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2020-09-27Merge tag 'v4.4.237' into toradex_vf_4.4Max Krummenacher
This is the 4.4.237 stable release Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
2020-08-21ARM: 8992/1: Fix unwind_frame for clang-built kernelsNathan Huckleberry
commit b4d5ec9b39f8b31d98f65bc5577b5d15d93795d7 upstream. Since clang does not push pc and sp in function prologues, the current implementation of unwind_frame does not work. By using the previous frame's lr/fp instead of saved pc/sp we get valid unwinds on clang-built kernels. The bounds check on next frame pointer must be changed as well since there are 8 less bytes between frames. This fixes /proc/<pid>/stack. Link: https://github.com/ClangBuiltLinux/linux/issues/912 Reported-by: Miles Chen <miles.chen@mediatek.com> Tested-by: Miles Chen <miles.chen@mediatek.com> Cc: stable@vger.kernel.org Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Huckleberry <nhuck@google.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21ARM: 8986/1: hw_breakpoint: Don't invoke overflow handler on uaccess watchpointsWill Deacon
[ Upstream commit eec13b42d41b0f3339dcf0c4da43734427c68620 ] Unprivileged memory accesses generated by the so-called "translated" instructions (e.g. LDRT) in kernel mode can cause user watchpoints to fire unexpectedly. In such cases, the hw_breakpoint logic will invoke the user overflow handler which will typically raise a SIGTRAP back to the current task. This is futile when returning back to the kernel because (a) the signal won't have been delivered and (b) userspace can't handle the thing anyway. Avoid invoking the user overflow handler for watchpoints triggered by kernel uaccess routines, and instead single-step over the faulting instruction as we would if no overflow handler had been installed. Cc: <stable@vger.kernel.org> Fixes: f81ef4a920c8 ("ARM: 6356/1: hw-breakpoint: add ARM backend for the hw-breakpoint framework") Reported-by: Luis Machado <luis.machado@linaro.org> Tested-by: Luis Machado <luis.machado@linaro.org> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-20ARM: 8977/1: ptrace: Fix mask for thumb breakpoint hookFredrik Strupe
[ Upstream commit 3866f217aaa81bf7165c7f27362eee5d7919c496 ] call_undef_hook() in traps.c applies the same instr_mask for both 16-bit and 32-bit thumb instructions. If instr_mask then is only 16 bits wide (0xffff as opposed to 0xffffffff), the first half-word of 32-bit thumb instructions will be masked out. This makes the function match 32-bit thumb instructions where the second half-word is equal to instr_val, regardless of the first half-word. The result in this case is that all undefined 32-bit thumb instructions with the second half-word equal to 0xde01 (udf #1) work as breakpoints and will raise a SIGTRAP instead of a SIGILL, instead of just the one intended 16-bit instruction. An example of such an instruction is 0xeaa0de01, which is unallocated according to Arm ARM and should raise a SIGILL, but instead raises a SIGTRAP. This patch fixes the issue by setting all the bits in instr_mask, which will still match the intended 16-bit thumb instruction (where the upper half is always 0), but not any 32-bit thumb instructions. Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Fredrik Strupe <fredrik@strupe.net> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-28Merge tag 'v4.4.217' into toradex_vf_4.4-nextMax Krummenacher
This is the 4.4.217 stable release
2020-03-20ARM: 8957/1: VDSO: Match ARMv8 timer in cntvct_functional()Florian Fainelli
commit 45939ce292b4b11159719faaf60aba7d58d5fe33 upstream. It is possible for a system with an ARMv8 timer to run a 32-bit kernel. When this happens we will unconditionally have the vDSO code remove the __vdso_gettimeofday and __vdso_clock_gettime symbols because cntvct_functional() returns false since it does not match that compatibility string. Fixes: ecf99a439105 ("ARM: 8331/1: VDSO initialization, mapping, and synchronization") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-24Merge tag 'v4.4.214' into toradex_vf_4.4-nextMax Krummenacher
This is the 4.4.214 stable release
2020-01-29ARM: 8847/1: pm: fix HYP/SVC mode mismatch when MCPM is usedMarek Szyprowski
