[PATCH 4.4 01/99] MIPS64: R6: R2 emulation bugfix

[PATCH 4.4 01/99] MIPS64: R6: R2 emulation bugfix

[Greg Kroah-Hartman]

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

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

From: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>

commit 41fa29e4d8cf4150568a0fe9bb4d62229f9caed5 upstream.

Error recovery pointers for fixups was improperly set as ".word"
which is unsuitable for MIPS64.

Replaced by STR(PTR)

[ralf@linux-mips.org: Apply changes as requested in the review process.]

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Fixes: b0a668fb2038 ("MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6")
Cc: macro@linux-mips.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9911/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/mips-r2-to-r6-emul.c |  105 +++++++++++++++++-----------------
 1 file changed, 53 insertions(+), 52 deletions(-)

--- a/arch/mips/kernel/mips-r2-to-r6-emul.c
+++ b/arch/mips/kernel/mips-r2-to-r6-emul.c
@@ -28,6 +28,7 @@
 #include <asm/inst.h>
 #include <asm/mips-r2-to-r6-emul.h>
 #include <asm/local.h>
+#include <asm/mipsregs.h>
 #include <asm/ptrace.h>
 #include <asm/uaccess.h>
 
@@ -1251,10 +1252,10 @@ fpu_emul:
 			"	j	10b\n"
 			"	.previous\n"
 			"	.section	__ex_table,\"a\"\n"
-			"	.word	1b,8b\n"
-			"	.word	2b,8b\n"
-			"	.word	3b,8b\n"
-			"	.word	4b,8b\n"
+			STR(PTR) " 1b,8b\n"
+			STR(PTR) " 2b,8b\n"
+			STR(PTR) " 3b,8b\n"
+			STR(PTR) " 4b,8b\n"
 			"	.previous\n"
 			"	.set	pop\n"
 			: "+&r"(rt), "=&r"(rs),
@@ -1326,10 +1327,10 @@ fpu_emul:
 			"	j	10b\n"
 			"       .previous\n"
 			"	.section	__ex_table,\"a\"\n"
-			"	.word	1b,8b\n"
-			"	.word	2b,8b\n"
-			"	.word	3b,8b\n"
-			"	.word	4b,8b\n"
+			STR(PTR) " 1b,8b\n"
+			STR(PTR) " 2b,8b\n"
+			STR(PTR) " 3b,8b\n"
+			STR(PTR) " 4b,8b\n"
 			"	.previous\n"
 			"	.set	pop\n"
 			: "+&r"(rt), "=&r"(rs),
@@ -1397,10 +1398,10 @@ fpu_emul:
 			"	j	9b\n"
 			"	.previous\n"
 			"	.section        __ex_table,\"a\"\n"
-			"	.word	1b,8b\n"
-			"	.word	2b,8b\n"
-			"	.word	3b,8b\n"
-			"	.word	4b,8b\n"
+			STR(PTR) " 1b,8b\n"
+			STR(PTR) " 2b,8b\n"
+			STR(PTR) " 3b,8b\n"
+			STR(PTR) " 4b,8b\n"
 			"	.previous\n"
 			"	.set	pop\n"
 			: "+&r"(rt), "=&r"(rs),
@@ -1467,10 +1468,10 @@ fpu_emul:
 			"	j	9b\n"
 			"	.previous\n"
 			"	.section        __ex_table,\"a\"\n"
-			"	.word	1b,8b\n"
-			"	.word	2b,8b\n"
-			"	.word	3b,8b\n"
-			"	.word	4b,8b\n"
+			STR(PTR) " 1b,8b\n"
+			STR(PTR) " 2b,8b\n"
+			STR(PTR) " 3b,8b\n"
+			STR(PTR) " 4b,8b\n"
 			"	.previous\n"
 			"	.set	pop\n"
 			: "+&r"(rt), "=&r"(rs),
@@ -1582,14 +1583,14 @@ fpu_emul:
 			"	j	9b\n"
 			"	.previous\n"
 			"	.section        __ex_table,\"a\"\n"
-			"	.word	1b,8b\n"
-			"	.word	2b,8b\n"
-			"	.word	3b,8b\n"
-			"	.word	4b,8b\n"
-			"	.word	5b,8b\n"
-			"	.word	6b,8b\n"
-			"	.word	7b,8b\n"
-			"	.word	0b,8b\n"
+			STR(PTR) " 1b,8b\n"
+			STR(PTR) " 2b,8b\n"
+			STR(PTR) " 3b,8b\n"
+			STR(PTR) " 4b,8b\n"
+			STR(PTR) " 5b,8b\n"
+			STR(PTR) " 6b,8b\n"
+			STR(PTR) " 7b,8b\n"
+			STR(PTR) " 0b,8b\n"
 			"	.previous\n"
 			"	.set	pop\n"
 			: "+&r"(rt), "=&r"(rs),
@@ -1701,14 +1702,14 @@ fpu_emul:
 			"	j      9b\n"
 			"	.previous\n"
 			"	.section        __ex_table,\"a\"\n"
-			"	.word  1b,8b\n"
-			"	.word  2b,8b\n"
-			"	.word  3b,8b\n"
-			"	.word  4b,8b\n"
-			"	.word  5b,8b\n"
-			"	.word  6b,8b\n"
-			"	.word  7b,8b\n"
-			"	.word  0b,8b\n"
+			STR(PTR) " 1b,8b\n"
+			STR(PTR) " 2b,8b\n"
+			STR(PTR) " 3b,8b\n"
+			STR(PTR) " 4b,8b\n"
+			STR(PTR) " 5b,8b\n"
+			STR(PTR) " 6b,8b\n"
+			STR(PTR) " 7b,8b\n"
+			STR(PTR) " 0b,8b\n"
 			"	.previous\n"
 			"	.set    pop\n"
 			: "+&r"(rt), "=&r"(rs),
@@ -1820,14 +1821,14 @@ fpu_emul:
 			"	j	9b\n"
 			"	.previous\n"
 			"	.section        __ex_table,\"a\"\n"
-			"	.word	1b,8b\n"
-			"	.word	2b,8b\n"
-			"	.word	3b,8b\n"
-			"	.word	4b,8b\n"
-			"	.word	5b,8b\n"
-			"	.word	6b,8b\n"
-			"	.word	7b,8b\n"
-			"	.word	0b,8b\n"
+			STR(PTR) " 1b,8b\n"
+			STR(PTR) " 2b,8b\n"
+			STR(PTR) " 3b,8b\n"
+			STR(PTR) " 4b,8b\n"
+			STR(PTR) " 5b,8b\n"
+			STR(PTR) " 6b,8b\n"
+			STR(PTR) " 7b,8b\n"
+			STR(PTR) " 0b,8b\n"
 			"	.previous\n"
 			"	.set	pop\n"
 			: "+&r"(rt), "=&r"(rs),
@@ -1938,14 +1939,14 @@ fpu_emul:
 			"       j	9b\n"
 			"       .previous\n"
 			"       .section        __ex_table,\"a\"\n"
-			"       .word	1b,8b\n"
-			"       .word	2b,8b\n"
-			"       .word	3b,8b\n"
-			"       .word	4b,8b\n"
-			"       .word	5b,8b\n"
-			"       .word	6b,8b\n"
-			"       .word	7b,8b\n"
-			"       .word	0b,8b\n"
+			STR(PTR) " 1b,8b\n"
+			STR(PTR) " 2b,8b\n"
+			STR(PTR) " 3b,8b\n"
+			STR(PTR) " 4b,8b\n"
+			STR(PTR) " 5b,8b\n"
+			STR(PTR) " 6b,8b\n"
+			STR(PTR) " 7b,8b\n"
+			STR(PTR) " 0b,8b\n"
 			"       .previous\n"
 			"       .set	pop\n"
 			: "+&r"(rt), "=&r"(rs),
@@ -2000,7 +2001,7 @@ fpu_emul:
 			"j	2b\n"
 			".previous\n"
 			".section        __ex_table,\"a\"\n"
-			".word  1b, 3b\n"
+			STR(PTR) " 1b,3b\n"
 			".previous\n"
 			: "=&r"(res), "+&r"(err)
 			: "r"(vaddr), "i"(SIGSEGV)
@@ -2058,7 +2059,7 @@ fpu_emul:
 			"j	2b\n"
 			".previous\n"
 			".section        __ex_table,\"a\"\n"
-			".word	1b, 3b\n"
+			STR(PTR) " 1b,3b\n"
 			".previous\n"
 			: "+&r"(res), "+&r"(err)
 			: "r"(vaddr), "i"(SIGSEGV));
@@ -2119,7 +2120,7 @@ fpu_emul:
 			"j	2b\n"
 			".previous\n"
 			".section        __ex_table,\"a\"\n"
-			".word  1b, 3b\n"
+			STR(PTR) " 1b,3b\n"
 			".previous\n"
 			: "=&r"(res), "+&r"(err)
 			: "r"(vaddr), "i"(SIGSEGV)
@@ -2182,7 +2183,7 @@ fpu_emul:
 			"j	2b\n"
 			".previous\n"
 			".section        __ex_table,\"a\"\n"
-			".word	1b, 3b\n"
+			STR(PTR) " 1b,3b\n"
 			".previous\n"
 			: "+&r"(res), "+&r"(err)
 			: "r"(vaddr), "i"(SIGSEGV));

