, factor out struct sigframe into a header to allow asm-offsets.c to output the offset for assembly. To work around a long-term issue in the libgcc unwinder (the pc is unconditionally substracted by 1: doing so is technically incorrect for a signal frame), a nop instruction is included with the two real instructions in __vdso_rt_sigreturn in the same FDE PC range. The same hack has been used on x86 for a long time. Cc: stable@vger.kernel.org Fixes: c6b99bed6b8f ("LoongArch: Add VDSO and VSYSCALL support") Signed-off-by: Xi Ruoyao <xry111@xry111.site> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2026-03-25T10:10:31+00:00 Tiezhu Yang yangtiezhu@loongson.cn 2026-03-16T02:36:01+00:00 urn:sha1:250aae6a5738a326287bd29aebf5beab44bf28fe commit a47f0754bdd01f971c9715acdbdd3a07515c8f83 upstream. If memory access such as copy_{from, to}_kernel_nofault() failed, its users do not know what happened, so it is very useful to print the exception code for such cases. Furthermore, it is better to print the caller function to know where is the entry. Here are the low level call chains: copy_from_kernel_nofault() copy_from_kernel_nofault_loop() __get_kernel_nofault() copy_to_kernel_nofault() copy_to_kernel_nofault_loop() __put_kernel_nofault() Cc: stable@vger.kernel.org Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2026-03-12T11:09:33+00:00 Tiezhu Yang yangtiezhu@loongson.cn 2026-02-10T11:31:13+00:00 urn:sha1:079deecc2c9f5bef4c6cbec66f4076a5542370ba [ Upstream commit 055c7e75190e0be43037bd663a3f6aced194416e ] After commit 4cd641a79e69 ("LoongArch: Remove unnecessary checks for ORC unwinder"), the system can not boot normally under some configs (such as enable KASAN), there are many error messages "cannot find unwind pc". The kernel boots normally with the defconfig, so no problem found out at the first time. Here is one way to reproduce: cd linux make mrproper defconfig -j"$(nproc)" scripts/config -e KASAN make olddefconfig all -j"$(nproc)" sudo make modules_install sudo make install sudo reboot The address that can not unwind is not a valid kernel address which is between "pcpu_handlers[cpu]" and "pcpu_handlers[cpu] + vec_sz" due to the code of eentry was copied to the new area of pcpu_handlers[cpu] in setup_tlb_handler(), handle this special case to get the valid address to unwind normally. Cc: stable@vger.kernel.org Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Sasha Levin <sashal@kernel.org> 2026-03-04T12:21:26+00:00 John Garry john.g.garry@oracle.com 2026-02-10T11:31:12+00:00 urn:sha1:61a56df2fbaad3a4d00f0c6a904b5d1ee8982eb4 [ Upstream commit 94b0c831eda778ae9e4f2164a8b3de485d8977bb ] The arch definition of cpumask_of_node() cannot handle NUMA_NO_NODE - which is a valid index - so add a check for this. Cc: stable@vger.kernel.org Signed-off-by: John Garry <john.g.garry@oracle.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Sasha Levin <sashal@kernel.org> 2026-01-08T09:17:06+00:00 WangYuli wangyl5933@chinaunicom.cn 2025-12-06T02:39:48+00:00 urn:sha1:f92ac4ad6c8634d82f79a76fa995d7b1b7b35584 commit 4a71df151e703b5e7e85b33369cee59ef2665e61 upstream. The __pmd() and __pte() helper macros provide the correct initialization syntax and abstraction for the pmd_t and pte_t types. Use __pmd() to fix follow warning about __swp_entry_to_pmd() with gcc-15 under specific configs [1] : In file included from ./include/linux/pgtable.h:6, from ./include/linux/mm.h:31, from ./include/linux/pagemap.h:8, from arch/loongarch/mm/init.c:14: ./include/linux/swapops.h: In function ‘swp_entry_to_pmd’: ./arch/loongarch/include/asm/pgtable.h:302:34: error: missing braces around initializer [-Werror=missing-braces] 302 | #define __swp_entry_to_pmd(x) ((pmd_t) { (x).val | _PAGE_HUGE }) | ^ ./include/linux/swapops.h:559:16: note: in expansion of macro ‘__swp_entry_to_pmd’ 559 | return __swp_entry_to_pmd(arch_entry); | ^~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors Also update __swp_entry_to_pte() to use __pte() for consistency. [1]. https://download.01.org/0day-ci/archive/20251119/202511190316.luI90kAo-lkp@intel.com/config Cc: stable@vger.kernel.org Signed-off-by: Yuli Wang <wangyl5933@chinaunicom.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2025-11-20T06:42:05+00:00 Huacai Chen chenhuacai@loongson.cn 2025-11-20T06:42:05+00:00 urn:sha1:1c004609fdefb48888ef98bc6e3b8fe78ae4e088 Some processors have no IOCSR.VENDOR and IOCSR.CPUNAME, some processors have these registers but there is no valid information. Consolidate CPU names in /proc/cpuinfo: 1. Add "PRID" to display the PRID & Core-Name; 2. Let "Model Name" display "Unknown" if no valid name. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2025-11-20T06:42:05+00:00 Thomas Weißschuh linux@weissschuh.net 2025-11-20T06:42:05+00:00 urn:sha1:20d7338f2d3bcb570068dd6d39b16f1a909fe976 The kernel UAPI headers already contain fixed-width integer types, there is no need to rely on the libc types. There may not be a libc available or the libc may not provides the <stdint.h>, like for example on nolibc. This also aligns the header with the rest of the LoongArch UAPI headers. Fixes: 803b0fc5c3f2 ("LoongArch: Add process management") Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2025-11-10T00:37:06+00:00 Huacai Chen chenhuacai@loongson.cn 2025-11-09T08:02:01+00:00 urn:sha1:eeeeaafa62ea0cd4b86390f657dc0aea73bff4f5 CSR.FWPC and CSR.MWPC are 32bit registers, so use csr_read32() rather than csr_read64() to read the values of FWPC/MWPC. Cc: stable@vger.kernel.org Fixes: edffa33c7bb5a73 ("LoongArch: Add hardware breakpoints/watchpoints support") Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2025-11-10T00:37:06+00:00 Tiezhu Yang yangtiezhu@loongson.cn 2025-11-09T08:02:01+00:00 urn:sha1:4c8a7c9827726f6e987b7a04af8ef58f1c7fe8d3 (1) Use the existing CPUCFG6_PMNUM_SHIFT macro definition instead of the magic value 4 to get the PMU number. (2) Detect the value of PMU bits via CPUCFG instruction according to the ISA manual instead of hard-coded as 64, because the value may be different for various micro-architectures. Link: https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#_cpucfg Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2025-11-10T00:37:06+00:00 Vishal Moola (Oracle) vishal.moola@gmail.com 2025-11-09T08:02:01+00:00 urn:sha1:17f838512ae50203ae2e3ce9b9f2689cc67beaa3 Remove the unnecessary __GFP_HIGHMEM masking in pud_alloc_one(), which was introduced with commit 382739797f79ec2 ("loongarch: convert various functions to use ptdescs"). GFP_KERNEL doesn't contain __GFP_HIGHMEM. Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>