[ Upstream commit ca70ea43f80c98582f5ffbbd1e6f4da2742da0c4 ] MCPM does a soft reset of the CPUs and uses common cpu_resume() routine to perform low-level platform initialization. This results in a try to install HYP stubs for the second time for each CPU and results in false HYP/SVC mode mismatch detection. The HYP stubs are already installed at the beginning of the kernel initialization on the boot CPU (head.S) or in the secondary_startup() for other CPUs. To fix this issue MCPM code should use a cpu_resume() routine without HYP stubs installation. This change fixes HYP/SVC mode mismatch on Samsung Exynos5422-based Odroid XU3/XU4/HC1 boards. Fixes: 3721924c8154 ("ARM: 8081/1: MCPM: provide infrastructure to allow for MCPM loopback") Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Nicolas Pitre <nico@linaro.org> Tested-by: Anand Moon <linux.amoon@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-25ARM: 8802/1: Call syscall_trace_exit even when system call skippedTimothy E Baldwin
[ Upstream commit f18aef742c8fbd68e280dff0a63ba0ca6ee8ad85 ] On at least x86 and ARM64, and as documented in the ptrace man page a skipped system call will still cause a syscall exit ptrace stop. Previous to this commit 32-bit ARM did not, resulting in strace being confused when seccomp skips system calls. This change also impacts programs that use ptrace to skip system calls. Fixes: ad75b51459ae ("ARM: 7579/1: arch/allow a scno of -1 to not cause a SIGILL") Signed-off-by: Timothy E Baldwin <T.E.Baldwin99@members.leeds.ac.uk> Signed-off-by: Eugene Syromyatnikov <evgsyr@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Eugene Syromyatnikov <evgsyr@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-10ARM: spectre-v2: per-CPU vtables to work around big.Little systemsRussell King
Commit 383fb3ee8024d596f488d2dbaf45e572897acbdb upstream. In big.Little systems, some CPUs require the Spectre workarounds in paths such as the context switch, but other CPUs do not. In order to handle these differences, we need per-CPU vtables. We are unable to use the kernel's per-CPU variables to support this as per-CPU is not initialised at times when we need access to the vtables, so we have to use an array indexed by logical CPU number. We use an array-of-pointers to avoid having function pointers in the kernel's read/write .data section. Note: Added include of linux/slab.h in arch/arm/smp.c. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: add PROC_VTABLE and PROC_TABLE macrosRussell King
Commit e209950fdd065d2cc46e6338e47e52841b830cba upstream. Allow the way we access members of the processor vtable to be changed at compile time. We will need to move to per-CPU vtables to fix the Spectre variant 2 issues on big.Little systems. However, we have a couple of calls that do not need the vtable treatment, and indeed cause a kernel warning due to the (later) use of smp_processor_id(), so also introduce the PROC_TABLE macro for these which always use CPU 0's function pointers. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: clean up per-processor check_bugs method callRussell King
Commit 945aceb1db8885d3a35790cf2e810f681db52756 upstream. Call the per-processor type check_bugs() method in the same way as we do other per-processor functions - move the "processor." detail into proc-fns.h. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: split out processor lookupRussell King
Commit 65987a8553061515b5851b472081aedb9837a391 upstream. Split out the lookup of the processor type and associated error handling from the rest of setup_processor() - we will need to use this in the secondary CPU bringup path for big.Little Spectre variant 2 mitigation. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: make lookup_processor_type() non-__initRussell King
Commit 899a42f836678a595f7d2bc36a5a0c2b03d08cbc upstream. Move lookup_processor_type() out of the __init section so it is callable from (eg) the secondary startup code during hotplug. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: 8793/1: signal: replace __put_user_error with __put_userJulien Thierry
