linux-next.git/arch/riscv/kernel/vmlinux.lds.S, branch master

riscv: Remove support for XIP kernel

2026-04-05T00:42:44+00:00

XIP has a history of being broken for long periods of time. In 2023, it was broken for 18 months before getting fixed [1]. In 2024 it was 4 months [2]. And now it is broken again since commit a44fb5722199 ("riscv: Add runtime constant support"), 10 months ago. These are clear signs that XIP feature is not being used. I occasionally looked after XIP, but mostly because I was bored and had nothing better to do. Remove XIP support. Revert is possible if someone shows up complaining. Link: https://lore.kernel.org/linux-riscv/20231212-customary-hardcover-e19462bf8e75@wendy/ [1] Link: https://lore.kernel.org/linux-riscv/20240526110104.470429-1-namcao@linutronix.de/ [2] Signed-off-by: Nam Cao Cc: Frederik Haxel Cc: Vitaly Wool Reviewed-by: Jisheng Zhang Acked-by: Conor Dooley Link: https://patch.msgid.link/20260202115403.2119218-1-namcao@linutronix.de [pjw@kernel.org: updated to apply] Signed-off-by: Paul Walmsley

kbuild: Split .modinfo out from ELF_DETAILS

2026-02-26T18:50:19+00:00

Commit 3e86e4d74c04 ("kbuild: keep .modinfo section in vmlinux.unstripped") added .modinfo to ELF_DETAILS while removing it from COMMON_DISCARDS, as it was needed in vmlinux.unstripped and ELF_DETAILS was present in all architecture specific vmlinux linker scripts. While this shuffle is fine for vmlinux, ELF_DETAILS and COMMON_DISCARDS may be used by other linker scripts, such as the s390 and x86 compressed boot images, which may not expect to have a .modinfo section. In certain circumstances, this could result in a bootloader failing to load the compressed kernel [1]. Commit ddc6cbef3ef1 ("s390/boot/vmlinux.lds.S: Ensure bzImage ends with SecureBoot trailer") recently addressed this for the s390 bzImage but the same bug remains for arm, parisc, and x86. The presence of .modinfo in the x86 bzImage was the root cause of the issue worked around with commit d50f21091358 ("kbuild: align modinfo section for Secureboot Authenticode EDK2 compat"). misc.c in arch/x86/boot/compressed includes lib/decompress_unzstd.c, which in turn includes lib/xxhash.c and its MODULE_LICENSE / MODULE_DESCRIPTION macros due to the STATIC definition. Split .modinfo out from ELF_DETAILS into its own macro and handle it in all vmlinux linker scripts. Discard .modinfo in the places where it was previously being discarded from being in COMMON_DISCARDS, as it has never been necessary in those uses. Cc: stable@vger.kernel.org Fixes: 3e86e4d74c04 ("kbuild: keep .modinfo section in vmlinux.unstripped") Reported-by: Ed W Closes: https://lore.kernel.org/587f25e0-a80e-46a5-9f01-87cb40cfa377@wildgooses.com/ [1] Tested-by: Ed W # x86_64 Link: https://patch.msgid.link/20260225-separate-modinfo-from-elf-details-v1-1-387ced6baf4b@kernel.org Signed-off-by: Nathan Chancellor

riscv: Add runtime constant support

2025-03-20T09:15:03+00:00

Implement the runtime constant infrastructure for riscv. Use this infrastructure to generate constants to be used by the d_hash() function. This is the riscv variant of commit 94a2bc0f611c ("arm64: add 'runtime constant' support") and commit e3c92e81711d ("runtime constants: add x86 architecture support"). [ alex: Remove trailing whitespace ] Signed-off-by: Charlie Jenkins Reviewed-by: Alexandre Ghiti Tested-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20250319-runtime_const_riscv-v10-2-745b31a11d65@rivosinc.com Signed-off-by: Alexandre Ghiti

riscv: Check if the code to patch lies in the exit section

2024-01-09T18:58:59+00:00

Otherwise we fall through to vmalloc_to_page() which panics since the address does not lie in the vmalloc region. Fixes: 043cb41a85de ("riscv: introduce interfaces to patch kernel code") Signed-off-by: Alexandre Ghiti Reviewed-by: Charlie Jenkins Link: https://lore.kernel.org/r/20231214091926.203439-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt

riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION

2023-06-25T23:24:05+00:00

Select CONFIG_HAVE_LD_DEAD_CODE_DATA_ELIMINATION for RISC-V, allowing the user to enable dead code elimination. In order for this to work, ensure that we keep the alternative table by annotating them with KEEP. This boots well on qemu with both rv32_defconfig & rv64 defconfig, but it only shrinks their builds by ~1%, a smaller config is thereforce customized to test this feature: | rv32 | rv64 --------|------------------------|--------------------- No DCE | 4460684 | 4893488 DCE | 3986716 | 4376400 Shrink | 473968 (~10.6%) | 517088 (~10.5%) The config used above only reserves necessary options to boot on qemu with serial console, more like the size-critical embedded scenes: - rv64 config: https://pastebin.com/crz82T0s - rv32 config: rv64 config + 32-bit.config Here is Jisheng's original commit-msg: When trying to run linux with various opensource riscv core on resource limited FPGA platforms, for example, those FPGAs with less than 16MB SDRAM, I want to save mem as much as possible. One of the major technologies is kernel size optimizations, I found that riscv does not currently support HAVE_LD_DEAD_CODE_DATA_ELIMINATION, which passes -fdata-sections, -ffunction-sections to CFLAGS and passes the --gc-sections flag to the linker. This not only benefits my case on FPGA but also benefits defconfigs. Here are some notable improvements from enabling this with defconfigs: nommu_k210_defconfig: text data bss dec hex 1112009 410288 59837 1582134 182436 before 962838 376656 51285 1390779 1538bb after rv32_defconfig: text data bss dec hex 8804455 2816544 290577 11911576 b5c198 before 8692295 2779872 288977 11761144 b375f8 after defconfig: text data bss dec hex 9438267 3391332 485333 13314932 cb2b74 before 9285914 3350052 483349 13119315 c82f53 after Signed-off-by: Zhangjin Wu Co-developed-by: Jisheng Zhang Signed-off-by: Jisheng Zhang Reviewed-by: Guo Ren Tested-by: Bin Meng Reviewed-by: Kefeng Wang Tested-by: Nick Desaulniers # build Link: https://lore.kernel.org/r/20230523165502.2592-5-jszhang@kernel.org Signed-off-by: Palmer Dabbelt

riscv: Fix orphan section warnings caused by kernel/pi

2023-05-10T01:20:23+00:00

kernel/pi gives rise to a lot of new sections that end up orphans: the first attempt to fix that tried to enumerate them all in the linker script, but kernel test robot with a random config keeps finding more of them. So prefix all those sections with .init.pi instead of only .init in order to be able to easily catch them all in the linker script. Reported-by: kernel test robot Link: https://lore.kernel.org/oe-kbuild-all/202304301606.Cgp113Ha-lkp@intel.com/ Fixes: 26e7aacb83df ("riscv: Allow to downgrade paging mode from the command line") Signed-off-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20230504120759.18730-1-alexghiti@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt

riscv: Move .rela.dyn to the init sections

2023-05-02T00:00:32+00:00

The recent introduction of relocatable kernels prepared the move of .rela.dyn to the init section, but actually forgot to do so, so do it here. Before this patch: "Freeing unused kernel image (initmem) memory: 2592K" After this patch: "Freeing unused kernel image (initmem) memory: 6288K" The difference corresponds to the size of the .rela.dyn section: "[42] .rela.dyn RELA ffffffff8197e798 0127f798 000000000039c660 0000000000000018 A 47 0 8" Fixes: 559d1e45a16d ("riscv: Use --emit-relocs in order to move .rela.dyn in init") Signed-off-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20230428120932.22735-1-alexghiti@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt

riscv: Allow to downgrade paging mode from the command line

2023-04-26T14:30:52+00:00

Add 2 early command line parameters that allow to downgrade satp mode (using the same naming as x86): - "no5lvl": use a 4-level page table (down from sv57 to sv48) - "no4lvl": use a 3-level page table (down from sv57/sv48 to sv39) Note that going through the device tree to get the kernel command line works with ACPI too since the efi stub creates a device tree anyway with the command line. In KASAN kernels, we can't use the libfdt that early in the boot process since we are not ready to execute instrumented functions. So instead of using the "generic" libfdt, we compile our own versions of those functions that are not instrumented and that are prefixed so that they do not conflict with the generic ones. We also need the non-instrumented versions of the string functions and the prefixed versions of memcpy/memmove. This is largely inspired by commit aacd149b6238 ("arm64: head: avoid relocating the kernel twice for KASLR") from which I removed compilation flags that were not relevant to RISC-V at the moment (LTO, SCS). Also note that we have to link with -z norelro to avoid ld.lld to throw a warning with the new .got sections, like in commit 311bea3cb9ee ("arm64: link with -z norelro for LLD or aarch64-elf"). Signed-off-by: Alexandre Ghiti Tested-by: Björn Töpel Reviewed-by: Björn Töpel Link: https://lore.kernel.org/r/20230424092313.178699-2-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt

riscv: Introduce CONFIG_RELOCATABLE

2023-04-19T14:46:30+00:00

This config allows to compile 64b kernel as PIE and to relocate it at any virtual address at runtime: this paves the way to KASLR. Runtime relocation is possible since relocation metadata are embedded into the kernel. Note that relocating at runtime introduces an overhead even if the kernel is loaded at the same address it was linked at and that the compiler options are those used in arm64 which uses the same RELA relocation format. Signed-off-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20230329045329.64565-4-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt

riscv: Move .rela.dyn outside of init to avoid empty relocations

2023-04-19T14:46:29+00:00

This is a preparatory patch for relocatable kernels: .rela.dyn should be in .init but doing so actually produces empty relocations, so this should be a temporary commit until we find a solution. This issue was reported here [1]. [1] https://lore.kernel.org/all/4a6fc7a3-9697-a49b-0941-97f32194b0d7@ghiti.fr/. Signed-off-by: Alexandre Ghiti Link: https://lore.kernel.org/r/20230329045329.64565-3-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt