commit f4324f3eeb311d1889b8c25076f2669012323842
author Ralf Baechle <ralf@linux-mips.org> Wed Apr 16 19:55:26 2008 +0100
committer Ralf Baechle <ralf@linux-mips.org> Mon May 12 16:46:51 2008 +0100
tree 4db25b6221447a64673e35fee2c97d31902f3118
parent 1928cc84a0a937ce7042d9235996ab380f36f18a

[MIPS] IRIX: Handle do_brk() error return correctly.

do_brk's return value was stored in an unsigned long variable before being
tested for less than zero making the test always fail.  Also do_brk's
called irix_map_prda_page wasn't forwarding do_brk() success.

Bug checking the return value of do_brk() and initial fix for it found
by Roel Kluin <12o3l@tiscali.nl>.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/irixelf.c

diff --git a/arch/mips/kernel/irixelf.c b/arch/mips/kernel/irixelf.c
index 290d8e3..469c723 100644
--- a/arch/mips/kernel/irixelf.c
+++ b/arch/mips/kernel/irixelf.c
@@ -578,7 +578,7 @@
  * process and the system, here we map the page and fill the
  * structure
  */
-static void irix_map_prda_page(void)
+static int irix_map_prda_page(void)
 {
 	unsigned long v;
 	struct prda *pp;
@@ -587,8 +587,8 @@
 	v =  do_brk(PRDA_ADDRESS, PAGE_SIZE);
 	up_write(&current->mm->mmap_sem);
 
-	if (v < 0)
-		return;
+	if (v != PRDA_ADDRESS)
+		return v;		/* v must be an error code */
 
 	pp = (struct prda *) v;
 	pp->prda_sys.t_pid  = task_pid_vnr(current);
@@ -596,6 +596,8 @@
 	pp->prda_sys.t_rpid = task_pid_vnr(current);
 
 	/* We leave the rest set to zero */
+
+	return 0;
 }
 
 
@@ -781,7 +783,8 @@
 	 * IRIX maps a page at 0x200000 which holds some system
 	 * information.  Programs depend on this.
 	 */
-	irix_map_prda_page();
+	if (irix_map_prda_page())
+		goto out_free_dentry;
 
 	padzero(elf_bss);