linux-toradex.git/arch/mips, branch v3.10.58

MIPS: mcount: Adjust stack pointer for static trace in MIPS32

2014-10-05T21:54:11+00:00

commit 8a574cfa2652545eb95595d38ac2a0bb501af0ae upstream.

Every mcount() call in the MIPS 32-bit kernel is done as follows:

[...]
move at, ra
jal _mcount
addiu sp, sp, -8
[...]

but upon returning from the mcount() function, the stack pointer
is not adjusted properly. This is explained in details in 58b69401c797
(MIPS: Function tracer: Fix broken function tracing).

Commit ad8c396936e3 ("MIPS: Unbreak function tracer for 64-bit kernel.)
fixed the stack manipulation for 64-bit but it didn't fix it completely
for MIPS32.

Signed-off-by: Markos Chandras 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7792/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: ZBOOT: add missing include

2014-10-05T21:54:10+00:00

commit 29593fd5a8149462ed6fad0d522234facdaee6c8 upstream.

Commit dc4d7b37 (MIPS: ZBOOT: gather string functions into string.c)
moved the string related functions into a separate file, which might
cause the following build error, depending on the configuration:

| CC      arch/mips/boot/compressed/decompress.o
| In file included from linux/arch/mips/boot/compressed/../../../../lib/decompress_unxz.c:234:0,
|                  from linux/arch/mips/boot/compressed/decompress.c:67:
| linux/arch/mips/boot/compressed/../../../../lib/xz/xz_dec_stream.c: In function 'fill_temp':
| linux/arch/mips/boot/compressed/../../../../lib/xz/xz_dec_stream.c:162:2: error: implicit declaration of function 'memcpy' [-Werror=implicit-function-declaration]
| cc1: some warnings being treated as errors
| linux/scripts/Makefile.build:308: recipe for target 'arch/mips/boot/compressed/decompress.o' failed
| make[6]: *** [arch/mips/boot/compressed/decompress.o] Error 1
| linux/arch/mips/Makefile:308: recipe for target 'vmlinuz' failed

It does not fail with the standard configuration, as when
CONFIG_DYNAMIC_DEBUG is not enabled  gets included in
include/linux/dynamic_debug.h. There might be other ways for it to
get indirectly included.

We can't add the include directly in xz_dec_stream.c as some
architectures might want to use a different version for the boot/
directory (see for example arch/x86/boot/string.h).

Signed-off-by: Aurelien Jarno 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7420/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: Fix accessing to per-cpu data when flushing the cache

2014-09-17T16:03:58+00:00

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 
Cc: Markos Chandras 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5835
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

MIPS: OCTEON: make get_system_type() thread-safe

2014-09-17T16:03:58+00:00

commit 608308682addfdc7b8e2aee88f0e028331d88e4d upstream.

get_system_type() is not thread-safe on OCTEON. It uses static data,
also more dangerous issue is that it's calling cvmx_fuse_read_byte()
every time without any synchronization. Currently it's possible to get
processes stuck looping forever in kernel simply by launching multiple
readers of /proc/cpuinfo:

	(while true; do cat /proc/cpuinfo > /dev/null; done) &
	(while true; do cat /proc/cpuinfo > /dev/null; done) &
	...

Fix by initializing the system type string only once during the early
boot.

Signed-off-by: Aaro Koskinen 
Reviewed-by: Markos Chandras 
Patchwork: http://patchwork.linux-mips.org/patch/7437/
Signed-off-by: James Hogan 
Signed-off-by: Greg Kroah-Hartman

MIPS: asm: thread_info: Add _TIF_SECCOMP flag

2014-09-17T16:03:58+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 
[bwh: Backported to 3.2: various other flags are not included in
 _TIF_WORK_SYSCALL_ENTRY]
Signed-off-by: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

MIPS: Cleanup flags in syscall flags handlers.

2014-09-17T16:03:58+00:00

commit e7f3b48af7be9f8007a224663a5b91340626fed5 upstream.

This will simplify further modifications.

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

2014-09-17T16:03:58+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: Remove BUG_ON(!is_fpu_owner()) in do_ade()

2014-09-17T16:03:58+00:00

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 
Signed-off-by: Jie Chen 
Signed-off-by: Rui Wang 
Cc: John Crispin 
Cc: Steven J. Hill 
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang 
Cc: Zhangjin Wu 
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: tlbex: Fix a missing statement for HUGETLB

2014-09-17T16:03:58+00:00

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 
Signed-off-by: Binbin Zhou 
Cc: John Crispin 
Cc: Steven J. Hill 
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang 
Cc: Zhangjin Wu 
Patchwork: https://patchwork.linux-mips.org/patch/7496/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: Prevent user from setting FCSR cause bits

2014-09-17T16:03:58+00:00

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 
Cc: linux-mips@linux-mips.org
Cc: Paul Burton 
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7438/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman