public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-08-05 16:54:27 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions
linux/kernel
History
Ard Biesheuvel 080b6f4076 bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE 
Commit 3193c0836 ("bpf: Disable GCC -fgcse optimization for
___bpf_prog_run()") introduced a __no_fgcse macro that expands to a
function scope __attribute__((optimize("-fno-gcse"))), to disable a
GCC specific optimization that was causing trouble on x86 builds, and
was not expected to have any positive effect in the first place.

However, as the GCC manual documents, __attribute__((optimize))
is not for production use, and results in all other optimization
options to be forgotten for the function in question. This can
cause all kinds of trouble, but in one particular reported case,
it causes -fno-asynchronous-unwind-tables to be disregarded,
resulting in .eh_frame info to be emitted for the function.

This reverts commit 3193c0836, and instead, it disables the -fgcse
optimization for the entire source file, but only when building for
X86 using GCC with CONFIG_BPF_JIT_ALWAYS_ON disabled. Note that the
original commit states that CONFIG_RETPOLINE=n triggers the issue,
whereas CONFIG_RETPOLINE=y performs better without the optimization,
so it is kept disabled in both cases.

Fixes: 3193c0836f ("bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/lkml/CAMuHMdUg0WJHEcq6to0-eODpXPOywLot6UD2=GFHpzoj_hCoBQ@mail.gmail.com/
Link: https://lore.kernel.org/bpf/20201028171506.15682-2-ardb@kernel.org
2020-10-29 20:01:46 -07:00
..
bpf bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE 2020-10-29 20:01:46 -07:00
cgroup kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
configs compiler: remove CONFIG_OPTIMIZE_INLINING entirely 2020-04-07 10:43:42 -07:00
debug kdb: Fix pager search for multi-line strings 2020-10-01 14:44:08 +01:00
dma kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
entry arch-cleanup-2020-10-22 2020-10-23 10:06:38 -07:00
events task_work: cleanup notification modes 2020-10-17 15:05:30 -06:00
gcov gcov: add support for GCC 10.1 2020-09-11 09:33:54 -07:00
irq task_work: cleanup notification modes 2020-10-17 15:05:30 -06:00
kcsan kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
livepatch kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
locking Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-10-18 14:34:50 -07:00
power kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
printk Urgent printk fix for 5.10 2020-10-16 12:52:37 -07:00
rcu Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-10-18 14:34:50 -07:00
sched task_work: cleanup notification modes 2020-10-17 15:05:30 -06:00
time Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-10-18 14:34:50 -07:00
trace Tracing: Fix mismatch section of adding early trace events 2020-10-16 14:56:52 -07:00
.gitignore
acct.c kernel: acct.c: fix some kernel-doc nits 2020-10-16 11:11:19 -07:00
async.c treewide: Remove uninitialized_var() usage 2020-07-16 12:35:15 -07:00
audit.c audit: Remove redundant null check 2020-08-26 09:10:39 -04:00
audit.h audit: change unnecessary globals into statics 2020-08-17 20:26:58 -04:00
audit_fsnotify.c fsnotify: create method handle_inode_event() in fsnotify_operations 2020-07-27 23:25:50 +02:00
audit_tree.c \n 2020-08-06 19:29:51 -07:00
audit_watch.c fsnotify: create method handle_inode_event() in fsnotify_operations 2020-07-27 23:25:50 +02:00
auditfilter.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
auditsc.c audit/stable-5.9 PR 20200803 2020-08-04 14:20:26 -07:00
backtracetest.c treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD() 2020-07-30 11:15:58 -07:00
bounds.c
capability.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
compat.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
configs.c
context_tracking.c context_tracking: Ensure that the critical path cannot be instrumented 2020-06-11 15:14:36 +02:00
cpu.c The changes in this cycle are: 2020-06-03 13:06:42 -07:00
cpu_pm.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
crash_core.c kdump: append kernel build-id string to VMCOREINFO 2020-08-12 10:58:01 -07:00
crash_dump.c crash_dump: Remove no longer used saved_max_pfn 2020-04-15 11:21:54 +02:00
cred.c exec: Teach prepare_exec_creds how exec treats uids & gids 2020-05-20 14:44:21 -05:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c pid: move pidfd_get_pid() to pid.c 2020-10-18 09:27:10 -07:00
extable.c kernel/extable.c: use address-of operator on section symbols 2020-04-07 10:43:42 -07:00
fail_function.c
fork.c kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
freezer.c
futex.c kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
