linux-toradex.git/arch/arm/kernel, branch v4.2.7 Linux kernel for Apalis and Colibri modules ARM: 8425/1: kgdb: Don't try to stop the machine when setting breakpoints 2015-10-22T21:49:16+00:00 Doug Anderson armlinux@m.disordat.com 2015-08-26T17:26:49+00:00 d05cc8b34fc73e40ef9df0dfa9924e33990daaa2 commit 7ae85dc7687c7e7119053d83d02c560ea217b772 upstream. In (23a4e40 arm: kgdb: Handle read-only text / modules) we moved to using patch_text() to set breakpoints so that we could handle the case when we had CONFIG_DEBUG_RODATA. That patch used patch_text(). Unfortunately, patch_text() assumes that we're not in atomic context when it runs since it needs to grab a mutex and also wait for other CPUs to stop (which it does with a completion). This would result in a stack crawl if you had CONFIG_DEBUG_ATOMIC_SLEEP and tried to set a breakpoint in kgdb. The crawl looked something like: BUG: scheduling while atomic: swapper/0/0/0x00010007 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc7-00133-geb63b34 #1073 Hardware name: Rockchip (Device Tree) (unwind_backtrace) from [<c00133d4>] (show_stack+0x20/0x24) (show_stack) from [<c05400e8>] (dump_stack+0x84/0xb8) (dump_stack) from [<c004913c>] (__schedule_bug+0x54/0x6c) (__schedule_bug) from [<c054065c>] (__schedule+0x80/0x668) (__schedule) from [<c0540cfc>] (schedule+0xb8/0xd4) (schedule) from [<c0543a3c>] (schedule_timeout+0x2c/0x234) (schedule_timeout) from [<c05417c0>] (wait_for_common+0xf4/0x188) (wait_for_common) from [<c0541874>] (wait_for_completion+0x20/0x24) (wait_for_completion) from [<c00a0104>] (__stop_cpus+0x58/0x70) (__stop_cpus) from [<c00a0580>] (stop_cpus+0x3c/0x54) (stop_cpus) from [<c00a06c4>] (__stop_machine+0xcc/0xe8) (__stop_machine) from [<c00a0714>] (stop_machine+0x34/0x44) (stop_machine) from [<c00173e8>] (patch_text+0x28/0x34) (patch_text) from [<c001733c>] (kgdb_arch_set_breakpoint+0x40/0x4c) (kgdb_arch_set_breakpoint) from [<c00a0d68>] (kgdb_validate_break_address+0x2c/0x60) (kgdb_validate_break_address) from [<c00a0e90>] (dbg_set_sw_break+0x1c/0xdc) (dbg_set_sw_break) from [<c00a2e88>] (gdb_serial_stub+0x9c4/0xba4) (gdb_serial_stub) from [<c00a11cc>] (kgdb_cpu_enter+0x1f8/0x60c) (kgdb_cpu_enter) from [<c00a18cc>] (kgdb_handle_exception+0x19c/0x1d0) (kgdb_handle_exception) from [<c0016f7c>] (kgdb_compiled_brk_fn+0x30/0x3c) (kgdb_compiled_brk_fn) from [<c00091a4>] (do_undefinstr+0x1a4/0x20c) (do_undefinstr) from [<c001400c>] (__und_svc_finish+0x0/0x34) It turns out that when we're in kgdb all the CPUs are stopped anyway so there's no reason we should be calling patch_text(). We can instead directly call __patch_text() which assumes that CPUs have already been stopped. Fixes: 23a4e4050ba9 ("arm: kgdb: Handle read-only text / modules") Reported-by: Aapo Vienamo <avienamo@nvidia.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7ae85dc7687c7e7119053d83d02c560ea217b772 upstream.

In (23a4e40 arm: kgdb: Handle read-only text / modules) we moved to
using patch_text() to set breakpoints so that we could handle the case
when we had CONFIG_DEBUG_RODATA.  That patch used patch_text().
Unfortunately, patch_text() assumes that we're not in atomic context
when it runs since it needs to grab a mutex and also wait for other
CPUs to stop (which it does with a completion).

