linux/tools
Peter Zijlstra 882a0db9d1 objtool: Improve UACCESS coverage
A clang build reported an (obvious) double CLAC while a GCC build did not;
it turns out that objtool only re-visits instructions if the first visit
was with AC=0. If OTOH the first visit was with AC=1, it completely ignores
any subsequent visit, even when it has AC=0.

Fix this by using a visited mask instead of a boolean, and (explicitly)
mark the AC state.

$ ./objtool check -b --no-fp --retpoline --uaccess drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool: .altinstr_replacement+0x22: redundant UACCESS disable
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool:   eb_copy_relocations.isra.34()+0xea: (alt)
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool:   .altinstr_replacement+0xffffffffffffffff: (branch)
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool:   eb_copy_relocations.isra.34()+0xd9: (alt)
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool:   eb_copy_relocations.isra.34()+0xb2: (branch)
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool:   eb_copy_relocations.isra.34()+0x39: (branch)
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool:   eb_copy_relocations.isra.34()+0x0: <=== (func)

Reported-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/617
Link: https://lkml.kernel.org/r/5359166aad2d53f3145cd442d83d0e5115e0cd17.1564007838.git.jpoimboe@redhat.com
2019-07-25 08:36:39 +02:00
..
accounting
arch tools arch x86: Sync asm/cpufeatures.h with the with the kernel 2019-07-08 13:47:14 -03:00
bpf Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-07-08 19:48:57 -07:00
build tools build: Check if gettid() is available before providing helper 2019-07-07 17:53:09 -03:00
cgroup
crypto
debugging
firewire treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
firmware Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
gpio Bulk GPIO changes for the v5.3 kernel cycle: 2019-07-09 09:07:00 -07:00
hv treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 280 2019-06-05 17:36:36 +02:00
iio Second set of IIO device support, features, cleanups and minor fixes for 5.3. 2019-07-01 10:58:13 +02:00
include docs: cgroup-v1: add it to the admin-guide book 2019-07-15 11:03:02 -03:00
io_uring tools/io_uring: sync with liburing 2019-05-23 10:25:26 -06:00
kvm/kvm_stat treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
laptop treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505 2019-06-19 17:11:22 +02:00
leds
lib perf/core improvements and fixes: 2019-07-13 11:12:47 +02:00
memory-model tools/memory-model: Improve data-race detection 2019-06-24 09:08:54 -07:00
nfsd
objtool objtool: Improve UACCESS coverage 2019-07-25 08:36:39 +02:00
pci pci-v5.3-changes 2019-07-15 20:44:49 -07:00
pcmcia treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 247 2019-06-19 17:09:08 +02:00
perf perf intel-pt: Fix potential NULL pointer dereference found by the smatch tool 2019-07-09 10:13:28 -03:00
power platform-drivers-x86 for v5.3-1 2019-07-14 16:51:47 -07:00
scripts
spi treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 178 2019-05-30 11:29:19 -07:00
testing Merge branch 'akpm' (patches from Andrew) 2019-07-17 08:58:04 -07:00
thermal/tmon treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 89 2019-05-24 17:37:52 +02:00
time treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
usb treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
virtio treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
vm tools/vm/slabinfo: add sorting info to help menu 2019-07-12 11:05:46 -07:00
wmi treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
Makefile tools/power/x86: A tool to validate Intel Speed Select commands 2019-07-03 15:37:09 +03:00