linux-toradex.git/arch/arc, branch v4.4.26 Linux kernel for Apalis and Colibri modules ARC: uaccess: get_user to zero out dest in cause of fault 2016-09-24T08:07:44+00:00 Vineet Gupta Vineet.Gupta1@synopsys.com 2016-08-19T19:10:02+00:00 59a2d6b2a6851435a34a7f42a1082367ac8296f0 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 <viro@ZenIV.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: mm: fix build breakage with STRICT_MM_TYPECHECKS 2016-09-24T08:07:37+00:00 Vineet Gupta vgupta@synopsys.com 2016-08-17T01:27:07+00:00 49bd6aea0081161a3c3ad241b3ea733008c0ebe4 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 <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: Elide redundant setup of DMA callbacks 2016-09-07T06:32:42+00:00 Vineet Gupta vgupta@synopsys.com 2016-06-13T14:38:27+00:00 03551c85c1c01bf7ec58218a2afb225d98da0b97 commit 45c3b08a117e2232fc8d7b9e849ead36386f4f96 upstream. For resources shared by all cores such as SLC and IOC, only the master core needs to do any setups / enabling / disabling etc. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 45c3b08a117e2232fc8d7b9e849ead36386f4f96 upstream.

For resources shared by all cores such as SLC and IOC, only the master
core needs to do any setups / enabling / disabling etc.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: Call trace_hardirqs_on() before enabling irqs 2016-09-07T06:32:42+00:00 Daniel Mentz danielmentz@google.com 2016-08-05T00:56:53+00:00 e44f5b5386f49f00d8d62880c28a814e8220c8ed 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 <danielmentz@google.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <danielmentz@google.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: use correct offset in pt_regs for saving/restoring user mode r25 2016-09-07T06:32:42+00:00 Liav Rehana liavr@mellanox.com 2016-08-16T07:55:35+00:00 45a945050dfa9619c3223add776c1b9d595a0655 commit 86147e3cfa5e118b61e78f4f0bf29e920dcbd477 upstream. User mode callee regs are explicitly collected before signal delivery or breakpoint trap. r25 is special for kernel as it serves as task pointer, so user mode value is clobbered very early. It is saved in pt_regs where generally only scratch (aka caller saved) regs are saved. The code to access the corresponding pt_regs location had a subtle bug as it was using load/store with scaling of offset, whereas the offset was already byte wise correct. So fix this by replacing LD.AS with a standard LD Signed-off-by: Liav Rehana <liavr@mellanox.com> Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com> [vgupta: rewrote title and commit log] Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 86147e3cfa5e118b61e78f4f0bf29e920dcbd477 upstream.

User mode callee regs are explicitly collected before signal delivery or
breakpoint trap. r25 is special for kernel as it serves as task pointer,
so user mode value is clobbered very early. It is saved in pt_regs where
generally only scratch (aka caller saved) regs are saved.

The code to access the corresponding pt_regs location had a subtle bug as
it was using load/store with scaling of offset, whereas the offset was already
byte wise correct. So fix this by replacing LD.AS with a standard LD

Signed-off-by: Liav Rehana <liavr@mellanox.com>
Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com>
[vgupta: rewrote title and commit log]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: build: Better way to detect ISA compatible toolchain 2016-09-07T06:32:42+00:00 Vineet Gupta vgupta@synopsys.com 2016-02-25T16:34:38+00:00 413d5877ef6f634f4f0346d75ccfca537b04518a commit 20d780374c81cf237834af2202c26df2100ddd69 upstream. ARC architecture has 2 instruction sets: ARCompact/ARCv2. While same gcc supports compiling for either (using appropriate toggles), we can't use the same toolchain to build kernel because libgcc needs to be unique and the toolchian (uClibc based) is not multilibed. uClibc toolchain is convenient since it allows all userspace and kernel to be built with a single install for an ISA. This however means 2 gnu installs (with same triplet prefix) are needed for building for 2 ISA and need to be in PATH. As developers we keep switching the builds, but would occassionally fail to update the PATH leading to usage of wrong tools. And this would only show up at the end of kernel build when linking incompatible libgcc. So the initial solution was to have gcc define a special preprocessor macro DEFAULT_CPU_xxx which is unique for default toolchain configuration. Claudiu proposed using grep for an existing preprocessor macro which is again uniquely defined per ISA. Cc: Michal Marek <mmarek@suse.cz> Suggested-by: Claudiu Zissulescu <claziss@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 20d780374c81cf237834af2202c26df2100ddd69 upstream.

ARC architecture has 2 instruction sets: ARCompact/ARCv2.
While same gcc supports compiling for either (using appropriate toggles),
we can't use the same toolchain to build kernel because libgcc needs
to be unique and the toolchian (uClibc based) is not multilibed.

uClibc toolchain is convenient since it allows all userspace and
kernel to be built with a single install for an ISA.

This however means 2 gnu installs (with same triplet prefix) are needed
for building for 2 ISA and need to be in PATH.
As developers we keep switching the builds, but would occassionally fail
to update the PATH leading to usage of wrong tools. And this would only
show up at the end of kernel build when linking incompatible libgcc.

So the initial solution was to have gcc define a special preprocessor macro
DEFAULT_CPU_xxx which is unique for default toolchain configuration.
Claudiu proposed using grep for an existing preprocessor macro which is
again uniquely defined per ISA.