[PATCH 4.4 02/99] MIPS: math-emu: Fix jalr emulation when rd == $0

[Greg Kroah-Hartman]

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

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

From: Paul Burton <paul.burton@imgtec.com>

commit ab4a92e66741b35ca12f8497896bafbe579c28a1 upstream.

When emulating a jalr instruction with rd == $0, the code in
isBranchInstr was incorrectly writing to GPR $0 which should actually
always remain zeroed. This would lead to any further instructions
emulated which use $0 operating on a bogus value until the task is next
context switched, at which point the value of $0 in the task context
would be restored to the correct zero by a store in SAVE_SOME. Fix this
by not writing to rd if it is $0.

Fixes: 102cedc32a6e ("MIPS: microMIPS: Floating point support.")
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13160/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/math-emu/cp1emu.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -445,9 +445,11 @@ static int isBranchInstr(struct pt_regs
 	case spec_op:
 		switch (insn.r_format.func) {
 		case jalr_op:
-			regs->regs[insn.r_format.rd] =
-				regs->cp0_epc + dec_insn.pc_inc +
-				dec_insn.next_pc_inc;
+			if (insn.r_format.rd != 0) {
+				regs->regs[insn.r_format.rd] =
+					regs->cp0_epc + dec_insn.pc_inc +
+					dec_insn.next_pc_inc;
+			}
 			/* Fall through */
 		case jr_op:
 			/* For R6, JR already emulated in jalr_op */

[PATCH 4.4 03/99] MIPS: MSA: Fix a link error on `_init_msa_upper with older GCC

[Greg Kroah-Hartman]

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

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

From: Maciej W. Rozycki <macro@imgtec.com>

commit e49d38488515057dba8f0c2ba4cfde5be4a7281f upstream.

Fix a build regression from commit c9017757c532 ("MIPS: init upper 64b
of vector registers when MSA is first used"):

arch/mips/built-in.o: In function `enable_restore_fp_context':
traps.c:(.text+0xbb90): undefined reference to `_init_msa_upper'
traps.c:(.text+0xbb90): relocation truncated to fit: R_MIPS_26 against `_init_msa_upper'
traps.c:(.text+0xbef0): undefined reference to `_init_msa_upper'
traps.c:(.text+0xbef0): relocation truncated to fit: R_MIPS_26 against `_init_msa_upper'

to !CONFIG_CPU_HAS_MSA configurations with older GCC versions, which are
unable to figure out that calls to `_init_msa_upper' are indeed dead.
Of the many ways to tackle this failure choose the approach we have
already taken in `thread_msa_context_live'.

[ralf@linux-mips.org: Drop patch segment to junk file.]

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13271/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/include/asm/msa.h |   13 +++++++++++++
 arch/mips/kernel/traps.c    |    6 +++---
 2 files changed, 16 insertions(+), 3 deletions(-)

--- a/arch/mips/include/asm/msa.h
+++ b/arch/mips/include/asm/msa.h
@@ -147,6 +147,19 @@ static inline void restore_msa(struct ta
 		_restore_msa(t);
 }
 
+static inline void init_msa_upper(void)
+{
+	/*
+	 * Check cpu_has_msa only if it's a constant. This will allow the
+	 * compiler to optimise out code for CPUs without MSA without adding
+	 * an extra redundant check for CPUs with MSA.
+	 */
+	if (__builtin_constant_p(cpu_has_msa) && !cpu_has_msa)
+		return;
+
+	_init_msa_upper();
+}
+
 #ifdef TOOLCHAIN_SUPPORTS_MSA
 
 #define __BUILD_MSA_CTL_REG(name, cs)				\
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1241,7 +1241,7 @@ static int enable_restore_fp_context(int
 		err = init_fpu();
 		if (msa && !err) {
 			enable_msa();
-			_init_msa_upper();
+			init_msa_upper();
 			set_thread_flag(TIF_USEDMSA);
 			set_thread_flag(TIF_MSA_CTX_LIVE);
 		}
@@ -1304,7 +1304,7 @@ static int enable_restore_fp_context(int
 	 */
 	prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
 	if (!prior_msa && was_fpu_owner) {
-		_init_msa_upper();
+		init_msa_upper();
 
 		goto out;
 	}
@@ -1321,7 +1321,7 @@ static int enable_restore_fp_context(int
 		 * of each vector register such that it cannot see data left
 		 * behind by another task.
 		 */
-		_init_msa_upper();
+		init_msa_upper();
 	} else {
 		/* We need to restore the vector context. */
 		restore_msa(current);

[PATCH 4.4 04/99] MIPS: Dont unwind to user mode with EVA

[Greg Kroah-Hartman]

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

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

From: James Hogan <james.hogan@imgtec.com>

commit a816b306c62195b7c43c92cb13330821a96bdc27 upstream.

When unwinding through IRQs and exceptions, the unwinding only continues
if the PC is a kernel text address, however since EVA it is possible for
user and kernel address ranges to overlap, potentially allowing
unwinding to continue to user mode if the user PC happens to be in the
kernel text address range.

Adjust the check to also ensure that the register state from before the
exception is actually running in kernel mode, i.e. !user_mode(regs).

I don't believe any harm can come of this problem, since the PC is only
output, the stack pointer is checked to ensure it resides within the
task's stack page before it is dereferenced in search of the return
address, and the return address register is similarly only output (if
the PC is in a leaf function or the beginning of a non-leaf function).

However unwind_stack() is only meant for unwinding kernel code, so to be
correct the unwind should stop there.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11700/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/process.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -457,7 +457,7 @@ unsigned long notrace unwind_stack_by_ad
 		    *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) {
 			regs = (struct pt_regs *)*sp;
 			pc = regs->cp0_epc;
-			if (__kernel_text_address(pc)) {
+			if (!user_mode(regs) && __kernel_text_address(pc)) {
 				*sp = regs->regs[29];
 				*ra = regs->regs[31];
 				return pc;

[PATCH 4.4 05/99] MIPS: Avoid using unwind_stack() with usermode

[Greg Kroah-Hartman]

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

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

From: James Hogan <james.hogan@imgtec.com>

commit 81a76d7119f63c359750e4adeff922a31ad1135f upstream.

