linux/arch/x86/kernel
Thomas Gleixner e81dc127ef x86/callthunks: Add call patching for call depth tracking
Mitigating the Intel SKL RSB underflow issue in software requires to
track the call depth. That is every CALL and every RET need to be
intercepted and additional code injected.

The existing retbleed mitigations already include means of redirecting
RET to __x86_return_thunk; this can be re-purposed and RET can be
redirected to another function doing RET accounting.

CALL accounting will use the function padding introduced in prior
patches. For each CALL instruction, the destination symbol's padding
is rewritten to do the accounting and the CALL instruction is adjusted
to call into the padding.

This ensures only affected CPUs pay the overhead of this accounting.
Unaffected CPUs will leave the padding unused and have their 'JMP
__x86_return_thunk' replaced with an actual 'RET' instruction.

Objtool has been modified to supply a .call_sites section that lists
all the 'CALL' instructions. Additionally the paravirt instruction
sites are iterated since they will have been patched from an indirect
call to direct calls (or direct instructions in which case it'll be
ignored).

Module handling and the actual thunk code for SKL will be added in
subsequent steps.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111147.470877038@infradead.org
2022-10-17 16:41:13 +02:00
..
acpi ACPI: CPPC: Fix enabling CPPC on AMD systems with shared memory 2022-07-13 21:13:14 +02:00
apic x86/apic: Don't disable x2APIC if locked 2022-08-31 14:34:11 -07:00
cpu x86/percpu: Move irq_stack variables next to current_task 2022-10-17 16:41:05 +02:00
fpu x86/fpu: Add a helper to prepare AMX state for low-power CPU idle 2022-07-19 18:46:15 +02:00
kprobes x86/modules: Set VM_FLUSH_RESET_PERMS in module_alloc() 2022-10-17 16:40:57 +02:00
.gitignore
alternative.c x86/callthunks: Add call patching for call depth tracking 2022-10-17 16:41:13 +02:00
amd_gart_64.c x86: Fix various duplicate-word comment typos 2022-08-15 19:17:52 +02:00
amd_nb.c x86/amd_nb: Add AMD PCI IDs for SMN communication 2022-07-20 17:35:40 +02:00
aperture_64.c x86: Fix various duplicate-word comment typos 2022-08-15 19:17:52 +02:00
apm_32.c x86/ibt: Disable IBT around firmware 2022-03-15 10:32:40 +01:00
asm-offsets.c x86/percpu: Move current_top_of_stack next to current_task 2022-10-17 16:41:05 +02:00
asm-offsets_32.c
asm-offsets_64.c x86: Fixup asm-offsets duplicate 2022-10-17 16:41:06 +02:00
audit_64.c audit: add support for the openat2 syscall 2021-10-01 16:52:48 -04:00
bootflag.c
callthunks.c x86/callthunks: Add call patching for call depth tracking 2022-10-17 16:41:13 +02:00
cfi.c x86: Add support for CONFIG_CFI_CLANG 2022-09-26 10:13:16 -07:00
check.c
cpuid.c
crash.c x86/crash: Fix minor typo/bug in debug message 2022-04-13 19:39:54 +02:00
crash_core_32.c
crash_core_64.c
crash_dump_32.c vmcore: convert copy_oldmem_page() to take an iov_iter 2022-04-29 14:37:59 -07:00
crash_dump_64.c vmcore: convert read_from_oldmem() to take an iov_iter 2022-04-29 14:37:59 -07:00
devicetree.c Devicetree updates for v5.16: 2021-11-02 22:22:13 -07:00
doublefault_32.c exit/doublefault: Remove apparently bogus comment about rewind_stack_do_exit 2021-10-20 13:09:43 -05:00
