From: Scott Wood <scott@thor.buserror.net>
Date: Mon, 12 May 2008 02:11:46 +0000 (-0500)
Subject: Cause excessively large malloc()s to fail rather than assert.
X-Git-Url: http://git.buserror.net/cgi-bin/gitweb.cgi?p=polintos%2Fscott%2Fpriv.git;a=commitdiff_plain;h=371d6008c5366f424e4bf8889febe3cc495d0d3e

Cause excessively large malloc()s to fail rather than assert.

GCC's exception frame searching will malloc() larger than a page;
returning NULL forces it to fall back on slower, in-place searching.

Signed-off-by: Scott Wood <scott@thor.buserror.net>
---

diff --git a/kernel/lib/libc.cc b/kernel/lib/libc.cc
index 6518988..8d9685a 100644
--- a/kernel/lib/libc.cc
+++ b/kernel/lib/libc.cc
@@ -34,7 +34,8 @@ void bzero(void *b, size_t len)
 
 void *malloc(size_t len)
 {
-	assert(len <= Arch::page_size - sizeof(size_t));
+	if (len > Arch::page_size - sizeof(size_t))
+		return NULL;
 
 	len = (len + sizeof(size_t) + Arch::page_size - 1) / Arch::page_size;
 	Mem::Page *page = Mem::PageAlloc::alloc(len);