diff options
| author | Gvozden Neskovic <[email protected]> | 2016-08-31 10:12:08 +0200 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2016-09-29 15:55:41 -0700 |
| commit | 031d7c2fe6afaa78943bd0a563b91fc84ace42d7 (patch) | |
| tree | e30c20bc233c680f997e8b11948988c7e97f1c83 /include/sys/dnode.h | |
| parent | 0b78aeae927833de580e140375a15ea5ea9d924a (diff) | |
fix: Shift exponent too large
Undefined operation is reported by running ztest (or zloop) compiled with GCC
UndefinedBehaviorSanitizer. Error only happens on top level of dnode indirection
with large enough offset values. Logically, left shift operation would work,
but bit shift semantics in C, and limitation of uint64_t, do not produce desired
result.
Issue #5059, #4883
Signed-off-by: Gvozden Neskovic <[email protected]>
Diffstat (limited to 'include/sys/dnode.h')
| -rw-r--r-- | include/sys/dnode.h | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/include/sys/dnode.h b/include/sys/dnode.h index 7b4d7b9d3..fe36e5989 100644 --- a/include/sys/dnode.h +++ b/include/sys/dnode.h @@ -104,9 +104,8 @@ extern "C" { #define DNODES_PER_LEVEL_SHIFT (DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT) #define DNODES_PER_LEVEL (1ULL << DNODES_PER_LEVEL_SHIFT) -/* The +2 here is a cheesy way to round up */ -#define DN_MAX_LEVELS (2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \ - (DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT))) +#define DN_MAX_LEVELS (DIV_ROUND_UP(DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT, \ + DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT) + 1) #define DN_BONUS(dnp) ((void*)((dnp)->dn_bonus + \ (((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t)))) |