kernel/linux.git/arch/loongarch/include, branch v6.12.80

LoongArch: vDSO: Emit GNU_EH_FRAME correctly

2026-04-02T11:09:49+00:00

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 Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman

LoongArch: Give more information if kmem access failed

2026-03-25T10:08:47+00:00

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 Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman

LoongArch: Handle percpu handler address for ORC unwinder

2026-03-13T16:20:31+00:00

[ 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 Signed-off-by: Huacai Chen Signed-off-by: Sasha Levin

LoongArch: Make cpumask_of_node() robust against NUMA_NO_NODE

2026-03-04T12:21:55+00:00

[ 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 Signed-off-by: Huacai Chen Signed-off-by: Sasha Levin

fgraph: Replace fgraph_ret_regs with ftrace_regs

2026-03-04T12:19:36+00:00

[ Upstream commit a3ed4157b7d89800a0008de0c9e46a438a5c3745 ] Use ftrace_regs instead of fgraph_ret_regs for tracing return value on function_graph tracer because of simplifying the callback interface. The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by CONFIG_HAVE_FUNCTION_GRAPH_FREGS. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens Acked-by: Will Deacon Cc: Catalin Marinas Cc: Alexei Starovoitov Cc: Florent Revest Cc: Martin KaFai Lau Cc: bpf Cc: Alexei Starovoitov Cc: Jiri Olsa Cc: Alan Maguire Cc: Mark Rutland Cc: Huacai Chen Cc: WANG Xuerui Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Heiko Carstens Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Mathieu Desnoyers Link: https://lore.kernel.org/173518991508.391279.16635322774382197642.stgit@devnote2 Signed-off-by: Steven Rostedt (Google) Stable-dep-of: aea251799998 ("x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path") Signed-off-by: Sasha Levin

ftrace: Consolidate ftrace_regs accessor functions for archs using pt_regs

2026-03-04T12:19:36+00:00

[ Upstream commit e4cf33ca48128d580e25ebe779b7ba7b4b4cf733 ] Most architectures use pt_regs within ftrace_regs making a lot of the accessor functions just calls to the pt_regs internally. Instead of duplication this effort, use a HAVE_ARCH_FTRACE_REGS for architectures that have their own ftrace_regs that is not based on pt_regs and will define all the accessor functions, and for the architectures that just use pt_regs, it will leave it undefined, and the default accessor functions will be used. Note, this will also make it easier to add new accessor functions to ftrace_regs as it will mean having to touch less architectures. Cc: Cc: "x86@kernel.org" Cc: Mathieu Desnoyers Cc: Mark Rutland Cc: Will Deacon Cc: Huacai Chen Cc: WANG Xuerui Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Naveen N Rao Cc: Madhavan Srinivasan Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Link: https://lore.kernel.org/20241010202114.2289f6fd@gandalf.local.home Acked-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens # s390 Acked-by: Catalin Marinas Acked-by: Michael Ellerman # powerpc Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) Stable-dep-of: aea251799998 ("x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path") Signed-off-by: Sasha Levin

ftrace: Make ftrace_regs abstract from direct use

2026-03-04T12:19:36+00:00

[ Upstream commit 7888af4166d4ab07ba51234be6ba332b7807e901 ] ftrace_regs was created to hold registers that store information to save function parameters, return value and stack. Since it is a subset of pt_regs, it should only be used by its accessor functions. But because pt_regs can easily be taken from ftrace_regs (on most archs), it is tempting to use it directly. But when running on other architectures, it may fail to build or worse, build but crash the kernel! Instead, make struct ftrace_regs an empty structure and have the architectures define __arch_ftrace_regs and all the accessor functions will typecast to it to get to the actual fields. This will help avoid usage of ftrace_regs directly. Link: https://lore.kernel.org/all/20241007171027.629bdafd@gandalf.local.home/ Cc: "linux-arch@vger.kernel.org" Cc: "x86@kernel.org" Cc: Mathieu Desnoyers Cc: Mark Rutland Cc: Will Deacon Cc: Huacai Chen Cc: WANG Xuerui Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Naveen N Rao Cc: Madhavan Srinivasan Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Link: https://lore.kernel.org/20241008230628.958778821@goodmis.org Acked-by: Catalin Marinas Signed-off-by: Steven Rostedt (Google) Acked-by: Masami Hiramatsu (Google) Acked-by: Heiko Carstens # s390 Signed-off-by: Steven Rostedt (Google) Stable-dep-of: aea251799998 ("x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs path") Signed-off-by: Sasha Levin

LoongArch: Use pmd()/pte() for swap entry conversions

2026-01-08T09:14:47+00:00

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 Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman

LoongArch: Use UAPI types in ptrace UAPI header

2025-12-01T10:43:34+00:00

[ Upstream commit 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 , 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 Signed-off-by: Huacai Chen Signed-off-by: Sasha Levin

LoongArch: Let {pte,pmd}_modify() record the status of _PAGE_DIRTY

2025-11-24T09:36:00+00:00

commit a073d637c8cfbfbab39b7272226a3fbf3b887580 upstream. 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 Signed-off-by: Liupu Wang Signed-off-by: Tianyang Zhang Signed-off-by: Greg Kroah-Hartman

kernel/linux.git/arch/loongarch/include, branch v6.12.80

LoongArch: vDSO: Emit GNU_EH_FRAME correctly

LoongArch: Give more information if kmem access failed

LoongArch: Handle percpu handler address for ORC unwinder

LoongArch: Make cpumask_of_node() robust against NUMA_NO_NODE

fgraph: Replace fgraph_ret_regs with ftrace_regs

ftrace: Consolidate ftrace_regs accessor functions for archs using pt_regs

ftrace: Make ftrace_regs abstract from direct use

LoongArch: Use __pmd()/__pte() for swap entry conversions

LoongArch: Use UAPI types in ptrace UAPI header

LoongArch: Let {pte,pmd}_modify() record the status of _PAGE_DIRTY

LoongArch: Use pmd()/pte() for swap entry conversions