1 files changed, 39 insertions, 0 deletions

diff --git a/src/malloc/oldmalloc/malloc.c b/src/malloc/oldmalloc/malloc.c
index 52af1975..25d00d44 100644
--- a/src/malloc/oldmalloc/malloc.c
+++ b/src/malloc/oldmalloc/malloc.c
@@ -9,6 +9,11 @@
 #include "atomic.h"
 #include "pthread_impl.h"
 #include "malloc_impl.h"
+#include "fork_impl.h"
+
+#define malloc __libc_malloc_impl
+#define realloc __libc_realloc
+#define free __libc_free
 
 #if defined(__GNUC__) && defined(__PIC__)
 #define inline inline __attribute__((always_inline))
@@ -385,6 +390,18 @@ void *realloc(void *p, size_t n)
 	/* Crash on corrupted footer (likely from buffer overflow) */
 	if (next->psize != self->csize) a_crash();
 
+	if (n < n0) {
+		int i = bin_index_up(n);
+		int j = bin_index(n0);
+		if (i<j && (mal.binmap & (1ULL << i)))
+			goto copy_realloc;
+		struct chunk *split = (void *)((char *)self + n);
+		self->csize = split->psize = n | C_INUSE;
+		split->csize = next->psize = n0-n | C_INUSE;
+		__bin_chunk(split);
+		return CHUNK_TO_MEM(self);
+	}
+
 	lock(mal.split_merge_lock);
 
 	size_t nsize = next->csize & C_INUSE ? 0 : CHUNK_SIZE(next);
@@ -464,12 +481,14 @@ void __bin_chunk(struct chunk *self)
 	if (size > RECLAIM && (size^(size-osize)) > size-osize) {
 		uintptr_t a = (uintptr_t)self + SIZE_ALIGN+PAGE_SIZE-1 & -PAGE_SIZE;
 		uintptr_t b = (uintptr_t)next - SIZE_ALIGN & -PAGE_SIZE;
+		int e = errno;
 #if 1
 		__madvise((void *)a, b-a, MADV_DONTNEED);
 #else
 		__mmap((void *)a, b-a, PROT_READ|PROT_WRITE,
 			MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0);
 #endif
+		errno = e;
 	}
 
 	unlock_bin(i);
@@ -482,7 +501,9 @@ static void unmap_chunk(struct chunk *self)
 	size_t len = CHUNK_SIZE(self) + extra;
 	/* Crash on double free */
 	if (extra & 1) a_crash();
+	int e = errno;
 	__munmap(base, len);
+	errno = e;
 }
 
 void free(void *p)
@@ -515,3 +536,21 @@ void __malloc_donate(char *start, char *end)
 	c->csize = n->psize = C_INUSE | (end-start);
 	__bin_chunk(c);
 }
+
+void __malloc_atfork(int who)
+{
+	if (who<0) {
+		lock(mal.split_merge_lock);
+		for (int i=0; i<64; i++)
+			lock(mal.bins[i].lock);
+	} else if (!who) {
+		for (int i=0; i<64; i++)
+			unlock(mal.bins[i].lock);
+		unlock(mal.split_merge_lock);
+	} else {
+		for (int i=0; i<64; i++)
+			mal.bins[i].lock[0] = mal.bins[i].lock[1] = 0;
+		mal.split_merge_lock[1] = 0;
+		mal.split_merge_lock[0] = 0;
+	}
+}