linux-toradex.git/arch/mips/include, branch v3.14.52

MIPS: Make set_pte() SMP safe.

2015-08-17T03:51:45+00:00

commit 46011e6ea39235e4aca656673c500eac81a07a17 upstream.

On MIPS the GLOBAL bit of the PTE must have the same value in any
aligned pair of PTEs.  These pairs of PTEs are referred to as
"buddies".  In a SMP system is is possible for two CPUs to be calling
set_pte() on adjacent PTEs at the same time.  There is a race between
setting the PTE and a different CPU setting the GLOBAL bit in its
buddy PTE.

This race can be observed when multiple CPUs are executing
vmap()/vfree() at the same time.

Make setting the buddy PTE's GLOBAL bit an atomic operation to close
the race condition.

The case of CONFIG_64BIT_PHYS_ADDR && CONFIG_CPU_MIPS32 is *not*
handled.

Signed-off-by: David Daney 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10835/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: Fix KVM guest fixmap address

2015-07-10T17:37:59+00:00

commit 8e748c8d09a9314eedb5c6367d9acfaacddcdc88 upstream.

KVM guest kernels for trap & emulate run in user mode, with a modified
set of kernel memory segments. However the fixmap address is still in
the normal KSeg3 region at 0xfffe0000 regardless, causing problems when
cache alias handling makes use of them when handling copy on write.

Therefore define FIXADDR_TOP as 0x7ffe0000 in the guest kernel mapped
region when CONFIG_KVM_GUEST is defined.

Signed-off-by: James Hogan 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9887/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

nosave: consolidate __nosave_{begin,end} in

2015-05-06T19:59:21+00:00

commit 7f8998c7aef3ac9c5f3f2943e083dfa6302e90d0 upstream.

The different architectures used their own (and different) declarations:

    extern __visible const void __nosave_begin, __nosave_end;
    extern const void __nosave_begin, __nosave_end;
    extern long __nosave_begin, __nosave_end;

Consolidate them using the first variant in .

Signed-off-by: Geert Uytterhoeven 
Cc: Russell King 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Martin Schwidefsky 
Cc: "David S. Miller" 
Cc: Guan Xuetao 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

MIPS: ftrace: Fix a microMIPS build problem

2014-11-14T16:59:57+00:00

commit aedd153f5bb5b1f1d6d9142014f521ae2ec294cc upstream.

Code before the .fixup section needs to have the .insn directive.
This has no side effects on MIPS32/64 but it affects the way microMIPS
loads the address for the return label.

Fixes the following build problem:
mips-linux-gnu-ld: arch/mips/built-in.o: .fixup+0x4a0: Unsupported jump between
ISA modes; consider recompiling with interlinking enabled.
mips-linux-gnu-ld: final link failed: Bad value
Makefile:819: recipe for target 'vmlinux' failed

The fix is similar to 1658f914ff91c3bf ("MIPS: microMIPS:
Disable LL/SC and fix linker bug.")

Signed-off-by: Markos Chandras 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8117/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: asm/reg.h: Make 32- and 64-bit definitions available at the same time

2014-09-17T16:19:15+00:00

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 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7451/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: O32/32-bit: Fix bug which can cause incorrect system call restarts

2014-09-17T16:19:14+00:00

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 
Reviewed-by: Aurelien Jarno 
Tested-by: Aurelien Jarno 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7454/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: asm: thread_info: Add _TIF_SECCOMP flag

2014-06-16T20:40:32+00:00

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 
Reviewed-by: Paul Burton 
Reviewed-by: James Hogan 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6405/
Signed-off-by: Ralf Baechle 
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

MIPS: Make local_irq_disable macro safe for non-Mipsr2

2014-03-20T12:46:15+00:00

For non-mipsr2 processors, the local_irq_disable contains an mfc0-mtc0
pair with instructions inbetween.  With preemption enabled, this sequence
may get preempted and effect a stale value of CP0_STATUS when executing
the mtc0 instruction.  This commit avoids this scenario by incrementing
the preempt count before the mfc0 and decrementing it after the mtc9.

[ralf@linux-mips.org: This patch is sorting out the part that were missed
by e97c5b6098 [MIPS: Make irqflags.h functions preempt-safe for non-mipsr2
cpus.]  I also re-enabled the inclusion of  at the top
of ].

Signed-off-by: Jim Quinlan 
Cc: linux-mips@linux-mips.org
Cc: cernekee@gmail.com
Patchwork: https://patchwork.linux-mips.org/patch/6164/
Signed-off-by: Ralf Baechle

MIPS: ftrace: Tweak safe_load()/safe_store() macros

2014-03-19T22:18:40+00:00

Due to name collision in ftrace safe_load and safe_store macros,
these macros cannot take expressions as operands.

For example, compiler will complain for a macro call like the following:
  safe_store_code(new_code2, ip + 4, faulted);

  arch/mips/include/asm/ftrace.h:61:6: note: in definition of macro 'safe_store'
     : [dst] "r" (dst), [src] "r" (src)\
        ^
  arch/mips/kernel/ftrace.c:118:2: note: in expansion of macro 'safe_store_code'
    safe_store_code(new_code2, ip + 4, faulted);
    ^
  arch/mips/kernel/ftrace.c:118:32: error: undefined named operand 'ip + 4'
    safe_store_code(new_code2, ip + 4, faulted);
                                  ^
  arch/mips/include/asm/ftrace.h:61:6: note: in definition of macro 'safe_store'
     : [dst] "r" (dst), [src] "r" (src)\
        ^
  arch/mips/kernel/ftrace.c:118:2: note: in expansion of macro 'safe_store_code'
    safe_store_code(new_code2, ip + 4, faulted);
    ^

This build error is triggered by a4671094 [MIPS: ftrace: Fix icache flush
range error].  Tweak variable naming in those macros to allow flexible
operands.

Signed-off-by: Viller Hsiao 
Cc: linux-mips@linux-mips.org
Cc: rostedt@goodmis.org
Cc: fweisbec@gmail.com
Cc: mingo@redhat.com
Cc: Qais.Yousef@imgtec.com
Patchwork: https://patchwork.linux-mips.org/patch/6622/
Signed-off-by: Ralf Baechle

MIPS: Fix syscall tracing interface

2014-03-17T14:38:38+00:00

Fix pointer computation for stack-based arguments.

Signed-off-by: Lars Persson 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6620/
Signed-off-by: Ralf Baechle