linux-stable.git/arch/arc/include, branch v4.4.142

futex: Remove duplicated code and fix undefined behaviour

2018-05-26T06:48:50+00:00

commit 30d6e0a4190d37740e9447e4e4815f06992dd8c3 upstream.

There is code duplicated over all architecture's headers for
futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr,
and comparison of the result.

Remove this duplication and leave up to the arches only the needed
assembly which is now in arch_futex_atomic_op_inuser.

This effectively distributes the Will Deacon's arm64 fix for undefined
behaviour reported by UBSAN to all architectures. The fix was done in
commit 5f16a046f8e1 (arm64: futex: Fix undefined behaviour with
FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump.

And as suggested by Thomas, check for negative oparg too, because it was
also reported to cause undefined behaviour report.

Note that s390 removed access_ok check in d12a29703 ("s390/uaccess:
remove pointless access_ok() checks") as access_ok there returns true.
We introduce it back to the helper for the sake of simplicity (it gets
optimized away anyway).

Signed-off-by: Jiri Slaby 
Signed-off-by: Thomas Gleixner 
Acked-by: Russell King 
Acked-by: Michael Ellerman  (powerpc)
Acked-by: Heiko Carstens  [s390]
Acked-by: Chris Metcalf  [for tile]
Reviewed-by: Darren Hart (VMware) 
Reviewed-by: Will Deacon  [core/arm64]
Cc: linux-mips@linux-mips.org
Cc: Rich Felker 
Cc: linux-ia64@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: peterz@infradead.org
Cc: Benjamin Herrenschmidt 
Cc: Max Filippov 
Cc: Paul Mackerras 
Cc: sparclinux@vger.kernel.org
Cc: Jonas Bonn 
Cc: linux-s390@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: Yoshinori Sato 
Cc: linux-hexagon@vger.kernel.org
Cc: Helge Deller 
Cc: "James E.J. Bottomley" 
Cc: Catalin Marinas 
Cc: Matt Turner 
Cc: linux-snps-arc@lists.infradead.org
Cc: Fenghua Yu 
Cc: Arnd Bergmann 
Cc: linux-xtensa@linux-xtensa.org
Cc: Stefan Kristiansson 
Cc: openrisc@lists.librecores.org
Cc: Ivan Kokshaysky 
Cc: Stafford Horne 
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Henderson 
Cc: Chris Zankel 
Cc: Michal Simek 
Cc: Tony Luck 
Cc: linux-parisc@vger.kernel.org
Cc: Vineet Gupta 
Cc: Ralf Baechle 
Cc: Richard Kuo 
Cc: linux-alpha@vger.kernel.org
Cc: Martin Schwidefsky 
Cc: linuxppc-dev@lists.ozlabs.org
Cc: "David S. Miller" 
Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

ARC: uaccess: dont use "l" gcc inline asm constraint modifier

2018-01-10T08:27:11+00:00

commit 79435ac78d160e4c245544d457850a56f805ac0d upstream.

This used to setup the LP_COUNT register automatically, but now has been
removed.

There was an earlier fix 3c7c7a2fc8811 which fixed instance in delay.h but
somehow missed this one as gcc change had not made its way into
production toolchains and was not pedantic as it is now !

Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARCv2: PAE40: Explicitly set MSB counterpart of SLC region ops addresses

2017-08-30T08:19:22+00:00

commit 7d79cee2c6540ea64dd917a14e2fd63d4ac3d3c0 upstream.

It is necessary to explicitly set both SLC_AUX_RGN_START1 and SLC_AUX_RGN_END1
which hold MSB bits of the physical address correspondingly of region start
and end otherwise SLC region operation is executed in unpredictable manner

Without this patch, SLC flushes on HSDK (IOC disabled) were taking
seconds.

Reported-by: Vladimir Kondratiev 
Signed-off-by: Alexey Brodkin 
Signed-off-by: Vineet Gupta 
[vgupta: PAR40 regs only written if PAE40 exist]
Signed-off-by: Greg Kroah-Hartman

ARCv2: save r30 on kernel entry as gcc uses it for code-gen

2017-05-03T04:19:56+00:00

commit ecd43afdbe72017aefe48080631eb625e177ef4d upstream.

This is not exposed to userspace debugers yet, which can be done
independently as a seperate patch !

Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: udelay: fix inline assembler by adding LP_COUNT to clobber list

2017-02-01T07:30:53+00:00

commit 36425cd67052e3becf325fd4d3ba5691791ef7e4 upstream.

commit 3c7c7a2fc8811bc ("ARC: Don't use "+l" inline asm constraint")
modified the inline assembly to setup LP_COUNT register manually and NOT
rely on gcc to do it (with the +l inline assembler contraint hint, now
being retired in the compiler)

However the fix was flawed as we didn't add LP_COUNT to asm clobber list,
meaning gcc doesn't know that LP_COUNT or zero-delay-loops are in action
in the inline asm.

This resulted in some fun - as nested ZOL loops were being generared

| mov lp_count,250000 ;16 # tmp235,
| lp .L__GCC__LP14 #		<======= OUTER LOOP (gcc generated)
|   .L14:
|   ld r2, [r5] # MEM[(volatile u32 *)prephitmp_43], w
|   dmb 1
|   breq r2, -1, @.L21 #, w,,
|   bbit0 r2,1,@.L13 # w,,
|   ld r4,[r7] ;25 # loops_per_jiffy, loops_per_jiffy
|   mpymu r3,r4,r6 #, loops_per_jiffy, tmp234
|
|   mov lp_count, r3 #		 <====== INNER LOOP (from inline asm)
|   lp 1f
| 	 nop
|   1:
|   nop_s
| .L__GCC__LP14: ; loop end, start is @.L14 #,

This caused issues with drivers relying on sane behaviour of udelay
friends.

