From: Gabor Juhos <juhosg@openwrt.org>
Date: Mon, 21 Mar 2016 13:15:29 +0000 (+0000)
Subject: ramips: lzma-loader: fix O32 ABI conformance
X-Git-Tag: reboot~164
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=fc5c19f45b3cf162f1417385edb8c9d9b337387d;p=openwrt%2Fstaging%2Flynxis.git

ramips: lzma-loader: fix O32 ABI conformance

According to the calling convention of the o32 ABI the
caller function must reserve stack space for $a0-$a3
registers in case the callee needs to save its arguments.

The assembly startup code does not reserve stack space
for these registers thus when the main C function needs
to save its arguments, that will cause a stack overflow.

Fix the assembly code to reserve stack space for the
registers to avoid that.

Untested. It seems that the lzma-loader is not used at all?

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

SVN-Revision: 49062
---

diff --git a/target/linux/ramips/image/lzma-loader/src/head.S b/target/linux/ramips/image/lzma-loader/src/head.S
index 543996a0da..47a7c9bd63 100644
--- a/target/linux/ramips/image/lzma-loader/src/head.S
+++ b/target/linux/ramips/image/lzma-loader/src/head.S
@@ -109,6 +109,9 @@ __bss_check:
 	/* Setup new "C" stack */
 	la	sp, _stack
 
+	/* reserve stack space for a0-a3 registers */
+	subu	sp, 16
+
 	/* jump to the decompressor routine */
 	la	t0, loader_main
 	jr	t0