Linux kernel development work - see feature branches https://git.zx2c4.com/linux-dev/atom/arch/arm64/kernel?h=master 2022-11-13T15:52:22Z 2022-11-13T15:52:22Z Linus Torvalds torvalds@linux-foundation.org 2022-11-13T15:52:22Z urn:sha1:ab57bc6f027c761d5411fae9492756b5fbb91108 Pull EFI fixes from Ard Biesheuvel: - Force the use of SetVirtualAddressMap() on Ampera Altra arm64 machines, which crash in SetTime() if no virtual remapping is used This is the first time we've added an SMBIOS based quirk on arm64, but fortunately, we can just call a EFI protocol to grab the type #1 SMBIOS record when running in the stub, so we don't need all the machinery we have in the kernel proper to parse SMBIOS data. - Drop a spurious warning on misaligned runtime regions when using 16k or 64k pages on arm64 * tag 'efi-fixes-for-v6.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: arm64: efi: Fix handling of misaligned runtime regions and drop warning arm64: efi: Force the use of SetVirtualAddressMap() on Altra machines 2022-11-10T22:14:15Z Ard Biesheuvel ardb@kernel.org 2022-11-06T14:53:54Z urn:sha1:9b9eaee9828fe98b030cf43ac50065a54a2f5d52 Currently, when mapping the EFI runtime regions in the EFI page tables, we complain about misaligned regions in a rather noisy way, using WARN(). Not only does this produce a lot of irrelevant clutter in the log, it is factually incorrect, as misaligned runtime regions are actually allowed by the EFI spec as long as they don't require conflicting memory types within the same 64k page. So let's drop the warning, and tweak the code so that we - take both the start and end of the region into account when checking for misalignment - only revert to RWX mappings for non-code regions if misaligned code regions are also known to exist. Cc: <stable@vger.kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 2022-11-05T02:52:24Z Linus Torvalds torvalds@linux-foundation.org 2022-11-05T02:52:24Z urn:sha1:b208b9fbbcba743fb269d15cb46a4036b01936b1 Pull arm64 fixes from Catalin Marinas: - Avoid kprobe recursion when cortex_a76_erratum_1463225_debug_handler() is not inlined (change to __always_inline). - Fix the visibility of compat hwcaps, broken by recent changes to consolidate the visibility of hwcaps and the user-space view of the ID registers. * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: cpufeature: Fix the visibility of compat hwcaps arm64: entry: avoid kprobe recursion 2022-11-04T21:37:25Z Linus Torvalds torvalds@linux-foundation.org 2022-11-04T21:37:25Z urn:sha1:1caa2f182afb59de9d6d5ba64b340df011a0b653 Pull EFI fixes from Ard Biesheuvel: - A pair of tweaks to the EFI random seed code so that externally provided version of this config table are handled more robustly - Another fix for the v6.0 EFI variable refactor that turned out to break Apple machines which don't provide QueryVariableInfo() - Add some guard rails to the EFI runtime service call wrapper so we can recover from synchronous exceptions caused by firmware * tag 'efi-fixes-for-v6.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: arm64: efi: Recover from synchronous exceptions occurring in firmware efi: efivars: Fix variable writes with unsupported query_variable_store() efi: random: Use 'ACPI reclaim' memory for random seed efi: random: reduce seed size to 32 bytes efi/tpm: Pass correct address to memblock_reserve 2022-11-03T18:04:56Z Amit Daniel Kachhap amit.kachhap@arm.com 2022-11-03T08:22:32Z urn:sha1:85f1506337f0c79a4955edfeee86a18628e3735f Commit 237405ebef58 ("arm64: cpufeature: Force HWCAP to be based on the sysreg visible to user-space") forced the hwcaps to use sanitised user-space view of the id registers. However, the ID register structures used to select few compat cpufeatures (vfp, crc32, ...) are masked and hence such hwcaps do not appear in /proc/cpuinfo anymore for PER_LINUX32 personality. Add the ID register structures explicitly and set the relevant entry as visible. As these ID registers are now of type visible so make them available in 64-bit userspace by making necessary changes in register emulation logic and documentation. While at it, update the comment for structure ftr_generic_32bits[] which lists the ID register that use it. Fixes: 237405ebef58 ("arm64: cpufeature: Force HWCAP to be based on the sysreg visible to user-space") Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Link: https://lore.kernel.org/r/20221103082232.19189-1-amit.kachhap@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 2022-11-03T17:01:15Z Ard Biesheuvel ardb@kernel.org 2022-10-28T14:39:14Z urn:sha1:23715a26c8d812912a70c6ac1ce67af649b95914 Unlike x86, which has machinery to deal with page faults that occur during the execution of EFI runtime services, arm64 has nothing like that, and a synchronous exception raised by firmware code brings down the whole system. With more