From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Wed, 25 Aug 2004 13:43:44 +0000 (+0000)
Subject: Fix problem with brk().  Thanks to Paull Mackerras for the patch.
X-Git-Tag: svn/VALGRIND_2_2_0~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2f53ead94d3a30d737e116aa75690fb19d9b0487;p=thirdparty%2Fvalgrind.git

Fix problem with brk().  Thanks to Paull Mackerras for the patch.
Added a regression test for it.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@2619
---

diff --git a/coregrind/vg_syscalls.c b/coregrind/vg_syscalls.c
index 0d87da856e..c279aaee39 100644
--- a/coregrind/vg_syscalls.c
+++ b/coregrind/vg_syscalls.c
@@ -900,6 +900,8 @@ static Addr do_brk(Addr newbrk)
    Addr ret = VG_(brk_limit);
    static const Bool debug = False;
    Segment *seg;
+   Addr current, newaddr;
+
 
    if (debug)
       VG_(printf)("do_brk: brk_base=%p brk_limit=%p newbrk=%p\n",
@@ -922,9 +924,9 @@ static Addr do_brk(Addr newbrk)
    if (seg != NULL && newbrk > seg->addr)
       return VG_(brk_limit);
 
-   if (PGROUNDDN(newbrk) != PGROUNDDN(VG_(brk_limit))) {
-      Addr current = PGROUNDUP(VG_(brk_limit));
-      Addr newaddr = PGROUNDUP(newbrk);
+   current = PGROUNDUP(VG_(brk_limit));
+   newaddr = PGROUNDUP(newbrk);
+   if (newaddr != current) {
 
       /* new brk in a new page - fix the mappings */
       if (newbrk > VG_(brk_limit)) {
diff --git a/memcheck/tests/Makefile.am b/memcheck/tests/Makefile.am
index 4d3035ed3b..a8fccb8c55 100644
--- a/memcheck/tests/Makefile.am
+++ b/memcheck/tests/Makefile.am
@@ -18,6 +18,7 @@ EXTRA_DIST = $(noinst_SCRIPTS) \
 	badloop.stderr.exp badloop.vgtest \
 	badrw.stderr.exp badrw.vgtest \
 	brk.stderr.exp brk.vgtest \
+	brk2.stderr.exp brk2.vgtest \
 	buflen_check.stderr.exp buflen_check.vgtest \
 	clientperm.stderr.exp \
 	clientperm.stdout.exp clientperm.vgtest \
@@ -77,7 +78,7 @@ EXTRA_DIST = $(noinst_SCRIPTS) \
 	zeropage.stderr.exp zeropage.vgtest
 
 check_PROGRAMS = \
-	badaddrvalue badfree badjump badloop badrw brk buflen_check \
+	badaddrvalue badfree badjump badloop badrw brk brk2 buflen_check \
 	clientperm custom_alloc \
 	doublefree error_counts errs1 exitprog execve execve2 \
 	fpeflags fprw fwrite inits inline \
@@ -100,6 +101,7 @@ badjump_SOURCES 	= badjump.c
 badloop_SOURCES 	= badloop.c
 badrw_SOURCES		= badrw.c
 brk_SOURCES 		= brk.c
+brk2_SOURCES 		= brk2.c
 buflen_check_SOURCES	= buflen_check.c
 clientperm_SOURCES 	= clientperm.c
 custom_alloc_SOURCES 	= custom_alloc.c
diff --git a/memcheck/tests/brk2.c b/memcheck/tests/brk2.c
new file mode 100644
index 0000000000..3a881335e4
--- /dev/null
+++ b/memcheck/tests/brk2.c
@@ -0,0 +1,25 @@
+#include <stdio.h>
+#include <unistd.h>
+
+#define MAX 3000
+
+// At one time, this was causing a seg fault within Valgrind -- it was when
+// extending the brk segment onto a new page.  Fixed in vg_syscalls.c 1.129.
+
+int main () {
+  char* ptr;
+  int i;
+
+  for (i=0; i<MAX; i++) {
+    ptr = sbrk(1);
+
+    if (ptr == (void*)-1) {
+      printf ("sbrk() failed!\n");
+      return 0;
+    }
+
+    *ptr = 0;
+  }
+
+  return 0;
+} 
diff --git a/memcheck/tests/brk2.stderr.exp b/memcheck/tests/brk2.stderr.exp
new file mode 100644
index 0000000000..c4aa6f04fe
--- /dev/null
+++ b/memcheck/tests/brk2.stderr.exp
@@ -0,0 +1,7 @@
+
+
+ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
+malloc/free: in use at exit: 0 bytes in 0 blocks.
+malloc/free: 0 allocs, 0 frees, 0 bytes allocated.
+For a detailed leak analysis,  rerun with: --leak-check=yes
+For counts of detected errors, rerun with: -v
diff --git a/memcheck/tests/brk2.vgtest b/memcheck/tests/brk2.vgtest
new file mode 100644
index 0000000000..951b3fabe2
--- /dev/null
+++ b/memcheck/tests/brk2.vgtest
@@ -0,0 +1 @@
+prog: brk2