linux-stable.git/arch/arc/include, branch v3.14.78

ARC: make sure instruction_pointer() returns unsigned value

2015-08-10T19:21:04+00:00

commit f51e2f1911122879eefefa4c592dea8bf794b39c upstream.

Currently instruction_pointer() returns pt_regs->ret and so return value
is of type "long", which implicitly stands for "signed long".

While that's perfectly fine when dealing with 32-bit values if return
value of instruction_pointer() gets assigned to 64-bit variable sign
extension may happen.

And at least in one real use-case it happens already.
In perf_prepare_sample() return value of perf_instruction_pointer()
(which is an alias to instruction_pointer() in case of ARC) is assigned
to (struct perf_sample_data)->ip (which type is "u64").

And what we see if instuction pointer points to user-space application
that in case of ARC lays below 0x8000_0000 "ip" gets set properly with
leading 32 zeros. But if instruction pointer points to kernel address
space that starts from 0x8000_0000 then "ip" is set with 32 leadig
"f"-s. I.e. id instruction_pointer() returns 0x8100_0000, "ip" will be
assigned with 0xffff_ffff__8100_0000. Which is obviously wrong.

In particular that issuse broke output of perf, because perf was unable
to associate addresses like 0xffff_ffff__8100_0000 with anything from
/proc/kallsyms.

That's what we used to see:
 ----------->8----------
  6.27%  ls       [unknown]                [k] 0xffffffff8046c5cc
  2.96%  ls       libuClibc-0.9.34-git.so  [.] memcpy
  2.25%  ls       libuClibc-0.9.34-git.so  [.] memset
  1.66%  ls       [unknown]                [k] 0xffffffff80666536
  1.54%  ls       libuClibc-0.9.34-git.so  [.] 0x000224d6
  1.18%  ls       libuClibc-0.9.34-git.so  [.] 0x00022472
 ----------->8----------

With that change perf output looks much better now:
 ----------->8----------
  8.21%  ls       [kernel.kallsyms]        [k] memset
  3.52%  ls       libuClibc-0.9.34-git.so  [.] memcpy
  2.11%  ls       libuClibc-0.9.34-git.so  [.] malloc
  1.88%  ls       libuClibc-0.9.34-git.so  [.] memset
  1.64%  ls       [kernel.kallsyms]        [k] _raw_spin_unlock_irqrestore
  1.41%  ls       [kernel.kallsyms]        [k] __d_lookup_rcu
 ----------->8----------

Signed-off-by: Alexey Brodkin 
Cc: arc-linux-dev@synopsys.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: add compiler barrier to LLSC based cmpxchg

2015-08-03T16:29:51+00:00

commit d57f727264f1425a94689bafc7e99e502cb135b5 upstream.

When auditing cmpxchg call sites, Chuck noted that gcc was optimizing
away some of the desired LDs.

|	do {
|		new = old = *ipi_data_ptr;
|		new |= 1U << msg;
|	} while (cmpxchg(ipi_data_ptr, old, new) != old);

was generating to below

| 8015cef8:	ld         r2,[r4,0]  <-- First LD
| 8015cefc:	bset       r1,r2,r1
|
| 8015cf00:	llock      r3,[r4]  <-- atomic op
| 8015cf04:	brne       r3,r2,8015cf10
| 8015cf08:	scond      r1,[r4]
| 8015cf0c:	bnz        8015cf00
|
| 8015cf10:	brne       r3,r2,8015cf00  <-- Branch doesn't go to orig LD

Although this was fixed by adding a ACCESS_ONCE in this call site, it
seems safer (for now at least) to add compiler barrier to LLSC based
cmpxchg

Reported-by: Chuck Jordan 
Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: Fix KSTK_ESP()

2015-03-18T12:31:31+00:00

commit 13648b0118a24f4fc76c34e6c7b6ccf447e46a2a upstream.

/proc//maps currently don't annotate stack vma with "[stack]"
This is because KSTK_ESP ie expected to return usermode SP of tsk while
currently it returns the kernel mode SP of a sleeping tsk.

