[PATCH 3.16 062/158] MIPS: ptrace: Test correct tasks flags in task_user_regset_view()

[Greg Kroah-Hartman]

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

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

From: Alex Smith <***@alex-smith.me.uk>

commit 65768a1a92cb12cbba87588927cf597a65d560aa upstream.

task_user_regset_view() should test for TIF_32BIT_REGS in the flags of
the specified task, not of the current task.

Signed-off-by: Alex Smith <***@alex-smith.me.uk>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7450/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

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

--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -398,7 +398,7 @@ const struct user_regset_view *task_user
#endif

#ifdef CONFIG_MIPS32_O32
- if (test_thread_flag(TIF_32BIT_REGS))
+ if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
return &user_mips_view;
#endif

[Greg Kroah-Hartman]

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

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

From: Alex Smith <***@imgtec.com>

commit e90e6fddc57055c4c6b57f92787fea1c065d440b upstream.

On 32-bit/O32, pt_regs has a padding area at the beginning into which the
syscall arguments passed via the user stack are copied. 4 arguments
totalling 16 bytes are copied to offset 16 bytes into this area, however
the area is only 24 bytes long. This means the last 2 arguments overwrite
pt_regs->regs[{0,1}].

If a syscall function returns an error, handle_sys stores the original
syscall number in pt_regs->regs[0] for syscall restart. signal.c checks
whether regs[0] is non-zero, if it is it will check whether the syscall
return value is one of the ERESTART* codes to see if it must be
restarted.

Should a syscall be made that results in a non-zero value being copied
off the user stack into regs[0], and then returns a positive (non-error)
value that matches one of the ERESTART* error codes, this can be mistaken
for requiring a syscall restart.

While the possibility for this to occur has always existed, it is made
much more likely to occur by commit 46e12c07b3b9 ("MIPS: O32 / 32-bit:
Always copy 4 stack arguments."), since now every syscall will copy 4
arguments and overwrite regs[0], rather than just those with 7 or 8
arguments.

Since that commit, booting Debian under a 32-bit MIPS kernel almost
always results in a hang early in boot, due to a wait4 syscall returning
a PID that matches one of the ERESTART* codes, which then causes an
incorrect restart of the syscall.

The problem is fixed by increasing the size of the padding area so that
arguments copied off the stack will not overwrite pt_regs->regs[{0,1}].

Signed-off-by: Alex Smith <***@imgtec.com>
Reviewed-by: Aurelien Jarno <***@aurel32.net>
Tested-by: Aurelien Jarno <***@aurel32.net>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7454/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/include/asm/ptrace.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/include/asm/ptrace.h
+++ b/arch/mips/include/asm/ptrace.h
@@ -23,7 +23,7 @@
struct pt_regs {
#ifdef CONFIG_32BIT
/* Pad bytes for argument save space on the stack. */
- unsigned long pad0[6];
+ unsigned long pad0[8];
#endif

/* Saved main processor registers. */

[Greg Kroah-Hartman]

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

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

From: Huacai Chen <***@lemote.com>

commit 8393c524a25609a30129e4a8975cf3b91f6c16a5 upstream.

In commit 2c8c53e28f1 (MIPS: Optimize TLB handlers for Octeon CPUs)
build_r4000_tlb_refill_handler() is modified. But it doesn't compatible
with the original code in HUGETLB case. Because there is a copy & paste
error and one line of code is missing. It is very easy to produce a bug
with LTP's hugemmap05 test.

Signed-off-by: Huacai Chen <***@lemote.com>
Signed-off-by: Binbin Zhou <***@lemote.com>
Cc: John Crispin <***@phrozen.org>
Cc: Steven J. Hill <***@imgtec.com>
Cc: linux-***@linux-mips.org
Cc: Fuxin Zhang <***@lemote.com>
Cc: Zhangjin Wu <***@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/7496/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/mm/tlbex.c | 1 +
1 file changed, 1 insertion(+)

--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -1299,6 +1299,7 @@ static void build_r4000_tlb_refill_handl
}
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
uasm_l_tlb_huge_update(&l, p);
+ UASM_i_LW(&p, K0, 0, K1);
build_huge_update_entries(&p, htlb_info.huge_pte, K1);
build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random,
htlb_info.restore_scratch);

[Greg Kroah-Hartman]

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

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

From: Huacai Chen <***@lemote.com>

commit 2e5767a27337812f6850b3fa362419e2f085e5c3 upstream.

