Discussion:
[PATCH 3.10 20/71] MIPS: Prevent user from setting FCSR cause bits
Greg Kroah-Hartman
2014-09-15 19:26:18 UTC
Permalink
3.10-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
@@ -161,6 +161,7 @@ int ptrace_setfpregs(struct task_struct
__get_user(fregs[i], i + (__u64 __user *) data);

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

/* FIR may not be written. */

@@ -451,7 +452,7 @@ 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;
Greg Kroah-Hartman
2014-09-15 19:26:19 UTC
Permalink
3.10-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
@@ -1329,6 +1329,7 @@ static void __cpuinit build_r4000_tlb_re
}
#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
2014-09-15 19:26:20 UTC
Permalink
3.10-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
@@ -604,7 +604,6 @@ 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
2014-09-15 19:26:21 UTC
Permalink
3.10-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
@@ -58,12 +58,6 @@ 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);
@@ -135,21 +129,21 @@ 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
2014-09-15 19:26:23 UTC
Permalink
3.10-stable review patch. If anyone has any objections, please let me know.

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

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

commit 137f7df8cead00688524c82360930845396b8a21 upstream.

Add _TIF_SECCOMP flag to _TIF_WORK_SYSCALL_ENTRY to indicate
that the system call needs to be checked against a seccomp filter.

Signed-off-by: Markos Chandras <***@imgtec.com>
Reviewed-by: Paul Burton <***@imgtec.com>
Reviewed-by: James Hogan <***@imgtec.com>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6405/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
[bwh: Backported to 3.2: various other flags are not included in
_TIF_WORK_SYSCALL_ENTRY]
Signed-off-by: Ben Hutchings <***@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

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

--- a/arch/mips/include/asm/thread_info.h
+++ b/arch/mips/include/asm/thread_info.h
@@ -131,7 +131,7 @@ static inline struct thread_info *curren
#define _TIF_FPUBOUND (1<<TIF_FPUBOUND)
#define _TIF_LOAD_WATCH (1<<TIF_LOAD_WATCH)

-#define _TIF_WORK_SYSCALL_ENTRY (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT)
+#define _TIF_WORK_SYSCALL_ENTRY (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP)

/* work to do in syscall_trace_leave() */
#define _TIF_WORK_SYSCALL_EXIT (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT)
Greg Kroah-Hartman
2014-09-15 19:26:25 UTC
Permalink
3.10-stable review patch. If anyone has any objections, please let me know.

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

From: Ralf Baechle <***@linux-mips.org>

commit ff522058bd717506b2fa066fa564657f2b86477e upstream.

This fixes the following issue

BUG: using smp_processor_id() in preemptible [00000000] code: kjournald/1761
caller is blast_dcache32+0x30/0x254
Call Trace:
[<8047f02c>] dump_stack+0x8/0x34
[<802e7e40>] debug_smp_processor_id+0xe0/0xf0
[<80114d94>] blast_dcache32+0x30/0x254
[<80118484>] r4k_dma_cache_wback_inv+0x200/0x288
[<80110ff0>] mips_dma_map_sg+0x108/0x180
[<80355098>] ide_dma_prepare+0xf0/0x1b8
[<8034eaa4>] do_rw_taskfile+0x1e8/0x33c
[<8035951c>] ide_do_rw_disk+0x298/0x3e4
[<8034a3c4>] do_ide_request+0x2e0/0x704
[<802bb0dc>] __blk_run_queue+0x44/0x64
[<802be000>] queue_unplugged.isra.36+0x1c/0x54
[<802beb94>] blk_flush_plug_list+0x18c/0x24c
[<802bec6c>] blk_finish_plug+0x18/0x48
[<8026554c>] journal_commit_transaction+0x3b8/0x151c
[<80269648>] kjournald+0xec/0x238
[<8014ac00>] kthread+0xb8/0xc0
[<8010268c>] ret_from_kernel_thread+0x14/0x1c

Caches in most systems are identical - but not always, so we can't avoid
the use of smp_call_function() by just looking at the boot CPU's data,
have to fiddle with preemption instead.

Signed-off-by: Ralf Baechle <***@linux-mips.org>
Cc: Markos Chandras <***@imgtec.com>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5835
Cc: Guenter Roeck <***@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/mm/c-r4k.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -12,6 +12,7 @@
#include <linux/highmem.h>
#include <linux/kernel.h>
#include <linux/linkage.h>
+#include <linux/preempt.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
@@ -601,6 +602,7 @@ static void r4k_dma_cache_wback_inv(unsi
/* Catch bad driver code */
BUG_ON(size == 0);

+ preempt_disable();
if (cpu_has_inclusive_pcaches) {
if (size >= scache_size)
r4k_blast_scache();
@@ -621,6 +623,7 @@ static void r4k_dma_cache_wback_inv(unsi
R4600_HIT_CACHEOP_WAR_IMPL;
blast_dcache_range(addr, addr + size);
}
+ preempt_enable();

bc_wback_inv(addr, size);
__sync();
@@ -631,6 +634,7 @@ static void r4k_dma_cache_inv(unsigned l
/* Catch bad driver code */
BUG_ON(size == 0);

+ preempt_disable();
if (cpu_has_inclusive_pcaches) {
if (size >= scache_size)
r4k_blast_scache();
@@ -655,6 +659,7 @@ static void r4k_dma_cache_inv(unsigned l
R4600_HIT_CACHEOP_WAR_IMPL;
blast_inv_dcache_range(addr, addr + size);
}
+ preempt_enable();

bc_inv(addr, size);
__sync();
Greg Kroah-Hartman
2014-09-15 19:26:17 UTC
Permalink
3.10-stable review patch. If anyone has any objections, please let me know.

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

From: Jeffrey Deans <***@imgtec.com>

commit ffc8415afab20bd97754efae6aad1f67b531132b upstream.

A GIC interrupt which is declared as having a GIC_MAP_TO_NMI_MSK
mapping causes the cpu parameter to gic_setup_intr() to be increased
to 32, causing memory corruption when pcpu_masks[] is written to again
later in the function.

Signed-off-by: Jeffrey Deans <***@imgtec.com>
Signed-off-by: Markos Chandras <***@imgtec.com>
Cc: linux-***@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7375/
Signed-off-by: Ralf Baechle <***@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
arch/mips/kernel/irq-gic.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/arch/mips/kernel/irq-gic.c
+++ b/arch/mips/kernel/irq-gic.c
@@ -256,11 +256,13 @@ static void __init gic_setup_intr(unsign

/* Setup Intr to Pin mapping */
if (pin & GIC_MAP_TO_NMI_MSK) {
+ int i;
+
GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)), pin);
/* FIXME: hack to route NMI to all cpu's */
- for (cpu = 0; cpu < NR_CPUS; cpu += 32) {
+ for (i = 0; i < NR_CPUS; i += 32) {
GICWRITE(GIC_REG_ADDR(SHARED,
- GIC_SH_MAP_TO_VPE_REG_OFF(intr, cpu)),
+ GIC_SH_MAP_TO_VPE_REG_OFF(intr, i)),
0xffffffff);
}
} else {

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