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  1. Jun 30, 2017
  2. Jun 29, 2017
  3. Jun 26, 2017
  4. Jun 24, 2017
    • Mark Rutland's avatar
      arm64: ftrace: fix !CONFIG_ARM64_MODULE_PLTS kernels · 8486e54d
      Mark Rutland authored
      When a kernel is built without CONFIG_ARM64_MODULE_PLTS, we don't
      generate the expected branch instruction in ftrace_make_nop(). This
      means we pass zero (rather than a valid branch) to ftrace_modify_code()
      as the expected instruction to validate. This causes us to return
      -EINVAL to the core ftrace code for a valid case, resulting in a splat
      at boot time.
      
      This was an unintended effect of commit:
      
        68764420 ("arm64: ftrace: fix building without CONFIG_MODULES")
      
      ... which incorrectly moved the generation of the branch instruction
      into the ifdef for CONFIG_ARM64_MODULE_PLTS.
      
      This patch fixes the issue by moving the ifdef inside of the relevant
      if-else case, and always checking that the branch is in range,
      regardless of CONFIG_ARM64_MODULE_PLTS. This ensures that we generate
      the expected branch instruction, and also improves our sanity checks.
      
      For consistency, both ftrace_make_nop() and ftrace_make_call() are
      updated with this pattern.
      
      Fixes: 68764420
      
       ("arm64: ftrace: fix building without CONFIG_MODULES")
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Reported-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Reviewed-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      8486e54d
    • Dave Martin's avatar
      arm64: signal: Allow expansion of the signal frame · 33f08261
      Dave Martin authored
      
      
      This patch defines an extra_context signal frame record that can be
      used to describe an expanded signal frame, and modifies the context
      block allocator and signal frame setup and parsing code to create,
      populate, parse and decode this block as necessary.
      
      To avoid abuse by userspace, parse_user_sigframe() attempts to
      ensure that:
      
       * no more than one extra_context is accepted;
       * the extra context data is a sensible size, and properly placed
         and aligned.
      
      The extra_context data is required to start at the first 16-byte
      aligned address immediately after the dummy terminator record
      following extra_context in rt_sigframe.__reserved[] (as ensured
      during signal delivery).  This serves as a sanity-check that the
      signal frame has not been moved or copied without taking the extra
      data into account.
      
      Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
      Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      [will: add __force annotation when casting extra_datap to __user pointer]
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      33f08261
  5. Jun 23, 2017
  6. Jun 22, 2017
    • Mark Rutland's avatar
      arm64: dump cpu_hwcaps at panic time · 8effeaaf
      Mark Rutland authored
      
      
      When debugging a kernel panic(), it can be useful to know which CPU
      features have been detected by the kernel, as some code paths can depend
      on these (and may have been patched at runtime).
      
      This patch adds a notifier to dump the detected CPU caps (as a hex
      string) at panic(), when we log other information useful for debugging.
      On a Juno R1 system running v4.12-rc5, this looks like:
      
      [  615.431249] Kernel panic - not syncing: Fatal exception in interrupt
      [  615.437609] SMP: stopping secondary CPUs
      [  615.441872] Kernel Offset: disabled
      [  615.445372] CPU features: 0x02086
      [  615.448522] Memory Limit: none
      
      A developer can decode this by looking at the corresponding
      <asm/cpucaps.h> bits. For example, the above decodes as:
      
      * bit  1: ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE
      * bit  2: ARM64_WORKAROUND_845719
      * bit  7: ARM64_WORKAROUND_834220
      * bit 13: ARM64_HAS_32BIT_EL0
      
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Acked-by: default avatarSteve Capper <steve.capper@arm.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      8effeaaf
    • Dave Martin's avatar
      arm64: ptrace: Flush user-RW TLS reg to thread_struct before reading · 936eb65c
      Dave Martin authored
      
      
      When reading current's user-writable TLS register (which occurs
      when dumping core for native tasks), it is possible that userspace
      has modified it since the time the task was last scheduled out.
      The new TLS register value is not guaranteed to have been written
      immediately back to thread_struct in this case.
      
      As a result, a coredump can capture stale data for this register.
      Reading the register for a stopped task via ptrace is unaffected.
      
      For native tasks, this patch explicitly flushes the TPIDR_EL0
      register back to thread_struct before dumping when operating on
      current, thus ensuring that coredump contents are up to date.  For
      compat tasks, the TLS register is not user-writable and so cannot
      be out of sync, so no flush is required in compat_tls_get().
      
      Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      936eb65c
    • Dave Martin's avatar
      arm64: ptrace: Flush FPSIMD regs back to thread_struct before reading · e1d5a8fb
      Dave Martin authored
      
      
      When reading the FPSIMD state of current (which occurs when dumping
      core), it is possible that userspace has modified the FPSIMD
      registers since the time the task was last scheduled out.  Such
      changes are not guaranteed to be reflected immedately in
      thread_struct.
      
      As a result, a coredump can contain stale values for these
      registers.  Reading the registers of a stopped task via ptrace is
      unaffected.
      
