linux/tools
Peter Zijlstra ba08abca66 objtool,x86: Fix uaccess PUSHF/POPF validation
Commit ab234a260b ("x86/pv: Rework arch_local_irq_restore() to not
use popf") replaced "push %reg; popf" with something like: "test
$0x200, %reg; jz 1f; sti; 1:", which breaks the pushf/popf symmetry
that commit ea24213d80 ("objtool: Add UACCESS validation") relies
on.

The result is:

  drivers/gpu/drm/amd/amdgpu/si.o: warning: objtool: si_common_hw_init()+0xf36: PUSHF stack exhausted

Meanwhile, commit c9c324dc22 ("objtool: Support stack layout changes
in alternatives") makes that we can actually use stack-ops in
alternatives, which means we can revert 1ff865e343 ("x86,smap: Fix
smap_{save,restore}() alternatives").

That in turn means we can limit the PUSHF/POPF handling of
ea24213d80 to those instructions that are in alternatives.

Fixes: ab234a260b ("x86/pv: Rework arch_local_irq_restore() to not use popf")
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/YEY4rIbQYa5fnnEp@hirez.programming.kicks-ass.net
2021-03-12 09:15:49 +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
debugging
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
include idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
io_uring
kvm/kvm_stat
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,x86: Fix uaccess PUSHF/POPF validation 2021-03-12 09:15:49 +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
virtio
vm
wmi
Makefile tracing/tools: Add the latency-collector to tools directory 2021-02-12 11:52:59 -05:00