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authorThomas Weißschuh <thomas.weissschuh@linutronix.de>2025-04-30 11:20:13 +0200
committerThomas Gleixner <tglx@linutronix.de>2025-05-02 20:57:11 +0200
commit0c314cda93258cd1f0055a278a6576b5d4aeabf5 (patch)
treea0ec96c1908d830fd02476fa01f54052777e9c2b
parentb71f9804f66c2592d4c3a2397b7374a4039005a5 (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.h13
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 */