Commit 18ea66bd6e7a95bdc598223d72757190916af28b upstream. With Spectre-v1.1 mitigations, __put_user_error is pointless. In an attempt to remove it, replace its references in frame setups with __put_user. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: 8792/1: oabi-compat: copy oabi events using __copy_to_user()Julien Thierry
Commit 319508902600c2688e057750148487996396e9ca upstream. Copy events to user using __copy_to_user() rather than copy members of individually with __put_user_error(). This has the benefit of disabling/enabling PAN once per event intead of once per event member. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: 8791/1: vfp: use __copy_to_user() when saving VFP stateJulien Thierry
Commit 3aa2df6ec2ca6bc143a65351cca4266d03a8bc41 upstream. Use __copy_to_user() rather than __put_user_error() for individual members when saving VFP state. This has the benefit of disabling/enabling PAN once per copied struct intead of once per write. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: 8789/1: signal: copy registers using __copy_to_user()Julien Thierry
Commit 5ca451cf6ed04443774bbb7ee45332dafa42e99f upstream. When saving the ARM integer registers, use __copy_to_user() to copy them into user signal frame, rather than __put_user_error(). This has the benefit of disabling/enabling PAN once for the whole copy intead of once per write. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: oabi-compat: copy semops using __copy_from_user()Russell King
Commit 8c8484a1c18e3231648f5ba7cc5ffb7fd70b3ca4 upstream. __get_user_error() is used as a fast accessor to make copying structure members as efficient as possible. However, with software PAN and the recent Spectre variant 1, the efficiency is reduced as these are no longer fast accessors. In the case of software PAN, it has to switch the domain register around each access, and with Spectre variant 1, it would have to repeat the access_ok() check for each access. Rather than using __get_user_error() to copy each semops element member, copy each semops element in full using __copy_from_user(). Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: vfp: use __copy_from_user() when restoring VFP stateRussell King
Commit 42019fc50dfadb219f9e6ddf4c354f3837057d80 upstream. __get_user_error() is used as a fast accessor to make copying structure members in the signal handling path as efficient as possible. However, with software PAN and the recent Spectre variant 1, the efficiency is reduced as these are no longer fast accessors. In the case of software PAN, it has to switch the domain register around each access, and with Spectre variant 1, it would have to repeat the access_ok() check for each access. Use __copy_from_user() rather than __get_user_err() for individual members when restoring VFP state. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: signal: copy registers using __copy_from_user()Russell King
Commit c32cd419d6650e42b9cdebb83c672ec945e6bd7e upstream. __get_user_error() is used as a fast accessor to make copying structure members in the signal handling path as efficient as possible. However, with software PAN and the recent Spectre variant 1, the efficiency is reduced as these are no longer fast accessors. In the case of software PAN, it has to switch the domain register around each access, and with Spectre variant 1, it would have to repeat the access_ok() check for each access. It becomes much more efficient to use __copy_from_user() instead, so let's use this for the ARM integer registers. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: spectre-v1: fix syscall entryRussell King
Commit 10573ae547c85b2c61417ff1a106cffbfceada35 upstream. Prevent speculation at the syscall table decoding by clamping the index used to zero on invalid system call numbers, and using the csdb speculative barrier. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Mark Rutland <mark.rutland@arm.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: bugs: add support for per-processor bug checkingRussell King
Commit 9d3a04925deeabb97c8e26d940b501a2873e8af3 upstream. Add support for per-processor bug checking - each processor function descriptor gains a function pointer for this check, which must not be an __init function. If non-NULL, this will be called whenever a CPU enters the kernel via which ever path (boot CPU, secondary CPU startup, CPU resuming, etc.) This allows processor specific bug checks to validate that workaround bits are properly enabled by firmware via all entry paths to the kernel. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: bugs: hook processor bug checking into SMP and suspend pathsRussell King