When showing backtraces in response to traps, for example crashes and
address errors (usually unaligned accesses) when they are set in debugfs
to be reported, unwind_stack will be used if the PC was in the kernel
text address range. However since EVA it is possible for user and kernel
address ranges to overlap, and even without EVA userland can still
trigger an address error by jumping to a KSeg0 address.

Adjust the check to also ensure that it was running in kernel mode. I
don't believe any harm can come of this problem, since unwind_stack() is
sufficiently defensive, however it is only meant for unwinding kernel
code, so to be correct it should use the raw backtracing instead.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11701/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit d2941a975ac745c607dfb590e92bb30bc352dad9)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/traps.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -144,7 +144,7 @@ static void show_backtrace(struct task_s
 	if (!task)
 		task = current;
 
-	if (raw_show_trace || !__kernel_text_address(pc)) {
+	if (raw_show_trace || user_mode(regs) || !__kernel_text_address(pc)) {
 		show_raw_backtrace(sp);
 		return;
 	}

[PATCH 4.4 06/99] MIPS: Fix siginfo.h to use strict posix types

[Greg Kroah-Hartman]

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

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

From: James Hogan <james.hogan@imgtec.com>

commit 5daebc477da4dfeb31ae193d83084def58fd2697 upstream.

Commit 85efde6f4e0d ("make exported headers use strict posix types")
changed the asm-generic siginfo.h to use the __kernel_* types, and
commit 3a471cbc081b ("remove __KERNEL_STRICT_NAMES") make the internal
types accessible only to the kernel, but the MIPS implementation hasn't
been updated to match.

Switch to proper types now so that the exported asm/siginfo.h won't
produce quite so many compiler errors when included alone by a user
program.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Christopher Ferris <cferris@google.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12477/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/include/uapi/asm/siginfo.h |   18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

--- a/arch/mips/include/uapi/asm/siginfo.h
+++ b/arch/mips/include/uapi/asm/siginfo.h
@@ -42,13 +42,13 @@ typedef struct siginfo {
 
 		/* kill() */
 		struct {
-			pid_t _pid;		/* sender's pid */
+			__kernel_pid_t _pid;	/* sender's pid */
 			__ARCH_SI_UID_T _uid;	/* sender's uid */
 		} _kill;
 
 		/* POSIX.1b timers */
 		struct {
-			timer_t _tid;		/* timer id */
+			__kernel_timer_t _tid;	/* timer id */
 			int _overrun;		/* overrun count */
 			char _pad[sizeof( __ARCH_SI_UID_T) - sizeof(int)];
 			sigval_t _sigval;	/* same as below */
@@ -57,26 +57,26 @@ typedef struct siginfo {
 
 		/* POSIX.1b signals */
 		struct {
-			pid_t _pid;		/* sender's pid */
+			__kernel_pid_t _pid;	/* sender's pid */
 			__ARCH_SI_UID_T _uid;	/* sender's uid */
 			sigval_t _sigval;
 		} _rt;
 
 		/* SIGCHLD */
 		struct {
-			pid_t _pid;		/* which child */
+			__kernel_pid_t _pid;	/* which child */
 			__ARCH_SI_UID_T _uid;	/* sender's uid */
 			int _status;		/* exit code */
-			clock_t _utime;
-			clock_t _stime;
+			__kernel_clock_t _utime;
+			__kernel_clock_t _stime;
 		} _sigchld;
 
 		/* IRIX SIGCHLD */
 		struct {
-			pid_t _pid;		/* which child */
-			clock_t _utime;
+			__kernel_pid_t _pid;	/* which child */
+			__kernel_clock_t _utime;
 			int _status;		/* exit code */
-			clock_t _stime;
+			__kernel_clock_t _stime;
 		} _irix_sigchld;
 
 		/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */

[PATCH 4.4 07/99] MIPS: Fix uapi include in exported asm/siginfo.h

[Greg Kroah-Hartman]

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

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

From: James Hogan <james.hogan@imgtec.com>

commit 987e5b834467c9251ca584febda65ef8f66351a9 upstream.

Since commit 8cb48fe169dd ("MIPS: Provide correct siginfo_t.si_stime"),
MIPS' uapi/asm/siginfo.h has included uapi/asm-generic/siginfo.h
directly before defining MIPS' struct siginfo, in order to get the
necessary definitions needed for the siginfo struct without the generic
copy_siginfo() hitting compiler errors due to struct siginfo not yet
being defined.

Now that the generic copy_siginfo() is moved out to linux/signal.h we
can safely include asm-generic/siginfo.h before defining the MIPS
specific struct siginfo, which avoids the uapi/ include as well as
breakage due to generic copy_siginfo() being defined before struct
siginfo.

Reported-by: Christopher Ferris <cferris@google.com>
Fixes: 8cb48fe169dd ("MIPS: Provide correct siginfo_t.si_stime")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Petr Malat <oss@malat.biz>
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/include/uapi/asm/siginfo.h |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

--- a/arch/mips/include/uapi/asm/siginfo.h
+++ b/arch/mips/include/uapi/asm/siginfo.h
@@ -28,7 +28,7 @@
 
 #define __ARCH_SIGSYS
 
-#include <uapi/asm-generic/siginfo.h>
+#include <asm-generic/siginfo.h>
 
 /* We can't use generic siginfo_t, because our si_code and si_errno are swapped */
 typedef struct siginfo {
@@ -118,6 +118,4 @@ typedef struct siginfo {
 #define SI_TIMER __SI_CODE(__SI_TIMER, -3) /* sent by timer expiration */
 #define SI_MESGQ __SI_CODE(__SI_MESGQ, -4) /* sent by real time mesq state change */
 
-#include <asm-generic/siginfo.h>
-
 #endif /* _UAPI_ASM_SIGINFO_H */

[PATCH 4.4 08/99] MIPS: Fix watchpoint restoration

[Greg Kroah-Hartman]

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

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

From: James Hogan <james.hogan@imgtec.com>

commit a7e89326b415b5d81c4b1016fd4a40db861eb58d upstream.

Commit f51246efee2b ("MIPS: Get rid of finish_arch_switch().") moved the
__restore_watch() call from finish_arch_switch() (i.e. after resume()
returns) to before the resume() call in switch_to(). This results in
watchpoints only being restored when a task is descheduled, preventing
the watchpoints from being effective most of the time, except due to
chance before the watchpoints are lazily removed.

Fix the call sequence from switch_to() through to
mips_install_watch_registers() to pass the task_struct pointer of the
next task, instead of using current. This allows the watchpoints for the
next (non-current) task to be restored without reintroducing
finish_arch_switch().

Fixes: f51246efee2b ("MIPS: Get rid of finish_arch_switch().")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12726/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/include/asm/switch_to.h |    2 +-
 arch/mips/include/asm/watch.h     |   10 +++++-----
 arch/mips/kernel/pm.c             |    2 +-
 arch/mips/kernel/watch.c          |    5 ++---
 4 files changed, 9 insertions(+), 10 deletions(-)

--- a/arch/mips/include/asm/switch_to.h
+++ b/arch/mips/include/asm/switch_to.h
@@ -105,7 +105,7 @@ do {									\
 	__clear_software_ll_bit();					\
 	if (cpu_has_userlocal)						\
 		write_c0_userlocal(task_thread_info(next)->tp_value);	\
-	__restore_watch();						\
+	__restore_watch(next);						\
 	(last) = resume(prev, next, task_thread_info(next));		\
 } while (0)
 
--- a/arch/mips/include/asm/watch.h
+++ b/arch/mips/include/asm/watch.h
@@ -12,21 +12,21 @@
 
 #include <asm/mipsregs.h>
 
-void mips_install_watch_registers(void);
+void mips_install_watch_registers(struct task_struct *t);
 void mips_read_watch_registers(void);
 void mips_clear_watch_registers(void);
 void mips_probe_watch_registers(struct cpuinfo_mips *c);
 