This would result in a stack crawl if you had
CONFIG_DEBUG_ATOMIC_SLEEP and tried to set a breakpoint in kgdb.  The
crawl looked something like:

 BUG: scheduling while atomic: swapper/0/0/0x00010007
 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc7-00133-geb63b34 #1073
 Hardware name: Rockchip (Device Tree)
  (unwind_backtrace) from [<c00133d4>] (show_stack+0x20/0x24)
  (show_stack) from [<c05400e8>] (dump_stack+0x84/0xb8)
  (dump_stack) from [<c004913c>] (__schedule_bug+0x54/0x6c)
  (__schedule_bug) from [<c054065c>] (__schedule+0x80/0x668)
  (__schedule) from [<c0540cfc>] (schedule+0xb8/0xd4)
  (schedule) from [<c0543a3c>] (schedule_timeout+0x2c/0x234)
  (schedule_timeout) from [<c05417c0>] (wait_for_common+0xf4/0x188)
  (wait_for_common) from [<c0541874>] (wait_for_completion+0x20/0x24)
  (wait_for_completion) from [<c00a0104>] (__stop_cpus+0x58/0x70)
  (__stop_cpus) from [<c00a0580>] (stop_cpus+0x3c/0x54)
  (stop_cpus) from [<c00a06c4>] (__stop_machine+0xcc/0xe8)
  (__stop_machine) from [<c00a0714>] (stop_machine+0x34/0x44)
  (stop_machine) from [<c00173e8>] (patch_text+0x28/0x34)
  (patch_text) from [<c001733c>] (kgdb_arch_set_breakpoint+0x40/0x4c)
  (kgdb_arch_set_breakpoint) from [<c00a0d68>] (kgdb_validate_break_address+0x2c/0x60)
  (kgdb_validate_break_address) from [<c00a0e90>] (dbg_set_sw_break+0x1c/0xdc)
  (dbg_set_sw_break) from [<c00a2e88>] (gdb_serial_stub+0x9c4/0xba4)
  (gdb_serial_stub) from [<c00a11cc>] (kgdb_cpu_enter+0x1f8/0x60c)
  (kgdb_cpu_enter) from [<c00a18cc>] (kgdb_handle_exception+0x19c/0x1d0)
  (kgdb_handle_exception) from [<c0016f7c>] (kgdb_compiled_brk_fn+0x30/0x3c)
  (kgdb_compiled_brk_fn) from [<c00091a4>] (do_undefinstr+0x1a4/0x20c)
  (do_undefinstr) from [<c001400c>] (__und_svc_finish+0x0/0x34)

It turns out that when we're in kgdb all the CPUs are stopped anyway
so there's no reason we should be calling patch_text().  We can
instead directly call __patch_text() which assumes that CPUs have
already been stopped.

Fixes: 23a4e4050ba9 ("arm: kgdb: Handle read-only text / modules")
Reported-by: Aapo Vienamo <avienamo@nvidia.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: fix Thumb2 signal handling when ARMv6 is enabled 2015-10-22T21:49:16+00:00 Russell King rmk+kernel@arm.linux.org.uk 2015-09-11T15:44:02+00:00 30477feadc4d86d40011326fb2f9e45f3987f504 commit 9b55613f42e8d40d5c9ccb8970bde6af4764b2ab upstream. When a kernel is built covering ARMv6 to ARMv7, we omit to clear the IT state when entering a signal handler. This can cause the first few instructions to be conditionally executed depending on the parent context. In any case, the original test for >= ARMv7 is broken - ARMv6 can have Thumb-2 support as well, and an ARMv6T2 specific build would omit this code too. Relax the test back to ARMv6 or greater. This results in us always clearing the IT state bits in the PSR, even on CPUs where these bits are reserved. However, they're reserved for the IT state, so this should cause no harm. Fixes: d71e1352e240 ("Clear the IT state when invoking a Thumb-2 signal handler") Acked-by: Tony Lindgren <tony@atomide.com> Tested-by: H. Nikolaus Schaller <hns@goldelico.com> Tested-by: Grazvydas Ignotas <notasas@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9b55613f42e8d40d5c9ccb8970bde6af4764b2ab upstream.

When a kernel is built covering ARMv6 to ARMv7, we omit to clear the
IT state when entering a signal handler.  This can cause the first
few instructions to be conditionally executed depending on the parent
context.

In any case, the original test for >= ARMv7 is broken - ARMv6 can have
Thumb-2 support as well, and an ARMv6T2 specific build would omit this
code too.

Relax the test back to ARMv6 or greater.  This results in us always
clearing the IT state bits in the PSR, even on CPUs where these bits
are reserved.  However, they're reserved for the IT state, so this
should cause no harm.