Commit 26602161b5ba795928a5a719fe1d5d9f2ab5c3ef upstream. Check for CPU bugs when secondary processors are being brought online, and also when CPUs are resuming from a low power mode. This gives an opportunity to check that processor specific bug workarounds are correctly enabled for all paths that a CPU re-enters the kernel. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: bugs: prepare processor bug infrastructureRussell King
Commit a5b9177f69329314721aa7022b7e69dab23fa1f0 upstream. Prepare the processor bug infrastructure so that it can be expanded to check for per-processor bugs. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: David A. Long <dave.long@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: 8481/2: drivers: psci: replace psci firmware callsJens Wiklander
Commit e679660dbb8347f275fe5d83a5dd59c1fb6c8e63 upstream. Switch to use a generic interface for issuing SMC/HVC based on ARM SMC Calling Convention. Removes now the now unused psci-call.S. Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-10ARM: 8479/2: add implementation for arm-smcccJens Wiklander
Commit b329f95d70f3f955093e9a2b18ac1ed3587a8f73 upstream. Adds implementation for arm-smccc and enables CONFIG_HAVE_SMCCC for architectures that may support arm-smccc. It's the responsibility of the caller to know if the SMC instruction is supported by the platform. Reviewed-by: Lars Persson <lars.persson@axis.com> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-27ARM: 8839/1: kprobe: make patch_lock a raw_spinlock_tYang Shi
[ Upstream commit 143c2a89e0e5fda6c6fd08d7bc1126438c19ae90 ] When running kprobe on -rt kernel, the below bug is caught: |BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:931 |in_atomic(): 1, irqs_disabled(): 128, pid: 14, name: migration/0 |Preemption disabled at:[<802f2b98>] cpu_stopper_thread+0xc0/0x140 |CPU: 0 PID: 14 Comm: migration/0 Tainted: G O 4.8.3-rt2 #1 |Hardware name: Freescale LS1021A |[<8025a43c>] (___might_sleep) |[<80b5b324>] (rt_spin_lock) |[<80b5c31c>] (__patch_text_real) |[<80b5c3ac>] (patch_text_stop_machine) |[<802f2920>] (multi_cpu_stop) Since patch_text_stop_machine() is called in stop_machine() which disables IRQ, sleepable lock should be not used in this atomic context, so replace patch_lock to raw lock. Signed-off-by: Yang Shi <yang.shi@linaro.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-27ARM: avoid Cortex-A9 livelock on tight dmb loopsRussell King
[ Upstream commit 5388a5b82199facacd3d7ac0d05aca6e8f902fed ] machine_crash_nonpanic_core() does this: while (1) cpu_relax(); because the kernel has crashed, and we have no known safe way to deal with the CPU. So, we place the CPU into an infinite loop which we expect it to never exit - at least not until the system as a whole is reset by some method. In the absence of erratum 754327, this code assembles to: b . In other words, an infinite loop. When erratum 754327 is enabled, this becomes: 1: dmb b 1b It has been observed that on some systems (eg, OMAP4) where, if a crash is triggered, the system tries to kexec into the panic kernel, but fails after taking the secondary CPU down - placing it into one of these loops. This causes the system to livelock, and the most noticable effect is the system stops after issuing: Loading crashdump kernel... to the system console. The tested as working solution I came up with was to add wfe() to these infinite loops thusly: while (1) { cpu_relax(); wfe(); } which, without 754327 builds to: 1: wfe b 1b or with 754327 is enabled: 1: dmb wfe b 1b Adding "wfe" does two things depending on the environment we're running under: - where we're running on bare metal, and the processor implements "wfe", it stops us spinning endlessly in a loop where we're never going to do any useful work. - if we're running in a VM, it allows the CPU to be given back to the hypervisor and rescheduled for other purposes (maybe a different VM) rather than wasting CPU cycles inside a crashed