diff options
author | Thomas Weißschuh <thomas.weissschuh@linutronix.de> | 2025-04-30 11:20:13 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2025-05-02 20:57:11 +0200 |
commit | 0c314cda93258cd1f0055a278a6576b5d4aeabf5 (patch) | |
tree | a0ec96c1908d830fd02476fa01f54052777e9c2b | |
parent | b71f9804f66c2592d4c3a2397b7374a4039005a5 (diff) |
arm64: vdso: Work around invalid absolute relocations from GCC
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 <jstancek@redhat.com>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
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/
-rw-r--r-- | arch/arm64/include/asm/vdso/gettimeofday.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h index 92a2b59a9f3d..3322c7047d84 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 */ |