 #ifdef CONFIG_HARDWARE_WATCHPOINTS
-#define __restore_watch() do {						\
+#define __restore_watch(task) do {					\
 	if (unlikely(test_bit(TIF_LOAD_WATCH,				\
-			      &current_thread_info()->flags))) {	\
-		mips_install_watch_registers();				\
+			      &task_thread_info(task)->flags))) {	\
+		mips_install_watch_registers(task);			\
 	}								\
 } while (0)
 
 #else
-#define __restore_watch() do {} while (0)
+#define __restore_watch(task) do {} while (0)
 #endif
 
 #endif /* _ASM_WATCH_H */
--- a/arch/mips/kernel/pm.c
+++ b/arch/mips/kernel/pm.c
@@ -56,7 +56,7 @@ static void mips_cpu_restore(void)
 		write_c0_userlocal(current_thread_info()->tp_value);
 
 	/* Restore watch registers */
-	__restore_watch();
+	__restore_watch(current);
 }
 
 /**
--- a/arch/mips/kernel/watch.c
+++ b/arch/mips/kernel/watch.c
@@ -15,10 +15,9 @@
  * Install the watch registers for the current thread.	A maximum of
  * four registers are installed although the machine may have more.
  */
-void mips_install_watch_registers(void)
+void mips_install_watch_registers(struct task_struct *t)
 {
-	struct mips3264_watch_reg_state *watches =
-		&current->thread.watch.mips3264;
+	struct mips3264_watch_reg_state *watches = &t->thread.watch.mips3264;
 	switch (current_cpu_data.watch_reg_use_cnt) {
 	default:
 		BUG();

[PATCH 4.4 09/99] MIPS: Handle highmem pages in __update_cache

[Greg Kroah-Hartman]

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

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

From: Paul Burton <paul.burton@imgtec.com>

commit f4281bba818105c7c91799abe40bc05c0dbdaa25 upstream.

The following patch will expose __update_cache to highmem pages. Handle
them by mapping them in for the duration of the cache maintenance, just
like in __flush_dcache_page. The code for that isn't shared because we
need the page address in __update_cache so sharing became messy. Given
that the entirity is an extra 5 lines, just duplicate it.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Lars Persson <lars.persson@axis.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12721/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/mm/cache.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -143,9 +143,17 @@ void __update_cache(struct vm_area_struc
 		return;
 	page = pfn_to_page(pfn);
 	if (page_mapping(page) && Page_dcache_dirty(page)) {
-		addr = (unsigned long) page_address(page);
+		if (PageHighMem(page))
+			addr = (unsigned long)kmap_atomic(page);
+		else
+			addr = (unsigned long)page_address(page);
+
 		if (exec || pages_do_alias(addr, address & PAGE_MASK))
 			flush_data_cache_page(addr);
+
+		if (PageHighMem(page))
+			__kunmap_atomic((void *)addr);
+
 		ClearPageDcacheDirty(page);
 	}
 }

[PATCH 4.4 10/99] MIPS: Sync icache & dcache in set_pte_at

[Greg Kroah-Hartman]

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

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

From: Paul Burton <paul.burton@imgtec.com>

commit 37d22a0d798b5c938b277d32cfd86dc231381342 upstream.

It's possible for pages to become visible prior to update_mmu_cache
running if a thread within the same address space preempts the current
thread or runs simultaneously on another CPU. That is, the following
scenario is possible:

    CPU0                            CPU1

    write to page
    flush_dcache_page
    flush_icache_page
    set_pte_at
                                    map page
    update_mmu_cache

If CPU1 maps the page in between CPU0's set_pte_at, which marks it valid
& visible, and update_mmu_cache where the dcache flush occurs then CPU1s
icache will fill from stale data (unless it fills from the dcache, in
which case all is good, but most MIPS CPUs don't have this property).
Commit 4d46a67a3eb8 ("MIPS: Fix race condition in lazy cache flushing.")
attempted to fix that by performing the dcache flush in
flush_icache_page such that it occurs before the set_pte_at call makes
the page visible. However it has the problem that not all code that
writes to pages exposed to userland call flush_icache_page. There are
many callers of set_pte_at under mm/ and only 2 of them do call
flush_icache_page. Thus the race window between a page becoming visible
& being coherent between the icache & dcache remains open in some cases.

To illustrate some of the cases, a WARN was added to __update_cache with
this patch applied that triggered in cases where a page about to be
flushed from the dcache was not the last page provided to
flush_icache_page. That is, backtraces were obtained for cases in which
the race window is left open without this patch. The 2 standout examples
follow.

When forking a process:

[   15.271842] [<80417630>] __update_cache+0xcc/0x188
[   15.277274] [<80530394>] copy_page_range+0x56c/0x6ac
[   15.282861] [<8042936c>] copy_process.part.54+0xd40/0x17ac
[   15.289028] [<80429f80>] do_fork+0xe4/0x420
[   15.293747] [<80413808>] handle_sys+0x128/0x14c

When exec'ing an ELF binary:

[   14.445964] [<80417630>] __update_cache+0xcc/0x188
[   14.451369] [<80538d88>] move_page_tables+0x414/0x498
[   14.457075] [<8055d848>] setup_arg_pages+0x220/0x318
[   14.462685] [<805b0f38>] load_elf_binary+0x530/0x12a0
[   14.468374] [<8055ec3c>] search_binary_handler+0xbc/0x214
[   14.474444] [<8055f6c0>] do_execveat_common+0x43c/0x67c
[   14.480324] [<8055f938>] do_execve+0x38/0x44
[   14.485137] [<80413808>] handle_sys+0x128/0x14c

These code paths write into a page, call flush_dcache_page then call
set_pte_at without flush_icache_page inbetween. The end result is that
the icache can become corrupted & userland processes may execute
unexpected or invalid code, typically resulting in a reserved
instruction exception, a trap or a segfault.

Fix this race condition fully by performing any cache maintenance
required to keep the icache & dcache in sync in set_pte_at, before the
page is made valid. This has the added bonus of ensuring the cache
maintenance always happens in one location, rather than being duplicated
in flush_icache_page & update_mmu_cache. It also matches the way other
architectures solve the same problem (see arm, ia64 & powerpc).

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reported-by: Ionela Voinescu <ionela.voinescu@imgtec.com>
Cc: Lars Persson <lars.persson@axis.com>
Fixes: 4d46a67a3eb8 ("MIPS: Fix race condition in lazy cache flushing.")
Cc: Steven J. Hill <sjhill@realitydiluted.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12722/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/include/asm/cacheflush.h |    6 ------
 arch/mips/include/asm/pgtable.h    |   26 +++++++++++++++++++++-----
 arch/mips/mm/cache.c               |   19 +++----------------
 3 files changed, 24 insertions(+), 27 deletions(-)

--- a/arch/mips/include/asm/cacheflush.h
+++ b/arch/mips/include/asm/cacheflush.h
@@ -51,7 +51,6 @@ extern void (*flush_cache_range)(struct
 	unsigned long start, unsigned long end);
 extern void (*flush_cache_page)(struct vm_area_struct *vma, unsigned long page, unsigned long pfn);
 extern void __flush_dcache_page(struct page *page);
-extern void __flush_icache_page(struct vm_area_struct *vma, struct page *page);
 
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 static inline void flush_dcache_page(struct page *page)
@@ -77,11 +76,6 @@ static inline void flush_anon_page(struc
 static inline void flush_icache_page(struct vm_area_struct *vma,
 	struct page *page)
 {
-	if (!cpu_has_ic_fills_f_dc && (vma->vm_flags & VM_EXEC) &&
-	    Page_dcache_dirty(page)) {
-		__flush_icache_page(vma, page);
-		ClearPageDcacheDirty(page);
-	}
 }
 
 extern void (*flush_icache_range)(unsigned long start, unsigned long end);
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -127,10 +127,14 @@ do {									\
 	}								\
 } while(0)
 
