mirror_ubuntu-kernels/tools
Peter Zijlstra d54dba4199 objtool: Allow UNWIND_HINT to suppress dodgy stack modifications
rewind_stack_do_exit()
	UNWIND_HINT_FUNC
	/* Prevent any naive code from trying to unwind to our caller. */

	xorl	%ebp, %ebp
	movq	PER_CPU_VAR(cpu_current_top_of_stack), %rax
	leaq	-PTREGS_SIZE(%rax), %rsp
	UNWIND_HINT_REGS

	call	do_exit

Does unspeakable things to the stack, which objtool currently fails to
detect due to a limitation in instruction decoding. This will be
rectified after which the above will result in:

arch/x86/entry/entry_64.o: warning: objtool: .text+0xab: unsupported stack register modification

Allow the UNWIND_HINT on the next instruction to suppress this, it
will overwrite the state anyway.

Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lkml.kernel.org/r/20210211173626.918498579@infradead.org
2021-03-06 12:44:22 +01:00
..
accounting
arch objtool updates: 2021-02-23 09:56:13 -08:00
bootconfig tools/bootconfig: Add tracing_on support to helper scripts 2021-01-14 10:32:20 -05:00
bpf New features: 2021-02-22 13:59:43 -08:00
build New features: 2021-02-22 13:59:43 -08:00
cgroup blk-iocost: update iocost_monitor.py 2020-09-01 19:38:33 -06:00
debugging docs: Update documentation to reflect what TAINT_CPU_OUT_OF_SPEC means 2020-12-08 10:53:58 -07:00
edid
firewire
firmware
gpio tools: gpio: remove uAPI v1 code no longer used by selftests 2021-02-15 11:43:28 +01:00
hv
iio iio: add IIO_MOD_O2 modifier 2020-08-22 10:53:12 +01:00
include idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
io_uring tools/io_uring: fix compile breakage 2020-09-21 07:50:58 -06:00
kvm/kvm_stat tools/kvm_stat: Exempt time-based counters 2020-12-11 19:18:51 -05:00
laptop
leds
lib New features: 2021-02-22 13:59:43 -08:00
memory-model tools/memory-model: Fix typo in klitmus7 compatibility table 2021-01-04 14:40:50 -08:00
objtool objtool: Allow UNWIND_HINT to suppress dodgy stack modifications 2021-03-06 12:44:22 +01:00
pci
pcmcia
perf New features: 2021-02-22 13:59:43 -08:00
power platform-drivers-x86 for v5.12-1 2021-02-22 08:50:01 -08:00
scripts New features: 2021-02-22 13:59:43 -08:00
spi
testing * Doc fixes 2021-03-04 11:26:17 -08:00
thermal/tmon
time
tracing tracing/tools: fix a couple of spelling mistakes 2021-02-25 12:54:16 -05:00
usb tools: usb: move to tools buildsystem 2020-08-19 14:11:44 +02:00
virtio tools/virtio: add barrier for aarch64 2020-12-18 16:14:30 -05:00
vm mm: Add PG_arch_2 page flag 2020-09-04 12:46:06 +01:00
wmi
Makefile tracing/tools: Add the latency-collector to tools directory 2021-02-12 11:52:59 -05:00