VM. However, in light of erratum 794072, Will Deacon wanted to see 10 nops as well - which is reasonable to cover the case where we have erratum 754327 enabled _and_ we have a processor that doesn't implement the wfe hint. So, we now end up with: 1: wfe b 1b when erratum 754327 is disabled, or: 1: dmb nop nop nop nop nop nop nop nop nop nop wfe b 1b when erratum 754327 is enabled. We also get the dmb + 10 nop sequence elsewhere in the kernel, in terminating loops. This is reasonable - it means we get the workaround for erratum 794072 when erratum 754327 is enabled, but still relinquish the dead processor - either by placing it in a lower power mode when wfe is implemented as such or by returning it to the hypervisior, or in the case where wfe is a no-op, we use the workaround specified in erratum 794072 to avoid the problem. These as two entirely orthogonal problems - the 10 nops addresses erratum 794072, and the wfe is an optimisation that makes the system more efficient when crashed either in terms of power consumption or by allowing the host/other VMs to make use of the CPU. I don't see any reason not to use kexec() inside a VM - it has the potential to provide automated recovery from a failure of the VMs kernel with the opportunity for saving a crashdump of the failure. A panic() with a reboot timeout won't do that, and reading the libvirt documentation, setting on_reboot to "preserve" won't either (the documentation states "The preserve action for an on_reboot event is treated as a destroy".) Surely it has to be a good thing to avoiding having CPUs spinning inside a VM that is doing no useful work. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-27ARM: 8840/1: use a raw_spinlock_t in unwindSebastian Andrzej Siewior
[ Upstream commit 74ffe79ae538283bbf7c155e62339f1e5c87b55a ] Mostly unwind is done with irqs enabled however SLUB may call it with irqs disabled while creating a new SLUB cache. I had system freeze while loading a module which called kmem_cache_create() on init. That means SLUB's __slab_alloc() disabled interrupts and then ->new_slab_objects() ->new_slab() ->setup_object() ->setup_object_debug() ->init_tracking() ->set_track() ->save_stack_trace() ->save_stack_trace_tsk() ->walk_stackframe() ->unwind_frame() ->unwind_find_idx() =>spin_lock_irqsave(&unwind_lock); Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-28Merge tag 'v4.4.177' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.8b6.183-20190331Marcel Ziswiler
This is the 4.4.177 stable release
2019-03-23ARM: 8824/1: fix a migrating irq bug when hotplug cpuDietmar Eggemann
[ Upstream commit 1b5ba350784242eb1f899bcffd95d2c7cff61e84 ] Arm TC2 fails cpu hotplug stress test. This issue was tracked down to a missing copy of the new affinity cpumask for the vexpress-spc interrupt into struct irq_common_data.affinity when the interrupt is migrated in migrate_one_irq(). Fix it by replacing the arm specific hotplug cpu migration with the generic irq code. This is the counterpart implementation to commit 217d453d473c ("arm64: fix a migrating irq bug when hotplug cpu"). Tested with cpu hotplug stress test on Arm TC2 (multi_v7_defconfig plus CONFIG_ARM_BIG_LITTLE_CPUFREQ=y and CONFIG_ARM_VEXPRESS_SPC_CPUFREQ=y). The vexpress-spc interrupt (irq=22) on this board is affine to CPU0. Its affinity cpumask now changes correctly e.g. from 0 to 1-4 when CPU0 is hotplugged out. Suggested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-20ARM: 8808/1: kexec:offline panic_smp_self_stop CPUYufen Wang
[ Upstream commit 82c08c3e7f171aa7f579b231d0abbc1d62e91974 ] In case panic() and panic() called at the same time on different CPUS. For example: CPU 0: panic() __crash_kexec machine_crash_shutdown crash_smp_send_stop machine_kexec BUG_ON(num_online_cpus() > 1); CPU 1: panic() local_irq_disable panic_smp_self_stop If CPU 1 calls panic_smp_self_stop() before crash_smp_send_stop(), kdump fails. CPU1 can't receive the ipi irq, CPU1 will be always online. To fix this problem, this patch split out the panic_smp_self_stop() and add set_cpu_online(smp_processor_id(), false). Signed-off-by: Yufen Wang <wangyufen@huawei.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-06-21Merge tag 'v4.4.138' into toradex_vf_4.4-nextMax Krummenacher