In do_ade(), is_fpu_owner() isn't preempt-safe. For example, when an
unaligned ldc1 is executed, do_cpu() is called and then FPU will be
enabled (and TIF_USEDFPU will be set for the current process). Then,
do_ade() is called because the access is unaligned. If the current
process is preempted at this time, TIF_USEDFPU will be cleard. So when
the process is scheduled again, BUG_ON(!is_fpu_owner()) is triggered.

This small program can trigger this BUG in a preemptible kernel:

int main (int argc, char *argv[])
{
double u64[2];

while (1) {
asm volatile (
".set push \n\t"
".set noreorder \n\t"
"ldc1 $f3, 4(%0) \n\t"
".set pop \n\t"
::"r"(u64):
);
}

return 0;
}

V2: Remove the BUG_ON() unconditionally due to Paul's suggestion.

Signed-off-by: Huacai Chen <***@lemote.com>
Signed-off-by: Jie Chen <***@lemote.com>
Signed-off-by: Rui Wang <***@lemote.com>
Cc: John Crispin <***@phrozen.org>
Cc: Steven J. Hill <***@imgtec.com>
Cc: linux-***@linux-mips.org
Cc: Fuxin Zhang <***@lemote.com>
Cc: Zhangjin Wu <***@gmail.com>
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/kernel/unaligned.c | 1 -
1 file changed, 1 deletion(-)

--- a/arch/mips/kernel/unaligned.c
+++ b/arch/mips/kernel/unaligned.c
@@ -690,7 +690,6 @@ static void emulate_load_store_insn(stru
case sdc1_op:
die_if_kernel("Unaligned FP access in kernel code", regs);
BUG_ON(!used_math());
- BUG_ON(!is_fpu_owner());

lose_fpu(1); /* Save FPU state for the emulator. */
res = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,

[Greg Kroah-Hartman]

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

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

From: James Hogan <***@imgtec.com>

commit 7d907fa1c6ccb64c7f64cc7d3dcc7f6fe30a67b4 upstream.

Commit d6d3c9afaab4 (MIPS: MT: proc: Add support for printing VPE and TC
ids) causes a link error when CONFIG_PROC_FS=n:

arch/mips/built-in.o: In function `proc_cpuinfo_notifier_init':
smp-mt.c: undefined reference to `register_proc_cpuinfo_notifier'

This is fixed by adding an ifdef around the procfs handling code
in smp-mt.c.

Signed-off-by: James Hogan <***@imgtec.com>
Reported-by: Markos Chandras <***@imgtec.com>
Reviewed-by: Markos Chandras <***@imgtec.com>
Cc: Ralf Baechle <***@linux-mips.org>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7244/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/kernel/smp-mt.c | 2 ++
1 file changed, 2 insertions(+)

--- a/arch/mips/kernel/smp-mt.c
+++ b/arch/mips/kernel/smp-mt.c
@@ -288,6 +288,7 @@ struct plat_smp_ops vsmp_smp_ops = {
.prepare_cpus = vsmp_prepare_cpus,
};

+#ifdef CONFIG_PROC_FS
static int proc_cpuinfo_chain_call(struct notifier_block *nfb,
unsigned long action_unused, void *data)
{
@@ -309,3 +310,4 @@ static int __init proc_cpuinfo_notifier_
}

subsys_initcall(proc_cpuinfo_notifier_init);
+#endif

[Greg Kroah-Hartman]

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

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

From: Alex Smith <***@alex-smith.me.uk>

commit bcec7c8da6b092b1ff3327fd83c2193adb12f684 upstream.

Get rid of the WANT_COMPAT_REG_H test and instead define both the 32-
and 64-bit register offset definitions at the same time with
MIPS{32,64}_ prefixes, then define the existing EF_* names to the
correct definitions for the kernel's bitness.

This patch is a prerequisite of the following bug fix patch.

Signed-off-by: Alex Smith <***@alex-smith.me.uk>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7451/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/include/asm/reg.h | 256 +++++++++++++++++++++++++--------------
arch/mips/kernel/binfmt_elfo32.c | 32 +---
2 files changed, 180 insertions(+), 108 deletions(-)

--- a/arch/mips/include/asm/reg.h
+++ b/arch/mips/include/asm/reg.h
@@ -12,116 +12,194 @@
#ifndef __ASM_MIPS_REG_H
#define __ASM_MIPS_REG_H

