kasan: disable kasan_non_canonical_hook() for HW tags
Subsystems (2)
PATCH 1/1 kasan: disable kasan_non_canonical_hook() for HW tags
From: Arnd Bergmann <[email protected]>
On arm64, building with CONFIG_KASAN_HW_TAGS now causes a compile-time error:
mm/kasan/report.c: In function 'kasan_non_canonical_hook':mm/kasan/report.c:637:20: error: 'KASAN_SHADOW_OFFSET' undeclared (first use in this function)
637 | if (addr < KASAN_SHADOW_OFFSET)
| ^~~~~~~~~~~~~~~~~~~
mm/kasan/report.c:637:20: note: each undeclared identifier is reported only once for each function it appears in mm/kasan/report.c:640:77: error: expected expression before ';' token
640 | orig_addr = (addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT;
This was caused by removing the dependency on CONFIG_KASAN_INLINE that used to prevent this from happening. Use the more specific dependency on KASAN_SW_TAGS || KASAN_GENERIC to only ignore the function for hwasan mode.
---
It looks like the comment above the function needs to be adjusted as well, and it's possible we should still provide it even for hwasan but fix it in a different way.
I saw this a few days ago but didn't actually send the patch right away, so there is a good chance that someone has already produced a better patch, just ignore my report in that case.
--- include/linux/kasan.h | 6 +++--- mm/kasan/report.c | 4 +++- 2 files changed, 6 insertions(+), 4 deletions(-)
include/linux/kasan.h +3 -3
@@ -468,10 +468,10 @@ static inline void kasan_free_module_shadow(const struct vm_struct *vm) {}#endif /* (CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) && !CONFIG_KASAN_VMALLOC */ -#ifdef CONFIG_KASAN +#if defined(CONFIG_KASAN_GENERIC ) || defined(CONFIG_KASAN_SW_TAGS )void kasan_non_canonical_hook (unsigned long addr); -#else /* CONFIG_KASAN */ +#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ static inline void kasan_non_canonical_hook (unsigned long addr) { } -#endif /* CONFIG_KASAN */ +#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ #endif /* LINUX_KASAN_H */
mm/kasan/report.c +3 -1
@@ -621,8 +621,9 @@ void kasan_report_async(void) }#endif /* CONFIG_KASAN_HW_TAGS */ +#if defined(CONFIG_KASAN_GENERIC ) || defined(CONFIG_KASAN_SW_TAGS )/* -* With CONFIG_KASAN, accesses to bogus pointers (outside the high +* With CONFIG_KASAN_INLINE, accesses to bogus pointers (outside the high * canonical half of the address space) cause out-of-bounds shadow memory reads * before the actual access. For addresses in the low canonical half of the * address space, as well as most non-canonical addresses, that out-of-bounds
@@ -658,3 +659,4 @@ void kasan_non_canonical_hook(unsigned long addr)pr_alert ("KASAN: %s in range [0x%016lx-0x%016lx]\n" , bug_type, orig_addr, orig_addr + KASAN_GRANULE_SIZE - 1); } +#endif
Signature · 1 line
2.39.2