Merge branch 'lwip' into elflink

Welcome to Syslinux 5.10.

Conflicts:
	NEWS
	com32/lib/Makefile
	com32/lib/sys/open.c
	com32/lib/syslinux/ipappend.c
	com32/modules/Makefile
	com32/modules/prdhcp.c
	core/Makefile
	core/cmdline.inc
	core/com32.inc
	core/comboot.inc
	core/configinit.inc
	core/fs/chdir.c
	core/fs/fs.c
	core/fs/pxe/dnsresolv.c
	core/fs/pxe/pxe.c
	core/fs/pxe/pxe.h
	core/idle.c
	core/include/ctype.h
	core/init.inc
	core/mem/init.c
	core/parseconfig.inc
	core/runkernel.inc
	core/syslinux.ld
	core/ui.inc
	doc/comboot.txt
	version

3 files changed, 20 insertions, 0 deletions

diff --git a/core/mem/free.c b/core/mem/free.c
index e8a9b048..d7f912b1 100644
--- a/core/mem/free.c
+++ b/core/mem/free.c
@@ -86,7 +86,9 @@ __export void free(void *ptr)
 	dprintf("invalid arena type: %d\n", ARENA_TYPE_GET(ah->a.attrs));
 #endif
 
+    sem_down(&__malloc_semaphore, 0);
     __free_block(ah);
+    sem_up(&__malloc_semaphore);
 
   /* Here we could insert code to return memory to the system. */
 }
@@ -108,6 +110,8 @@ void __inject_free_block(struct free_arena_header *ah)
 	    ARENA_SIZE_GET(ah->a.attrs), ah,
 	    ARENA_HEAP_GET(ah->a.attrs), head);
 
+    sem_down(&__malloc_semaphore, 0);
+
     for (nah = head->a.next ; nah != head ; nah = nah->a.next) {
         n_end = (size_t) nah + ARENA_SIZE_GET(nah->a.attrs);
 
@@ -122,6 +126,7 @@ void __inject_free_block(struct free_arena_header *ah)
 	printf("conflict:ah: %p, a_end: %p, nah: %p, n_end: %p\n", ah, a_end, nah, n_end);
 
         /* Otherwise we have some sort of overlap - reject this block */
+	sem_up(&__malloc_semaphore);
         return;
     }
 
@@ -132,6 +137,8 @@ void __inject_free_block(struct free_arena_header *ah)
     ah->a.prev->a.next = ah;
 
     __free_block(ah);
+
+    sem_up(&__malloc_semaphore);
 }
 
 /*
@@ -141,6 +148,8 @@ static void __free_tagged(malloc_tag_t tag) {
     struct free_arena_header *fp, *head;
     int i;
 
+    sem_down(&__malloc_semaphore, 0);
+
     for (i = 0; i < NHEAP; i++) {
 	dprintf("__free_tagged(%u) heap %d\n", tag, i);
 	head = &__core_malloc_head[i];
@@ -151,6 +160,7 @@ static void __free_tagged(malloc_tag_t tag) {
 	}
     }
 
+    sem_up(&__malloc_semaphore);
     dprintf("__free_tagged(%u) done\n", tag);
 }
 
diff --git a/core/mem/malloc.c b/core/mem/malloc.c
index 6cd3b33d..f64850d1 100644
--- a/core/mem/malloc.c
+++ b/core/mem/malloc.c
@@ -12,6 +12,9 @@
 #include <minmax.h>
 
 #include "malloc.h"
+#include "thread.h"
+
+DECLARE_INIT_SEMAPHORE(__malloc_semaphore, 1);
 
 static void *__malloc_from_block(struct free_arena_header *fp,
 				 size_t size, malloc_tag_t tag)
@@ -72,6 +75,8 @@ static void *_malloc(size_t size, enum heap heap, malloc_tag_t tag)
     dprintf("_malloc(%zu, %u, %u) @ %p = ",
 	size, heap, tag, __builtin_return_address(0));
 
+    sem_down(&__malloc_semaphore, 0);
+
     if (size) {
 	/* Add the obligatory arena header, and round up */
 	size = (size + 2 * sizeof(struct arena_header) - 1) & ARENA_SIZE_MASK;
@@ -85,6 +90,8 @@ static void *_malloc(size_t size, enum heap heap, malloc_tag_t tag)
         }
     }
 
+    sem_up(&__malloc_semaphore);
+
     dprintf("%p\n", p);
     return p;
 }
diff --git a/core/mem/malloc.h b/core/mem/malloc.h
index d0d135bc..4611a306 100644
--- a/core/mem/malloc.h
+++ b/core/mem/malloc.h
@@ -7,6 +7,9 @@
 #include <stdint.h>
 #include <stddef.h>
 #include "core.h"
+#include "thread.h"
+
+extern struct semaphore __malloc_semaphore;
 
 /*
  * This is a temporary hack.  In Syslinux 5 this will be a pointer to