EFI based systems appearing that were not built to run Linux (such as the Windows-on-ARM laptops based on Qualcomm SOCs), as well as the introduction of PRM (platform specific firmware routines that are callable just like EFI runtime services), we are more likely to run into issues of this sort, and it is much more likely that we can identify and work around such issues if they don't bring down the system entirely. Since we already use a EFI runtime services call wrapper in assembler, we can quite easily add some code that captures the execution state at the point where the call is made, allowing us to revert to this state and proceed execution if the call triggered a synchronous exception. Given that the kernel and the firmware don't share any data structures that could end up in an indeterminate state, we can happily continue running, as long as we mark the EFI runtime services as unavailable from that point on. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> 2022-11-01T17:43:31Z Mark Rutland mark.rutland@arm.com 2022-10-17T09:01:57Z urn:sha1:024f4b2e1f874934943eb2d3d288ebc52c79f55c The cortex_a76_erratum_1463225_debug_handler() function is called when handling debug exceptions (and synchronous exceptions from BRK instructions), and so is called when a probed function executes. If the compiler does not inline cortex_a76_erratum_1463225_debug_handler(), it can be probed. If cortex_a76_erratum_1463225_debug_handler() is probed, any debug exception or software breakpoint exception will result in recursive exceptions leading to a stack overflow. This can be triggered with the ftrace multiple_probes selftest, and as per the example splat below. This is a regression caused by commit: 6459b8469753e9fe ("arm64: entry: consolidate Cortex-A76 erratum 1463225 workaround") ... which removed the NOKPROBE_SYMBOL() annotation associated with the function. My intent was that cortex_a76_erratum_1463225_debug_handler() would be inlined into its caller, el1_dbg(), which is marked noinstr and cannot be probed. Mark cortex_a76_erratum_1463225_debug_handler() as __always_inline to ensure this. Example splat prior to this patch (with recursive entries elided): | # echo p cortex_a76_erratum_1463225_debug_handler > /sys/kernel/debug/tracing/kprobe_events | # echo p do_el0_svc >> /sys/kernel/debug/tracing/kprobe_events | # echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable | Insufficient stack space to handle exception! | ESR: 0x0000000096000047 -- DABT (current EL) | FAR: 0xffff800009cefff0 | Task stack: [0xffff800009cf0000..0xffff800009cf4000] | IRQ stack: [0xffff800008000000..0xffff800008004000] | Overflow stack: [0xffff00007fbc00f0..0xffff00007fbc10f0] | CPU: 0 PID: 145 Comm: sh Not tainted 6.0.0 #2 | Hardware name: linux,dummy-virt (DT) | pstate: 604003c5 (nZCv DAIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : arm64_enter_el1_dbg+0x4/0x20 | lr : el1_dbg+0x24/0x5c | sp : ffff800009cf0000 | x29: ffff800009cf0000 x28: ffff000002c74740 x27: 0000000000000000 | x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 | x23: 00000000604003c5 x22: ffff80000801745c x21: 0000aaaac95ac068 | x20: 00000000f2000004 x19: ffff800009cf0040 x18: 0000000000000000 | x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 | x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 | x11: 0000000000000010 x10: ffff800008c87190 x9 : ffff800008ca00d0 | x8 : 000000000000003c x7 : 0000000000000000 x6 : 0000000000000000 | x5 : 0000000000000000 x4 : 0000000000000000 x3 : 00000000000043a4 | x2 : 00000000f2000004 x1 : 00000000f2000004 x0 : ffff800009cf0040 | Kernel panic - not syncing: kernel stack overflow | CPU: 0 PID: 145 Comm: sh Not tainted 6.0.0 #2 | Hardware name: linux,dummy-virt (DT) | Call trace: | dump_backtrace+0xe4/0x104 | show_stack+0x18/0x4c | dump_stack_lvl+0x64/0x7c | dump_stack+0x18/0x38 | panic+0x14c/0x338 | test_taint+0x0/0x2c | panic_bad_stack+0x104/0x118 | handle_bad_stack+0x34/0x48 | __bad_stack+0x78/0x7c | arm64_enter_el1_dbg+0x4/0x20 | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | cortex_a76_erratum_1463225_debug_handler+0x0/0x34 ... | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | cortex_a76_erratum_1463225_debug_handler+0x0/0x34 ... | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | cortex_a76_erratum_1463225_debug_handler+0x0/0x34 | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | do_el0_svc+0x0/0x28 | el0t_64_sync_handler+0x84/0xf0 | el0t_64_sync+0x18c/0x190 | Kernel Offset: disabled | CPU features: 0x0080,00005021,19001080 | Memory Limit: none | ---[ end Kernel panic - not syncing: kernel stack overflow ]--- With this patch, cortex_a76_erratum_1463225_debug_handler() is inlined into el1_dbg(), and el1_dbg() cannot be probed: | # echo p cortex_a76_erratum_1463225_debug_handler > /sys/kernel/debug/tracing/kprobe_events | sh: write error: No