linux-stable.git/arch/arm64, branch linux-3.16.y Linux kernel stable tree KVM: arm64: Only sign-extend MMIO up to register width 2020-05-22T20:19:29+00:00 Christoffer Dall christoffer.dall@arm.com 2019-12-12T19:50:55+00:00 6a73af05d634d774f72ea41f9518c777743726bc commit b6ae256afd32f96bec0117175b329d0dd617655e upstream. On AArch64 you can do a sign-extended load to either a 32-bit or 64-bit register, and we should only sign extend the register up to the width of the register as specified in the operation (by using the 32-bit Wn or 64-bit Xn register specifier). As it turns out, the architecture provides this decoding information in the SF ("Sixty-Four" -- how cute...) bit. Let's take advantage of this with the usual 32-bit/64-bit header file dance and do the right thing on AArch64 hosts. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20191212195055.5541-1-christoffer.dall@arm.com [bwh: Backported to 3.16: - Use ESR_EL2_SF - Adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit b6ae256afd32f96bec0117175b329d0dd617655e upstream.

On AArch64 you can do a sign-extended load to either a 32-bit or 64-bit
register, and we should only sign extend the register up to the width of
the register as specified in the operation (by using the 32-bit Wn or
64-bit Xn register specifier).

As it turns out, the architecture provides this decoding information in
the SF ("Sixty-Four" -- how cute...) bit.

Let's take advantage of this with the usual 32-bit/64-bit header file
dance and do the right thing on AArch64 hosts.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20191212195055.5541-1-christoffer.dall@arm.com
[bwh: Backported to 3.16:
 - Use ESR_EL2_SF
 - Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
arm64: debug: Ensure debug handlers check triggering exception level 2020-01-11T02:04:59+00:00 Will Deacon will.deacon@arm.com 2019-03-01T13:28:01+00:00 551da7ca4fa4e7356fc921077b0f8419280a34f4 commit 6bd288569b50bc89fa5513031086746968f585cb upstream. Debug exception handlers may be called for exceptions generated both by user and kernel code. In many cases, this is checked explicitly, but in other cases things either happen to work by happy accident or they go slightly wrong. For example, executing 'brk #4' from userspace will enter the kprobes code and be ignored, but the instruction will be retried forever in userspace instead of delivering a SIGTRAP. Fix this issue in the most stable-friendly fashion by simply adding explicit checks of the triggering exception level to all of our debug exception handlers. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 6bd288569b50bc89fa5513031086746968f585cb upstream.

Debug exception handlers may be called for exceptions generated both by
user and kernel code. In many cases, this is checked explicitly, but
in other cases things either happen to work by happy accident or they
go slightly wrong. For example, executing 'brk #4' from userspace will
enter the kprobes code and be ignored, but the instruction will be
retried forever in userspace instead of delivering a SIGTRAP.

Fix this issue in the most stable-friendly fashion by simply adding
explicit checks of the triggering exception level to all of our debug
exception handlers.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
arm64: debug: Don't propagate UNKNOWN FAR into si_code for debug signals 2020-01-11T02:04:59+00:00 Will Deacon will.deacon@arm.com 2019-03-01T13:28:00+00:00 e2c3a06b65720b4f1f5932e9cb649798d5a82e24 commit b9a4b9d084d978f80eb9210727c81804588b42ff upstream. FAR_EL1 is UNKNOWN for all debug exceptions other than those caused by taking a hardware watchpoint. Unfortunately, if a debug handler returns a non-zero value, then we will propagate the UNKNOWN FAR value to userspace via the si_addr field of the SIGTRAP siginfo_t. Instead, let's set si_addr to take on the PC of the faulting instruction, which we have available in the current pt_regs. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit b9a4b9d084d978f80eb9210727c81804588b42ff upstream.

FAR_EL1 is UNKNOWN for all debug exceptions other than those caused by
taking a hardware watchpoint. Unfortunately, if a debug handler returns
a non-zero value, then we will propagate the UNKNOWN FAR value to
userspace via the si_addr field of the SIGTRAP siginfo_t.