-
-#if defined(CONFIG_32BIT) || defined(WANT_COMPAT_REG_H)
-
-#define EF_R0 6
-#define EF_R1 7
-#define EF_R2 8
-#define EF_R3 9
-#define EF_R4 10
-#define EF_R5 11
-#define EF_R6 12
-#define EF_R7 13
-#define EF_R8 14
-#define EF_R9 15
-#define EF_R10 16
-#define EF_R11 17
-#define EF_R12 18
-#define EF_R13 19
-#define EF_R14 20
-#define EF_R15 21
-#define EF_R16 22
-#define EF_R17 23
-#define EF_R18 24
-#define EF_R19 25
-#define EF_R20 26
-#define EF_R21 27
-#define EF_R22 28
-#define EF_R23 29
-#define EF_R24 30
-#define EF_R25 31
+#define MIPS32_EF_R0 6
+#define MIPS32_EF_R1 7
+#define MIPS32_EF_R2 8
+#define MIPS32_EF_R3 9
+#define MIPS32_EF_R4 10
+#define MIPS32_EF_R5 11
+#define MIPS32_EF_R6 12
+#define MIPS32_EF_R7 13
+#define MIPS32_EF_R8 14
+#define MIPS32_EF_R9 15
+#define MIPS32_EF_R10 16
+#define MIPS32_EF_R11 17
+#define MIPS32_EF_R12 18
+#define MIPS32_EF_R13 19
+#define MIPS32_EF_R14 20
+#define MIPS32_EF_R15 21
+#define MIPS32_EF_R16 22
+#define MIPS32_EF_R17 23
+#define MIPS32_EF_R18 24
+#define MIPS32_EF_R19 25
+#define MIPS32_EF_R20 26
+#define MIPS32_EF_R21 27
+#define MIPS32_EF_R22 28
+#define MIPS32_EF_R23 29
+#define MIPS32_EF_R24 30
+#define MIPS32_EF_R25 31

/*
* k0/k1 unsaved
*/
-#define EF_R26 32
-#define EF_R27 33
+#define MIPS32_EF_R26 32
+#define MIPS32_EF_R27 33

-#define EF_R28 34
-#define EF_R29 35
-#define EF_R30 36
-#define EF_R31 37
+#define MIPS32_EF_R28 34
+#define MIPS32_EF_R29 35
+#define MIPS32_EF_R30 36
+#define MIPS32_EF_R31 37

/*
* Saved special registers
*/
-#define EF_LO 38
-#define EF_HI 39
+#define MIPS32_EF_LO 38
+#define MIPS32_EF_HI 39

-#define EF_CP0_EPC 40
-#define EF_CP0_BADVADDR 41
-#define EF_CP0_STATUS 42
-#define EF_CP0_CAUSE 43
-#define EF_UNUSED0 44
-
-#define EF_SIZE 180
-
-#endif
-
-#if defined(CONFIG_64BIT) && !defined(WANT_COMPAT_REG_H)
-
-#define EF_R0 0
-#define EF_R1 1
-#define EF_R2 2
-#define EF_R3 3
-#define EF_R4 4
-#define EF_R5 5
-#define EF_R6 6
-#define EF_R7 7
-#define EF_R8 8
-#define EF_R9 9
-#define EF_R10 10
-#define EF_R11 11
-#define EF_R12 12
-#define EF_R13 13
-#define EF_R14 14
-#define EF_R15 15
-#define EF_R16 16
-#define EF_R17 17
-#define EF_R18 18
-#define EF_R19 19
-#define EF_R20 20
-#define EF_R21 21
-#define EF_R22 22
-#define EF_R23 23
-#define EF_R24 24
-#define EF_R25 25
+#define MIPS32_EF_CP0_EPC 40
+#define MIPS32_EF_CP0_BADVADDR 41
+#define MIPS32_EF_CP0_STATUS 42
+#define MIPS32_EF_CP0_CAUSE 43
+#define MIPS32_EF_UNUSED0 44
+
+#define MIPS32_EF_SIZE 180
+
+#define MIPS64_EF_R0 0
+#define MIPS64_EF_R1 1
+#define MIPS64_EF_R2 2
+#define MIPS64_EF_R3 3
+#define MIPS64_EF_R4 4
+#define MIPS64_EF_R5 5
+#define MIPS64_EF_R6 6
+#define MIPS64_EF_R7 7
+#define MIPS64_EF_R8 8
+#define MIPS64_EF_R9 9
+#define MIPS64_EF_R10 10
+#define MIPS64_EF_R11 11
+#define MIPS64_EF_R12 12
+#define MIPS64_EF_R13 13
+#define MIPS64_EF_R14 14
+#define MIPS64_EF_R15 15
+#define MIPS64_EF_R16 16
+#define MIPS64_EF_R17 17
+#define MIPS64_EF_R18 18
+#define MIPS64_EF_R19 19
+#define MIPS64_EF_R20 20
+#define MIPS64_EF_R21 21
+#define MIPS64_EF_R22 22
+#define MIPS64_EF_R23 23
+#define MIPS64_EF_R24 24
+#define MIPS64_EF_R25 25