dumpstack.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
dumpstack_32.c x86/percpu: Move irq_stack variables next to current_task 2022-10-17 16:41:05 +02:00
dumpstack_64.c x86/percpu: Move irq_stack variables next to current_task 2022-10-17 16:41:05 +02:00
e820.c x86/kexec: Carry forward IMA measurement log on kexec 2022-07-01 15:22:16 +02:00
early-quirks.c drm/i915/rpl-p: Add PCI IDs 2022-04-19 17:14:09 -07:00
early_printk.c x86/earlyprintk: Clean up pciserial 2022-08-29 12:19:25 +02:00
ebda.c
eisa.c
espfix_64.c random: handle archrandom with multiple longs 2022-07-25 13:26:14 +02:00
ftrace.c x86/modules: Set VM_FLUSH_RESET_PERMS in module_alloc() 2022-10-17 16:40:57 +02:00
ftrace_32.S x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
ftrace_64.S x86/ftrace: Remove OBJECT_FILES_NON_STANDARD usage 2022-06-06 11:50:22 -07:00
head32.c
head64.c x86: Clear .brk area at early boot 2022-07-01 11:11:34 +02:00
head_32.S x86/asm/32: Fix ANNOTATE_UNRET_SAFE use on 32-bit 2022-07-13 12:43:26 +02:00
head_64.S x86/callthunks: Add call patching for call depth tracking 2022-10-17 16:41:13 +02:00
hpet.c rtc: Check return value from mc146818_get_time() 2021-12-16 21:50:06 +01:00
hw_breakpoint.c
i8237.c
i8253.c
i8259.c
idt.c x86/traps: Add #VE support for TDX guest 2022-04-07 08:27:51 -07:00
io_delay.c
ioport.c
irq.c x86/irq: Ensure PI wakeup handler is unregistered before module unload 2021-10-22 12:45:35 -04:00
irq_32.c x86/percpu: Move irq_stack variables next to current_task 2022-10-17 16:41:05 +02:00
irq_64.c x86/percpu: Move irq_stack variables next to current_task 2022-10-17 16:41:05 +02:00
irq_work.c
irqflags.S x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
irqinit.c
itmt.c x86/sched: Decrease further the priorities of SMT siblings 2021-10-05 15:51:59 +02:00
jailhouse.c
jump_label.c jump_label: make initial NOP patching the special case 2022-06-24 09:48:55 +02:00
kdebugfs.c x86/boot: Fix memremap of setup_indirect structures 2022-03-09 12:49:44 +01:00
kexec-bzimage64.c integrity-v6.0 2022-08-02 15:21:18 -07:00
kgdb.c
ksysfs.c x86/boot: Fix memremap of setup_indirect structures 2022-03-09 12:49:44 +01:00
kvm.c x86/paravirt: Properly align PV functions 2022-10-17 16:40:59 +02:00
kvmclock.c x86/kvm: Don't waste kvmclock memory if there is nopv parameter 2022-04-13 13:37:19 -04:00
ldt.c
machine_kexec_32.c
machine_kexec_64.c x86/kexec: fix memory leak of elf header buffer 2022-06-01 15:57:16 -07:00
Makefile x86/callthunks: Add call patching for call depth tracking 2022-10-17 16:41:13 +02:00
mmconf-fam10h_64.c
module.c x86/modules: Set VM_FLUSH_RESET_PERMS in module_alloc() 2022-10-17 16:40:57 +02:00
mpparse.c
msr.c
nmi.c x86/nmi: Make register_nmi_handler() more robust 2022-05-17 09:25:25 +02:00
nmi_selftest.c
paravirt-spinlocks.c
paravirt.c x86/paravirt: Properly align PV functions 2022-10-17 16:40:59 +02:00
pci-dma.c swiotlb: merge swiotlb-xen initialization into swiotlb 2022-04-18 07:21:13 +02:00
pcspeaker.c
perf_regs.c
platform-quirks.c
pmem.c x86/pmem: Fix platform-device leak in error path 2022-06-20 18:01:16 +02:00
probe_roms.c x86/kernel: Validate ROM memory before accessing when SEV-SNP is active 2022-04-06 13:23:09 +02:00
process.c treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
process.h x86: Snapshot thread flags 2021-12-01 00:06:43 +01:00