Instead, let's set si_addr to take on the PC of the faulting instruction,
which we have available in the current pt_regs.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
arm64: support keyctl() system call in 32-bit mode 2020-01-11T02:04:58+00:00 Eric Biggers ebiggers@google.com 2017-03-09T00:27:04+00:00 546383d4dae597b45f76610be2c54909f38fea9e commit 5c2a625937ba49bc691089370638223d310cda9a upstream. As is the case for a number of other architectures that have a 32-bit compat mode, enable KEYS_COMPAT if both COMPAT and KEYS are enabled. This allows AArch32 programs to use the keyctl() system call when running on an AArch64 kernel. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 5c2a625937ba49bc691089370638223d310cda9a upstream.

As is the case for a number of other architectures that have a 32-bit
compat mode, enable KEYS_COMPAT if both COMPAT and KEYS are enabled.
This allows AArch32 programs to use the keyctl() system call when
running on an AArch64 kernel.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
arm64: kconfig: drop CONFIG_RTC_LIB dependency 2020-01-11T02:04:57+00:00 Ezequiel Garcia ezequiel@vanguardiasur.com.ar 2016-04-27T16:55:28+00:00 0e741f5ce13aef3dfc3e129357cf096da958912c commit 99a507771fa57238dc7ffe674ae06090333d02c9 upstream. The rtc-lib dependency is not required, and seems it was just copy-pasted from ARM's Kconfig. If platform requires rtc-lib, they should select it individually. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 99a507771fa57238dc7ffe674ae06090333d02c9 upstream.

The rtc-lib dependency is not required, and seems it was just
copy-pasted from ARM's Kconfig. If platform requires rtc-lib,
they should select it individually.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
arm64: kernel: Include _AC definition in page.h 2020-01-11T02:04:54+00:00 James Morse james.morse@arm.com 2016-04-27T16:47:08+00:00 4d1a9f511b3ae28bc83af2c05cd0c39656dcd49a commit 812264550dcba6cdbe84bfac2f27e7d23b5b8733 upstream. page.h uses '_AC' in the definition of PAGE_SIZE, but doesn't include linux/const.h where this is defined. This produces build warnings when only asm/page.h is included by asm code. Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 812264550dcba6cdbe84bfac2f27e7d23b5b8733 upstream.

page.h uses '_AC' in the definition of PAGE_SIZE, but doesn't include
linux/const.h where this is defined. This produces build warnings when only
asm/page.h is included by asm code.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
arm64/kernel: fix incorrect EL0 check in inv_entry macro 2020-01-11T02:04:54+00:00 Ard Biesheuvel ard.biesheuvel@linaro.org 2016-03-18T09:58:09+00:00 3865feeeed4502f7281041b9390b6d06750d9605 commit b660950c60a7278f9d8deb7c32a162031207c758 upstream. The implementation of macro inv_entry refers to its 'el' argument without the required leading backslash, which results in an undefined symbol 'el' to be passed into the kernel_entry macro rather than the index of the exception level as intended. This undefined symbol strangely enough does not result in build failures, although it is visible in vmlinux: $ nm -n vmlinux |head U el 0000000000000000 A _kernel_flags_le_hi32 0000000000000000 A _kernel_offset_le_hi32 0000000000000000 A _kernel_size_le_hi32 000000000000000a A _kernel_flags_le_lo32 ..... However, it does result in incorrect code being generated for invalid exceptions taken from EL0, since the argument check in kernel_entry assumes EL1 if its argument does not equal '0'. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit b660950c60a7278f9d8deb7c32a162031207c758 upstream.

The implementation of macro inv_entry refers to its 'el' argument without
the required leading backslash, which results in an undefined symbol
'el' to be passed into the kernel_entry macro rather than the index of
the exception level as intended.