/*
* k0/k1 unsaved
*/
-#define EF_R26 26
-#define EF_R27 27
+#define MIPS64_EF_R26 26
+#define MIPS64_EF_R27 27


-#define EF_R28 28
-#define EF_R29 29
-#define EF_R30 30
-#define EF_R31 31
+#define MIPS64_EF_R28 28
+#define MIPS64_EF_R29 29
+#define MIPS64_EF_R30 30
+#define MIPS64_EF_R31 31

/*
* Saved special registers
*/
-#define EF_LO 32
-#define EF_HI 33
-
-#define EF_CP0_EPC 34
-#define EF_CP0_BADVADDR 35
-#define EF_CP0_STATUS 36
-#define EF_CP0_CAUSE 37
+#define MIPS64_EF_LO 32
+#define MIPS64_EF_HI 33

-#define EF_SIZE 304 /* size in bytes */
+#define MIPS64_EF_CP0_EPC 34
+#define MIPS64_EF_CP0_BADVADDR 35
+#define MIPS64_EF_CP0_STATUS 36
+#define MIPS64_EF_CP0_CAUSE 37
+
+#define MIPS64_EF_SIZE 304 /* size in bytes */
+
+#if defined(CONFIG_32BIT)
+
+#define EF_R0 MIPS32_EF_R0
+#define EF_R1 MIPS32_EF_R1
+#define EF_R2 MIPS32_EF_R2
+#define EF_R3 MIPS32_EF_R3
+#define EF_R4 MIPS32_EF_R4
+#define EF_R5 MIPS32_EF_R5
+#define EF_R6 MIPS32_EF_R6
+#define EF_R7 MIPS32_EF_R7
+#define EF_R8 MIPS32_EF_R8
+#define EF_R9 MIPS32_EF_R9
+#define EF_R10 MIPS32_EF_R10
+#define EF_R11 MIPS32_EF_R11
+#define EF_R12 MIPS32_EF_R12
+#define EF_R13 MIPS32_EF_R13
+#define EF_R14 MIPS32_EF_R14
+#define EF_R15 MIPS32_EF_R15
+#define EF_R16 MIPS32_EF_R16
+#define EF_R17 MIPS32_EF_R17
+#define EF_R18 MIPS32_EF_R18
+#define EF_R19 MIPS32_EF_R19
+#define EF_R20 MIPS32_EF_R20
+#define EF_R21 MIPS32_EF_R21
+#define EF_R22 MIPS32_EF_R22
+#define EF_R23 MIPS32_EF_R23
+#define EF_R24 MIPS32_EF_R24
+#define EF_R25 MIPS32_EF_R25
+#define EF_R26 MIPS32_EF_R26
+#define EF_R27 MIPS32_EF_R27
+#define EF_R28 MIPS32_EF_R28
+#define EF_R29 MIPS32_EF_R29
+#define EF_R30 MIPS32_EF_R30
+#define EF_R31 MIPS32_EF_R31
+#define EF_LO MIPS32_EF_LO
+#define EF_HI MIPS32_EF_HI
+#define EF_CP0_EPC MIPS32_EF_CP0_EPC
+#define EF_CP0_BADVADDR MIPS32_EF_CP0_BADVADDR
+#define EF_CP0_STATUS MIPS32_EF_CP0_STATUS
+#define EF_CP0_CAUSE MIPS32_EF_CP0_CAUSE
+#define EF_UNUSED0 MIPS32_EF_UNUSED0
+#define EF_SIZE MIPS32_EF_SIZE
+
+#elif defined(CONFIG_64BIT)
+
+#define EF_R0 MIPS64_EF_R0
+#define EF_R1 MIPS64_EF_R1
+#define EF_R2 MIPS64_EF_R2
+#define EF_R3 MIPS64_EF_R3
+#define EF_R4 MIPS64_EF_R4
+#define EF_R5 MIPS64_EF_R5
+#define EF_R6 MIPS64_EF_R6
+#define EF_R7 MIPS64_EF_R7
+#define EF_R8 MIPS64_EF_R8
+#define EF_R9 MIPS64_EF_R9
+#define EF_R10 MIPS64_EF_R10
+#define EF_R11 MIPS64_EF_R11
+#define EF_R12 MIPS64_EF_R12
+#define EF_R13 MIPS64_EF_R13
+#define EF_R14 MIPS64_EF_R14
+#define EF_R15 MIPS64_EF_R15
+#define EF_R16 MIPS64_EF_R16
+#define EF_R17 MIPS64_EF_R17
+#define EF_R18 MIPS64_EF_R18
+#define EF_R19 MIPS64_EF_R19
+#define EF_R20 MIPS64_EF_R20
+#define EF_R21 MIPS64_EF_R21
+#define EF_R22 MIPS64_EF_R22
+#define EF_R23 MIPS64_EF_R23
+#define EF_R24 MIPS64_EF_R24
+#define EF_R25 MIPS64_EF_R25
+#define EF_R26 MIPS64_EF_R26
+#define EF_R27 MIPS64_EF_R27
+#define EF_R28 MIPS64_EF_R28
+#define EF_R29 MIPS64_EF_R29
+#define EF_R30 MIPS64_EF_R30
+#define EF_R31 MIPS64_EF_R31
+#define EF_LO MIPS64_EF_LO
+#define EF_HI MIPS64_EF_HI
+#define EF_CP0_EPC MIPS64_EF_CP0_EPC
+#define EF_CP0_BADVADDR MIPS64_EF_CP0_BADVADDR
+#define EF_CP0_STATUS MIPS64_EF_CP0_STATUS
+#define EF_CP0_CAUSE MIPS64_EF_CP0_CAUSE
+#define EF_SIZE MIPS64_EF_SIZE