      This patch explicitly flushes the CPU state back to thread_struct
      before dumping when operating on current, thus ensuring that
      coredump contents are up to date.
      
      Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      e1d5a8fb
    • Dave Martin's avatar
      arm64: ptrace: Fix VFP register dumping in compat coredumps · af66b2d8
      Dave Martin authored
      
      
      Currently, VFP registers are omitted from coredumps for compat
      processes, due to a bug in the REGSET_COMPAT_VFP regset
      implementation.
      
      compat_vfp_get() needs to transfer non-contiguous data from
      thread_struct.fpsimd_state, and uses put_user() to handle the
      offending trailing word (FPSCR).  This fails when copying to a
      kernel address (i.e., kbuf && !ubuf), which is what happens when
      dumping core.  As a result, the ELF coredump core code silently
      omits the NT_ARM_VFP note from the dump.
      
      It would be possible to work around this with additional special
      case code for the put_user(), but since user_regset_copyout() is
      explicitly designed to handle this scenario it is cleaner to port
      the put_user() to a user_regset_copyout() call, which this patch
      does.
      
      Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      af66b2d8
    • Tyler Baicar's avatar
      efi: parse ARM processor error · 2f74f09b
      Tyler Baicar authored
      
      
      Add support for ARM Common Platform Error Record (CPER).
      UEFI 2.6 specification adds support for ARM specific
      processor error information to be reported as part of the
      CPER records. This provides more detail on for processor error logs.
      
      Signed-off-by: default avatarTyler Baicar <tbaicar@codeaurora.org>
      CC: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
      Reviewed-by: default avatarJames Morse <james.morse@arm.com>
      Reviewed-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      2f74f09b
    • Tyler Baicar's avatar
      cper: add timestamp print to CPER status printing · 8a94471f
      Tyler Baicar authored
      
      
      The ACPI 6.1 spec added a timestamp to the generic error data
      entry structure. Print the timestamp out when printing out the
      error information.
      
      Signed-off-by: default avatarTyler Baicar <tbaicar@codeaurora.org>
      CC: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      8a94471f
    • Tyler Baicar's avatar
      ras: acpi/apei: cper: add support for generic data v3 structure · bbcc2e7b
      Tyler Baicar authored
      
      
      The ACPI 6.1 spec adds a new revision of the generic error data
      entry structure. Add support to handle the new structure as well
      as properly verify and iterate through the generic data entries.
      
      Signed-off-by: default avatarTyler Baicar <tbaicar@codeaurora.org>
      CC: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      bbcc2e7b
    • Tyler Baicar's avatar
      acpi: apei: read ack upon ghes record consumption · 42aa5604
      Tyler Baicar authored
      
      
      A RAS (Reliability, Availability, Serviceability) controller
      may be a separate processor running in parallel with OS
      execution, and may generate error records for consumption by
      the OS. If the RAS controller produces multiple error records,
      then they may be overwritten before the OS has consumed them.
      
      The Generic Hardware Error Source (GHES) v2 structure
      introduces the capability for the OS to acknowledge the
      consumption of the error record generated by the RAS
      controller. A RAS controller supporting GHESv2 shall wait for
      the acknowledgment before writing a new error record, thus
      eliminating the race condition.
      
      Add support for parsing of GHESv2 sub-tables as well.
      
      Signed-off-by: default avatarTyler Baicar <tbaicar@codeaurora.org>
      CC: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
      Reviewed-by: default avatarJames Morse <james.morse@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      42aa5604
  7. Jun 21, 2017
  8. Jun 20, 2017
    • Luc Van Oostenryck's avatar
      arm64: pass machine size to sparse · f5d28490
      Luc Van Oostenryck authored
      
      
      When using sparse on the arm64 tree we get many thousands of
      warnings like 'constant ... is so big it is unsigned long long'
      or 'shift too big (32) for type unsigned long'. This happens
      because by default sparse considers the machine as 32bit and
      defines the size of the types accordingly.
      
      Fix this by passing the '-m64' flag to sparse so that
      sparse can correctly define longs as being 64bit.
      
      CC: Catalin Marinas <catalin.marinas@arm.com>
      CC: Will Deacon <will.deacon@arm.com>
      CC: linux-arm-kernel@lists.infradead.org
      Signed-off-by: default avatarLuc Van Oostenryck <luc.vanoostenryck@gmail.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      f5d28490
    • Dave Martin's avatar
      arm64: signal: factor out signal frame record allocation · bb4322f7
      Dave Martin authored
      
      
      This patch factors out the allocator for signal frame optional
      records into a separate function, to ensure consistency and
      facilitate later expansion.
      
      No overrun checking is currently done, because the allocation is in
      user memory and anyway the kernel never tries to allocate enough
      space in the signal frame yet for an overrun to occur.  This
      behaviour will be refined in future patches.
      
      The approach taken in this patch to allocation of the terminator
      record is not very clean: this will also be replaced in subsequent
      patches.
      
      For future extension, a comment is added in sigcontext.h
      documenting the current static allocations in __reserved[].  This
      will be important for determining under what circumstances
      userspace may or may not see an expanded signal frame.
      
      Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      bb4322f7