[PATCH 3.16 193/357] MIPS: Fix MFC1 & MFHC1 emulation for 64-bit MIPS systems

[Greg Kroah-Hartman]

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

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

From: Paul Burton <***@imgtec.com>

commit c8c0da6bdf0f0d6f59fc23aab6ee373a131df82d upstream.

Commit bbd426f542cb "MIPS: Simplify FP context access" modified the
SIFROMREG & SIFROMHREG macros such that they return unsigned rather
than signed 32b integers. I had believed that to be fine, but
inadvertently missed the MFC1 & MFHC1 cases which write to a struct
pt_regs regs element. On MIPS32 this is fine, but on 64 bit those
saved regs' fields are 64 bit wide. Using unsigned values caused the
32 bit value from the FP register to be zero rather than sign extended
as the architecture specifies, causing incorrect emulation of the
MFC1 & MFHc1 instructions. Fix by reintroducing the casts to signed
integers, and therefore the sign extension.

Signed-off-by: Paul Burton <***@imgtec.com>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7848/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/math-emu/cp1emu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -650,9 +650,9 @@ static inline int cop1_64bit(struct pt_r
#define SIFROMREG(si, x) \
do { \
if (cop1_64bit(xcp)) \
- (si) = get_fpr32(&ctx->fpr[x], 0); \
+ (si) = (int)get_fpr32(&ctx->fpr[x], 0); \
else \
- (si) = get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \
+ (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \
} while (0)

#define SITOREG(si, x) \
@@ -667,7 +667,7 @@ do { \
} \
} while (0)

-#define SIFROMHREG(si, x) ((si) = get_fpr32(&ctx->fpr[x], 1))
+#define SIFROMHREG(si, x) ((si) = (int)get_fpr32(&ctx->fpr[x], 1))

#define SITOHREG(si, x) \
do { \

[Greg Kroah-Hartman]

3.16-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: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/kernel/mcount.S | 12 ++++++++++++
1 file changed, 12 insertions(+)

--- 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)

[Greg Kroah-Hartman]

3.16-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: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/boot/compressed/decompress.c | 1 +
1 file changed, 1 insertion(+)

--- 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>