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, pte_t pteval);
+
 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 
 #define pte_none(pte)		(!(((pte).pte_high) & ~_PAGE_GLOBAL))
 #define pte_present(pte)	((pte).pte_low & _PAGE_PRESENT)
+#define pte_no_exec(pte)	((pte).pte_low & _PAGE_NO_EXEC)
 
 static inline void set_pte(pte_t *ptep, pte_t pte)
 {
@@ -148,7 +152,6 @@ static inline void set_pte(pte_t *ptep,
 			buddy->pte_high |= _PAGE_GLOBAL;
 	}
 }
-#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
 
 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
@@ -166,6 +169,7 @@ static inline void pte_clear(struct mm_s
 
 #define pte_none(pte)		(!(pte_val(pte) & ~_PAGE_GLOBAL))
 #define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
+#define pte_no_exec(pte)	(pte_val(pte) & _PAGE_NO_EXEC)
 
 /*
  * Certain architectures need to do special things when pte's
@@ -218,7 +222,6 @@ static inline void set_pte(pte_t *ptep,
 	}
 #endif
 }
-#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
 
 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
@@ -234,6 +237,22 @@ static inline void pte_clear(struct mm_s
 }
 #endif
 
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, pte_t pteval)
+{
+	extern void __update_cache(unsigned long address, pte_t pte);
+
+	if (!pte_present(pteval))
+		goto cache_sync_done;
+
+	if (pte_present(*ptep) && (pte_pfn(*ptep) == pte_pfn(pteval)))
+		goto cache_sync_done;
+
+	__update_cache(addr, pteval);
+cache_sync_done:
+	set_pte(ptep, pteval);
+}
+
 /*
  * (pmds are folded into puds so this doesn't get actually called,
  * but the define is needed for a generic inline function.)
@@ -430,15 +449,12 @@ static inline pte_t pte_modify(pte_t pte
 
 extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
 	pte_t pte);
-extern void __update_cache(struct vm_area_struct *vma, unsigned long address,
-	pte_t pte);
 
 static inline void update_mmu_cache(struct vm_area_struct *vma,
 	unsigned long address, pte_t *ptep)
 {
 	pte_t pte = *ptep;
 	__update_tlb(vma, address, pte);
-	__update_cache(vma, address, pte);
 }
 
 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -119,30 +119,17 @@ void __flush_anon_page(struct page *page
 
 EXPORT_SYMBOL(__flush_anon_page);
 
-void __flush_icache_page(struct vm_area_struct *vma, struct page *page)
-{
-	unsigned long addr;
-
-	if (PageHighMem(page))
-		return;
-
-	addr = (unsigned long) page_address(page);
-	flush_data_cache_page(addr);
-}
-EXPORT_SYMBOL_GPL(__flush_icache_page);
-
-void __update_cache(struct vm_area_struct *vma, unsigned long address,
-	pte_t pte)
+void __update_cache(unsigned long address, pte_t pte)
 {
 	struct page *page;
 	unsigned long pfn, addr;
-	int exec = (vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc;
+	int exec = !pte_no_exec(pte) && !cpu_has_ic_fills_f_dc;
 
 	pfn = pte_pfn(pte);
 	if (unlikely(!pfn_valid(pfn)))
 		return;
 	page = pfn_to_page(pfn);
-	if (page_mapping(page) && Page_dcache_dirty(page)) {
+	if (Page_dcache_dirty(page)) {
 		if (PageHighMem(page))
 			addr = (unsigned long)kmap_atomic(page);
 		else

[PATCH 4.4 12/99] MIPS: Reserve nosave data for hibernation

[Greg Kroah-Hartman]

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

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

From: Huacai Chen <chenhc@lemote.com>

commit a95d069204e178f18476f5499abab0d0d9cbc32c upstream.

After commit 92923ca3aacef63c92d ("mm: meminit: only set page reserved
in the memblock region"), the MIPS hibernation is broken. Because pages
in nosave data section should be "reserved", but currently they aren't
set to "reserved" at initialization. This patch makes hibernation work
again.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12888/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/setup.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -706,6 +706,9 @@ static void __init arch_mem_init(char **
 	for_each_memblock(reserved, reg)
 		if (reg->size != 0)
 			reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
+
+	reserve_bootmem_region(__pa_symbol(&__nosave_begin),
+			__pa_symbol(&__nosave_end)); /* Reserve for hibernation */
 }
 
 static void __init resource_init(void)

[PATCH 4.4 13/99] MIPS: Loongson-3: Reserve 32MB for RS780E integrated GPU

[Greg Kroah-Hartman]

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

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

From: Huacai Chen <chenhc@lemote.com>

commit 3484de7bcbed20ecbf2b8d80671619e7059e2dd7 upstream.

Due to datasheet, reserving 0xff800000~0xffffffff (8MB below 4GB) is
not enough for RS780E integrated GPU's TOM (top of memory) registers
and MSI/MSI-x memory region, so we reserve 0xfe000000~0xffffffff (32MB
below 4GB).

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12889/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/loongson64/loongson-3/numa.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/mips/loongson64/loongson-3/numa.c
+++ b/arch/mips/loongson64/loongson-3/numa.c
@@ -213,10 +213,10 @@ static void __init node_mem_init(unsigne
 		BOOTMEM_DEFAULT);
 
 	if (node == 0 && node_end_pfn(0) >= (0xffffffff >> PAGE_SHIFT)) {
-		/* Reserve 0xff800000~0xffffffff for RS780E integrated GPU */
+		/* Reserve 0xfe000000~0xffffffff for RS780E integrated GPU */
 		reserve_bootmem_node(NODE_DATA(node),
-				(node_addrspace_offset | 0xff800000),
-				8 << 20, BOOTMEM_DEFAULT);
+				(node_addrspace_offset | 0xfe000000),
+				32 << 20, BOOTMEM_DEFAULT);
 	}
 
 	sparse_memory_present_with_active_regions(node);

[PATCH 4.4 14/99] MIPS: Use copy_s.fmt rather than copy_u.fmt

[Greg Kroah-Hartman]

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

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

From: Paul Burton <paul.burton@imgtec.com>

commit 8a3c8b48aca8771bff3536e40aa26ffb311699d1 upstream.

In revision 1.12 of the MSA specification, the copy_u.w instruction has
been removed for MIPS32 & the copy_u.d instruction has been removed for
MIPS64. Newer toolchains (eg. Codescape SDK essentials 2015.10) will
complain about this like so:

arch/mips/kernel/r4k_fpu.S:290: Error: opcode not supported on this
processor: mips32r2 (mips32r2) `copy_u.w $1,$w26[3]'

Since we always copy to the width of a GPR, simply use copy_s instead of
copy_u to fix this.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13061/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/include/asm/asmmacro.h |   24 ++++++++++++------------
 arch/mips/kernel/r4k_fpu.S       |   10 +++++-----
 2 files changed, 17 insertions(+), 17 deletions(-)

--- a/arch/mips/include/asm/asmmacro.h
+++ b/arch/mips/include/asm/asmmacro.h
@@ -298,21 +298,21 @@
 	.set	pop
 	.endm
 
-	.macro	copy_u_w	ws, n
+	.macro	copy_s_w	ws, n
 	.set	push
 	.set	mips32r2
 	.set	fp=64
 	.set	msa
-	copy_u.w $1, $w\ws[\n]
+	copy_s.w $1, $w\ws[\n]
 	.set	pop
 	.endm
 
-	.macro	copy_u_d	ws, n
+	.macro	copy_s_d	ws, n
 	.set	push
 	.set	mips64r2
 	.set	fp=64
 	.set	msa
-	copy_u.d $1, $w\ws[\n]
+	copy_s.d $1, $w\ws[\n]
 	.set	pop
 	.endm
 
