Avoid overflow

jserv · jserv · commit db81bd697ea6 · 2023-03-13T02:22:33.000Z
diff --git a/tlsf.c b/tlsf.c
@@ -130,7 +130,7 @@ INLINE void block_set_prev_free(tlsf_block_t *block, bool free)
 INLINE size_t align_up(size_t x, size_t align)
 {
     ASSERT(!(align & (align - 1)), "must align to a power of two");
-    return (x + (align - 1)) & ~(align - 1);
+    return (((x - 1) | (align - 1)) + 1);
 }
 
 INLINE char *align_ptr(char *p, size_t align)

Original file line number	Diff line number	Diff line change
`@@ -130,7 +130,7 @@ INLINE void block_set_prev_free(tlsf_block_t *block, bool free)`
`130`	`130`	`INLINE size_t align_up(size_t x, size_t align)`
`131`	`131`	`{`
`132`	`132`	`ASSERT(!(align & (align - 1)), "must align to a power of two");`
`133`		`- return (x + (align - 1)) & ~(align - 1);`
	`133`	`+ return (((x - 1) \| (align - 1)) + 1);`
`134`	`134`	`}`
`135`	`135`
`136`	`136`	`INLINE char align_ptr(char p, size_t align)`