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From:   Christian Brauner <christian@brauner.io>
To:     mtk.manpages@gmail.com
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        avagin@gmail.com, christian.brauner@ubuntu.com,
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Subject: [PATCH 2/3] clone.2: Check for MAP_FAILED not NULL on mmap()
Date:   Sat, 16 Nov 2019 12:41:13 +0100
Message-Id: <20191116114114.7066-2-christian@brauner.io>
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From: Christian Brauner <christian.brauner@ubuntu.com>

If mmap() fails it will return MAP_FAILED which according to the manpage
is (void *)-1 not NULL.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
 man2/clone.2 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/man2/clone.2 b/man2/clone.2
index 57a9eaba7..faff2ada6 100644
--- a/man2/clone.2
+++ b/man2/clone.2
@@ -1628,7 +1628,7 @@ main(int argc, char *argv[])
 
     stack = mmap(NULL, STACK_SIZE, PROT_READ | PROT_WRITE,
                  MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, \-1, 0);
-    if (stack == NULL)
+    if (stack == MAP_FAILED)
         errExit("mmap");
 
     stackTop = stack + STACK_SIZE;  /* Assume stack grows downward */
-- 
2.24.0