While the fix is trivial, we also need to adjust the ARC kernel stack
unwinder to not use KSTK_SP and friends any more.

Reported-and-suggested-by: Alexey Brodkin 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE

2015-03-06T22:43:31+00:00

commit 06f34e1c28f3608b0ce5b310e41102d3fe7b65a1 upstream.

We used to calculate page address differently in 2 cases:

1. In virt_to_page(x) we do
 --->8---
 mem_map + (x - CONFIG_LINUX_LINK_BASE) >> PAGE_SHIFT
 --->8---

2. In in pte_page(x) we do
 --->8---
 mem_map + (pte_val(x) - PAGE_OFFSET) >> PAGE_SHIFT
 --->8---

That leads to problems in case PAGE_OFFSET != CONFIG_LINUX_LINK_BASE -
different pages will be selected depending on where and how we calculate
page address.

In particular in the STAR 9000853582 when gdb attempted to read memory
of another process it got improper page in get_user_pages() because this
is exactly one of the places where we search for a page by pte_page().

The fix is trivial - we need to calculate page address similarly in both
cases.

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

ARC: Delete stale barrier.h

2015-01-30T01:40:50+00:00

commit 64ee9f32c33cbd53545284742e73c17fedf9d429 upstream.

Commit 93ea02bb8435 ("arch: Clean up asm/barrier.h implementations")
wired generic barrier.h for ARC, but failed to delete the existing file.

In 3.15, due to rcupdate.h updates, this causes a build breakage on ARC:

      CC      arch/arc/kernel/asm-offsets.s
    In file included from include/linux/sched.h:45:0,
                     from arch/arc/kernel/asm-offsets.c:9:
    include/linux/rculist.h: In function __list_add_rcu:
    include/linux/rculist.h:54:2: error: implicit declaration of function smp_store_release [-Werror=implicit-function-declaration]
      rcu_assign_pointer(list_next_rcu(prev), new);
      ^

Cc: Peter Zijlstra 
Signed-off-by: Vineet Gupta 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ARC: switch to generic ENTRY/END assembler annotations

2015-01-27T16:18:54+00:00

commit ec7ac6afd07b2d958aab9dfc0a686300b856922a upstream.

With commit 9df62f054406 "arch: use ASM_NL instead of ';'" the generic
macros can handle the arch specific newline quirk. Hence we can get rid
of ARC asm macros and use the "C" style macros.

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

ARC: Disable caches in early boot if so configured

2014-11-14T16:59:56+00:00

commit ef680cdc24376f394841a3f19b3a7ef6d57a009d upstream.

Requested-by: Noam Camus 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: Update order of registers in KGDB to match GDB 7.5

2014-11-14T16:59:56+00:00

commit ebc0c74e76cec9c4dd860eb0ca1c0b39dc63c482 upstream.

Order of registers has changed in GDB moving from 6.8 to 7.5. This patch
updates KGDB to work properly with GDB 7.5, though makes it incompatible
with 6.8.

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

ARC: Implement ptrace(PTRACE_GET_THREAD_AREA)

2014-07-28T15:06:04+00:00

commit a4b6cb735b25aa84a462a1985e3e43bebaf5beb4 upstream.

This patch adds implementation of GET_THREAD_AREA ptrace request type. This
is required by GDB to debug NPTL applications.

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

Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

2014-01-31T00:58:05+00:00

Pull kbuild changes from Michal Marek:
 - fix make -s detection with make-4.0
 - fix for scripts/setlocalversion when the kernel repository is a
   submodule
 - do not hardcode ';' in macros that expand to assembler code, as some
   architectures' assemblers use a different character for newline
 - Fix passing --gdwarf-2 to the assembler

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  frv: Remove redundant debugging info flag
  mn10300: Remove redundant debugging info flag
  kbuild: Fix debugging info generation for .S files
  arch: use ASM_NL instead of ';' for assembler new line character in the macro
  kbuild: Fix silent builds with make-4
  Fix detectition of kernel git repository in setlocalversion script [take #2]