process_32.c x86/percpu: Move current_top_of_stack next to current_task 2022-10-17 16:41:05 +02:00
process_64.c x86/percpu: Move irq_stack variables next to current_task 2022-10-17 16:41:05 +02:00
ptrace.c x86/32: Remove lazy GS macros 2022-04-14 14:09:43 +02:00
pvclock.c
quirks.c
reboot.c x86: Use do_kernel_power_off() 2022-05-19 19:30:31 +02:00
reboot_fixups_32.c
relocate_kernel_32.S x86/kexec: Disable RET on kexec 2022-07-09 13:12:32 +02:00
relocate_kernel_64.S x86/callthunks: Add call patching for call depth tracking 2022-10-17 16:41:13 +02:00
resource.c x86/PCI: Revert "x86/PCI: Clip only host bridge windows for E820 regions" 2022-06-17 14:24:14 -05:00
rethook.c x86,rethook: Fix arch_rethook_trampoline() to generate a complete pt_regs 2022-03-28 19:38:51 -07:00
rtc.c x86/rtc: Rename mach_set_rtc_mmss() to mach_set_cmos_time() 2022-08-14 11:24:29 +02:00
setup.c x86/setup: Use rng seeds from setup_data 2022-07-11 09:59:31 +02:00
setup_percpu.c x86/percpu: Move cpu_number next to current_task 2022-10-17 16:41:04 +02:00
sev-shared.c Revert "x86/sev: Expose sev_es_ghcb_hv_call() for use by HyperV" 2022-07-27 18:09:13 +02:00
sev.c x86/sev: Mark snp_abort() noreturn 2022-08-25 15:54:03 +02:00
sev_verify_cbit.S x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
signal.c x86/32: Remove lazy GS macros 2022-04-14 14:09:43 +02:00
signal_compat.c signal: Deliver SIGTRAP on perf event asynchronously if blocked 2022-04-22 12:14:05 +02:00
smp.c
smpboot.c x86/percpu: Move current_top_of_stack next to current_task 2022-10-17 16:41:05 +02:00
stacktrace.c x86: remove __range_not_ok() 2022-02-25 09:36:05 +01:00
static_call.c x86/static_call: Serialize __static_call_fixup() properly 2022-07-12 14:23:32 +02:00
step.c ptrace: Reimplement PTRACE_KILL by always sending SIGKILL 2022-05-11 14:34:28 -05:00
sys_ia32.c
sys_x86_64.c x86/mm: Cleanup the control_va_addr_alignment() __setup handler 2022-05-04 18:20:42 +02:00
tboot.c mm: remove rb tree. 2022-09-26 19:46:16 -07:00
time.c
tls.c
tls.h
topology.c drivers/base/node: consolidate node device subsystem initialization in node_dev_init() 2022-03-22 15:57:10 -07:00
trace.c trace/osnoise: Fix an ifdef comment 2021-10-25 23:02:36 -04:00
trace_clock.c
tracepoint.c x86/traceponit: Fix comment about irq vector tracepoints 2022-05-26 22:03:52 -04:00
traps.c x86/percpu: Move current_top_of_stack next to current_task 2022-10-17 16:41:05 +02:00
tsc.c x86/tsc: Be consistent about use_tsc_delay() 2022-03-15 18:20:33 +01:00
tsc_msr.c
tsc_sync.c x86/tsc: Add a timer to make sure TSC_adjust is always checked 2021-12-02 00:40:35 +01:00
umip.c
unwind_frame.c x86: kmsan: don't instrument stack walking functions 2022-10-03 14:03:25 -07:00
unwind_guess.c x86/unwind: Recover kretprobe trampoline entry 2021-09-30 21:24:07 -04:00
unwind_orc.c x86/unwind/orc: Unwind ftrace trampolines with correct ORC entry 2022-08-21 12:19:32 +02:00
uprobes.c
verify_cpu.S x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
vm86_32.c x86/32: Remove lazy GS macros 2022-04-14 14:09:43 +02:00
vmlinux.lds.S x86/callthunks: Add call patching for call depth tracking 2022-10-17 16:41:13 +02:00
vsmp_64.c
x86_init.c x86/rtc: Rename mach_set_rtc_mmss() to mach_set_cmos_time() 2022-08-14 11:24:29 +02:00