linux-toradex.git/arch/arm64/kernel/hw_breakpoint.c, branch v4.16-rc3

arm64: hw_breakpoint: Use linux/uaccess.h instead of asm/uaccess.h

2017-12-12T11:53:26+00:00

The only inclusion of asm/uaccess.h should be by linux/uaccess.h. All
other headers should use the latter.

Reported-by: Al Viro 
Signed-off-by: Will Deacon

arm64: hw_breakpoint: fix watchpoint matching for tagged pointers

2017-05-09T16:26:40+00:00

When we take a watchpoint exception, the address that triggered the
watchpoint is found in FAR_EL1. We compare it to the address of each
configured watchpoint to see which one was hit.

The configured watchpoint addresses are untagged, while the address in
FAR_EL1 will have an address tag if the data access was done using a
tagged address. The tag needs to be removed to compare the address to
the watchpoints.

Currently we don't remove it, and as a result can report the wrong
watchpoint as being hit (specifically, always either the highest TTBR0
watchpoint or lowest TTBR1 watchpoint). This patch removes the tag.

Fixes: d50240a5f6ce ("arm64: mm: permit use of tagged pointers at EL0")
Cc:  # 3.12.x-
Acked-by: Mark Rutland 
Acked-by: Will Deacon 
Signed-off-by: Kristina Martsenko 
Signed-off-by: Catalin Marinas

cpu/hotplug: Cleanup state names

2016-12-25T09:47:44+00:00

When the state names got added a script was used to add the extra argument
to the calls. The script basically converted the state constant to a
string, but the cleanup to convert these strings into meaningful ones did
not happen.

Replace all the useless strings with 'subsys/xxx/yyy:state' strings which
are used in all the other places already.

Signed-off-by: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Sebastian Siewior 
Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de
Signed-off-by: Thomas Gleixner

arm64: Allow hw watchpoint of length 3,5,6 and 7

2016-11-18T17:26:14+00:00

Since, arm64 can support all offset within a double word limit. Therefore,
now support other lengths within that range as well.

Signed-off-by: Pratyush Anand 
Signed-off-by: Will Deacon

arm64: hw_breakpoint: Handle inexact watchpoint addresses

2016-11-18T17:25:50+00:00

Arm64 hardware does not always report a watchpoint hit address that
matches one of the watchpoints set. It can also report an address
"near" the watchpoint if a single instruction access both watched and
unwatched addresses. There is no straight-forward way, short of
disassembling the offending instruction, to map that address back to
the watchpoint.

Previously, when the hardware reported a watchpoint hit on an address
that did not match our watchpoint (this happens in case of instructions
which access large chunks of memory such as "stp") the process would
enter a loop where we would be continually resuming it (because we did
not recognise that watchpoint hit) and it would keep hitting the
watchpoint again and again. The tracing process would never get
notified of the watchpoint hit.

This commit fixes the problem by looking at the watchpoints near the
address reported by the hardware. If the address does not exactly match
one of the watchpoints we have set, it attributes the hit to the
nearest watchpoint we have.  This heuristic is a bit dodgy, but I don't
think we can do much more, given the hardware limitations.

Signed-off-by: Pavel Labath 
[panand: reworked to rebase on his patches]
Signed-off-by: Pratyush Anand 
[will: use __ffs instead of ffs - 1]
Signed-off-by: Will Deacon

arm64: Allow hw watchpoint at varied offset from base address

2016-11-18T17:23:17+00:00

ARM64 hardware supports watchpoint at any double word aligned address.
However, it can select any consecutive bytes from offset 0 to 7 from that
base address. For example, if base address is programmed as 0x420030 and
byte select is 0x1C, then access of 0x420032,0x420033 and 0x420034 will
generate a watchpoint exception.

Currently, we do not have such modularity. We can only program byte,
halfword, word and double word access exception from any base address.

This patch adds support to overcome above limitations.

Signed-off-by: Pratyush Anand 
Signed-off-by: Will Deacon

arm64: hw_breakpoint: convert CPU hotplug notifier to new infrastructure

2016-09-01T12:45:51+00:00

The arm64 hw_breakpoint implementation uses a CPU hotplug notifier to
reset the {break,watch}point registers when CPUs come online.

This patch converts the code to the new hotplug mechanism, whilst moving
the invocation earlier to remove the need to disable IRQs explicitly in
the driver (which could cause havok if we trip a watchpoint in an IRQ
handler whilst restoring the debug register state).

Cc: Sebastian Andrzej Siewior 
Reviewed-by: Lorenzo Pieralisi 
Signed-off-by: Will Deacon

arm64: Blacklist non-kprobe-able symbol

2016-07-19T14:03:20+00:00

Add all function symbols which are called from do_debug_exception under
NOKPROBE_SYMBOL, as they can not kprobed.

Signed-off-by: Pratyush Anand 
Acked-by: Masami Hiramatsu 
Signed-off-by: Catalin Marinas

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2016-05-17T00:17:24+00:00

Pull arm64 updates from Will Deacon:

 - virt_to_page/page_address optimisations

 - support for NUMA systems described using device-tree

 - support for hibernate/suspend-to-disk

 - proper support for maxcpus= command line parameter

 - detection and graceful handling of AArch64-only CPUs

 - miscellaneous cleanups and non-critical fixes

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits)
  arm64: do not enforce strict 16 byte alignment to stack pointer
  arm64: kernel: Fix incorrect brk randomization
  arm64: cpuinfo: Missing NULL terminator in compat_hwcap_str
  arm64: secondary_start_kernel: Remove unnecessary barrier
  arm64: Ensure pmd_present() returns false after pmd_mknotpresent()
  arm64: Replace hard-coded values in the pmd/pud_bad() macros
  arm64: Implement pmdp_set_access_flags() for hardware AF/DBM
  arm64: Fix typo in the pmdp_huge_get_and_clear() definition
  arm64: mm: remove unnecessary EXPORT_SYMBOL_GPL
  arm64: always use STRICT_MM_TYPECHECKS
  arm64: kvm: Fix kvm teardown for systems using the extended idmap
  arm64: kaslr: increase randomization granularity
  arm64: kconfig: drop CONFIG_RTC_LIB dependency
  arm64: make ARCH_SUPPORTS_DEBUG_PAGEALLOC depend on !HIBERNATION
  arm64: hibernate: Refuse to hibernate if the boot cpu is offline
  arm64: kernel: Add support for hibernate/suspend-to-disk
  PM / Hibernate: Call flush_icache_range() on pages restored in-place
  arm64: Add new asm macro copy_page
  arm64: Promote KERNEL_START/KERNEL_END definitions to a header file
  arm64: kernel: Include _AC definition in page.h
  ...

arm64: hw-breakpoint: Remove superfluous SMP function call

2016-04-14T17:13:03+00:00

Since commit 1cf4f629d9d2 ("cpu/hotplug: Move online calls to
hotplugged cpu") it is ensured that callbacks of CPU_ONLINE and
CPU_DOWN_PREPARE are processed on the hotplugged CPU. Due to this SMP
function calls are no longer required.

Replace smp_call_function_single() with a direct call of
hw_breakpoint_reset(). To keep the calling convention, interrupts are
explicitly disabled around the call.

Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Anna-Maria Gleixner 
Signed-off-by: Will Deacon