@@ -346,8 +346,8 @@
 #define STH_MSA_INSN		0x5800081f
 #define STW_MSA_INSN		0x5800082f
 #define STD_MSA_INSN		0x5800083f
-#define COPY_UW_MSA_INSN	0x58f00056
-#define COPY_UD_MSA_INSN	0x58f80056
+#define COPY_SW_MSA_INSN	0x58b00056
+#define COPY_SD_MSA_INSN	0x58b80056
 #define INSERT_W_MSA_INSN	0x59300816
 #define INSERT_D_MSA_INSN	0x59380816
 #else
@@ -361,8 +361,8 @@
 #define STH_MSA_INSN		0x78000825
 #define STW_MSA_INSN		0x78000826
 #define STD_MSA_INSN		0x78000827
-#define COPY_UW_MSA_INSN	0x78f00059
-#define COPY_UD_MSA_INSN	0x78f80059
+#define COPY_SW_MSA_INSN	0x78b00059
+#define COPY_SD_MSA_INSN	0x78b80059
 #define INSERT_W_MSA_INSN	0x79300819
 #define INSERT_D_MSA_INSN	0x79380819
 #endif
@@ -461,21 +461,21 @@
 	.set	pop
 	.endm
 
-	.macro	copy_u_w	ws, n
+	.macro	copy_s_w	ws, n
 	.set	push
 	.set	noat
 	SET_HARDFLOAT
 	.insn
-	.word	COPY_UW_MSA_INSN | (\n << 16) | (\ws << 11)
+	.word	COPY_SW_MSA_INSN | (\n << 16) | (\ws << 11)
 	.set	pop
 	.endm
 
-	.macro	copy_u_d	ws, n
+	.macro	copy_s_d	ws, n
 	.set	push
 	.set	noat
 	SET_HARDFLOAT
 	.insn
-	.word	COPY_UD_MSA_INSN | (\n << 16) | (\ws << 11)
+	.word	COPY_SD_MSA_INSN | (\n << 16) | (\ws << 11)
 	.set	pop
 	.endm
 
--- a/arch/mips/kernel/r4k_fpu.S
+++ b/arch/mips/kernel/r4k_fpu.S
@@ -244,17 +244,17 @@ LEAF(\name)
 	.set	push
 	.set	noat
 #ifdef CONFIG_64BIT
-	copy_u_d \wr, 1
+	copy_s_d \wr, 1
 	EX sd	$1, \off(\base)
 #elif defined(CONFIG_CPU_LITTLE_ENDIAN)
-	copy_u_w \wr, 2
+	copy_s_w \wr, 2
 	EX sw	$1, \off(\base)
-	copy_u_w \wr, 3
+	copy_s_w \wr, 3
 	EX sw	$1, (\off+4)(\base)
 #else /* CONFIG_CPU_BIG_ENDIAN */
-	copy_u_w \wr, 2
+	copy_s_w \wr, 2
 	EX sw	$1, (\off+4)(\base)
-	copy_u_w \wr, 3
+	copy_s_w \wr, 3
 	EX sw	$1, \off(\base)
 #endif
 	.set	pop

[PATCH 4.4 15/99] MIPS: Fix MSA ld_*/st_* asm macros to use PTR_ADDU

[Greg Kroah-Hartman]

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

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

From: James Hogan <james.hogan@imgtec.com>

commit ea1688573426adc2587ed52d086b51c7c62eaca3 upstream.

The MSA ld_*/st_* assembler macros for when the toolchain doesn't
support MSA use addu to offset the base address. However it is a virtual
memory pointer so fix it to use PTR_ADDU which expands to daddu for
64-bit kernels.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13062/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/include/asm/asmmacro.h |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

--- a/arch/mips/include/asm/asmmacro.h
+++ b/arch/mips/include/asm/asmmacro.h
@@ -393,7 +393,7 @@
 	.set	push
 	.set	noat
 	SET_HARDFLOAT
-	addu	$1, \base, \off
+	PTR_ADDU $1, \base, \off
 	.word	LDB_MSA_INSN | (\wd << 6)
 	.set	pop
 	.endm
@@ -402,7 +402,7 @@
 	.set	push
 	.set	noat
 	SET_HARDFLOAT
-	addu	$1, \base, \off
+	PTR_ADDU $1, \base, \off
 	.word	LDH_MSA_INSN | (\wd << 6)
 	.set	pop
 	.endm
@@ -411,7 +411,7 @@
 	.set	push
 	.set	noat
 	SET_HARDFLOAT
-	addu	$1, \base, \off
+	PTR_ADDU $1, \base, \off
 	.word	LDW_MSA_INSN | (\wd << 6)
 	.set	pop
 	.endm
@@ -420,7 +420,7 @@
 	.set	push
 	.set	noat
 	SET_HARDFLOAT
-	addu	$1, \base, \off
+	PTR_ADDU $1, \base, \off
 	.word	LDD_MSA_INSN | (\wd << 6)
 	.set	pop
 	.endm
@@ -429,7 +429,7 @@
 	.set	push
 	.set	noat
 	SET_HARDFLOAT
-	addu	$1, \base, \off
+	PTR_ADDU $1, \base, \off
 	.word	STB_MSA_INSN | (\wd << 6)
 	.set	pop
 	.endm
@@ -438,7 +438,7 @@
 	.set	push
 	.set	noat
 	SET_HARDFLOAT
-	addu	$1, \base, \off
+	PTR_ADDU $1, \base, \off
 	.word	STH_MSA_INSN | (\wd << 6)
 	.set	pop
 	.endm
@@ -447,7 +447,7 @@
 	.set	push
 	.set	noat
 	SET_HARDFLOAT
-	addu	$1, \base, \off
+	PTR_ADDU $1, \base, \off
 	.word	STW_MSA_INSN | (\wd << 6)
 	.set	pop
 	.endm
@@ -456,7 +456,7 @@
 	.set	push
 	.set	noat
 	SET_HARDFLOAT
-	addu	$1, \base, \off
+	PTR_ADDU $1, \base, \off
 	.word	STD_MSA_INSN | (\wd << 6)
 	.set	pop
 	.endm

[PATCH 4.4 16/99] MIPS: Prevent "restoration" of MSA context in non-MSA kernels

[Greg Kroah-Hartman]

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

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

From: Paul Burton <paul.burton@imgtec.com>

commit 6533af4d4831c421cd9aa4dce7cfc19a3514cc09 upstream.

If a kernel doesn't support MSA context (ie. CONFIG_CPU_HAS_MSA=n) then
it will only keep 64 bits per FP register in thread context, and the
calls to set_fpr64 in restore_msa_extcontext will overrun the end of the
FP register context into the FCSR & MSACSR values. GCC 6.x has become
smart enough to detect this & complain like so:

    arch/mips/kernel/signal.c: In function 'protected_restore_fp_context':
    ./arch/mips/include/asm/processor.h:114:17: error: array subscript is above array bounds [-Werror=array-bounds]
      fpr->val##width[FPR_IDX(width, idx)] = val;   \
      ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
    ./arch/mips/include/asm/processor.h:118:1: note: in expansion of macro 'BUILD_FPR_ACCESS'
     BUILD_FPR_ACCESS(64)

The only way to trigger this code to run would be for a program to set
up an artificial extended MSA context structure following a sigframe &
execute sigreturn. Whilst this doesn't allow a program to write to any
state that it couldn't already, it makes little sense to allow this
"restoration" of MSA context in a system that doesn't support MSA.