#endif /* CONFIG_64BIT */

--- a/arch/mips/kernel/binfmt_elfo32.c
+++ b/arch/mips/kernel/binfmt_elfo32.c
@@ -72,12 +72,6 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_N

#include <asm/processor.h>

-/*
- * When this file is selected, we are definitely running a 64bit kernel.
- * So using the right regs define in asm/reg.h
- */
-#define WANT_COMPAT_REG_H
-
/* These MUST be defined before elf.h gets included */
extern void elf32_core_copy_regs(elf_gregset_t grp, struct pt_regs *regs);
#define ELF_CORE_COPY_REGS(_dest, _regs) elf32_core_copy_regs(_dest, _regs);
@@ -149,21 +143,21 @@ void elf32_core_copy_regs(elf_gregset_t
{
int i;

- for (i = 0; i < EF_R0; i++)
+ for (i = 0; i < MIPS32_EF_R0; i++)
grp[i] = 0;
- grp[EF_R0] = 0;
+ grp[MIPS32_EF_R0] = 0;
for (i = 1; i <= 31; i++)
- grp[EF_R0 + i] = (elf_greg_t) regs->regs[i];
- grp[EF_R26] = 0;
- grp[EF_R27] = 0;
- grp[EF_LO] = (elf_greg_t) regs->lo;
- grp[EF_HI] = (elf_greg_t) regs->hi;
- grp[EF_CP0_EPC] = (elf_greg_t) regs->cp0_epc;
- grp[EF_CP0_BADVADDR] = (elf_greg_t) regs->cp0_badvaddr;
- grp[EF_CP0_STATUS] = (elf_greg_t) regs->cp0_status;
- grp[EF_CP0_CAUSE] = (elf_greg_t) regs->cp0_cause;
-#ifdef EF_UNUSED0
- grp[EF_UNUSED0] = 0;
+ grp[MIPS32_EF_R0 + i] = (elf_greg_t) regs->regs[i];
+ grp[MIPS32_EF_R26] = 0;
+ grp[MIPS32_EF_R27] = 0;
+ grp[MIPS32_EF_LO] = (elf_greg_t) regs->lo;
+ grp[MIPS32_EF_HI] = (elf_greg_t) regs->hi;
+ grp[MIPS32_EF_CP0_EPC] = (elf_greg_t) regs->cp0_epc;
+ grp[MIPS32_EF_CP0_BADVADDR] = (elf_greg_t) regs->cp0_badvaddr;
+ grp[MIPS32_EF_CP0_STATUS] = (elf_greg_t) regs->cp0_status;
+ grp[MIPS32_EF_CP0_CAUSE] = (elf_greg_t) regs->cp0_cause;
+#ifdef MIPS32_EF_UNUSED0
+ grp[MIPS32_EF_UNUSED0] = 0;
#endif
}

[Greg Kroah-Hartman]

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

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

From: Alex Smith <***@alex-smith.me.uk>

commit 656ff9bef08c19a6471b49528dacb4cbbeb1e537 upstream.

