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path: root/arch/arm/mm/proc-v7-bugs.c
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2022-07-06ARM: 9213/1: Print message about disabled Spectre workarounds only onceDmitry Osipenko
Print the message about disabled Spectre workarounds only once. The message is printed each time CPU goes out from idling state on NVIDIA Tegra boards, causing storm in KMSG that makes system unusable. Cc: stable@vger.kernel.org Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2022-07-06ARM: 9209/1: Spectre-BHB: avoid pr_info() every time a CPU comes out of idleArd Biesheuvel
Jon reports that the Spectre-BHB init code is filling up the kernel log with spurious notifications about which mitigation has been enabled, every time any CPU comes out of a low power state. Given that Spectre-BHB mitigations are system wide, only a single mitigation can be enabled, and we already print an error if two types of CPUs coexist in a single system that require different Spectre-BHB mitigations. This means that the pr_info() that describes the selected mitigation does not need to be emitted for each CPU anyway, and so we can simply emit it only once. In order to clarify the above in the log message, update it to describe that the selected mitigation will be enabled on all CPUs, including ones that are unaffected. If another CPU comes up later that is affected and requires a different mitigation, we report an error as before. Fixes: b9baf5c8c5c3 ("ARM: Spectre-BHB workaround") Tested-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2022-05-18ARM: 9196/1: spectre-bhb: enable for Cortex-A15Ard Biesheuvel
The Spectre-BHB mitigations were inadvertently left disabled for Cortex-A15, due to the fact that cpu_v7_bugs_init() is not called in that case. So fix that. Fixes: b9baf5c8c5c3 ("ARM: Spectre-BHB workaround") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2022-03-10ARM: fix build warning in proc-v7-bugs.cRussell King (Oracle)
The kernel test robot discovered that building without HARDEN_BRANCH_PREDICTOR issues a warning due to a missing argument to pr_info(). Add the missing argument. Reported-by: kernel test robot <lkp@intel.com> Fixes: 9dd78194a372 ("ARM: report Spectre v2 status through sysfs") Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-05ARM: Spectre-BHB workaroundRussell King (Oracle)
Workaround the Spectre BHB issues for Cortex-A15, Cortex-A57, Cortex-A72, Cortex-A73 and Cortex-A75. We also include Brahma B15 as well to be safe, which is affected by Spectre V2 in the same ways as Cortex-A15. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2022-03-05ARM: report Spectre v2 status through sysfsRussell King (Oracle)
As per other architectures, add support for reporting the Spectre vulnerability status via sysfs CPU. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2019-11-30Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds
Pull ARM updates from Russell King: - improve ARM implementation of pfn_valid() - various sparse fixes - spelling fixes - add further ARMv8 debug architecture versions - clang fix for decompressor - update to generic vDSO - remove Brahma-B53 from spectre hardening - initialise broadcast hrtimer device - use correct nm executable in decompressor - remove old mcount et.al. * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (26 commits) ARM: 8940/1: ftrace: remove mcount(),ftrace_caller_old() and ftrace_call_old() ARM: 8939/1: kbuild: use correct nm executable ARM: 8938/1: kernel: initialize broadcast hrtimer based clock event device ARM: 8937/1: spectre-v2: remove Brahma-B53 from hardening ARM: 8933/1: replace Sun/Solaris style flag on section directive ARM: 8932/1: Add clock_gettime64 entry point ARM: 8931/1: Add clock_getres entry point ARM: 8930/1: Add support for generic vDSO ARM: 8929/1: use APSR_nzcv instead of r15 as mrc operand ARM: 8927/1: ARM/hw_breakpoint: add more ARMv8 debug architecture versions support ARM: 8918/2: only build return_address() if needed ARM: 8928/1: ARM_ERRATA_775420: Spelling s/date/data/ ARM: 8925/1: tcm: include <asm/tcm.h> for missing declarations ARM: 8924/1: tcm: make dtcm_end and itcm_end static ARM: 8923/1: mm: include <asm/vga.h> for vga_base ARM: 8922/1: parse_dt_topology() rate is pointer to __be32 ARM: 8920/1: share get_signal_page from signal.c to process.c ARM: 8919/1: make unexported functions static ARM: 8917/1: mm: include <asm/set_memory.h> ARM: 8916/1: mm: make set_section_perms() static ...
2019-11-16ARM: 8937/1: spectre-v2: remove Brahma-B53 from hardeningDoug Berger
When the default processor handling was added to the function cpu_v7_spectre_init() it only excluded other ARM implemented processor cores. The Broadcom Brahma B53 core is not implemented by ARM so it ended up falling through into the set of processors that attempt to use the ARM_SMCCC_ARCH_WORKAROUND_1 service to harden the branch predictor. Since this workaround is not necessary for the Brahma-B53 this commit explicitly checks for it and prevents it from applying a branch predictor hardening workaround. Fixes: 10115105cb3a ("ARM: spectre-v2: add firmware based hardening") Signed-off-by: Doug Berger <opendmb@gmail.com> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-10-21arm/arm64: Make use of the SMCCC 1.1 wrapperSteven Price
Rather than directly choosing which function to use based on psci_ops.conduit, use the new arm_smccc_1_1 wrapper instead. In some cases we still need to do some operations based on the conduit, but the code duplication is removed. No functional change. Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-14arm: spectre-v2: use arm_smccc_1_1_get_conduit()Mark Rutland
Now that we have arm_smccc_1_1_get_conduit(), we can hide the PSCI implementation details from the arm spectre-v2 code, so let's do so. As arm_smccc_1_1_get_conduit() implicitly checks that the SMCCC version is at least SMCCC_VERSION_1_1, we no longer need to check this explicitly where switch statements have a default case. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-11-12ARM: spectre-v2: per-CPU vtables to work around big.Little systemsRussell King
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. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-05-31ARM: spectre-v2: warn about incorrect context switching functionsRussell King
Warn at error level if the context switching function is not what we are expecting. This can happen with big.Little systems, which we currently do not support. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-31ARM: spectre-v2: add firmware based hardeningRussell King
Add firmware based hardening for cores that require more complex handling in firmware. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-31ARM: spectre-v2: harden user aborts in kernel spaceRussell King
In order to prevent aliasing attacks on the branch predictor, invalidate the BTB or instruction cache on CPUs that are known to be affected when taking an abort on a address that is outside of a user task limit: Cortex A8, A9, A12, A17, A73, A75: flush BTB. Cortex A15, Brahma B15: invalidate icache. If the IBE bit is not set, then there is little point to enabling the workaround. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Boot-tested-by: Tony Lindgren <tony@atomide.com> Reviewed-by: Tony Lindgren <tony@atomide.com>
2018-05-31ARM: spectre-v2: add Cortex A8 and A15 validation of the IBE bitRussell King
When the branch predictor hardening is enabled, firmware must have set the IBE bit in the auxiliary control register. If this bit has not been set, the Spectre workarounds will not be functional. Add validation that this bit is set, and print a warning at alert level if this is not the case. 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>