kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-14 05:55:17 +00:00
Code Issues Releases Packages Activity
No description
1,143,702 commits 116 branches 5,791 tags 5.6 GiB
  • C 96.9%
  • Assembly 0.9%
  • Rust 0.6%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Xu Kuohai 8b9c64942a bpf, arm64: Fixed a BTI error on returning to patched function 
[ Upstream commit 738a96c4a8 ]

When BPF_TRAMP_F_CALL_ORIG is set, BPF trampoline uses BLR to jump
back to the instruction next to call site to call the patched function.
For BTI-enabled kernel, the instruction next to call site is usually
PACIASP, in this case, it's safe to jump back with BLR. But when
the call site is not followed by a PACIASP or bti, a BTI exception
is triggered.

Here is a fault log:

 Unhandled 64-bit el1h sync exception on CPU0, ESR 0x0000000034000002 -- BTI
 CPU: 0 PID: 263 Comm: test_progs Tainted: GF
 Hardware name: linux,dummy-virt (DT)
 pstate: 40400805 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=-c)
 pc : bpf_fentry_test1+0xc/0x30
 lr : bpf_trampoline_6442573892_0+0x48/0x1000
 sp : ffff80000c0c3a50
 x29: ffff80000c0c3a90 x28: ffff0000c2e6c080 x27: 0000000000000000
 x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000050
 x23: 0000000000000000 x22: 0000ffffcfd2a7f0 x21: 000000000000000a
 x20: 0000ffffcfd2a7f0 x19: 0000000000000000 x18: 0000000000000000
 x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffffcfd2a7f0
 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
 x11: 0000000000000000 x10: ffff80000914f5e4 x9 : ffff8000082a1528
 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0101010101010101
 x5 : 0000000000000000 x4 : 00000000fffffff2 x3 : 0000000000000001
 x2 : ffff8001f4b82000 x1 : 0000000000000000 x0 : 0000000000000001
 Kernel panic - not syncing: Unhandled exception
 CPU: 0 PID: 263 Comm: test_progs Tainted: GF
 Hardware name: linux,dummy-virt (DT)
 Call trace:
  dump_backtrace+0xec/0x144
  show_stack+0x24/0x7c
  dump_stack_lvl+0x8c/0xb8
  dump_stack+0x18/0x34
  panic+0x1cc/0x3ec
  __el0_error_handler_common+0x0/0x130
  el1h_64_sync_handler+0x60/0xd0
  el1h_64_sync+0x78/0x7c
  bpf_fentry_test1+0xc/0x30
  bpf_fentry_test1+0xc/0x30
  bpf_prog_test_run_tracing+0xdc/0x2a0
  __sys_bpf+0x438/0x22a0
  __arm64_sys_bpf+0x30/0x54
  invoke_syscall+0x78/0x110
  el0_svc_common.constprop.0+0x6c/0x1d0
  do_el0_svc+0x38/0xe0
  el0_svc+0x30/0xd0
  el0t_64_sync_handler+0x1ac/0x1b0
  el0t_64_sync+0x1a0/0x1a4
 Kernel Offset: disabled
 CPU features: 0x0000,00034c24,f994fdab
 Memory Limit: none

And the instruction next to call site of bpf_fentry_test1 is ADD,
not PACIASP:

<bpf_fentry_test1>:
	bti     c
	nop
	nop
	add     w0, w0, #0x1
	paciasp

For BPF prog, JIT always puts a PACIASP after call site for BTI-enabled
kernel, so there is no problem. To fix it, replace BLR with RET to bypass
the branch target check.

Fixes: efc9909fdc ("bpf, arm64: Add bpf trampoline for arm64")
Reported-by: Florent Revest <revest@chromium.org>
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Florent Revest <revest@chromium.org>
Acked-by: Florent Revest <revest@chromium.org>
Link: https://lore.kernel.org/bpf/20230401234144.3719742-1-xukuohai@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2023-04-20 12:35:08 +02:00
arch bpf, arm64: Fixed a BTI error on returning to patched function 2023-04-20 12:35:08 +02:00
block blk-throttle: Fix that bps of child could exceed bps limited in parent 2023-04-13 16:55:37 +02:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto crypto: rsa-pkcs1pad - Use akcipher_request_complete 2023-03-10 09:33:03 +01:00
Documentation ALSA: hda/sigmatel: add pin overrides for Intel DP45SG motherboard 2023-04-20 12:35:05 +02:00
drivers dmaengine: apple-admac: Fix 'current_tx' not getting freed 2023-04-20 12:35:08 +02:00
fs btrfs: fix fast csum implementation detection 2023-04-20 12:35:06 +02:00
include mm: enable maple tree RCU mode by default. 2023-04-13 16:55:40 +02:00
init gcc: disable -Warray-bounds for gcc-11 too 2023-01-14 10:33:43 +01:00
io_uring io_uring: fix memory leak when removing provided buffers 2023-04-13 16:55:31 +02:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel mm: enable maple tree RCU mode by default. 2023-04-13 16:55:40 +02:00
lib maple_tree: add RCU lock checking to rcu callback functions 2023-04-13 16:55:40 +02:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm: enable maple tree RCU mode by default. 2023-04-13 16:55:40 +02:00
net 9p/xen : Fix use after free bug in xen_9pfs_front_remove due to race condition 2023-04-20 12:35:08 +02:00
rust rust: print: avoid evaluating arguments in pr_* macros in unsafe blocks 2023-02-06 08:06:34 +01:00
samples ftrace: Export ftrace_free_filter() to modules 2023-02-01 08:34:37 +01:00
scripts modpost: Fix processing of CRCs on 32-bit build machines 2023-04-06 12:10:53 +02:00
security keys: Do not cache key in task struct if key is requested from kernel thread 2023-03-30 12:49:07 +02:00
sound ALSA: hda/hdmi: disable KAE for Intel DG2 2023-04-20 12:35:06 +02:00
tools bpftool: Print newline before '}' for struct with padding only fields 2023-04-13 16:55:40 +02:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt KVM: Register /dev/kvm as the _very_ last thing during initialization 2023-03-10 09:34:11 +01:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS audit: update the mailing list in MAINTAINERS 2023-02-25 11:25:42 +01:00
Makefile Linux 6.1.24 2023-04-13 16:55:40 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.