This is the 4.4.138 stable release
2018-05-30ARM: 8748/1: mm: Define vdso_start, vdso_end as arrayJinbum Park
[ Upstream commit 73b9160d0dfe44dfdaffd6465dc1224c38a4a73c ] Define vdso_start, vdso_end as array to avoid compile-time analysis error for the case of built with CONFIG_FORTIFY_SOURCE. and, since vdso_start, vdso_end are used in vdso.c only, move extern-declaration from vdso.h to vdso.c. If kernel is built with CONFIG_FORTIFY_SOURCE, compile-time error happens at this code. - if (memcmp(&vdso_start, "177ELF", 4)) The size of "&vdso_start" is recognized as 1 byte, but n is 4, So that compile-time error is reported. Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jinbum Park <jinb.park7@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-26ARM: 8771/1: kprobes: Prohibit kprobes on do_undefinstrMasami Hiramatsu
commit eb0146daefdde65665b7f076fbff7b49dade95b9 upstream. Prohibit kprobes on do_undefinstr because kprobes on arm is implemented by undefined instruction. This means if we probe do_undefinstr(), it can cause infinit recursive exception. Fixes: 24ba613c9d6c ("ARM kprobes: core code") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-24ARM: 8668/1: ftrace: Fix dynamic ftrace with DEBUG_RODATA and !FRAME_POINTERAbel Vesa
[ Upstream commit 6f05d0761af612e04572ba4d65b4c0274a88444f ] The support for dynamic ftrace with CONFIG_DEBUG_RODATA involves overriding the weak arch_ftrace_update_code() with a variant which makes the kernel text writable around the patching. This override was however added under the CONFIG_OLD_MCOUNT ifdef, and CONFIG_OLD_MCOUNT is only enabled if frame pointers are enabled. This leads to non-functional dynamic ftrace (ftrace triggers a WARN_ON()) when CONFIG_DEBUG_RODATA is enabled and CONFIG_FRAME_POINTER is not. Move the override out of that ifdef and into the CONFIG_DYNAMIC_FTRACE ifdef where it belongs. Fixes: 80d6b0c2eed2a ("ARM: mm: allow text and rodata sections to be read-only") Suggested-by: Nicolai Stange <nicstange@gmail.com> Suggested-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Abel Vesa <abelvesa@gmail.com> Acked-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-21Merge tag 'v4.4.107' into toradex_vf_4.4-nextMarcel Ziswiler
This is the 4.4.107 stable release
2017-12-16ARM: avoid faulting on qemuRussell King
commit 3aaf33bebda8d4ffcc0fc8ef39e6c1ac68823b11 upstream. When qemu starts a kernel in a bare environment, the default SCR has the AW and FW bits clear, which means that the kernel can't modify the PSR A or PSR F bits, and means that FIQs and imprecise aborts are always masked. When running uboot under qemu, the AW and FW SCR bits are set, and the kernel functions normally - and this is how real hardware behaves. Fix this for qemu by ignoring the FIQ bit. Fixes: 8bafae202c82 ("ARM: BUG if jumping to usermode address in kernel mode") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Cc: Alex Shi <alex.shi@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-16ARM: BUG if jumping to usermode address in kernel modeRussell King
commit 8bafae202c82dc257f649ea3c275a0f35ee15113 upstream. Detect if we are returning to usermode via the normal kernel exit paths but the saved PSR value indicates that we are in kernel mode. This could occur due to corrupted stack state, which has been observed with "ftracetest". This ensures that we catch the problem case before we get to user code. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Cc: Alex Shi <alex.shi@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15ARM: 8720/1: ensure dump_instr() checks addr_limitMark Rutland
commit b9dd05c7002ee0ca8b676428b2268c26399b5e31 upstream. When CONFIG_DEBUG_USER is enabled, it's possible for a user to deliberately trigger dump_instr() with a chosen kernel address. Let's avoid problems resulting from this by using get_user() rather than __get_user(), ensuring that we don't erroneously access kernel memory. So that we can use the same code to dump user instructions and kernel instructions, the common dumping code is factored out to __dump_instr(), with the fs manipulated appropriately in dump_instr() around calls to this. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-17Merge tag 'v4.4.73' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.7b3-20170630Marcel Ziswiler
