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01f810ace9
android_kernel_samsung_sm8650/kernel
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Andrei Matei 01f810ace9 bpf: Allow variable-offset stack access 
Before this patch, variable offset access to the stack was dissalowed
for regular instructions, but was allowed for "indirect" accesses (i.e.
helpers). This patch removes the restriction, allowing reading and
writing to the stack through stack pointers with variable offsets. This
makes stack-allocated buffers more usable in programs, and brings stack
pointers closer to other types of pointers.

The motivation is being able to use stack-allocated buffers for data
manipulation. When the stack size limit is sufficient, allocating
buffers on the stack is simpler than per-cpu arrays, or other
alternatives.

In unpriviledged programs, variable-offset reads and writes are
disallowed (they were already disallowed for the indirect access case)
because the speculative execution checking code doesn't support them.
Additionally, when writing through a variable-offset stack pointer, if
any pointers are in the accessible range, there's possilibities of later
leaking pointers because the write cannot be tracked precisely.

Writes with variable offset mark the whole range as initialized, even
though we don't know which stack slots are actually written. This is in
order to not reject future reads to these slots. Note that this doesn't
affect writes done through helpers; like before, helpers need the whole
stack range to be initialized to begin with.
All the stack slots are in range are considered scalars after the write;
variable-offset register spills are not tracked.

For reads, all the stack slots in the variable range needs to be
initialized (but see above about what writes do), otherwise the read is
rejected. All register spilled in stack slots that might be read are
marked as having been read, however reads through such pointers don't do
register filling; the target register will always be either a scalar or
a constant zero.

Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210207011027.676572-2-andreimatei1@gmail.com
2021-02-10 10:44:19 -08:00
..
bpf bpf: Allow variable-offset stack access 2021-02-10 10:44:19 -08:00
cgroup Merge branch 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2020-12-28 11:16:38 -08:00
configs staging: ION: remove some references to CONFIG_ION 2021-01-06 17:39:38 +01:00
debug smp: Cleanup smp_call_function*() 2020-11-24 16:47:49 +01:00
dma dma-mapping updates for 5.11: 2020-12-22 13:19:43 -08:00
entry The new preemtible kmap_local() implementation: 2020-12-14 18:35:53 -08:00
events perf: Add build id data in mmap2 event 2021-01-14 19:29:58 -08:00
gcov gcov: fix kernel-doc markup issue 2020-12-15 22:46:18 -08:00
irq genirq: Fix export of irq_to_desc() for powerpc KVM 2020-12-25 11:02:39 -08:00
kcsan kcsan: Fix encoding masks and regain address bit 2020-11-06 17:19:26 -08:00
livepatch livepatch: Use the default ftrace_ops instead of REGS when ARGS is available 2020-11-13 12:15:28 -05:00
locking A moderate set of locking updates: 2020-12-14 17:27:47 -08:00
power Power management updates for 5.11-rc1 2020-12-15 16:30:31 -08:00
printk printk changes for 5.11 2020-12-16 10:45:11 -08:00
rcu Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu 2021-01-04 10:55:19 -08:00
sched Fix a context switch performance regression. 2020-12-27 09:00:47 -08:00
time Update/fix two CPU sanity checks in the hotplug and the boot code, 2020-12-27 09:03:41 -08:00
trace tracing/kprobes: Do the notrace functions check without kprobes on ftrace 2021-01-11 16:09:53 -05:00
.gitignore
acct.c kernel/acct.c: use #elif instead of #end and #elif 2020-12-15 22:46:15 -08:00
async.c treewide: Remove uninitialized_var() usage 2020-07-16 12:35:15 -07:00
audit_fsnotify.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
audit_tree.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
audit_watch.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
audit.c audit: replace atomic_add_return() 2020-12-02 22:52:16 -05:00
audit.h audit: change unnecessary globals into statics 2020-08-17 20:26:58 -04:00
auditfilter.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
auditsc.c audit/stable-5.11 PR 20201214 2020-12-16 10:54:03 -08:00
backtracetest.c treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD() 2020-07-30 11:15:58 -07:00
bounds.c
capability.c LSM: Signal to SafeSetID when setting group IDs 2020-10-13 09:17:34 -07:00
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_pm.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
cpu.c Scheduler updates: 2020-12-14 18:29:11 -08:00
crash_core.c kdump: append uts_namespace.name offset to VMCOREINFO 2020-12-15 22:46:18 -08:00
crash_dump.c
cred.c exec: Teach prepare_exec_creds how exec treats uids & gids 2020-05-20 14:44:21 -05:00
delayacct.c
dma.c
exec_domain.c
exit.c kernel/io_uring: cancel io_uring before task works 2020-12-30 19:36:54 -07:00
extable.c
fail_function.c fault-injection: handle EI_ETYPE_TRUE 2020-12-15 22:46:19 -08:00
fork.c kasan: rename (un)poison_shadow to (un)poison_range 2020-12-22 12:55:06 -08:00
freezer.c
futex.c Merge branch 'locking/rwsem' 2020-12-09 17:08:45 +01:00
gen_kheaders.sh kbuild: add variables for compression tools 2020-06-06 23:42:01 +09:00
groups.c LSM: Signal to SafeSetID when setting group IDs 2020-10-13 09:17:34 -07:00
hung_task.c kernel/hung_task.c: make type annotations consistent 2020-11-02 12:14:19 -08:00
iomem.c
irq_work.c irq_work: Optimize irq_work_single() 2020-11-24 16:47:49 +01:00
jump_label.c jump_label: Fix usage in module __init 2020-12-18 16:53:12 +01:00
kallsyms.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
kcmp.c Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kernel: make kcov_common_handle consider the current context 2020-11-02 18:00:20 -08:00
kexec_core.c crypto: sha - split sha.h into sha1.h and sha2.h 2020-11-20 14:45:33 +11:00
kexec_elf.c
kexec_file.c crypto: sha - split sha.h into sha1.h and sha2.h 2020-11-20 14:45:33 +11:00
kexec_internal.h
kexec.c LSM: Introduce kernel_post_load_data() hook 2020-10-05 13:37:03 +02:00
kheaders.c
kmod.c kmod: remove redundant "be an" in the comment 2020-08-12 10:58:01 -07:00
kprobes.c Merge branch 'linus' into perf/kprobes 2020-11-07 13:18:49 +01:00
ksysfs.c
kthread.c Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
latencytop.c
Makefile kcov: don't instrument with UBSAN 2020-12-15 22:46:19 -08:00
module_signature.c
module_signing.c
module-internal.h
module.c Modules updates for v5.11 2020-12-17 13:01:31 -08:00
notifier.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
nsproxy.c fixes-v5.11 2020-12-14 16:40:27 -08:00
padata.c padata: fix possible padata_works_lock deadlock 2020-09-04 17:51:55 +10:00
panic.c panic: don't dump stack twice on warn 2020-11-14 11:26:04 -08:00
params.c Modules updates for v5.11 2020-12-17 13:01:31 -08:00
pid_namespace.c fixes-v5.11 2020-12-14 16:40:27 -08:00
pid.c Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
profile.c
ptrace.c Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
range.c kernel.h: split out min()/max() et al. helpers 2020-10-16 11:11:19 -07:00
reboot.c reboot: hide from sysfs not applicable settings 2020-12-15 22:46:19 -08:00
regset.c regset: kill ->get() 2020-07-27 14:31:12 -04:00
relay.c relay: allow the use of const callback structs 2020-12-15 22:46:18 -08:00
resource_kunit.c resource: provide meaningful MODULE_LICENSE() in test suite 2020-11-25 18:52:35 +01:00
resource.c kernel/resource.c: fix kernel-doc markups 2020-12-15 22:46:18 -08:00
rseq.c
scftorture.c scftorture: Add full-test stutter capability 2020-11-06 17:13:56 -08:00
scs.c scs: switch to vmapped shadow stacks 2020-12-01 10:30:28 +00:00
seccomp.c seccomp updates for v5.11-rc1 2020-12-16 11:30:10 -08:00
signal.c task_work: unconditionally run task_work from get_signal() 2021-01-08 09:14:21 -07:00
smp.c Merge branch 'linus' into sched/core, to resolve semantic conflict 2020-11-27 11:10:50 +01:00
smpboot.c
smpboot.h
softirq.c Misc fixes/updates: 2020-12-27 09:06:10 -08:00
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 Merge branch 'linus' into sched/core, to resolve semantic conflict 2020-11-27 11:10:50 +01:00
sys_ni.c epoll: wire up syscall epoll_pwait2 2020-12-19 11:18:38 -08:00
sys.c kernel: Implement selective syscall userspace redirection 2020-12-02 15:07:56 +01:00
sysctl-test.c
sysctl.c rcu: Panic after fixed number of stalls 2020-11-19 19:37:16 -08:00
task_work.c task_work: remove legacy TWA_SIGNAL path 2020-12-12 09:17:38 -07:00
taskstats.c treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
test_kprobes.c
torture.c rcutorture: Make stutter_wait() caller restore priority 2020-11-06 17:13:54 -08:00
tracepoint.c tracepoints: Migrate to use SYSCALL_WORK flag 2020-11-16 21:53:15 +01:00
tsacct.c
ucount.c
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_namespace.c fixes-v5.11 2020-12-14 16:40:27 -08:00
user-return-notifier.c
user.c user: Use generic ns_common::count 2020-08-19 14:14:12 +02:00
usermode_driver.c umd: Stop using split_argv 2020-07-07 11:58:59 -05:00
utsname_sysctl.c
utsname.c uts: Use generic ns_common::count 2020-08-19 14:13:20 +02:00
watch_queue.c watch_queue: Limit the number of watches a user can hold 2020-08-17 09:39:18 -07:00
watchdog_hld.c
watchdog.c kernel/watchdog: fix watchdog_allowed_mask not used warning 2020-11-14 11:26:03 -08:00
workqueue_internal.h
workqueue.c Merge branch 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2020-12-28 11:23:02 -08:00