This undefined symbol strangely enough does not result in build failures,
although it is visible in vmlinux:

     $ nm -n vmlinux |head
                      U el
     0000000000000000 A _kernel_flags_le_hi32
     0000000000000000 A _kernel_offset_le_hi32
     0000000000000000 A _kernel_size_le_hi32
     000000000000000a A _kernel_flags_le_lo32
     .....

However, it does result in incorrect code being generated for invalid
exceptions taken from EL0, since the argument check in kernel_entry
assumes EL1 if its argument does not equal '0'.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
arm64: fix COMPAT_SHMLBA definition for large pages 2020-01-11T02:04:49+00:00 Yury Norov ynorov@caviumnetworks.com 2015-12-02T14:00:10+00:00 c325515b53a6e378f2e2c78be2dc970ae7ad2302 commit b9b7aebb42d1b1392f3111de61136bb6cf3aae3f upstream. ARM glibc uses (4 * __getpagesize()) for SHMLBA, which is correct for 4KB pages and works fine for 64KB pages, but the kernel uses a hardcoded 16KB that is too small for 64KB page based kernels. This changes the definition to what user space sees when using 64KB pages. Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit b9b7aebb42d1b1392f3111de61136bb6cf3aae3f upstream.

ARM glibc uses (4 * __getpagesize()) for SHMLBA, which is correct for
4KB pages and works fine for 64KB pages, but the kernel uses a hardcoded
16KB that is too small for 64KB page based kernels. This changes the
definition to what user space sees when using 64KB pages.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
arm64: traps: disable irq in die() 2020-01-11T02:04:48+00:00 Qiao Zhou qiaozhou@asrmicro.com 2017-07-07T09:29:34+00:00 ec4efc4c5fbdd9ad303a9b078b4d72f5a4c7844b commit 6f44a0bacb79a03972c83759711832b382b1b8ac upstream. In current die(), the irq is disabled for __die() handle, not including the possible panic() handling. Since the log in __die() can take several hundreds ms, new irq might come and interrupt current die(). If the process calling die() holds some critical resource, and some other process scheduled later also needs it, then it would deadlock. The first panic will not be executed. So here disable irq for the whole flow of die(). Signed-off-by: Qiao Zhou <qiaozhou@asrmicro.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 6f44a0bacb79a03972c83759711832b382b1b8ac upstream.

In current die(), the irq is disabled for __die() handle, not
including the possible panic() handling. Since the log in __die()
can take several hundreds ms, new irq might come and interrupt
current die().

If the process calling die() holds some critical resource, and some
other process scheduled later also needs it, then it would deadlock.
The first panic will not be executed.

So here disable irq for the whole flow of die().

Signed-off-by: Qiao Zhou <qiaozhou@asrmicro.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
arm64: mm: Add trace_irqflags annotations to do_debug_exception() 2020-01-11T02:04:44+00:00 James Morse james.morse@arm.com 2016-04-13T12:40:00+00:00 fc77274ef0da62cce42699f523bf92794e43e4dd commit 6afedcd23cfd7ac56c011069e4a8db37b46e4623 upstream. With CONFIG_PROVE_LOCKING, CONFIG_DEBUG_LOCKDEP and CONFIG_TRACE_IRQFLAGS enabled, lockdep will compare current->hardirqs_enabled with the flags from local_irq_save(). When a debug exception occurs, interrupts are disabled in entry.S, but lockdep isn't told, resulting in: DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) ------------[ cut here ]------------ WARNING: at ../kernel/locking/lockdep.c:3523 Modules linked in: CPU: 3 PID: 1752 Comm: perf Not tainted 4.5.0-rc4+ #2204 Hardware name: ARM Juno development board (r1) (DT) task: ffffffc974868000 ti: ffffffc975f40000 task.ti: ffffffc975f40000 PC is at check_flags.part.35+0x17c/0x184 LR is at check_flags.part.35+0x17c/0x184 pc : [<ffffff80080fc93c>] lr : [<ffffff80080fc93c>] pstate: 600003c5 [...] ---[ end trace 74631f9305ef5020 ]--- Call trace: [<ffffff80080fc93c>] check_flags.part.35+0x17c/0x184 [<ffffff80080ffe30>] lock_acquire+0xa8/0xc4 [<ffffff8008093038>] breakpoint_handler+0x118/0x288 [<ffffff8008082434>] do_debug_exception+0x3c/0xa8 [<ffffff80080854b4>] el1_dbg+0x18/0x6c [<ffffff80081e82f4>] do_filp_open+0x64/0xdc [<ffffff80081d6e60>] do_sys_open+0x140/0x204 [<ffffff80081d6f58>] SyS_openat+0x10/0x18 [<ffffff8008085d30>] el0_svc_naked+0x24/0x28 possible reason: unannotated irqs-off. irq event stamp: 65857 hardirqs last enabled at (65857): [<ffffff80081fb1c0>] lookup_mnt+0xf4/0x1b4 hardirqs last disabled at (65856): [<ffffff80081fb188>] lookup_mnt+0xbc/0x1b4 softirqs last enabled at (65790): [<ffffff80080bdca4>] __do_softirq+0x1f8/0x290 softirqs last disabled at (65757): [<ffffff80080be038>] irq_exit+0x9c/0xd0 This patch adds the annotations to do_debug_exception(), while trying not to call trace_hardirqs_off() if el1_dbg() interrupted a task that already had irqs disabled. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 6afedcd23cfd7ac56c011069e4a8db37b46e4623 upstream.

With CONFIG_PROVE_LOCKING, CONFIG_DEBUG_LOCKDEP and CONFIG_TRACE_IRQFLAGS
enabled, lockdep will compare current->hardirqs_enabled with the flags from
local_irq_save().

When a debug exception occurs, interrupts are disabled in entry.S, but
lockdep isn't told, resulting in:
DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)
------------[ cut here ]------------
WARNING: at ../kernel/locking/lockdep.c:3523
Modules linked in:
CPU: 3 PID: 1752 Comm: perf Not tainted 4.5.0-rc4+ #2204
Hardware name: ARM Juno development board (r1) (DT)
task: ffffffc974868000 ti: ffffffc975f40000 task.ti: ffffffc975f40000
PC is at check_flags.part.35+0x17c/0x184
LR is at check_flags.part.35+0x17c/0x184
pc : [<ffffff80080fc93c>] lr : [<ffffff80080fc93c>] pstate: 600003c5
[...]
---[ end trace 74631f9305ef5020 ]---
Call trace:
[<ffffff80080fc93c>] check_flags.part.35+0x17c/0x184
[<ffffff80080ffe30>] lock_acquire+0xa8/0xc4
[<ffffff8008093038>] breakpoint_handler+0x118/0x288
[<ffffff8008082434>] do_debug_exception+0x3c/0xa8
[<ffffff80080854b4>] el1_dbg+0x18/0x6c
[<ffffff80081e82f4>] do_filp_open+0x64/0xdc
[<ffffff80081d6e60>] do_sys_open+0x140/0x204
[<ffffff80081d6f58>] SyS_openat+0x10/0x18
[<ffffff8008085d30>] el0_svc_naked+0x24/0x28
possible reason: unannotated irqs-off.
irq event stamp: 65857
hardirqs last  enabled at (65857): [<ffffff80081fb1c0>] lookup_mnt+0xf4/0x1b4
hardirqs last disabled at (65856): [<ffffff80081fb188>] lookup_mnt+0xbc/0x1b4
softirqs last  enabled at (65790): [<ffffff80080bdca4>] __do_softirq+0x1f8/0x290
softirqs last disabled at (65757): [<ffffff80080be038>] irq_exit+0x9c/0xd0

This patch adds the annotations to do_debug_exception(), while trying not
to call trace_hardirqs_off() if el1_dbg() interrupted a task that already
had irqs disabled.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>