linux/arch/arm64/kernel
Mark Brown 10a33d1d05 arm64/sve: Lower the maximum allocation for the SVE ptrace regset
[ Upstream commit 2813926261 ]

Doug Anderson observed that ChromeOS crashes are being reported which
include failing allocations of order 7 during core dumps due to ptrace
allocating storage for regsets:

  chrome: page allocation failure: order:7,
          mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO),
          nodemask=(null),cpuset=urgent,mems_allowed=0
   ...
  regset_get_alloc+0x1c/0x28
  elf_core_dump+0x3d8/0xd8c
  do_coredump+0xeb8/0x1378

with further investigation showing that this is:

   [   66.957385] DOUG: Allocating 279584 bytes

which is the maximum size of the SVE regset. As Doug observes it is not
entirely surprising that such a large allocation of contiguous memory might
fail on a long running system.

The SVE regset is currently sized to hold SVE registers with a VQ of
SVE_VQ_MAX which is 512, substantially more than the architectural maximum
of 16 which we might see even in a system emulating the limits of the
architecture. Since we don't expose the size we tell the regset core
externally let's define ARCH_SVE_VQ_MAX with the actual architectural
maximum and use that for the regset, we'll still overallocate most of the
time but much less so which will be helpful even if the core is fixed to
not require contiguous allocations.

Specify ARCH_SVE_VQ_MAX in terms of the maximum value that can be written
into ZCR_ELx.LEN (where this is set in the hardware). For consistency
update the maximum SME vector length to be specified in the same style
while we are at it.

We could also teach the ptrace core about runtime discoverable regset sizes
but that would be a more invasive change and this is being observed in
practical systems.