Fixes: d71e1352e240 ("Clear the IT state when invoking a Thumb-2 signal handler")
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: H. Nikolaus Schaller <hns@goldelico.com>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: 8401/1: perf: Set affinity for PPI based PMUs 2015-10-22T21:49:15+00:00 Stephen Boyd sboyd@codeaurora.org 2015-07-07T17:16:15+00:00 75c0dceaa2c4517d3939a9ee1f64fcc6048c23d8 commit 8ded1e1a92daa96307e4b84b707fee5993bc6047 upstream. For PPI based PMUs, we bail out early in of_pmu_irq_cfg() without setting the PMU's supported_cpus bitmap. This causes the smp_call_function_any() in armv7_probe_num_events() to fail. Set the bitmap to be all CPUs so that we properly probe PMUs that use PPIs. Fixes: cc88116da0d1 ("arm: perf: treat PMUs as CPU affine") Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8ded1e1a92daa96307e4b84b707fee5993bc6047 upstream.

For PPI based PMUs, we bail out early in of_pmu_irq_cfg() without
setting the PMU's supported_cpus bitmap. This causes the
smp_call_function_any() in armv7_probe_num_events() to fail. Set
the bitmap to be all CPUs so that we properly probe PMUs that use
PPIs.

Fixes: cc88116da0d1 ("arm: perf: treat PMUs as CPU affine")
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: 8410/1: VDSO: fix coarse clock monotonicity regression 2015-08-11T12:42:44+00:00 Nathan Lynch nathan_lynch@mentor.com 2015-08-10T16:36:06+00:00 09edea4f8fdeb4e292b80d493296070f5ec64e6e Since 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the real timekeeper last") it has become possible on ARM to: - Obtain a CLOCK_MONOTONIC_COARSE or CLOCK_REALTIME_COARSE timestamp via syscall. - Subsequently obtain a timestamp for the same clock ID via VDSO which predates the first timestamp (by one jiffy). This is because ARM's update_vsyscall is deriving the coarse time using the __current_kernel_time interface, when it should really be using the timekeeper object provided to it by the timekeeping core. It happened to work before only because __current_kernel_time would access the same timekeeper object which had been passed to update_vsyscall. This is no longer the case. Cc: stable@vger.kernel.org Fixes: 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the real timekeeper last") Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Since 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the
real timekeeper last") it has become possible on ARM to:

- Obtain a CLOCK_MONOTONIC_COARSE or CLOCK_REALTIME_COARSE timestamp
  via syscall.
- Subsequently obtain a timestamp for the same clock ID via VDSO which
  predates the first timestamp (by one jiffy).

This is because ARM's update_vsyscall is deriving the coarse time
using the __current_kernel_time interface, when it should really be
using the timekeeper object provided to it by the timekeeping core.
It happened to work before only because __current_kernel_time would
access the same timekeeper object which had been passed to
update_vsyscall.  This is no longer the case.

Cc: stable@vger.kernel.org
Fixes: 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the real timekeeper last")
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 8409/1: Mark ret_fast_syscall as a function 2015-08-07T18:57:02+00:00 Drew Richardson drew.richardson@arm.com 2015-08-06T17:50:27+00:00 e83dd3770021910293edea6fb2dc2fa306b1bf34 ret_fast_syscall runs when user space makes a syscall. However it needs to be marked as such so the ELF information is correct. Before it was: 101: 8000f300 0 NOTYPE LOCAL DEFAULT 2 ret_fast_syscall But with this change it correctly shows as: 101: 8000f300 96 FUNC LOCAL DEFAULT 2 ret_fast_syscall I see this function when using perf to unwind call stacks from kernel space to user space. Without this change I would need to add some special case logic when using the vmlinux ELF information. Signed-off-by: Drew Richardson <drew.richardson@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
ret_fast_syscall runs when user space makes a syscall. However it
needs to be marked as such so the ELF information is correct. Before
it was:

   101: 8000f300     0 NOTYPE  LOCAL  DEFAULT    2 ret_fast_syscall

But with this change it correctly shows as:

   101: 8000f300    96 FUNC    LOCAL  DEFAULT    2 ret_fast_syscall

I see this function when using perf to unwind call stacks from kernel
space to user space. Without this change I would need to add some
special case logic when using the vmlinux ELF information.

Signed-off-by: Drew Richardson <drew.richardson@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 8408/1: Fix the secondary_startup function in Big Endian case 2015-08-07T18:57:02+00:00 Gregory CLEMENT gregory.clement@free-electrons.com 2015-08-06T14:07:04+00:00 998ef5d81c74c752d74c7925bc370909b84adb9d Since the commit "b2c3e38a5471 ARM: redo TTBR setup code for LPAE", the setup code had been reworked. As a result the secondary CPUs failed to come online in Big Endian. As explained by Russell, the new code expected the value in r4/r5 to be the least significant 32bits in r4 and the most significant 32bits in r5. However, in the secondary code, we load this using ldrd, which on BE reverses that. This patch swap r4/r5 after the ldrd. It is done using the xor instructions in order to not use a temporary register. Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Since the commit "b2c3e38a5471 ARM: redo TTBR setup code for LPAE",
the setup code had been reworked. As a result the secondary CPUs
failed to come online in Big Endian.

