[PATCH 3.13 142/163] MIPS: mcount: Adjust stack pointer for static trace in MIPS32

[Kamal Mostafa]

3.13.11.9 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Markos Chandras <***@imgtec.com>

commit 8a574cfa2652545eb95595d38ac2a0bb501af0ae upstream.

Every mcount() call in the MIPS 32-bit kernel is done as follows:

[...]
move at, ra
jal _mcount
addiu sp, sp, -8
[...]

but upon returning from the mcount() function, the stack pointer
is not adjusted properly. This is explained in details in 58b69401c797
(MIPS: Function tracer: Fix broken function tracing).

Commit ad8c396936e3 ("MIPS: Unbreak function tracer for 64-bit kernel.)
fixed the stack manipulation for 64-bit but it didn't fix it completely
for MIPS32.

Signed-off-by: Markos Chandras <***@imgtec.com>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7792/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Kamal Mostafa <***@canonical.com>
---
arch/mips/kernel/mcount.S | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S
index 539b629..8f89ff4 100644
--- a/arch/mips/kernel/mcount.S
+++ b/arch/mips/kernel/mcount.S
@@ -123,7 +123,11 @@ NESTED(_mcount, PT_SIZE, ra)
nop
#endif
b ftrace_stub
+#ifdef CONFIG_32BIT
+ addiu sp, sp, 8
+#else
nop
+#endif

static_trace:
MCOUNT_SAVE_REGS
@@ -133,6 +137,9 @@ static_trace:
move a1, AT /* arg2: parent's return address */

MCOUNT_RESTORE_REGS
+#ifdef CONFIG_32BIT
+ addiu sp, sp, 8
+#endif
.globl ftrace_stub
ftrace_stub:
RETURN_BACK
@@ -177,6 +184,11 @@ NESTED(ftrace_graph_caller, PT_SIZE, ra)
jal prepare_ftrace_return
nop
MCOUNT_RESTORE_REGS
+#ifndef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_32BIT
+ addiu sp, sp, 8
+#endif
+#endif
RETURN_BACK
END(ftrace_graph_caller)

[Kamal Mostafa]

3.13.11.9 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Aurelien Jarno <***@aurel32.net>

commit 29593fd5a8149462ed6fad0d522234facdaee6c8 upstream.

Commit dc4d7b37 (MIPS: ZBOOT: gather string functions into string.c)
moved the string related functions into a separate file, which might
cause the following build error, depending on the configuration:

| CC arch/mips/boot/compressed/decompress.o
| In file included from linux/arch/mips/boot/compressed/../../../../lib/decompress_unxz.c:234:0,
| from linux/arch/mips/boot/compressed/decompress.c:67:
| linux/arch/mips/boot/compressed/../../../../lib/xz/xz_dec_stream.c: In function 'fill_temp':
| linux/arch/mips/boot/compressed/../../../../lib/xz/xz_dec_stream.c:162:2: error: implicit declaration of function 'memcpy' [-Werror=implicit-function-declaration]
| cc1: some warnings being treated as errors
| linux/scripts/Makefile.build:308: recipe for target 'arch/mips/boot/compressed/decompress.o' failed
| make[6]: *** [arch/mips/boot/compressed/decompress.o] Error 1
| linux/arch/mips/Makefile:308: recipe for target 'vmlinuz' failed

It does not fail with the standard configuration, as when
CONFIG_DYNAMIC_DEBUG is not enabled <linux/string.h> gets included in
include/linux/dynamic_debug.h. There might be other ways for it to
get indirectly included.

We can't add the include directly in xz_dec_stream.c as some
architectures might want to use a different version for the boot/
directory (see for example arch/x86/boot/string.h).

Signed-off-by: Aurelien Jarno <***@aurel32.net>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7420/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Kamal Mostafa <***@canonical.com>
---
arch/mips/boot/compressed/decompress.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/mips/boot/compressed/decompress.c b/arch/mips/boot/compressed/decompress.c
index a8c6fd6..193ceae 100644
--- a/arch/mips/boot/compressed/decompress.c
+++ b/arch/mips/boot/compressed/decompress.c
@@ -13,6 +13,7 @@

#include <linux/types.h>
#include <linux/kernel.h>
+#include <linux/string.h>

#include <asm/addrspace.h>