Cc: Michal Marek <mmarek@suse.cz>
Suggested-by: Claudiu Zissulescu <claziss@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: mm: don't loose PTE_SPECIAL in pte_modify() 2016-08-20T16:09:20+00:00 Vineet Gupta vgupta@synopsys.com 2016-07-28T18:35:50+00:00 f2aa5d3771351ed45cf9f5ce73bc4695a09318be commit 3925a16ae980c79d1a8fd182d7f9487da1edd4dc upstream. LTP madvise05 was generating mm splat | [ARCLinux]# /sd/ltp/testcases/bin/madvise05 | BUG: Bad page map in process madvise05 pte:80e08211 pmd:9f7d4000 | page:9fdcfc90 count:1 mapcount:-1 mapping: (null) index:0x0 flags: 0x404(referenced|reserved) | page dumped because: bad pte | addr:200b8000 vm_flags:00000070 anon_vma: (null) mapping: (null) index:1005c | file: (null) fault: (null) mmap: (null) readpage: (null) | CPU: 2 PID: 6707 Comm: madvise05 And for newer kernels, the system was rendered unusable afterwards. The problem was mprotect->pte_modify() clearing PTE_SPECIAL (which is set to identify the special zero page wired to the pte). When pte was finally unmapped, special casing for zero page was not done, and instead it was treated as a "normal" page, tripping on the map counts etc. This fixes ARC STAR 9001053308 Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3925a16ae980c79d1a8fd182d7f9487da1edd4dc upstream.

LTP madvise05 was generating mm splat

| [ARCLinux]# /sd/ltp/testcases/bin/madvise05
| BUG: Bad page map in process madvise05  pte:80e08211 pmd:9f7d4000
| page:9fdcfc90 count:1 mapcount:-1 mapping:  (null) index:0x0 flags: 0x404(referenced|reserved)
| page dumped because: bad pte
| addr:200b8000 vm_flags:00000070 anon_vma:  (null) mapping:  (null) index:1005c
| file:  (null) fault:  (null) mmap:  (null) readpage:  (null)
| CPU: 2 PID: 6707 Comm: madvise05

And for newer kernels, the system was rendered unusable afterwards.

The problem was mprotect->pte_modify() clearing PTE_SPECIAL (which is
set to identify the special zero page wired to the pte).
When pte was finally unmapped, special casing for zero page was not
done, and instead it was treated as a "normal" page, tripping on the
map counts etc.

This fixes ARC STAR 9001053308

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARC: unwind: ensure that .debug_frame is generated (vs. .eh_frame) 2016-08-10T09:49:25+00:00 Vineet Gupta vgupta@synopsys.com 2016-06-28T04:12:25+00:00 6bce4d0eb37b1c4268b728985e98dbdcd9592632 commit f52e126cc7476196f44f3c313b7d9f0699a881fc upstream. With recent binutils update to support dwarf CFI pseudo-ops in gas, we now get .eh_frame vs. .debug_frame. Although the call frame info is exactly the same in both, the CIE differs, which the current kernel unwinder can't cope with. This broke both the kernel unwinder as well as loadable modules (latter because of a new unhandled relo R_ARC_32_PCREL from .rela.eh_frame in the module loader) The ideal solution would be to switch unwinder to .eh_frame. For now however we can make do by just ensureing .debug_frame is generated by removing -fasynchronous-unwind-tables .eh_frame generated with -gdwarf-2 -fasynchronous-unwind-tables .debug_frame generated with -gdwarf-2 Fixes STAR 9001058196 Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f52e126cc7476196f44f3c313b7d9f0699a881fc upstream.

With recent binutils update to support dwarf CFI pseudo-ops in gas, we
now get .eh_frame vs. .debug_frame. Although the call frame info is
exactly the same in both, the CIE differs, which the current kernel
unwinder can't cope with.

This broke both the kernel unwinder as well as loadable modules (latter
because of a new unhandled relo R_ARC_32_PCREL from .rela.eh_frame in
the module loader)

The ideal solution would be to switch unwinder to .eh_frame.
For now however we can make do by just ensureing .debug_frame is
generated by removing -fasynchronous-unwind-tables

 .eh_frame    generated with -gdwarf-2 -fasynchronous-unwind-tables
 .debug_frame generated with -gdwarf-2

Fixes STAR 9001058196

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arc: unwind: warn only once if DW2_UNWIND is disabled 2016-08-10T09:49:25+00:00 Alexey Brodkin Alexey.Brodkin@synopsys.com 2016-06-23T08:00:39+00:00 e0bc4e7e1c876f8e58ba381bf5194a8b8c8d448f commit 9bd54517ee86cb164c734f72ea95aeba4804f10b upstream. If CONFIG_ARC_DW2_UNWIND is disabled every time arc_unwind_core() gets called following message gets printed in debug console: ----------------->8--------------- CONFIG_ARC_DW2_UNWIND needs to be enabled ----------------->8--------------- That message makes sense if user indeed wants to see a backtrace or get nice function call-graphs in perf but what if user disabled unwinder for the purpose? Why pollute his debug console? So instead we'll warn user about possibly missing feature once and let him decide if that was what he or she really wanted. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9bd54517ee86cb164c734f72ea95aeba4804f10b upstream.

If CONFIG_ARC_DW2_UNWIND is disabled every time arc_unwind_core()
gets called following message gets printed in debug console:
----------------->8---------------
CONFIG_ARC_DW2_UNWIND needs to be enabled
----------------->8---------------

That message makes sense if user indeed wants to see a backtrace or
get nice function call-graphs in perf but what if user disabled
unwinder for the purpose? Why pollute his debug console?

So instead we'll warn user about possibly missing feature once and
let him decide if that was what he or she really wanted.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARCv2: LLSC: software backoff is NOT needed starting HS2.1c 2016-07-27T16:47:31+00:00 Vineet Gupta vgupta@synopsys.com 2016-03-15T06:06:43+00:00 fb4d339f0ffdbe8b6b3aa57940c4a40f538a1887 commit b31ac42697bef4a3aa5d0aa42375a55657f57174 upstream. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b31ac42697bef4a3aa5d0aa42375a55657f57174 upstream.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>