This is the 4.4.73 stable release
2017-05-14ARM: 8452/3: PJ4: make coprocessor access sequences buildable in Thumb2 modeArd Biesheuvel
commit 5008efc83bf85b647aa1cbc44718b1675bbb7444 upstream. The PJ4 inline asm sequence to write to cp15 cannot be built in Thumb-2 mode, due to the way it performs arithmetic on the program counter, so it is built in ARM mode instead. However, building C files in ARM mode under CONFIG_THUMB2_KERNEL is problematic, since the instrumentation performed by subsystems like ftrace does not expect having to deal with interworking branches. Since the sequence in question is simply a poor man's ISB instruction, let's use a straight 'isb' instead when building in Thumb2 mode. Thumb2 implies V7, so 'isb' should always be supported in that case. Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-04Merge tag 'v4.4.59' into toradex_vf_4.4-nextMarcel Ziswiler
This is the 4.4.59 stable release
2017-02-14ARM: 8643/3: arm/ptrace: Preserve previous registers for short regset writeDave Martin
commit 228dbbfb5d77f8e047b2a1d78da14b7158433027 upstream. Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill all the registers, the thread's old registers are preserved. Fixes: 5be6f62b0059 ("ARM: 6883/1: ptrace: Migrate to regsets framework") Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-26ARM: 8613/1: Fix the uaccess crash on PB11MPCoreLinus Walleij
commit 90f92c631b210c1e97080b53a9d863783281a932 upstream. The following patch was sketched by Russell in response to my crashes on the PB11MPCore after the patch for software-based priviledged no access support for ARMv8.1. See this thread: http://marc.info/?l=linux-arm-kernel&m=144051749807214&w=2 I am unsure what is going on, I suspect everyone involved in the discussion is. I just want to repost this to get the discussion restarted, as I still have to apply this patch with every kernel iteration to get my PB11MPCore Realview running. Testing by Neil Armstrong on the Oxnas NAS has revealed that this bug exist also on that widely deployed hardware, so we are probably currently regressing all ARM11MPCore systems. Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Fixes: a5e090acbf54 ("ARM: software-based priviledged-no-access support") Tested-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-26ARM: 8634/1: hw_breakpoint: blacklist Scorpion CPUsMark Rutland
commit ddc37832a1349f474c4532de381498020ed71d31 upstream. On APQ8060, the kernel crashes in arch_hw_breakpoint_init, taking an undefined instruction trap within write_wb_reg. This is because Scorpion CPUs erroneously appear to set DBGPRSR.SPD when WFI is issued, even if the core is not powered down. When DBGPRSR.SPD is set, breakpoint and watchpoint registers are treated as undefined. It's possible to trigger similar crashes later on from userspace, by requesting the kernel to install a breakpoint or watchpoint, as we can go idle at any point between the reset of the debug registers and their later use. This has always been the case. Given that this has always been broken, no-one has complained until now, and there is no clear workaround, disable hardware breakpoints and watchpoints on Scorpion to avoid these issues. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11Merge tag 'v4.4.39' into toradex_vf_4.4-nextStefan Agner
This is the 4.4.39 stable release
2016-10-07ARM: 8616/1: dt: Respect property size when parsing CPUsRobin Murphy
commit ba6dea4f7cedb4b1c17e36f4087675d817c2e24b upstream. Whilst MPIDR values themselves are less than 32 bits, it is still perfectly valid for a DT to have #address-cells > 1 in the CPUs node, resulting in the "reg" property having leading zero cell(s). In that situation, the big-endian nature of the data conspires with the current behaviour of only reading the first cell to cause the kernel to think all CPUs have ID 0, and become resoundingly unhappy as a consequence. Take the full property length into account when parsing CPUs so as to be correct under any circumstances. Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-29Merge tag 'v4.4.21' into toradex_vf_4.4-nextStefan Agner
This is the 4.4.21 stable release