From 0c314cda93258cd1f0055a278a6576b5d4aeabf5 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Thomas=20Wei=C3=9Fschuh?= Date: Wed, 30 Apr 2025 11:20:13 +0200 Subject: [PATCH] arm64: vdso: Work around invalid absolute relocations from GCC MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit All vDSO code needs to be completely position independent. Symbol references are marked as hidden so the compiler emits PC-relative relocations. However GCC emits absolute relocations for symbol-relative references with an offset >= 64KiB. After recent refactorings in the vDSO code this is the case in __arch_get_vdso_u_timens_data() with a page size of 64KiB. Work around the issue by preventing the optimizer from seeing the offsets. Fixes: 83a2a6b8cfc5 ("vdso/gettimeofday: Prepare do_hres_timens() for introduction of struct vdso_clock") Reported-by: Jan Stancek Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Acked-by: Catalin Marinas Link: https://lore.kernel.org/all/20250430-vdso-absolute-reloc-v2-1-5efcc3bc4b26@linutronix.de Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120002 Closes: https://lore.kernel.org/lkml/aApGPAoctq_eoE2g@t14ultra/ --- arch/arm64/include/asm/vdso/gettimeofday.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h index 92a2b59a9f3df..3322c7047d84f 100644 --- a/arch/arm64/include/asm/vdso/gettimeofday.h +++ b/arch/arm64/include/asm/vdso/gettimeofday.h @@ -99,6 +99,19 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode, return res; } +#if IS_ENABLED(CONFIG_CC_IS_GCC) && IS_ENABLED(CONFIG_PAGE_SIZE_64KB) +static __always_inline const struct vdso_time_data *__arch_get_vdso_u_time_data(void) +{ + const struct vdso_time_data *ret = &vdso_u_time_data; + + /* Work around invalid absolute relocations */ + OPTIMIZER_HIDE_VAR(ret); + + return ret; +} +#define __arch_get_vdso_u_time_data __arch_get_vdso_u_time_data +#endif /* IS_ENABLED(CONFIG_CC_IS_GCC) && IS_ENABLED(CONFIG_PAGE_SIZE_64KB) */ + #endif /* !__ASSEMBLY__ */ #endif /* __ASM_VDSO_GETTIMEOFDAY_H */ -- 2.47.2