diff options
Diffstat (limited to 'src/cmd/venti/srv/zblock.c')
| -rw-r--r-- | src/cmd/venti/srv/zblock.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/src/cmd/venti/srv/zblock.c b/src/cmd/venti/srv/zblock.c index 87c31765..afff0801 100644 --- a/src/cmd/venti/srv/zblock.c +++ b/src/cmd/venti/srv/zblock.c @@ -16,6 +16,9 @@ fmtzbinit(Fmt *f, ZBlock *b) #define ROUNDUP(p, n) ((void*)(((uintptr)(p)+(n)-1)&~(uintptr)((n)-1))) +enum { + OverflowCheck = 32 +}; static char zmagic[] = "1234567890abcdefghijklmnopqrstuvxyz"; ZBlock * @@ -29,7 +32,7 @@ alloczblock(u32int size, int zeroed, uint blocksize) if(blocksize == 0) blocksize = 32; /* try for cache line alignment */ - n = size+32/*XXX*/+sizeof(ZBlock)+blocksize+8; + n = size+OverflowCheck+sizeof(ZBlock)+blocksize+8; p = malloc(n); if(p == nil){ seterr(EOk, "out of memory"); @@ -37,7 +40,7 @@ alloczblock(u32int size, int zeroed, uint blocksize) } data = ROUNDUP(p, blocksize); - b = ROUNDUP(data+size+32/*XXX*/, 8); + b = ROUNDUP(data+size+OverflowCheck, 8); if(0) fprint(2, "alloc %p-%p data %p-%p b %p-%p\n", p, p+n, data, data+size, b, b+1); *b = z; @@ -47,7 +50,7 @@ alloczblock(u32int size, int zeroed, uint blocksize) b->_size = size; if(zeroed) memset(b->data, 0, size); - memmove(b->data+size, zmagic, 32/*XXX*/); + memmove(b->data+size, zmagic, OverflowCheck); return b; } @@ -55,9 +58,9 @@ void freezblock(ZBlock *b) { if(b){ - if(memcmp(b->data+b->_size, zmagic, 32) != 0) + if(memcmp(b->data+b->_size, zmagic, OverflowCheck) != 0) abort(); - memset(b->data+b->_size, 0, 32); + memset(b->data+b->_size, 0, OverflowCheck); free(b->free); } } |