With LP_COUNT added to clobber list, gcc doesn't generate the outer
loop in say above case.

Addresses STAR 9001146134

Reported-by: Joao Pinto 
Fixes: 3c7c7a2fc8811bc ("ARC: Don't use "+l" inline asm constraint")
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: mm: arc700: Don't assume 2 colours for aliasing VIPT dcache

2017-01-09T07:07:48+00:00

commit 08fe007968b2b45e831daf74899f79a54d73f773 upstream.

An ARC700 customer reported linux boot crashes when upgrading to bigger
L1 dcache (64K from 32K). Turns out they had an aliasing VIPT config and
current code only assumed 2 colours, while theirs had 4. So default to 4
colours and complain if there are fewer. Ideally this needs to be a
Kconfig option, but heck that's too much of hassle for a single user.

Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: Don't use "+l" inline asm constraint

2016-12-08T06:15:24+00:00

commit 3c7c7a2fc8811bc7097479f69acf2527693d7562 upstream.

Apparenty this is coming in the way of gcc fix which inhibits the usage
of LP_COUNT as a gpr.

Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: uaccess: get_user to zero out dest in cause of fault

2016-09-24T08:07:44+00:00

commit 05d9d0b96e53c52a113fd783c0c97c830c8dc7af upstream.

Al reported potential issue with ARC get_user() as it wasn't clearing
out destination pointer in case of fault due to bad address etc.

Verified using following

| {
|  	u32 bogus1 = 0xdeadbeef;
|	u64 bogus2 = 0xdead;
|	int rc1, rc2;
|
|  	pr_info("Orig values %x %llx\n", bogus1, bogus2);
|	rc1 = get_user(bogus1, (u32 __user *)0x40000000);
|	rc2 = get_user(bogus2, (u64 __user *)0x50000000);
|	pr_info("access %d %d, new values %x %llx\n",
|		rc1, rc2, bogus1, bogus2);
| }

| [ARCLinux]# insmod /mnt/kernel-module/qtn.ko
| Orig values deadbeef dead
| access -14 -14, new values 0 0

Reported-by: Al Viro 
Cc: Linus Torvalds 
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta 
Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

ARC: mm: fix build breakage with STRICT_MM_TYPECHECKS

2016-09-24T08:07:37+00:00

commit 1c3c909303924d30145601f47b6c058fdd2cbc2e upstream.

|  CC      mm/memory.o
| In file included from ../mm/memory.c:53:0:
| ../include/linux/pfn_t.h: In function ‘pfn_t_pte’:
| ../include/linux/pfn_t.h:78:2: error: conversion to non-scalar type requested
|  return pfn_pte(pfn_t_to_pfn(pfn), pgprot);

With STRICT_MM_TYPECHECKS pte_t is a struct and the offending code
forces a cast which ends up shifting a struct and hence the gcc warning.

Note that in recent past some of the arches (aarch64, s390) made
STRICT_MM_TYPECHECKS default, but we don't for ARC as this leads to slightly
worse generated code, given ARC ABI definition of returning structs
(which pte_t would become)

Quoting from ARC ABI...

  "Results of type struct are returned in a caller-supplied temporary
  variable whose address is passed in r0.
  For such functions, the arguments are shifted so that they are
  passed in r1 and up."

So
 - struct to be returned would be allocated on stack requiring extra
   code at call sites
 - callee updates stack memory to facilitate the return (vs. simple
   MOV into return reg r0)

Hence STRICT_MM_TYPECHECKS is not enabled by default for ARC

Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: Call trace_hardirqs_on() before enabling irqs

2016-09-07T06:32:42+00:00

commit 18b43e89d295cc65151c505c643c98fb2c320e59 upstream.

trace_hardirqs_on_caller() in lockdep.c expects to be called before, not
after interrupts are actually enabled.

The following comment in kernel/locking/lockdep.c substantiates this
claim:

"
/*
 * We're enabling irqs and according to our state above irqs weren't
 * already enabled, yet we find the hardware thinks they are in fact
 * enabled.. someone messed up their IRQ state tracing.
 */
"

An example can be found in include/linux/irqflags.h:

	do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0)

Without this change, we hit the following DEBUG_LOCKS_WARN_ON.

[    7.760000] ------------[ cut here ]------------
[    7.760000] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:2711 resume_user_mode_begin+0x48/0xf0
[    7.770000] DEBUG_LOCKS_WARN_ON(!irqs_disabled())
[    7.780000] Modules linked in:
[    7.780000] CPU: 0 PID: 1 Comm: init Not tainted 4.7.0-00003-gc668bb9-dirty #366
[    7.790000]
[    7.790000] Stack Trace:
[    7.790000]   arc_unwind_core.constprop.1+0xa4/0x118
[    7.800000]   warn_slowpath_fmt+0x72/0x158
[    7.800000]   resume_user_mode_begin+0x48/0xf0
[    7.810000] ---[ end trace 6f6a7a8fae20d2f0 ]---

Signed-off-by: Daniel Mentz 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman