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2019-02-21Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxLinus Torvalds2-9/+9
Pull late arm64 fixes from Will Deacon: "Three small arm64 fixes for 5.0. They fix a build breakage with clang introduced in 4.20, an oversight in our sigframe restoration relating to the SSBS bit and a boot fix for systems with newer revisions of our interrupt controller. Summary: - Fix handling of PSTATE.SSBS bit in sigreturn() - Fix version checking of the GIC during early boot - Fix clang builds failing due to use of NEON in the crypto code" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: Relax GIC version check during early boot arm64/neon: Disable -Wincompatible-pointer-types when building with Clang arm64: fix SSBS sanitization
2019-02-21kasan: fix random seed generation for tag-based modeAndrey Konovalov1-0/+3
There are two issues with assigning random percpu seeds right now: 1. We use for_each_possible_cpu() to iterate over cpus, but cpumask is not set up yet at the moment of kasan_init(), and thus we only set the seed for cpu #0. 2. A call to get_random_u32() always returns the same number and produces a message in dmesg, since the random subsystem is not yet initialized. Fix 1 by calling kasan_init_tags() after cpumask is set up. Fix 2 by using get_cycles() instead of get_random_u32(). This gives us lower quality random numbers, but it's good enough, as KASAN is meant to be used as a debugging tool and not a mitigation. Link: http://lkml.kernel.org/r/1f815cc914b61f3516ed4cc9bfd9eeca9bd5d9de.1550677973.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-20arm64: Relax GIC version check during early bootVladimir Murzin1-2/+1
Updates to the GIC architecture allow ID_AA64PFR0_EL1.GIC to have values other than 0 or 1. At the moment, Linux is quite strict in the way it handles this field at early boot stage (cpufeature is fine) and will refuse to use the system register CPU interface if it doesn't find the value 1. Fixes: 021f653791ad17e03f98aaa7fb933816ae16f161 ("irqchip: gic-v3: Initial support for GICv3") Reported-by: Chase Conklin <Chase.Conklin@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-02-18arm64: fix SSBS sanitizationMark Rutland1-7/+8
In valid_user_regs() we treat SSBS as a RES0 bit, and consequently it is unexpectedly cleared when we restore a sigframe or fiddle with GPRs via ptrace. This patch fixes valid_user_regs() to account for this, updating the function to refer to the latest ARM ARM (ARM DDI 0487D.a). For AArch32 tasks, SSBS appears in bit 23 of SPSR_EL1, matching its position in the AArch32-native PSR format, and we don't need to translate it as we have to for DIT. There are no other bit assignments that we need to account for today. As the recent documentation describes the DIT bit, we can drop our comment regarding DIT. While removing SSBS from the RES0 masks, existing inconsistent whitespace is corrected. Fixes: d71be2b6c0e19180 ("arm64: cpufeature: Detect SSBS and advertise to userspace") Signed-off-by: Mark Rutland <mark.rutland@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: Will Deacon <will.deacon@arm.com>
2019-02-16efi/arm: Revert "Defer persistent reservations until after paging_init()"Ard Biesheuvel1-1/+0
This reverts commit eff896288872d687d9662000ec9ae11b6d61766f, which deferred the processing of persistent memory reservations to a point where the memory may have already been allocated and overwritten, defeating the purpose. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20190215123333.21209-3-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-05arm64: kexec_file: handle empty command-lineJean-Philippe Brucker1-1/+3
Calling strlen() on cmdline == NULL produces a kernel oops. Since having a NULL cmdline is valid, handle this case explicitly. Fixes: 52b2a8af7436 ("arm64: kexec_file: load initrd and device-tree") Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-02-01arm64: hibernate: Clean the __hyp_text to PoC after resumeJames Morse1-1/+3
During resume hibernate restores all physical memory. Any memory that is accessed with the MMU disabled needs to be cleaned to the PoC. KVMs __hyp_text was previously ommitted as it runs with the MMU enabled, but now that the hyp-stub is located in this section, we must clean __hyp_text too. This ensures secondary CPUs that come online after hibernate has finished resuming, and load KVM via the freshly written hyp-stub see the correct instructions. Signed-off-by: James Morse <james.morse@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-02-01arm64: hyp-stub: Forbid kprobing of the hyp-stubJames Morse1-0/+2
The hyp-stub is loaded by the kernel's early startup code at EL2 during boot, before KVM takes ownership later. The hyp-stub's text is part of the regular kernel text, meaning it can be kprobed. A breakpoint in the hyp-stub causes the CPU to spin in el2_sync_invalid. Add it to the __hyp_text. Signed-off-by: James Morse <james.morse@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-02-01arm64: kprobe: Always blacklist the KVM world-switch codeJames Morse1-3/+3
On systems with VHE the kernel and KVM's world-switch code run at the same exception level. Code that is only used on a VHE system does not need to be annotated as __hyp_text as it can reside anywhere in the kernel text. __hyp_text was also used to prevent kprobes from patching breakpoint instructions into this region, as this code runs at a different exception level. While this is no longer true with VHE, KVM still switches VBAR_EL1, meaning a kprobe's breakpoint executed in the world-switch code will cause a hyp-panic. Move the __hyp_text check in the kprobes blacklist so it applies on VHE systems too, to cover the common code and guest enter/exit assembly. Fixes: 888b3c8720e0 ("arm64: Treat all entry code as non-kprobe-able") Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-02-01arm64: kaslr: ensure randomized quantities are clean also when kaslr is offArd Biesheuvel1-0/+1
Commit 1598ecda7b23 ("arm64: kaslr: ensure randomized quantities are clean to the PoC") added cache maintenance to ensure that global variables set by the kaslr init routine are not wiped clean due to cache invalidation occurring during the second round of page table creation. However, if kaslr_early_init() exits early with no randomization being applied (either due to the lack of a seed, or because the user has disabled kaslr explicitly), no cache maintenance is performed, leading to the same issue we attempted to fix earlier, as far as the module_alloc_base variable is concerned. Note that module_alloc_base cannot be initialized statically, because that would cause it to be subject to a R_AARCH64_RELATIVE relocation, causing it to be overwritten by the second round of KASLR relocation processing. Fixes: f80fb3a3d508 ("arm64: add support for kernel ASLR") Cc: <stable@vger.kernel.org> # v4.6+ Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-01-16arm64: kaslr: ensure randomized quantities are clean to the PoCArd Biesheuvel1-2/+6
kaslr_early_init() is called with the kernel mapped at its link time offset, and if it returns with a non-zero offset, the kernel is unmapped and remapped again at the randomized offset. During its execution, kaslr_early_init() also randomizes the base of the module region and of the linear mapping of DRAM, and sets two variables accordingly. However, since these variables are assigned with the caches on, they may get lost during the cache maintenance that occurs when unmapping and remapping the kernel, so ensure that these values are cleaned to the PoC. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Fixes: f80fb3a3d508 ("arm64: add support for kernel ASLR") Cc: <stable@vger.kernel.org> # v4.6+ Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-01-11arm64: kexec_file: return successfully even if kaslr-seed doesn't existAKASHI Takahiro1-1/+3
In kexec_file_load, kaslr-seed property of the current dtb will be deleted any way before setting a new value if possible. It doesn't matter whether it exists in the current dtb. So "ret" should be reset to 0 here. Fixes: commit 884143f60c89 ("arm64: kexec_file: add kaslr support") Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-01-10arm64: kpti: Avoid rewriting early page tables when KASLR is enabledWill Deacon3-3/+9
A side effect of commit c55191e96caa ("arm64: mm: apply r/o permissions of VM areas to its linear alias as well") is that the linear map is created with page granularity, which means that transitioning the early page table from global to non-global mappings when enabling kpti can take a significant amount of time during boot. Given that most CPU implementations do not require kpti, this mainly impacts KASLR builds where kpti is forcefully enabled. However, in these situations we know early on that non-global mappings are required and can avoid the use of global mappings from the beginning. The only gotcha is Cavium erratum #27456, which we must detect based on the MIDR value of the boot CPU. Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reported-by: John Garry <john.garry@huawei.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-01-06jump_label: move 'asm goto' support test to KconfigMasahiro Yamada1-4/+0
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
2019-01-05Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxLinus Torvalds4-53/+40
Pull arm64 fixes from Will Deacon: "I'm safely chained back up to my desk, so please pull these arm64 fixes for -rc1 that address some issues that cropped up during the merge window: - Prevent KASLR from mapping the top page of the virtual address space - Fix device-tree probing of SDEI driver - Fix incorrect register offset definition in Hisilicon DDRC PMU driver - Fix compilation issue with older binutils not liking unsigned immediates - Fix uapi headers so that libc can provide its own sigcontext definition - Fix handling of private compat syscalls - Hook up compat io_pgetevents() syscall for 32-bit tasks - Cleanup to arm64 Makefile (including now to avoid silly conflicts)" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: compat: Hook up io_pgetevents() for 32-bit tasks arm64: compat: Don't pull syscall number from regs in arm_compat_syscall arm64: compat: Avoid sending SIGILL for unallocated syscall numbers arm64/sve: Disentangle <uapi/asm/ptrace.h> from <uapi/asm/sigcontext.h> arm64/sve: ptrace: Fix SVE_PT_REGS_OFFSET definition drivers/perf: hisi: Fixup one DDRC PMU register offset arm64: replace arm64-obj-* in Makefile with obj-* arm64: kaslr: Reserve size of ARM64_MEMSTART_ALIGN in linear region firmware: arm_sdei: Fix DT platform device creation firmware: arm_sdei: fix wrong of_node_put() in init function arm64: entry: remove unused register aliases arm64: smp: Fix compilation error
2019-01-04arm64: compat: Don't pull syscall number from regs in arm_compat_syscallWill Deacon2-10/+8
The syscall number may have been changed by a tracer, so we should pass the actual number in from the caller instead of pulling it from the saved r7 value directly. Cc: <stable@vger.kernel.org> Cc: Pi-Hsun Shih <pihsun@chromium.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-01-04arm64: compat: Avoid sending SIGILL for unallocated syscall numbersWill Deacon1-2/+2
The ARM Linux kernel handles the EABI syscall numbers as follows: 0 - NR_SYSCALLS-1 : Invoke syscall via syscall table NR_SYSCALLS - 0xeffff : -ENOSYS (to be allocated in future) 0xf0000 - 0xf07ff : Private syscall or -ENOSYS if not allocated > 0xf07ff : SIGILL Our compat code gets this wrong and ends up sending SIGILL in response to all syscalls greater than NR_SYSCALLS which have a value greater than 0x7ff in the bottom 16 bits. Fix this by defining the end of the ARM private syscall region and checking the syscall number against that directly. Update the comment while we're at it. Cc: <stable@vger.kernel.org> Cc: Dave Martin <Dave.Martin@arm.com> Reported-by: Pi-Hsun Shih <pihsun@chromium.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-01-04arm64: replace arm64-obj-* in Makefile with obj-*Masahiro Yamada1-31/+30
Use the standard obj-$(CONFIG_...) syntex. The behavior is still the same. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-01-03Remove 'type' argument from access_ok() functionLinus Torvalds5-10/+10
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-03arm64: entry: remove unused register aliasesMark Rutland1-11/+1
In commit: 3b7142752e4bee15 ("arm64: convert native/compat syscall entry to C") ... we moved the syscall invocation code from assembly to C, but left behind a number of register aliases which are now unused. Let's remove them before they confuse someone. Cc: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-01-01Merge tag 'kgdb-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linuxLinus Torvalds1-13/+1
Pull kgdb updates from Daniel Thompson: "Mostly clean ups although while Doug's was chasing down a odd lockdep warning he also did some work to improved debugger resilience when some CPUs fail to respond to the round up request. The main changes are: - Fixing a lockdep warning on architectures that cannot use an NMI for the round up plus related changes to make CPU round up and all CPU backtrace more resilient. - Constify the arch ops tables - A couple of other small clean ups Two of the three patchsets here include changes that spill over into arch/. Changes in the arch space are relatively narrow in scope (and directly related to kgdb). Didn't get comprehensive acks but all impacted maintainers were Cc:ed in good time" * tag 'kgdb-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux: kgdb/treewide: constify struct kgdb_arch arch_kgdb_ops mips/kgdb: prepare arch_kgdb_ops for constness kdb: use bool for binary state indicators kdb: Don't back trace on a cpu that didn't round up kgdb: Don't round up a CPU that failed rounding up before kgdb: Fix kgdb_roundup_cpus() for arches who used smp_call_function() kgdb: Remove irq flags from roundup
2018-12-31Merge tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-traceLinus Torvalds7-13/+13
Pull tracing updates from Steven Rostedt: - Rework of the kprobe/uprobe and synthetic events to consolidate all the dynamic event code. This will make changes in the future easier. - Partial rewrite of the function graph tracing infrastructure. This will allow for multiple users of hooking onto functions to get the callback (return) of the function. This is the ground work for having kprobes and function graph tracer using one code base. - Clean up of the histogram code that will facilitate adding more features to the histograms in the future. - Addition of str_has_prefix() and a few use cases. There currently is a similar function strstart() that is used in a few places, but only returns a bool and not a length. These instances will be removed in the future to use str_has_prefix() instead. - A few other various clean ups as well. * tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits) tracing: Use the return of str_has_prefix() to remove open coded numbers tracing: Have the historgram use the result of str_has_prefix() for len of prefix tracing: Use str_has_prefix() instead of using fixed sizes tracing: Use str_has_prefix() helper for histogram code string.h: Add str_has_prefix() helper function tracing: Make function ‘ftrace_exports’ static tracing: Simplify printf'ing in seq_print_sym tracing: Avoid -Wformat-nonliteral warning tracing: Merge seq_print_sym_short() and seq_print_sym_offset() tracing: Add hist trigger comments for variable-related fields tracing: Remove hist trigger synth_var_refs tracing: Use hist trigger's var_ref array to destroy var_refs tracing: Remove open-coding of hist trigger var_ref management tracing: Use var_refs[] for hist trigger reference checking tracing: Change strlen to sizeof for hist trigger static strings tracing: Remove unnecessary hist trigger struct field tracing: Fix ftrace_graph_get_ret_stack() to use task and not current seq_buf: Use size_t for len in seq_buf_puts() seq_buf: Make seq_buf_puts() null-terminate the buffer arm64: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack ...
2018-12-30kgdb/treewide: constify struct kgdb_arch arch_kgdb_opsChristophe Leroy1-1/+1
checkpatch.pl reports the following: WARNING: struct kgdb_arch should normally be const #28: FILE: arch/mips/kernel/kgdb.c:397: +struct kgdb_arch arch_kgdb_ops = { This report makes sense, as all other ops struct, this one should also be const. This patch does the change. Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: James Hogan <jhogan@kernel.org> Cc: Ley Foon Tan <lftan@altera.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: x86@kernel.org Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Acked-by: Paul Burton <paul.burton@mips.com> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2018-12-30kgdb: Fix kgdb_roundup_cpus() for arches who used smp_call_function()Douglas Anderson1-12/+0
When I had lockdep turned on and dropped into kgdb I got a nice splat on my system. Specifically it hit: DEBUG_LOCKS_WARN_ON(current->hardirq_context) Specifically it looked like this: sysrq: SysRq : DEBUG ------------[ cut here ]------------ DEBUG_LOCKS_WARN_ON(current->hardirq_context) WARNING: CPU: 0 PID: 0 at .../kernel/locking/lockdep.c:2875 lockdep_hardirqs_on+0xf0/0x160 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0 #27 pstate: 604003c9 (nZCv DAIF +PAN -UAO) pc : lockdep_hardirqs_on+0xf0/0x160 ... Call trace: lockdep_hardirqs_on+0xf0/0x160 trace_hardirqs_on+0x188/0x1ac kgdb_roundup_cpus+0x14/0x3c kgdb_cpu_enter+0x53c/0x5cc kgdb_handle_exception+0x180/0x1d4 kgdb_compiled_brk_fn+0x30/0x3c brk_handler+0x134/0x178 do_debug_exception+0xfc/0x178 el1_dbg+0x18/0x78 kgdb_breakpoint+0x34/0x58 sysrq_handle_dbg+0x54/0x5c __handle_sysrq+0x114/0x21c handle_sysrq+0x30/0x3c qcom_geni_serial_isr+0x2dc/0x30c ... ... irq event stamp: ...45 hardirqs last enabled at (...44): [...] __do_softirq+0xd8/0x4e4 hardirqs last disabled at (...45): [...] el1_irq+0x74/0x130 softirqs last enabled at (...42): [...] _local_bh_enable+0x2c/0x34 softirqs last disabled at (...43): [...] irq_exit+0xa8/0x100 ---[ end trace adf21f830c46e638 ]--- Looking closely at it, it seems like a really bad idea to be calling local_irq_enable() in kgdb_roundup_cpus(). If nothing else that seems like it could violate spinlock semantics and cause a deadlock. Instead, let's use a private csd alongside smp_call_function_single_async() to round up the other CPUs. Using smp_call_function_single_async() doesn't require interrupts to be enabled so we can remove the offending bit of code. In order to avoid duplicating this across all the architectures that use the default kgdb_roundup_cpus(), we'll add a "weak" implementation to debug_core.c. Looking at all the people who previously had copies of this code, there were a few variants. I've attempted to keep the variants working like they used to. Specifically: * For arch/arc we passed NULL to kgdb_nmicallback() instead of get_irq_regs(). * For arch/mips there was a bit of extra code around kgdb_nmicallback() NOTE: In this patch we will still get into trouble if we try to round up a CPU that failed to round up before. We'll try to round it up again and potentially hang when we try to grab the csd lock. That's not new behavior but we'll still try to do better in a future patch. Suggested-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: James Hogan <jhogan@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2018-12-30kgdb: Remove irq flags from roundupDouglas Anderson1-1/+1
The function kgdb_roundup_cpus() was passed a parameter that was documented as: > the flags that will be used when restoring the interrupts. There is > local_irq_save() call before kgdb_roundup_cpus(). Nobody used those flags. Anyone who wanted to temporarily turn on interrupts just did local_irq_enable() and local_irq_disable() without looking at them. So we can definitely remove the flags. Signed-off-by: Douglas Anderson <dianders@chromium.org> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: James Hogan <jhogan@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2018-12-28kasan, arm64: add brk handler for inline instrumentationAndrey Konovalov1-0/+60
Tag-based KASAN inline instrumentation mode (which embeds checks of shadow memory into the generated code, instead of inserting a callback) generates a brk instruction when a tag mismatch is detected. This commit adds a tag-based KASAN specific brk handler, that decodes the immediate value passed to the brk instructions (to extract information about the memory access that triggered the mismatch), reads the register values (x0 contains the guilty address) and reports the bug. Link: http://lkml.kernel.org/r/c91fe7684070e34dc34b419e6b69498f4dcacc2d.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-25Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxLinus Torvalds29-560/+1079
Pull arm64 festive updates from Will Deacon: "In the end, we ended up with quite a lot more than I expected: - Support for ARMv8.3 Pointer Authentication in userspace (CRIU and kernel-side support to come later) - Support for per-thread stack canaries, pending an update to GCC that is currently undergoing review - Support for kexec_file_load(), which permits secure boot of a kexec payload but also happens to improve the performance of kexec dramatically because we can avoid the sucky purgatory code from userspace. Kdump will come later (requires updates to libfdt). - Optimisation of our dynamic CPU feature framework, so that all detected features are enabled via a single stop_machine() invocation - KPTI whitelisting of Cortex-A CPUs unaffected by Meltdown, so that they can benefit from global TLB entries when KASLR is not in use - 52-bit virtual addressing for userspace (kernel remains 48-bit) - Patch in LSE atomics for per-cpu atomic operations - Custom preempt.h implementation to avoid unconditional calls to preempt_schedule() from preempt_enable() - Support for the new 'SB' Speculation Barrier instruction - Vectorised implementation of XOR checksumming and CRC32 optimisations - Workaround for Cortex-A76 erratum #1165522 - Improved compatibility with Clang/LLD - Support for TX2 system PMUS for profiling the L3 cache and DMC - Reflect read-only permissions in the linear map by default - Ensure MMIO reads are ordered with subsequent calls to Xdelay() - Initial support for memory hotplug - Tweak the threshold when we invalidate the TLB by-ASID, so that mremap() performance is improved for ranges spanning multiple PMDs. - Minor refactoring and cleanups" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (125 commits) arm64: kaslr: print PHYS_OFFSET in dump_kernel_offset() arm64: sysreg: Use _BITUL() when defining register bits arm64: cpufeature: Rework ptr auth hwcaps using multi_entry_cap_matches arm64: cpufeature: Reduce number of pointer auth CPU caps from 6 to 4 arm64: docs: document pointer authentication arm64: ptr auth: Move per-thread keys from thread_info to thread_struct arm64: enable pointer authentication arm64: add prctl control for resetting ptrauth keys arm64: perf: strip PAC when unwinding userspace arm64: expose user PAC bit positions via ptrace arm64: add basic pointer authentication support arm64/cpufeature: detect pointer authentication arm64: Don't trap host pointer auth use to EL2 arm64/kvm: hide ptrauth from guests arm64/kvm: consistently handle host HCR_EL2 flags arm64: add pointer authentication register bits arm64: add comments about EC exception levels arm64: perf: Treat EXCLUDE_EL* bit definitions as unsigned arm64: kpti: Whitelist Cortex-A CPUs that don't implement the CSV3 field arm64: enable per-task stack canaries ...
2018-12-22arm64: Use ftrace_graph_get_ret_stack() instead of curr_ret_stackSteven Rostedt (VMware)6-10/+12
The structure of the ret_stack array on the task struct is going to change, and accessing it directly via the curr_ret_stack index will no longer give the ret_stack entry that holds the return address. To access that, architectures must now use ftrace_graph_get_ret_stack() to get the associated ret_stack that matches the saved return address. Cc: linux-arm-kernel@lists.infradead.org Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-14arm64: kaslr: print PHYS_OFFSET in dump_kernel_offset()Miles Chen1-0/+1
When debug with kaslr, it is sometimes necessary to have PHYS_OFFSET to perform linear virtual address to physical address translation. Sometimes we're debugging with only few information such as a kernel log and a symbol file, print PHYS_OFFSET in dump_kernel_offset() for that case. Tested by: echo c > /proc/sysrq-trigger [ 11.996161] SMP: stopping secondary CPUs [ 11.996732] Kernel Offset: 0x2522200000 from 0xffffff8008000000 [ 11.996881] PHYS_OFFSET: 0xffffffeb40000000 Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Miles Chen <miles.chen@mediatek.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-13arm64: cpufeature: Rework ptr auth hwcaps using multi_entry_cap_matchesWill Deacon2-76/+53
Open-coding the pointer-auth HWCAPs is a mess and can be avoided by reusing the multi-cap logic from the CPU errata framework. Move the multi_entry_cap_matches code to cpufeature.h and reuse it for the pointer auth HWCAPs. Reviewed-by: Suzuki Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-13arm64: cpufeature: Reduce number of pointer auth CPU caps from 6 to 4Will Deacon1-10/+1
We can easily avoid defining the two meta-capabilities for the address and generic keys, so remove them and instead just check both of the architected and impdef capabilities when determining the level of system support. Reviewed-by: Suzuki Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-13arm64: ptr auth: Move per-thread keys from thread_info to thread_structWill Deacon1-1/+1
We don't need to get at the per-thread keys from assembly at all, so they can live alongside the rest of the per-thread register state in thread_struct instead of thread_info. This will also allow straighforward whitelisting of the keys for hardened usercopy should we expose them via a ptrace request later on. Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-13arm64: add prctl control for resetting ptrauth keysKristina Martsenko2-0/+48
Add an arm64-specific prctl to allow a thread to reinitialize its pointer authentication keys to random values. This can be useful when exec() is not used for starting new processes, to ensure that different processes still have different keys. Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-13arm64: perf: strip PAC when unwinding userspaceMark Rutland1-1/+5
When the kernel is unwinding userspace callchains, we can't expect that the userspace consumer of these callchains has the data necessary to strip the PAC from the stored LR. This patch has the kernel strip the PAC from user stackframes when the in-kernel unwinder is used. This only affects the LR value, and not the FP. This only affects the in-kernel unwinder. When userspace performs unwinding, it is up to userspace to strip PACs as necessary (which can be determined from DWARF information). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ramana Radhakrishnan <ramana.radhakrishnan@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-13arm64: expose user PAC bit positions via ptraceMark Rutland1-0/+38
When pointer authentication is in use, data/instruction pointers have a number of PAC bits inserted into them. The number and position of these bits depends on the configured TCR_ELx.TxSZ and whether tagging is enabled. ARMv8.3 allows tagging to differ for instruction and data pointers. For userspace debuggers to unwind the stack and/or to follow pointer chains, they need to be able to remove the PAC bits before attempting to use a pointer. This patch adds a new structure with masks describing the location of the PAC bits in userspace instruction and data pointers (i.e. those addressable via TTBR0), which userspace can query via PTRACE_GETREGSET. By clearing these bits from pointers (and replacing them with the value of bit 55), userspace can acquire the PAC-less versions. This new regset is exposed when the kernel is built with (user) pointer authentication support, and the address authentication feature is enabled. Otherwise, the regset is hidden. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ramana Radhakrishnan <ramana.radhakrishnan@arm.com> Cc: Will Deacon <will.deacon@arm.com> [will: Fix to use vabits_user instead of VA_BITS and rename macro] Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-13arm64: add basic pointer authentication supportMark Rutland3-0/+19
This patch adds basic support for pointer authentication, allowing userspace to make use of APIAKey, APIBKey, APDAKey, APDBKey, and APGAKey. The kernel maintains key values for each process (shared by all threads within), which are initialised to random values at exec() time. The ID_AA64ISAR1_EL1.{APA,API,GPA,GPI} fields are exposed to userspace, to describe that pointer authentication instructions are available and that the kernel is managing the keys. Two new hwcaps are added for the same reason: PACA (for address authentication) and PACG (for generic authentication). Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Tested-by: Adam Wallis <awallis@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ramana Radhakrishnan <ramana.radhakrishnan@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will.deacon@arm.com> [will: Fix sizeof() usage and unroll address key initialisation] Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-13arm64/cpufeature: detect pointer authenticationMark Rutland1-0/+90
So that we can dynamically handle the presence of pointer authentication functionality, wire up probing code in cpufeature.c. From ARMv8.3 onwards, ID_AA64ISAR1 is no longer entirely RES0, and now has four fields describing the presence of pointer authentication functionality: * APA - address authentication present, using an architected algorithm * API - address authentication present, using an IMP DEF algorithm * GPA - generic authentication present, using an architected algorithm * GPI - generic authentication present, using an IMP DEF algorithm This patch checks for both address and generic authentication, separately. It is assumed that if all CPUs support an IMP DEF algorithm, the same algorithm is used across all CPUs. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@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: Will Deacon <will.deacon@arm.com>
2018-12-13arm64/kvm: consistently handle host HCR_EL2 flagsMark Rutland1-3/+2
In KVM we define the configuration of HCR_EL2 for a VHE HOST in HCR_HOST_VHE_FLAGS, but we don't have a similar definition for the non-VHE host flags, and open-code HCR_RW. Further, in head.S we open-code the flags for VHE and non-VHE configurations. In future, we're going to want to configure more flags for the host, so lets add a HCR_HOST_NVHE_FLAGS defintion, and consistently use both HCR_HOST_VHE_FLAGS and HCR_HOST_NVHE_FLAGS in the kvm code and head.S. We now use mov_q to generate the HCR_EL2 value, as we use when configuring other registers in head.S. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: kvmarm@lists.cs.columbia.edu Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-13arm64: kpti: Whitelist Cortex-A CPUs that don't implement the CSV3 fieldWill Deacon1-0/+6
While the CSV3 field of the ID_AA64_PFR0 CPU ID register can be checked to see if a CPU is susceptible to Meltdown and therefore requires kpti to be enabled, existing CPUs do not implement this field. We therefore whitelist all unaffected Cortex-A CPUs that do not implement the CSV3 field. Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-12Merge branch 'for-next/perf' into aarch64/for-next/coreWill Deacon1-166/+55
Merge in arm64 perf and PMU driver updates, including support for the system/uncore PMU in the ThunderX2 platform.
2018-12-12arm64: enable per-task stack canariesArd Biesheuvel2-1/+4
This enables the use of per-task stack canary values if GCC has support for emitting the stack canary reference relative to the value of sp_el0, which holds the task struct pointer in the arm64 kernel. The $(eval) extends KBUILD_CFLAGS at the moment the make rule is applied, which means asm-offsets.o (which we rely on for the offset value) is built without the arguments, and everything built afterwards has the options set. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-11arm64: preempt: Fix big-endian when checking preempt count in assemblyWill Deacon1-4/+2
Commit 396244692232 ("arm64: preempt: Provide our own implementation of asm/preempt.h") extended the preempt count field in struct thread_info to 64 bits, so that it consists of a 32-bit count plus a 32-bit flag indicating whether or not the current task needs rescheduling. Whilst the asm-offsets definition of TSK_TI_PREEMPT was updated to point to this new field, the assembly usage was left untouched meaning that a 32-bit load from TSK_TI_PREEMPT on a big-endian machine actually returns the reschedule flag instead of the count. Whilst we could fix this by pointing TSK_TI_PREEMPT at the count field, we're actually better off reworking the two assembly users so that they operate on the whole 64-bit value in favour of inspecting the thread flags separately in order to determine whether a reschedule is needed. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reported-by: "kernelci.org bot" <bot@kernelci.org> Tested-by: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-11arm64: kexec_file: include linux/vmalloc.hArnd Bergmann1-0/+1
This is needed for compilation in some configurations that don't include it implicitly: arch/arm64/kernel/machine_kexec_file.c: In function 'arch_kimage_file_post_load_cleanup': arch/arm64/kernel/machine_kexec_file.c:37:2: error: implicit declaration of function 'vfree'; did you mean 'kvfree'? [-Werror=implicit-function-declaration] Fixes: 52b2a8af7436 ("arm64: kexec_file: load initrd and device-tree") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10Merge branch 'for-next/kexec' into aarch64/for-next/coreWill Deacon8-17/+386
Merge in kexec_file_load() support from Akashi Takahiro.
