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Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm
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Pull ARM fixes from Russell King:
 "This round of fixes is smaller than previous: a couple more updates
  for the security fixes, and a one-liner kexec fix"

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7816/1: CONFIG_KUSER_HELPERS: fix help text
  ARM: 7815/1: kexec: offline non panic CPUs on Kdump panic
  ARM: 7819/1: fiq: Cast the first argument of flush_icache_range()
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Linus Torvalds committed Aug 25, 2013
2 parents 4d4323e + e1f0203 commit 1b4757e
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Showing 3 changed files with 9 additions and 4 deletions.
3 changes: 2 additions & 1 deletion arch/arm/kernel/fiq.c
Original file line number Diff line number Diff line change
Expand Up @@ -89,7 +89,8 @@ void set_fiq_handler(void *start, unsigned int length)

memcpy(base + offset, start, length);
if (!cache_is_vipt_nonaliasing())
flush_icache_range(base + offset, offset + length);
flush_icache_range((unsigned long)base + offset, offset +
length);
flush_icache_range(0xffff0000 + offset, 0xffff0000 + offset + length);
}

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1 change: 1 addition & 0 deletions arch/arm/kernel/machine_kexec.c
Original file line number Diff line number Diff line change
Expand Up @@ -82,6 +82,7 @@ void machine_crash_nonpanic_core(void *unused)
crash_save_cpu(&regs, smp_processor_id());
flush_cache_all();

set_cpu_online(smp_processor_id(), false);
atomic_dec(&waiting_for_crash_ipi);
while (1)
cpu_relax();
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9 changes: 6 additions & 3 deletions arch/arm/mm/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -809,15 +809,18 @@ config KUSER_HELPERS
the CPU type fitted to the system. This permits binaries to be
run on ARMv4 through to ARMv7 without modification.

See Documentation/arm/kernel_user_helpers.txt for details.

However, the fixed address nature of these helpers can be used
by ROP (return orientated programming) authors when creating
exploits.

If all of the binaries and libraries which run on your platform
are built specifically for your platform, and make no use of
these helpers, then you can turn this option off. However,
when such an binary or library is run, it will receive a SIGILL
signal, which will terminate the program.
these helpers, then you can turn this option off to hinder
such exploits. However, in that case, if a binary or library
relying on those helpers is run, it will receive a SIGILL signal,
which will terminate the program.

Say N here only if you are absolutely certain that you do not
need these helpers; otherwise, the safe option is to say Y.
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