Whenever ptrace attempts to retrieve the FPU implementation register it
accesses it through current_cpu_data, which calls smp_processor_id().
Since the code may execute with preemption enabled, this can trigger
a warning. Fix this by using boot_cpu_data to get the IR instead.

Signed-off-by: Alex Smith <***@alex-smith.me.uk>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7449/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/kernel/ptrace.c | 4 ++--
arch/mips/kernel/ptrace32.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -129,7 +129,7 @@ int ptrace_getfpregs(struct task_struct
}

__put_user(child->thread.fpu.fcr31, data + 64);
- __put_user(current_cpu_data.fpu_id, data + 65);
+ __put_user(boot_cpu_data.fpu_id, data + 65);

return 0;
}
@@ -611,7 +611,7 @@ long arch_ptrace(struct task_struct *chi
break;
case FPC_EIR:
/* implementation / version register */
- tmp = current_cpu_data.fpu_id;
+ tmp = boot_cpu_data.fpu_id;
break;
case DSP_BASE ... DSP_BASE + 5: {
dspreg_t *dregs;
--- a/arch/mips/kernel/ptrace32.c
+++ b/arch/mips/kernel/ptrace32.c
@@ -129,7 +129,7 @@ long compat_arch_ptrace(struct task_stru
break;
case FPC_EIR:
/* implementation / version register */
- tmp = current_cpu_data.fpu_id;
+ tmp = boot_cpu_data.fpu_id;
break;
case DSP_BASE ... DSP_BASE + 5: {
dspreg_t *dregs;

[Greg Kroah-Hartman]

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

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

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

commit 64615682658373516863b5b5971ff1d922d0ae7b upstream.

Using kstrtol to parse the "{e,}memsize" variables was wrong because this
parses signed long numbers. In case of '{e,}memsize' >= 2G, the top bit
is set, resulting to -ERANGE errors and possibly random system memory
boundaries. We fix this by replacing "kstrtol" with "kstrtoul".
We also improve the code to check the kstrtoul return value and
print a warning if an error was returned.

Signed-off-by: Markos Chandras <***@imgtec.com>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7543/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/mti-malta/malta-memory.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

--- a/arch/mips/mti-malta/malta-memory.c
+++ b/arch/mips/mti-malta/malta-memory.c
@@ -34,13 +34,19 @@ fw_memblock_t * __init fw_getmdesc(int e
/* otherwise look in the environment */

memsize_str = fw_getenv("memsize");
- if (memsize_str)
- tmp = kstrtol(memsize_str, 0, &memsize);
+ if (memsize_str) {
+ tmp = kstrtoul(memsize_str, 0, &memsize);
+ if (tmp)
+ pr_warn("Failed to read the 'memsize' env variable.\n");
+ }
if (eva) {
/* Look for ememsize for EVA */
ememsize_str = fw_getenv("ememsize");
- if (ememsize_str)
- tmp = kstrtol(ememsize_str, 0, &ememsize);
+ if (ememsize_str) {
+ tmp = kstrtoul(ememsize_str, 0, &ememsize);
+ if (tmp)
+ pr_warn("Failed to read the 'ememsize' env variable.\n");
+ }
}
if (!memsize && !ememsize) {
pr_warn("memsize not set in YAMON, set to default (32Mb)\n");

[Greg Kroah-Hartman]

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

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

From: Alex Smith <***@alex-smith.me.uk>

commit c23b3d1a53119849dc3c23c417124deb067aa33d upstream.

Commit 6a9c001b7ec3 ("MIPS: Switch ELF core dumper to use regsets.")
switched the core dumper to use regsets, however the GP regset code
simply makes a direct copy of the kernel's pt_regs, which does not
match the original core dump register layout as defined in asm/reg.h.
Furthermore, the definition of pt_regs can vary with certain Kconfig
variables, therefore the GP regset can never be relied upon to return
registers in the same layout.

Therefore, this patch changes the GP regset to match the original core
dump layout. The layout differs for 32- and 64-bit processes, so
separate implementations of the get/set functions are added for the
32- and 64-bit regsets.

