d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

uma: Fix a few problems with KASAN integration

Browse Source 
- Ensure that all items returned by UMA are aligned to
  KASAN_SHADOW_SCALE (8).  This was true in practice since smaller
  alignments are not used by any consumers, but we should enforce it
  anyway.
- Use a non-zero code for marking redzones that appear naturally in
  items that are not a multiple of the scale factor in size.  Currently
  we do not modify keg layouts to force the creation of redzones.
- Use a non-zero code for marking freed per-CPU items, otherwise
  accesses of freed per-CPU items are not detected by the runtime.

Sponsored by:	The FreeBSD Foundation
This commit is contained in:
Mark Johnston 2021-07-09 20:38:21 -04:00
parent 36226163fa
commit b0dfc48684
1 changed files with 13 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
sys/vm/uma_core.c
View File

@ -556,11 +556,12 @@ kasan_mark_item_valid(uma_zone_t zone, void *item)
sz = zone->uz_size;
rsz = roundup2(sz, KASAN_SHADOW_SCALE);
if ((zone->uz_flags & UMA_ZONE_PCPU) == 0) {
kasan_mark(item, sz, rsz, 0);
kasan_mark(item, sz, rsz, KASAN_GENERIC_REDZONE);
} else {
pcpu_item = zpcpu_base_to_offset(item);
for (i = 0; i <= mp_maxid; i++)
kasan_mark(zpcpu_get_cpu(pcpu_item, i), sz, rsz, 0);
kasan_mark(zpcpu_get_cpu(pcpu_item, i), sz, rsz,
KASAN_GENERIC_REDZONE);
}
}
@ -580,7 +581,8 @@ kasan_mark_item_invalid(uma_zone_t zone, void *item)
} else {
pcpu_item = zpcpu_base_to_offset(item);
for (i = 0; i <= mp_maxid; i++)
kasan_mark(zpcpu_get_cpu(pcpu_item, i), 0, sz, 0);
kasan_mark(zpcpu_get_cpu(pcpu_item, i), 0, sz,
KASAN_UMA_FREED);
}
}
@ -2238,6 +2240,14 @@ keg_layout(uma_keg_t keg)
PRINT_UMA_ZFLAGS));
alignsize = keg->uk_align + 1;
#ifdef KASAN
/*
* ASAN requires that each allocation be aligned to the shadow map
* scale factor.
*/
if (alignsize < KASAN_SHADOW_SCALE)
alignsize = KASAN_SHADOW_SCALE;
#endif
/*
* Calculate the size of each allocation (rsize) according to