As explained by Russell, the new code expected the value in r4/r5 to
be the least significant 32bits in r4 and the most significant 32bits
in r5. However, in the secondary code, we load this using ldrd, which
on BE reverses that.

This patch swap r4/r5 after the ldrd. It is done using the xor
instructions in order to not use a temporary register.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 8402/1: perf: Don't use of_node after putting it 2015-07-17T14:08:38+00:00 Stephen Boyd sboyd@codeaurora.org 2015-07-07T17:17:05+00:00 8e0c34b0d268f10d84cb3f79f59c140d545a553a It's possible, albeit unlikely, that using the of_node here will reference freed memory. Call of_node_put() after printing the name to be safe. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
It's possible, albeit unlikely, that using the of_node here will
reference freed memory. Call of_node_put() after printing the
name to be safe.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 8400/1: use virt_to_idmap to get phys_reset address 2015-07-17T14:08:17+00:00 Vitaly Andrianov vitalya@ti.com 2015-07-06T15:43:18+00:00 df9de3c4295afa45d9c58c3d9039098af5765a21 This patch is to get correct physical address of the reset function for PAE systems, which use aliased physical memory for booting. See the "ARM: mm: Introduce virt_to_idmap() with an arch hook" for details. Signed-off-by: Vitaly Andrianov <vitalya@ti.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
This patch is to get correct physical address of the reset function for
PAE systems, which use aliased physical memory for booting.

See the "ARM: mm: Introduce virt_to_idmap() with an arch hook" for details.

Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2015-07-07T22:19:09+00:00 Linus Torvalds torvalds@linux-foundation.org 2015-07-07T22:19:09+00:00 d6ac4ffc61ace6ed6f183e9fd7f207c0ddafb897 Pull ARM updates from Russell King: "These are late by a week; they should have been merged during the merge window, but unfortunately, the ARM kernel build/boot farms were indicating random failures, and it wasn't clear whether the cause was something in these changes or something during the merge window. This is a set of merge window fixes with some documentation additions" * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: ARM: avoid unwanted GCC memset()/memcpy() optimisations for IO variants ARM: pgtable: document mapping types ARM: io: convert ioremap*() to functions ARM: io: fix ioremap_wt() implementation ARM: io: document ARM specific behaviour of ioremap*() implementations ARM: fix lockdep unannotated irqs-off warning ARM: 8397/1: fix vdsomunge not to depend on glibc specific error.h ARM: add helpful message when truncating physical memory ARM: add help text for HIGHPTE configuration entry ARM: fix DEBUG_SET_MODULE_RONX build dependencies ARM: 8396/1: use phys_addr_t in pfn_to_kaddr() ARM: 8394/1: update memblock limit after mapping lowmem ARM: 8393/1: smp: Fix suspicious RCU usage with ipi tracepoints 
Pull ARM updates from Russell King:
 "These are late by a week; they should have been merged during the
  merge window, but unfortunately, the ARM kernel build/boot farms were
  indicating random failures, and it wasn't clear whether the cause was
  something in these changes or something during the merge window.

  This is a set of merge window fixes with some documentation additions"

* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: avoid unwanted GCC memset()/memcpy() optimisations for IO variants
  ARM: pgtable: document mapping types
  ARM: io: convert ioremap*() to functions
  ARM: io: fix ioremap_wt() implementation
  ARM: io: document ARM specific behaviour of ioremap*() implementations
  ARM: fix lockdep unannotated irqs-off warning
  ARM: 8397/1: fix vdsomunge not to depend on glibc specific error.h
  ARM: add helpful message when truncating physical memory
  ARM: add help text for HIGHPTE configuration entry
  ARM: fix DEBUG_SET_MODULE_RONX build dependencies
  ARM: 8396/1: use phys_addr_t in pfn_to_kaddr()
  ARM: 8394/1: update memblock limit after mapping lowmem
  ARM: 8393/1: smp: Fix suspicious RCU usage with ipi tracepoints
Merge branches 'fixes' and 'ioremap' into for-linus 2015-07-07T11:35:33+00:00 Russell King rmk+kernel@arm.linux.org.uk 2015-07-07T11:35:33+00:00 06be5eefe1192eb8ce8d07497f67595b6bfe9741