Signed-off-by: Alex Smith <***@alex-smith.me.uk>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7452/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/kernel/ptrace.c | 189 ++++++++++++++++++++++++++++++++++++++--------
1 file changed, 160 insertions(+), 29 deletions(-)

--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -246,36 +246,160 @@ int ptrace_set_watch_regs(struct task_st

/* regset get/set implementations */

-static int gpr_get(struct task_struct *target,
- const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+#if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
+
+static int gpr32_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
{
struct pt_regs *regs = task_pt_regs(target);
+ u32 uregs[ELF_NGREG] = {};
+ unsigned i;
+
+ for (i = MIPS32_EF_R1; i <= MIPS32_EF_R31; i++) {
+ /* k0/k1 are copied as zero. */
+ if (i == MIPS32_EF_R26 || i == MIPS32_EF_R27)
+ continue;

- return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
- regs, 0, sizeof(*regs));
+ uregs[i] = regs->regs[i - MIPS32_EF_R0];
+ }
+
+ uregs[MIPS32_EF_LO] = regs->lo;
+ uregs[MIPS32_EF_HI] = regs->hi;
+ uregs[MIPS32_EF_CP0_EPC] = regs->cp0_epc;
+ uregs[MIPS32_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
+ uregs[MIPS32_EF_CP0_STATUS] = regs->cp0_status;
+ uregs[MIPS32_EF_CP0_CAUSE] = regs->cp0_cause;
+
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
+ sizeof(uregs));
}

-static int gpr_set(struct task_struct *target,
- const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- const void *kbuf, const void __user *ubuf)
+static int gpr32_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ struct pt_regs *regs = task_pt_regs(target);
+ u32 uregs[ELF_NGREG];
+ unsigned start, num_regs, i;
+ int err;
+
+ start = pos / sizeof(u32);
+ num_regs = count / sizeof(u32);
+
+ if (start + num_regs > ELF_NGREG)
+ return -EIO;
+
+ err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
+ sizeof(uregs));
+ if (err)
+ return err;
+
+ for (i = start; i < num_regs; i++) {
+ /*
+ * Cast all values to signed here so that if this is a 64-bit
+ * kernel, the supplied 32-bit values will be sign extended.
+ */
+ switch (i) {
+ case MIPS32_EF_R1 ... MIPS32_EF_R25:
+ /* k0/k1 are ignored. */
+ case MIPS32_EF_R28 ... MIPS32_EF_R31:
+ regs->regs[i - MIPS32_EF_R0] = (s32)uregs[i];
+ break;
+ case MIPS32_EF_LO:
+ regs->lo = (s32)uregs[i];
+ break;
+ case MIPS32_EF_HI:
+ regs->hi = (s32)uregs[i];
+ break;
+ case MIPS32_EF_CP0_EPC:
+ regs->cp0_epc = (s32)uregs[i];
+ break;
+ }
+ }
+
+ return 0;
+}
+
+#endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
+
+#ifdef CONFIG_64BIT
+
+static int gpr64_get(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf)
{
- struct pt_regs newregs;
- int ret;
+ struct pt_regs *regs = task_pt_regs(target);
+ u64 uregs[ELF_NGREG] = {};
+ unsigned i;

- ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
- &newregs,
- 0, sizeof(newregs));
- if (ret)
- return ret;
+ for (i = MIPS64_EF_R1; i <= MIPS64_EF_R31; i++) {
+ /* k0/k1 are copied as zero. */
+ if (i == MIPS64_EF_R26 || i == MIPS64_EF_R27)
+ continue;
+
+ uregs[i] = regs->regs[i - MIPS64_EF_R0];
+ }

- *task_pt_regs(target) = newregs;
+ uregs[MIPS64_EF_LO] = regs->lo;
+ uregs[MIPS64_EF_HI] = regs->hi;
+ uregs[MIPS64_EF_CP0_EPC] = regs->cp0_epc;
+ uregs[MIPS64_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
+ uregs[MIPS64_EF_CP0_STATUS] = regs->cp0_status;
+ uregs[MIPS64_EF_CP0_CAUSE] = regs->cp0_cause;
+
+ return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
+ sizeof(uregs));
+}
+
+static int gpr64_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ struct pt_regs *regs = task_pt_regs(target);
+ u64 uregs[ELF_NGREG];
+ unsigned start, num_regs, i;
+ int err;
+
+ start = pos / sizeof(u64);
+ num_regs = count / sizeof(u64);
+
+ if (start + num_regs > ELF_NGREG)
+ return -EIO;
+
+ err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
+ sizeof(uregs));
+ if (err)
+ return err;
+
+ for (i = start; i < num_regs; i++) {
+ switch (i) {
+ case MIPS64_EF_R1 ... MIPS64_EF_R25:
+ /* k0/k1 are ignored. */
+ case MIPS64_EF_R28 ... MIPS64_EF_R31:
+ regs->regs[i - MIPS64_EF_R0] = uregs[i];
+ break;
+ case MIPS64_EF_LO:
+ regs->lo = uregs[i];
+ break;
+ case MIPS64_EF_HI:
+ regs->hi = uregs[i];
+ break;
+ case MIPS64_EF_CP0_EPC:
+ regs->cp0_epc = uregs[i];
+ break;
+ }
+ }