Reported-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20240213-arm64-sve-ptrace-regset-size-v2-1-c7600ca74b9b@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2024-03-26 18:19:11 -04:00
..
pi arm64: unwind: add asynchronous unwind tables to kernel and modules 2022-11-09 18:06:35 +00:00
probes arm64: kprobes: Drop ID map text from kprobes blacklist 2023-02-07 18:25:10 +00:00
vdso arm64: vdso: remove two .altinstructions related symbols 2023-07-27 12:32:43 +01:00
vdso32 kbuild: Drop -Wdeclaration-after-statement 2023-06-26 11:14:19 +02:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
acpi.c arm64: acpi: Fix possible memory leak of ffh_ctxt 2023-02-24 14:21:49 +00:00
acpi_numa.c arm64: numa: Don't check node against MAX_NUMNODES 2022-07-19 19:10:28 +01:00
acpi_parking_protocol.c treewide: Drop function_nocfi 2022-09-26 10:13:14 -07:00
alternative.c Merge branches 'for-next/kpti', 'for-next/missing-proto-warn', 'for-next/iss2-decode', 'for-next/kselftest', 'for-next/misc', 'for-next/feat_mops', 'for-next/module-alloc', 'for-next/sysreg', 'for-next/cpucap', 'for-next/acpi', 'for-next/kdump', 'for-next/acpi-doc', 'for-next/doc' and 'for-next/tpidr2-fix', remote-tracking branch 'arm64/for-next/perf' into for-next/core 2023-06-23 18:32:20 +01:00
armv8_deprecated.c sysctl: Add size to register_sysctl 2023-08-15 15:26:17 -07:00
asm-offsets.c arm64: ftrace: fix build error with CONFIG_FUNCTION_GRAPH_TRACER=n 2023-07-05 09:46:19 -04:00
cacheinfo.c cacheinfo: Add arm64 early level initializer implementation 2023-04-13 09:32:33 +01:00
compat_alignment.c arm64: compat: Work around uninitialized variable warning 2023-04-05 17:51:47 +01:00
cpu-reset.S arm64: kernel: remove SHF_WRITE|SHF_EXECINSTR from .idmap.text 2023-05-02 12:42:22 +01:00
cpu_errata.c arm64: Subscribe Microsoft Azure Cobalt 100 to ARM Neoverse N2 errata 2024-02-23 09:25:14 +01:00
cpu_ops.c arm64: Introduce get_cpu_ops() helper function 2020-03-24 17:24:19 +00:00
cpufeature.c arm64: cpufeature: Fix CLRBHB and BC detection 2023-09-18 10:45:11 +01:00
cpuidle.c arm64: Explicitly include correct DT includes 2023-07-31 14:45:38 +01:00
cpuinfo.c arm64: add HWCAP for FEAT_HBC (hinted conditional branches) 2023-08-04 17:32:13 +01:00
crash_core.c arm64: move PAC masks to <asm/pointer_auth.h> 2023-04-13 12:27:11 +01:00
crash_dump.c vmcore: convert copy_oldmem_page() to take an iov_iter 2022-04-29 14:37:59 -07:00
debug-monitors.c arm64: kgdb: Set PSTATE.SS to 1 to re-enable single-step 2023-04-14 13:39:47 +01:00
efi-header.S arm64: efi: Enable BTI codegen and add PE/COFF annotation 2023-04-20 15:43:45 +02:00
efi-rt-wrapper.S arm64: efi: Avoid workqueue to check whether EFI runtime is live 2023-01-16 15:27:31 +01:00
efi.c drm for 6.6-rc1 2023-08-30 13:34:34 -07:00
elfcore.c arm64: mte: Avoid the racy walk of the vma list during core dump 2023-01-05 15:12:12 +00:00
entry-common.c arm64: syscall: unmask DAIF earlier for SVCs 2023-08-11 12:23:48 +01:00
entry-fpsimd.S arm64/sme: Implement context switching for ZT0 2023-01-20 12:23:06 +00:00
entry-ftrace.S arm64: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL 2023-06-20 18:38:37 -04:00
entry.S arm64: entry: fix ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD 2024-01-31 16:18:55 -08:00
fpsimd.c arm64/sme: Restore SMCR_EL1.EZT0 on exit from suspend 2024-03-01 13:35:08 +01:00
ftrace.c arm64: module: mandate MODULE_PLTS 2023-06-06 17:39:05 +01:00
head.S arm64/mm: Directly use ID_AA64MMFR2_EL1_VARange_MASK 2023-07-27 11:11:44 +01:00
hibernate-asm.S arm64: kexec: install a copy of the linear-map 2021-10-01 13:31:00 +01:00
hibernate.c arm64: hibernate: remove WARN_ON in save_processor_state 2023-06-21 13:33:49 +01:00
hw_breakpoint.c hw_breakpoint: fix single-stepping when using bpf_overflow_handler 2023-08-18 17:04:09 +01:00
hyp-stub.S ARM64: 2023-07-03 15:32:22 -07:00
idle.c arch/idle: Change arch_cpu_idle() behavior: always exit with IRQs disabled 2023-01-13 11:48:15 +01:00
idreg-override.c arm64/sysreg: Fix broken strncpy() -> strscpy() conversion 2023-09-06 19:22:54 +01:00
image-vars.h efi/zboot: arm64: Inject kernel code size symbol into the zboot payload 2023-04-26 18:01:41 +02:00
image.h arm64: get rid of TEXT_OFFSET 2020-09-07 15:00:52 +01:00
io.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
irq.c arm64: irq: set the correct node for shadow call stack 2024-02-05 20:14:38 +00:00
jump_label.c jump_label: make initial NOP patching the special case 2022-06-24 09:48:55 +02:00
kaslr.c Merge branch for-next/module-alloc into kvmarm/next 2023-06-15 13:04:15 +00:00
kexec_image.c arm64: Fix dangling references to Documentation/arm64 2023-06-21 08:53:31 -06:00
kgdb.c arm64: kgdb: Set PSTATE.SS to 1 to re-enable single-step 2023-04-14 13:39:47 +01:00
kuser32.S arm64: Update Documentation/arm references 2023-06-12 06:33:48 -06:00
machine_kexec.c Merge branch 'for-next/misc' into for-next/core 2023-04-20 11:22:09 +01:00
machine_kexec_file.c arm64/kexec: Fix missing extra range for crashkres_low. 2022-09-01 11:50:00 +01:00
Makefile - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in 2023-06-28 10:59:38 -07:00
module-plts.c arm64: module: Fix PLT counting when CONFIG_RANDOMIZE_BASE=n 2023-11-28 17:20:00 +00:00
module.c arm64: module: rework module VA range selection 2023-06-06 17:39:06 +01:00
mte.c arm64: mte: simplify swap tag restoration logic 2023-08-18 10:12:02 -07:00
paravirt.c arm64: paravirt: remove conduit check in has_pv_steal_clock 2022-11-09 18:11:56 +00:00
patch-scs.c arm64: Apply dynamic shadow call stack patching in two passes 2023-01-26 17:54:15 +00:00
patching.c arm64: patching: Add aarch64_insn_write_literal_u64() 2023-01-24 11:49:43 +00:00
pci.c arm64: Explicitly include correct DT includes 2023-07-31 14:45:38 +01:00
perf_callchain.c arm64: use XPACLRI to strip PAC 2023-04-13 12:27:11 +01:00
perf_regs.c perf: arm64: Add SVE vector granule register to user regs 2022-09-22 15:06:02 +01:00
pointer_auth.c arm64: move preemption disablement to prctl handlers 2021-07-28 18:33:49 +01:00
process.c Objtool changes for v6.4: 2023-04-28 14:02:54 -07:00
proton-pack.c arm64: delete dead code in this_cpu_set_vectors() 2023-04-20 10:44:54 +01:00
psci.c treewide: Drop function_nocfi 2022-09-26 10:13:14 -07:00
ptrace.c arm64/sve: Lower the maximum allocation for the SVE ptrace regset 2024-03-26 18:19:11 -04:00
reloc_test_core.c ARM64: reloc_test: add __init/__exit annotations to module init/exit funcs 2022-09-29 18:04:25 +01:00
reloc_test_syms.S arm64: kernel: Convert to modern annotations for assembly functions 2020-05-04 12:46:03 +01:00
relocate_kernel.S arm64: kexec: load from kimage prior to clobbering 2022-05-17 14:25:35 +01:00
return_address.c arm64: Make return_address() use arch_stack_walk() 2021-12-10 14:06:04 +00:00
sdei.c arm64: sdei: abort running SDEI handlers during crash 2023-08-04 17:35:33 +01:00
setup.c arm64: kaslr: split kaslr/module initialization 2023-06-06 17:39:05 +01:00
signal.c arm64/signal: Don't assume that TIF_SVE means we saved SVE state 2024-02-23 09:25:13 +01:00
signal32.c x86/shstk: Add user control-protection fault handler 2023-08-02 15:01:50 -07:00
sigreturn32.S arm64: compat: Move sigreturn32.S to .rodata section 2022-07-01 12:05:45 +01:00
sleep.S arm64: kernel: remove SHF_WRITE|SHF_EXECINSTR from .idmap.text 2023-05-02 12:42:22 +01:00
smccc-call.S arm64: smccc: Save lr before calling __arm_smccc_sve_check() 2021-07-21 11:23:25 +01:00
smp.c arm64: sdei: abort running SDEI handlers during crash 2023-08-04 17:35:33 +01:00
smp_spin_table.c treewide: Drop function_nocfi 2022-09-26 10:13:14 -07:00
stacktrace.c arm64: use XPACLRI to strip PAC 2023-04-13 12:27:11 +01:00
suspend.c arm64/sme: Restore SME registers on exit from suspend 2024-03-01 13:35:08 +01:00
sys.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
sys32.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 452 2019-06-19 17:09:08 +02:00
sys_compat.c arm64: compat: Do not treat syscall number as ESR_ELx for a bad syscall 2022-04-29 19:26:27 +01:00
syscall.c arm64: syscall: unmask DAIF earlier for SVCs 2023-08-11 12:23:48 +01:00
time.c arm64: Make profile_pc() use arch_stack_walk() 2021-12-10 14:06:04 +00:00
topology.c RISC-V Patches for the 6.1 Merge Window, Part 1 2022-10-09 13:24:01 -07:00
trace-events-emulation.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
traps.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
vdso-wrap.S arm64: do not descend to vdso directories twice 2021-01-20 12:18:46 +00:00
vdso.c arm64: vdso: Pass (void *) to virt_to_page() 2023-05-16 14:53:36 +01:00
vdso32-wrap.S arm64: do not descend to vdso directories twice 2021-01-20 12:18:46 +00:00
vmlinux.lds.S arm64: lds: move .got section out of .text 2023-05-02 13:12:45 +01:00
watchdog_hld.c arm64: enable perf events based hard lockup detector 2023-06-09 17:44:22 -07:00