Fix this by killing a program with SIGSYS if it tries something as crazy
as "restoring" fake MSA context in this way, also fixing the build error
& allowing for most of restore_msa_extcontext to be optimised out of
kernels without support for MSA.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reported-by: Michal Toman <michal.toman@imgtec.com>
Fixes: bf82cb30c7e5 ("MIPS: Save MSA extended context around signals")
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Michal Toman <michal.toman@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13164/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/signal.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -195,6 +195,9 @@ static int restore_msa_extcontext(void _
 	unsigned int csr;
 	int i, err;
 
+	if (!config_enabled(CONFIG_CPU_HAS_MSA))
+		return SIGSYS;
+
 	if (size != sizeof(*msa))
 		return -EINVAL;
 
@@ -398,8 +401,8 @@ int protected_restore_fp_context(void __
 	}
 
 fp_done:
-	if (used & USED_EXTCONTEXT)
-		err |= restore_extcontext(sc_to_extcontext(sc));
+	if (!err && (used & USED_EXTCONTEXT))
+		err = restore_extcontext(sc_to_extcontext(sc));
 
 	return err ?: sig;
 }

[PATCH 4.4 17/99] MIPS: Disable preemption during prctl(PR_SET_FP_MODE, ...)

[Greg Kroah-Hartman]

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

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

From: Paul Burton <paul.burton@imgtec.com>

commit bd239f1e1429e7781096bf3884bdb1b2b1bb4f28 upstream.

Whilst a PR_SET_FP_MODE prctl is performed there are decisions made
based upon whether the task is executing on the current CPU. This may
change if we're preempted, so disable preemption to avoid such changes
for the lifetime of the mode switch.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: 9791554b45a2 ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS")
Reviewed-by: Maciej W. Rozycki <macro@imgtec.com>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13144/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/process.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -603,6 +603,9 @@ int mips_set_process_fp_mode(struct task
 	if (!(value & PR_FP_MODE_FR) && cpu_has_fpu && cpu_has_mips_r6)
 		return -EOPNOTSUPP;
 
+	/* Proceed with the mode switch */
+	preempt_disable();
+
 	/* Save FP & vector context, then disable FPU & MSA */
 	if (task->signal == current->signal)
 		lose_fpu(1);
@@ -661,6 +664,7 @@ int mips_set_process_fp_mode(struct task
 
 	/* Allow threads to use FP again */
 	atomic_set(&task->mm->context.fp_mode_switching, 0);
+	preempt_enable();
 
 	return 0;
 }

[PATCH 4.4 18/99] MIPS: ptrace: Fix FP context restoration FCSR regression

[Greg Kroah-Hartman]

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

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

From: Maciej W. Rozycki <macro@imgtec.com>

commit 4249548454f7ba4581aeee26bd83f42b48a14d15 upstream.

Fix a floating-point context restoration regression introduced with
commit 9b26616c8d9d ("MIPS: Respect the ISA level in FCSR handling")
that causes a Floating Point exception and consequently a kernel oops
with hard float configurations when one or more FCSR Enable and their
corresponding Cause bits are set both at a time via a ptrace(2) call.

To do so reinstate Cause bit masking originally introduced with commit
b1442d39fac2 ("MIPS: Prevent user from setting FCSR cause bits") to
address this exact problem and then inadvertently removed from the
PTRACE_SETFPREGS request with the commit referred above.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13238/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/ptrace.c |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -176,6 +176,7 @@ int ptrace_setfpregs(struct task_struct
 	}
 
 	__get_user(value, data + 64);
+	value &= ~FPU_CSR_ALL_X;
 	fcr31 = child->thread.fpu.fcr31;
 	mask = boot_cpu_data.fpu_msk31;
 	child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);

[PATCH 4.4 19/99] MIPS: ptrace: Prevent writes to read-only FCSR bits

[Greg Kroah-Hartman]

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

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

From: Maciej W. Rozycki <macro@imgtec.com>

commit abf378be49f38c4d3e23581d3df3fa9f1b1b11d2 upstream.

Correct the cases missed with commit 9b26616c8d9d ("MIPS: Respect the
ISA level in FCSR handling") and prevent writes to read-only FCSR bits
there.

This in particular applies to FP context initialisation where any IEEE
754-2008 bits preset by `mips_set_personality_nan' are cleared before
the relevant ptrace(2) call takes effect and the PTRACE_POKEUSR request
addressing FPC_CSR where no masking of read-only FCSR bits is done.

Remove the FCSR clearing from FP context initialisation then and unify
PTRACE_POKEUSR/FPC_CSR and PTRACE_SETFPREGS handling, by factoring out
code from `ptrace_setfpregs' and calling it from both places.

This mostly matters to soft float configurations where the emulator can
be switched this way to a mode which should not be accessible and cannot
be set with the CTC1 instruction.  With hard float configurations any
effect is transient anyway as read-only bits will retain their values at
the time the FP context is restored.

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13239/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/ptrace.c |   28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -57,8 +57,7 @@ static void init_fp_ctx(struct task_stru
 	/* Begin with data registers set to all 1s... */
 	memset(&target->thread.fpu.fpr, ~0, sizeof(target->thread.fpu.fpr));
 
-	/* ...and FCSR zeroed */
-	target->thread.fpu.fcr31 = 0;
+	/* FCSR has been preset by `mips_set_personality_nan'.  */
 
 	/*
 	 * Record that the target has "used" math, such that the context
@@ -80,6 +79,22 @@ void ptrace_disable(struct task_struct *
 }
 
 /*
+ * Poke at FCSR according to its mask.  Don't set the cause bits as
+ * this is currently not handled correctly in FP context restoration
+ * and will cause an oops if a corresponding enable bit is set.
+ */
+static void ptrace_setfcr31(struct task_struct *child, u32 value)
+{
+	u32 fcr31;
+	u32 mask;
+
+	value &= ~FPU_CSR_ALL_X;
+	fcr31 = child->thread.fpu.fcr31;
+	mask = boot_cpu_data.fpu_msk31;
+	child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
+}
+
+/*
  * Read a general register set.	 We always use the 64-bit format, even
  * for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
  * Registers are sign extended to fill the available space.
@@ -159,9 +174,7 @@ int ptrace_setfpregs(struct task_struct
 {
 	union fpureg *fregs;
 	u64 fpr_val;
-	u32 fcr31;
 	u32 value;
-	u32 mask;
 	int i;
 
 	if (!access_ok(VERIFY_READ, data, 33 * 8))
@@ -176,10 +189,7 @@ int ptrace_setfpregs(struct task_struct
 	}
 
 	__get_user(value, data + 64);
-	value &= ~FPU_CSR_ALL_X;
-	fcr31 = child->thread.fpu.fcr31;
-	mask = boot_cpu_data.fpu_msk31;
-	child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
+	ptrace_setfcr31(child, value);
 
 	/* FIR may not be written.  */
 
@@ -809,7 +819,7 @@ long arch_ptrace(struct task_struct *chi
 			break;
 #endif
 		case FPC_CSR:
-			child->thread.fpu.fcr31 = data & ~FPU_CSR_ALL_X;
+			ptrace_setfcr31(child, data);
 			break;
 		case DSP_BASE ... DSP_BASE + 5: {
 			dspreg_t *dregs;

[PATCH 4.4 20/99] MIPS: Fix sigreturn via VDSO on microMIPS kernel

[Greg Kroah-Hartman]

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

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

From: James Hogan <james.hogan@imgtec.com>

commit 13eb192d10bcc9ac518d57356179071d603bcb4e upstream.

In microMIPS kernels, handle_signal() sets the isa16 mode bit in the
vdso address so that the sigreturn trampolines (which are offset from
the VDSO) get executed as microMIPS.

However commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
changed the offsets to come from the VDSO image, which already have the
isa16 mode bit set correctly since they're extracted from the VDSO
shared library symbol table.

Drop the isa16 mode bit handling from handle_signal() to fix sigreturn
for cores which support both microMIPS and normal MIPS. This doesn't fix
microMIPS only cores, since the VDSO is still built for normal MIPS, but
thats a separate problem.

Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13348/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/signal.c |    8 --------
 1 file changed, 8 deletions(-)

--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -770,15 +770,7 @@ static void handle_signal(struct ksignal
 	sigset_t *oldset = sigmask_to_save();
 	int ret;
 	struct mips_abi *abi = current->thread.abi;
-#ifdef CONFIG_CPU_MICROMIPS
-	void *vdso;
-	unsigned long tmp = (unsigned long)current->mm->context.vdso;
-
-	set_isa16_mode(tmp);
-	vdso = (void *)tmp;
-#else
 	void *vdso = current->mm->context.vdso;
-#endif
 
 	if (regs->regs[0]) {
 		switch(regs->regs[2]) {

[PATCH 4.4 21/99] MIPS: Build microMIPS VDSO for microMIPS kernels

[Greg Kroah-Hartman]

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

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

From: James Hogan <james.hogan@imgtec.com>

commit bb93078e655be1e24d68f28f2756676e62c037ce upstream.

MicroMIPS kernels may be expected to run on microMIPS only cores which
don't support the normal MIPS instruction set, so be sure to pass the
-mmicromips flag through to the VDSO cflags.

Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13349/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/vdso/Makefile |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/mips/vdso/Makefile
+++ b/arch/mips/vdso/Makefile
@@ -5,6 +5,7 @@ obj-vdso-y := elf.o gettimeofday.o sigre
 ccflags-vdso := \
 	$(filter -I%,$(KBUILD_CFLAGS)) \
 	$(filter -E%,$(KBUILD_CFLAGS)) \
+	$(filter -mmicromips,$(KBUILD_CFLAGS)) \
 	$(filter -march=%,$(KBUILD_CFLAGS))
 cflags-vdso := $(ccflags-vdso) \
 	$(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \

[PATCH 4.4 22/99] MIPS: lib: Mark intrinsics notrace

[Greg Kroah-Hartman]

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

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

From: Harvey Hunt <harvey.hunt@imgtec.com>

commit aedcfbe06558a9f53002e82d5be64c6c94687726 upstream.

On certain MIPS32 devices, the ftrace tracer "function_graph" uses
__lshrdi3() during the capturing of trace data. ftrace then attempts to
trace __lshrdi3() which leads to infinite recursion and a stack overflow.
Fix this by marking __lshrdi3() as notrace. Mark the other compiler
intrinsics as notrace in case the compiler decides to use them in the
ftrace path.

Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Cc: <linux-mips@linux-mips.org>
Cc: <linux-kernel@vger.kernel.org>
Patchwork: https://patchwork.linux-mips.org/patch/13354/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/lib/ashldi3.c |    2 +-
 arch/mips/lib/ashrdi3.c |    2 +-
 arch/mips/lib/bswapdi.c |    2 +-
 arch/mips/lib/bswapsi.c |    2 +-
 arch/mips/lib/cmpdi2.c  |    2 +-
 arch/mips/lib/lshrdi3.c |    2 +-
 arch/mips/lib/ucmpdi2.c |    2 +-
 7 files changed, 7 insertions(+), 7 deletions(-)

--- a/arch/mips/lib/ashldi3.c
+++ b/arch/mips/lib/ashldi3.c
@@ -2,7 +2,7 @@
 
 #include "libgcc.h"
 
-long long __ashldi3(long long u, word_type b)
+long long notrace __ashldi3(long long u, word_type b)
 {
 	DWunion uu, w;
 	word_type bm;
--- a/arch/mips/lib/ashrdi3.c
+++ b/arch/mips/lib/ashrdi3.c
@@ -2,7 +2,7 @@
 
 #include "libgcc.h"
 
-long long __ashrdi3(long long u, word_type b)
+long long notrace __ashrdi3(long long u, word_type b)
 {
 	DWunion uu, w;
 	word_type bm;
--- a/arch/mips/lib/bswapdi.c
+++ b/arch/mips/lib/bswapdi.c
@@ -1,6 +1,6 @@
 #include <linux/module.h>
 
-unsigned long long __bswapdi2(unsigned long long u)
+unsigned long long notrace __bswapdi2(unsigned long long u)
 {
 	return (((u) & 0xff00000000000000ull) >> 56) |
 	       (((u) & 0x00ff000000000000ull) >> 40) |
--- a/arch/mips/lib/bswapsi.c
+++ b/arch/mips/lib/bswapsi.c
@@ -1,6 +1,6 @@
 #include <linux/module.h>
 
-unsigned int __bswapsi2(unsigned int u)
+unsigned int notrace __bswapsi2(unsigned int u)
 {
 	return (((u) & 0xff000000) >> 24) |
 	       (((u) & 0x00ff0000) >>  8) |
--- a/arch/mips/lib/cmpdi2.c
+++ b/arch/mips/lib/cmpdi2.c
@@ -2,7 +2,7 @@
 
 #include "libgcc.h"
 
-word_type __cmpdi2(long long a, long long b)
+word_type notrace __cmpdi2(long long a, long long b)
 {
 	const DWunion au = {
 		.ll = a
--- a/arch/mips/lib/lshrdi3.c
+++ b/arch/mips/lib/lshrdi3.c
@@ -2,7 +2,7 @@
 
 #include "libgcc.h"
 
-long long __lshrdi3(long long u, word_type b)
+long long notrace __lshrdi3(long long u, word_type b)
 {
 	DWunion uu, w;
 	word_type bm;
--- a/arch/mips/lib/ucmpdi2.c
+++ b/arch/mips/lib/ucmpdi2.c
@@ -2,7 +2,7 @@
 
 #include "libgcc.h"
 
-word_type __ucmpdi2(unsigned long long a, unsigned long long b)
+word_type notrace __ucmpdi2(unsigned long long a, unsigned long long b)
 {
 	const DWunion au = {.ll = a};
 	const DWunion bu = {.ll = b};

[PATCH 4.4 23/99] MIPS: VDSO: Build with `-fno-strict-aliasing

[Greg Kroah-Hartman]

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

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

From: Maciej W. Rozycki <macro@imgtec.com>

commit 94cc36b84acc29f543b48bc5ed786011b112a666 upstream.

Avoid an aliasing issue causing a build error in VDSO:

In file included from include/linux/srcu.h:34:0,
                 from include/linux/notifier.h:15,
                 from ./arch/mips/include/asm/uprobes.h:9,
                 from include/linux/uprobes.h:61,
                 from include/linux/mm_types.h:13,
                 from ./arch/mips/include/asm/vdso.h:14,
                 from arch/mips/vdso/vdso.h:27,
                 from arch/mips/vdso/gettimeofday.c:11:
include/linux/workqueue.h: In function 'work_static':
include/linux/workqueue.h:186:2: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
  return *work_data_bits(work) & WORK_STRUCT_STATIC;
  ^
cc1: all warnings being treated as errors
make[2]: *** [arch/mips/vdso/gettimeofday.o] Error 1

with a CONFIG_DEBUG_OBJECTS_WORK configuration and GCC 5.2.0.  Include
`-fno-strict-aliasing' along with compiler options used, as required for
kernel code, fixing a problem present since the introduction of VDSO
with commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO").

Thanks to Tejun for diagnosing this properly!

Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13357/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/vdso/Makefile |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/mips/vdso/Makefile
+++ b/arch/mips/vdso/Makefile
@@ -9,7 +9,8 @@ ccflags-vdso := \
 	$(filter -march=%,$(KBUILD_CFLAGS))
 cflags-vdso := $(ccflags-vdso) \
 	$(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \
-	-O2 -g -fPIC -fno-common -fno-builtin -G 0 -DDISABLE_BRANCH_PROFILING \
+	-O2 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \
+	-DDISABLE_BRANCH_PROFILING \
 	$(call cc-option, -fno-stack-protector)
 aflags-vdso := $(ccflags-vdso) \
 	$(filter -I%,$(KBUILD_CFLAGS)) \