2018-12-10Merge branch 'kvm/cortex-a76-erratum-1165522' into aarch64/for-next/coreWill Deacon1-0/+8
Pull in KVM workaround for A76 erratum #116522. Conflicts: arch/arm64/include/asm/cpucaps.h
2018-12-10arm64: smp: Handle errors reported by the firmwareSuzuki K Poulose1-0/+1
The __cpu_up() routine ignores the errors reported by the firmware for a CPU bringup operation and looks for the error status set by the booting CPU. If the CPU never entered the kernel, we could end up in assuming stale error status, which otherwise would have been set/cleared appropriately by the booting CPU. Reported-by: Steve Capper <steve.capper@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10arm64: smp: Rework early feature mismatched detectionWill Deacon2-14/+9
Rather than add additional variables to detect specific early feature mismatches with secondary CPUs, we can instead dedicate the upper bits of the CPU boot status word to flag specific mismatches. This allows us to communicate both granule and VA-size mismatches back to the primary CPU without the need for additional book-keeping. Tested-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10arm64: Kconfig: Re-jig CONFIG options for 52-bit VAWill Deacon2-3/+3
Enabling 52-bit VAs for userspace is pretty confusing, since it requires you to select "48-bit" virtual addressing in the Kconfig. Rework the logic so that 52-bit user virtual addressing is advertised in the "Virtual address space size" choice, along with some help text to describe its interaction with Pointer Authentication. The EXPERT-only option to force all user mappings to the 52-bit range is then made available immediately below the VA size selection. Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10arm64: mm: introduce 52-bit userspace supportSteve Capper1-0/+13
On arm64 there is optional support for a 52-bit virtual address space. To exploit this one has to be running with a 64KB page size and be running on hardware that supports this. For an arm64 kernel supporting a 48 bit VA with a 64KB page size, some changes are needed to support a 52-bit userspace: * TCR_EL1.T0SZ needs to be 12 instead of 16, * TASK_SIZE needs to reflect the new size. This patch implements the above when the support for 52-bit VAs is detected at early boot time. On arm64 userspace addresses translation is controlled by TTBR0_EL1. As well as userspace, TTBR0_EL1 controls: * The identity mapping, * EFI runtime code. It is possible to run a kernel with an identity mapping that has a larger VA size than userspace (and for this case __cpu_set_tcr_t0sz() would set TCR_EL1.T0SZ as appropriate). However, when the conditions for 52-bit userspace are met; it is possible to keep TCR_EL1.T0SZ fixed at 12. Thus in this patch, the TCR_EL1.T0SZ size changing logic is disabled. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10arm64: mm: Prevent mismatched 52-bit VA supportSteve Capper2-0/+31
For cases where there is a mismatch in ARMv8.2-LVA support between CPUs we have to be careful in allowing secondary CPUs to boot if 52-bit virtual addresses have already been enabled on the boot CPU. This patch adds code to the secondary startup path. If the boot CPU has enabled 52-bit VAs then ID_AA64MMFR2_EL1 is checked to see if the secondary can also enable 52-bit support. If not, the secondary is prevented from booting and an error message is displayed indicating why. Technically this patch could be implemented using the cpufeature code when considering 52-bit userspace support. However, we employ low level checks here as the cpufeature code won't be able to run if we have mismatched 52-bit kernel va support. Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>