gen_kheaders.sh kbuild: add variables for compression tools 2020-06-06 23:42:01 +09:00
groups.c mm: remove the pgprot argument to __vmalloc 2020-06-02 10:59:11 -07:00
hung_task.c kernel/hung_task.c: introduce sysctl to print all traces when a hung task is detected 2020-06-08 11:05:56 -07:00
iomem.c
irq_work.c irq_work, smp: Allow irq_work on call_single_queue 2020-05-28 10:54:15 +02:00
jump_label.c kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
kallsyms.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: make some symbols static 2020-08-12 10:58:02 -07:00
kexec.c LSM: Introduce kernel_post_load_data() hook 2020-10-05 13:37:03 +02:00
kexec_core.c kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
kexec_elf.c
kexec_file.c kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED 2020-10-16 11:11:18 -07:00
kexec_internal.h
kheaders.c
kmod.c kmod: remove redundant "be an" in the comment 2020-08-12 10:58:01 -07:00
kprobes.c Updates for tracing and bootconfig: 2020-10-15 15:51:28 -07:00
ksysfs.c
kthread.c kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
latencytop.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
Makefile Kbuild updates for v5.10 2020-10-22 13:13:57 -07:00
module-internal.h
module.c Modules updates for v5.10 2020-10-22 13:08:57 -07:00
module_signature.c
module_signing.c
notifier.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
nsproxy.c nsproxy: support CLONE_NEWTIME with setns() 2020-07-08 11:14:22 +02:00
padata.c padata: fix possible padata_works_lock deadlock 2020-09-04 17:51:55 +10:00
panic.c panic: dump registers on panic_on_warn 2020-10-16 11:11:22 -07:00
params.c moduleparams: Add hexint type parameter 2020-07-28 13:44:53 +02:00
pid.c pid: move pidfd_get_pid() to pid.c 2020-10-18 09:27:10 -07:00
pid_namespace.c kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
profile.c
ptrace.c
range.c kernel.h: split out min()/max() et al. helpers 2020-10-16 11:11:19 -07:00
reboot.c arch: remove unicore32 port 2020-07-01 12:09:13 +03:00
regset.c regset: kill ->get() 2020-07-27 14:31:12 -04:00
relay.c kernel/relay.c: drop unneeded initialization 2020-10-16 11:11:22 -07:00
resource.c kernel/resource: make iomem_resource implicit in release_mem_region_adjustable() 2020-10-16 11:11:18 -07:00
rseq.c
scftorture.c scftorture: Add cond_resched() to test loop 2020-08-24 18:38:38 -07:00
scs.c mm: memcontrol: account kernel stack per node 2020-08-07 11:33:25 -07:00
seccomp.c seccomp: Make duplicate listener detection non-racy 2020-10-08 13:17:47 -07:00
signal.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
smp.c Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-10-18 14:34:50 -07:00
smpboot.c
smpboot.h
softirq.c softirq: Add debug check to __raise_softirq_irqoff() 2020-09-16 15:18:56 +02:00
stackleak.c stackleak: let stack_erasing_sysctl take a kernel pointer buffer 2020-09-19 13:13:39 -07:00
stacktrace.c stacktrace: Remove reliable argument from arch_stack_walk() callback 2020-09-18 14:24:16 +01:00
static_call.c static_call: Fix return type of static_call_init 2020-10-02 21:18:25 +02:00
stop_machine.c
sys.c kernel/sys.c: replace do_brk with do_brk_flags in comment of prctl_set_mm_map() 2020-10-16 11:11:19 -07:00
sys_ni.c mm/madvise: introduce process_madvise() syscall: an external memory hinting API 2020-10-18 09:27:10 -07:00
sysctl-test.c
sysctl.c mm: allow a controlled amount of unfairness in the page lock 2020-09-17 10:26:41 -07:00
task_work.c task_work: cleanup notification modes 2020-10-17 15:05:30 -06:00
taskstats.c taskstats: move specifying netlink policy back to ops 2020-10-02 19:11:12 -07:00
test_kprobes.c
torture.c torture: Dump ftrace at shutdown only if requested 2020-06-29 12:01:45 -07:00
tracepoint.c tracepoint: Fix out of sync data passing by static caller 2020-10-02 21:18:25 +02:00
tsacct.c
ucount.c ucount: Make sure ucounts in /proc/sys/user don't regress again 2020-04-07 21:51:27 +02:00
uid16.c
uid16.h
umh.c usermodehelper: reset umask to default before executing user process 2020-10-06 10:31:52 -07:00
up.c
user-return-notifier.c
user.c user.c: make uidhash_table static 2020-06-04 19:06:24 -07:00
user_namespace.c kernel/: fix repeated words in comments 2020-10-16 11:11:19 -07:00
usermode_driver.c umd: Stop using split_argv 2020-07-07 11:58:59 -05:00
utsname.c nsproxy: add struct nsset 2020-05-09 13:57:12 +02:00
utsname_sysctl.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
watch_queue.c watch_queue: Limit the number of watches a user can hold 2020-08-17 09:39:18 -07:00
watchdog.c kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases 2020-06-08 11:05:56 -07:00
watchdog_hld.c
workqueue.c workqueue: fix a kernel-doc warning 2020-10-16 07:28:20 +02:00
workqueue_internal.h