return 0;
}

+#endif /* CONFIG_64BIT */
+
static int fpr_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
@@ -337,14 +461,16 @@ enum mips_regset {
REGSET_FPR,
};

+#if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
+
static const struct user_regset mips_regsets[] = {
[REGSET_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = ELF_NGREG,
.size = sizeof(unsigned int),
.align = sizeof(unsigned int),
- .get = gpr_get,
- .set = gpr_set,
+ .get = gpr32_get,
+ .set = gpr32_set,
},
[REGSET_FPR] = {
.core_note_type = NT_PRFPREG,
@@ -364,14 +490,18 @@ static const struct user_regset_view use
.n = ARRAY_SIZE(mips_regsets),
};

+#endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
+
+#ifdef CONFIG_64BIT
+
static const struct user_regset mips64_regsets[] = {
[REGSET_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = ELF_NGREG,
.size = sizeof(unsigned long),
.align = sizeof(unsigned long),
- .get = gpr_get,
- .set = gpr_set,
+ .get = gpr64_get,
+ .set = gpr64_set,
},
[REGSET_FPR] = {
.core_note_type = NT_PRFPREG,
@@ -384,25 +514,26 @@ static const struct user_regset mips64_r
};

static const struct user_regset_view user_mips64_view = {
- .name = "mips",
+ .name = "mips64",
.e_machine = ELF_ARCH,
.ei_osabi = ELF_OSABI,
.regsets = mips64_regsets,
- .n = ARRAY_SIZE(mips_regsets),
+ .n = ARRAY_SIZE(mips64_regsets),
};

+#endif /* CONFIG_64BIT */
+
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
#ifdef CONFIG_32BIT
return &user_mips_view;
-#endif
-
+#else
#ifdef CONFIG_MIPS32_O32
- if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
- return &user_mips_view;
+ if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
+ return &user_mips_view;
#endif
-
return &user_mips64_view;
+#endif
}

long arch_ptrace(struct task_struct *child, long request,

[Greg Kroah-Hartman]

This post might be inappropriate. Click to display it.

[Greg Kroah-Hartman]

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

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

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

commit b1442d39fac2fcfbe6a4814979020e993ca59c9e upstream.

If one or more matching FCSR cause & enable bits are set in saved thread
context then when that context is restored the kernel will take an FP
exception. This is of course undesirable and considered an oops, leading
to the kernel writing a backtrace to the console and potentially
rebooting depending upon the configuration. Thus the kernel avoids this
situation by clearing the cause bits of the FCSR register when handling
FP exceptions and after emulating FP instructions.

However the kernel does not prevent userland from setting arbitrary FCSR
cause & enable bits via ptrace, using either the PTRACE_POKEUSR or
PTRACE_SETFPREGS requests. This means userland can trivially cause the
kernel to oops on any system with an FPU. Prevent this from happening
by clearing the cause bits when writing to the saved FCSR context via
ptrace.

This problem appears to exist at least back to the beginning of the git
era in the PTRACE_POKEUSR case.

Signed-off-by: Paul Burton <***@imgtec.com>
Cc: linux-***@linux-mips.org
Cc: Paul Burton <***@imgtec.com>
Cc: ***@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7438/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/kernel/ptrace.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -151,6 +151,7 @@ int ptrace_setfpregs(struct task_struct
}

__get_user(child->thread.fpu.fcr31, data + 64);
+ child->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;

/* FIR may not be written. */

@@ -696,7 +697,7 @@ long arch_ptrace(struct task_struct *chi
break;
#endif
case FPC_CSR:
- child->thread.fpu.fcr31 = data;
+ child->thread.fpu.fcr31 = data & ~FPU_CSR_ALL_X;
break;
case DSP_BASE ... DSP_BASE + 5: {
dspreg_t *dregs;