such file or directory | # grep -w cortex_a76_erratum_1463225_debug_handler /proc/kallsyms | wc -l | 0 | # echo p el1_dbg > /sys/kernel/debug/tracing/kprobe_events | sh: write error: Invalid argument | # grep -w el1_dbg /proc/kallsyms | wc -l | 1 Fixes: 6459b8469753 ("arm64: entry: consolidate Cortex-A76 erratum 1463225 workaround") Cc: <stable@vger.kernel.org> # 5.12.x Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20221017090157.2881408-1-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 2022-10-20T15:10:27Z Peter Zijlstra peterz@infradead.org 2022-10-18T11:49:21Z urn:sha1:883bbbffa5a4ffd1915f8b42934dab81b7f87226 Different function signatures means they needs to be different functions; otherwise CFI gets upset. As triggered by the ftrace boot tests: [] CFI failure at ftrace_return_to_handler+0xac/0x16c (target: ftrace_stub+0x0/0x14; expected type: 0x0a5d5347) Fixes: 3c516f89e17e ("x86: Add support for CONFIG_CFI_CLANG") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Link: https://lkml.kernel.org/r/Y06dg4e1xF6JTdQq@hirez.programming.kicks-ass.net 2022-10-16T22:27:07Z Linus Torvalds torvalds@linux-foundation.org 2022-10-16T22:27:07Z urn:sha1:f1947d7c8a61db1cb0ef909a6512ede0b1f2115b Pull more random number generator updates from Jason Donenfeld: "This time with some large scale treewide cleanups. The intent of this pull is to clean up the way callers fetch random integers. The current rules for doing this right are: - If you want a secure or an insecure random u64, use get_random_u64() - If you want a secure or an insecure random u32, use get_random_u32() The old function prandom_u32() has been deprecated for a while now and is just a wrapper around get_random_u32(). Same for get_random_int(). - If you want a secure or an insecure random u16, use get_random_u16() - If you want a secure or an insecure random u8, use get_random_u8() - If you want secure or insecure random bytes, use get_random_bytes(). The old function prandom_bytes() has been deprecated for a while now and has long been a wrapper around get_random_bytes() - If you want a non-uniform random u32, u16, or u8 bounded by a certain open interval maximum, use prandom_u32_max() I say "non-uniform", because it doesn't do any rejection sampling or divisions. Hence, it stays within the prandom_*() namespace, not the get_random_*() namespace. I'm currently investigating a "uniform" function for 6.2. We'll see what comes of that. By applying these rules uniformly, we get several benefits: - By using prandom_u32_max() with an upper-bound that the compiler can prove at compile-time is ≤65536 or ≤256, internally get_random_u16() or get_random_u8() is used, which wastes fewer batched random bytes, and hence has higher throughput. - By using prandom_u32_max() instead of %, when the upper-bound is not a constant, division is still avoided, because prandom_u32_max() uses a faster multiplication-based trick instead. - By using get_random_u16() or get_random_u8() in cases where the return value is intended to indeed be a u16 or a u8, we waste fewer batched random bytes, and hence have higher throughput. This series was originally done by hand while I was on an airplane without Internet. Later, Kees and I worked on retroactively figuring out what could be done with Coccinelle and what had to be done manually, and then we split things up based on that. So while this touches a lot of files, the actual amount of code that's hand fiddled is comfortably small" * tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: prandom: remove unused functions treewide: use get_random_bytes() when possible treewide: use get_random_u32() when possible treewide: use get_random_{u8,u16}() when possible, part 2 treewide: use get_random_{u8,u16}() when possible, part 1 treewide: use prandom_u32_max() when possible, part 2 treewide: use prandom_u32_max() when possible, part 1 2022-10-14T19:38:03Z Linus Torvalds torvalds@linux-foundation.org 2022-10-14T19:38:03Z urn:sha1:1df046ab1c6520911774911f8c710ca8e981305c Pull arm64 fixes from Catalin Marinas: - Cortex-A55 errata workaround (repeat TLBI) - AMPERE1 added to the Spectre-BHB affected list - MTE fix to avoid setting PG_mte_tagged if no tags have been touched on a page - Fixed typo in the SCTLR_EL1.SPINTMASK bit naming (the commit log has other typos) - perf: return value check in ali_drw_pmu_probe(), ALIBABA_UNCORE_DRW_PMU dependency on ACPI * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: Add AMPERE1 to the Spectre-BHB affected list arm64: mte: Avoid setting PG_mte_tagged if no tags cleared or restored MAINTAINERS: rectify file entry in ALIBABA PMU DRIVER drivers/perf: ALIBABA_UNCORE_DRW_PMU should depend on ACPI drivers/perf: fix return value check in ali_drw_pmu_probe() arm64: errata: Add Cortex-A55 to the repeat tlbi list arm64/sysreg: Fix typo in SCTR_EL1.SPINTMASK