Changes in Makefile

eb13a1ff271b0d180687eebb30611b0b276d5193 - random: vDSO: avoid call to memset() when zeroing reserved parameter

Fri, 25 Sep 2026 23:46:32 +0200

random: vDSO: avoid call to memset() when zeroing reserved parameterAfter a recent change in LLVM [1], builds with the random vDSOimplementation, such as PowerPC and RISC-V, fail when checking the vDSO: arch/powerpc/kernel/vdso/vdso32.so.dbg: dynamic relocations are not supported arch/riscv/kernel/vdso/vdso.so.dbg: dynamic relocations are not supportedmemset() is now generated when zeroing params->reserved for some buildsbecause LLVM has an optimization (now run in more instances) that canrecognize at compile time when it is assigning a static value to acontiguous area of memory and turn that into a call to memset(). Bothclang and GCC assume memset() is always available [2].Clang has an internal fiddly hook, -max-store-memset, which we can setto a high number, to disable generating out of line memset calls [3].Similarly, GCC has -finline-stringops=memset to do the same [4], shouldthis issue ever hit future version of GCC. While these options wouldn'tmake sense for normal kernel code, it is fine for the extremely limitedand intentionally compact vDSO code.Link: https://github.com/llvm/llvm-project/commit/90cebef1411617fc3eedd359bdf00cb44b1c2439 [1]Link: https://gcc.gnu.org/onlinedocs/gcc-16.2.0/gcc/Standards.html#index-ffreestanding [2]Link: https://github.com/llvm/llvm-project/commit/b28eeb28bea39148738dc375e8a97072a1907e64 [3]Link: https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-finline-stringops [4]Closes: https://github.com/ClangBuiltLinux/linux/issues/2183Cc: stable@vger.kernel.org # v6.12+Signed-off-by: Nathan Chancellor Signed-off-by: Jason A. Donenfeld List of files: /linux/arch/s390/kernel/vdso/Makefile

dc161efb6df8518b3cfa7f0a5efdc16a1aee815b - s390/vdso: Pass --eh-frame-hdr to the linker

Mon, 13 Jul 2026 16:42:30 +0200

s390/vdso: Pass --eh-frame-hdr to the linkerCommit 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to linkvDSO") accidentally broke the GNU_EH_FRAME program table entry inthe vDSO, causing it to be empty: $ readelf --program-headers arch/s390/kernel/vdso/vdso.so ... Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flags Align ... GNU_EH_FRAME 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x8 ...Originally, the compiler would implicitly add --eh-frame-hdr wheninvoking the linker, but when this Makefile was converted from invokingthe linker via the compiler, to invoking it directly, the option wasmissed.This is the s390 variant of x86 commit cd01544a268a ("x86/vdso: Pass--eh-frame-hdr to the linker").Fixes: 2b2a25845d53 ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO")Reviewed-by: Ilya Leoshkevich Acked-by: Heiko Carstens Signed-off-by: Jens Remus Signed-off-by: Vasily Gorbik List of files: /linux/arch/s390/kernel/vdso/Makefile

576b1b7b1148517364303f0a52d27034b01796be - s390/vdso: Disable kstack erase

Fri, 09 Jan 2026 10:33:14 +0100

s390/vdso: Disable kstack eraseFor some reason gcc 8, 9, 10, and 11 generate a dynamic relocation invdso.so.dbg if CONFIG_KSTACK_ERASE is enabled:>> arch/s390/kernel/vdso/vdso.so.dbg: dynamic relocations are not supported make[3]: *** [arch/s390/kernel/vdso/Makefile:54: arch/s390/kernel/vdso/vdso.so.dbg] Error 1$ readelf -rW arch/s390/kernel/vdso/vdso.so.dbgRelocation section '.rela.dyn' at offset 0x15c0 contains 1 entry: Offset Info Type Symbol's Value Symbol's Name + Addend00000000000015f0 000000010000000b R_390_JMP_SLOT 0000000000000000 __sanitizer_cov_stack_depth + 0Add $(DISABLE_KSTACK_ERASE) to vdso compile flags to fix this.Reported-by: kernel test robot Closes: https://lore.kernel.org/r/202601070505.xQcLr5KV-lkp@intel.com/Signed-off-by: Heiko Carstens List of files: /linux/arch/s390/kernel/vdso/Makefile

509c34924d5a89a73c1470e9265be86baffd1286 - s390/vdso: Get rid of -m64 flag handling

Tue, 25 Nov 2025 12:36:26 +0100

s390/vdso: Get rid of -m64 flag handlingThe compiler/assembler flag -m64 is added and removed at two locations.This pointless exercise is a leftover to keep the 31 and 64 bit vdsoMakefiles as symmetrical as possible. Given that the 31 bit vdso codedoes not exist anymore, remove the -m64 flag handling.Suggested-by: Jens Remus Reviewed-by: Jens Remus Signed-off-by: Heiko Carstens List of files: /linux/arch/s390/kernel/vdso/Makefile

c0087d807ae86cc82cc356e366d2dccf0e3bb225 - s390/vdso: Rename vdso64 to vdso

Mon, 24 Nov 2025 16:04:29 +0100

s390/vdso: Rename vdso64 to vdsoSince compat is gone there is only a 64 bit vdso left.Remove the superfluous "64" suffix everywhere.Reviewed-by: Jens Remus Signed-off-by: Heiko Carstens List of files: /linux/arch/s390/kernel/vdso/Makefile