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Eduard Zingerman 6efbde200b bpf: Handle scalar spill vs all MISC in stacksafe()
When check_stack_read_fixed_off() reads value from an spi
all stack slots of which are set to STACK_{MISC,INVALID},
the destination register is set to unbound SCALAR_VALUE.

Exploit this fact by allowing stacksafe() to use a fake
unbound scalar register to compare 'mmmm mmmm' stack value
in old state vs spilled 64-bit scalar in current state
and vice versa.

Veristat results after this patch show some gains:

./veristat -C -e file,prog,states -f 'states_pct>10'  not-opt after
File                     Program                States   (DIFF)
-----------------------  ---------------------  ---------------
bpf_overlay.o            tail_rev_nodeport_lb4    -45 (-15.85%)
bpf_xdp.o                tail_lb_ipv4            -541 (-19.57%)
pyperf100.bpf.o          on_event                -680 (-10.42%)
pyperf180.bpf.o          on_event               -2164 (-19.62%)
pyperf600.bpf.o          on_event               -9799 (-24.84%)
strobemeta.bpf.o         on_event               -9157 (-65.28%)
xdp_synproxy_kern.bpf.o  syncookie_tc             -54 (-19.29%)
xdp_synproxy_kern.bpf.o  syncookie_xdp            -74 (-24.50%)

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240127175237.526726-6-maxtram95@gmail.com
2024-02-02 13:22:14 -08:00
arch riscv, bpf: Enable inline bpf_kptr_xchg() for RV64 2024-02-01 11:35:48 +01:00
block for-6.8/block-2024-01-18 2024-01-18 18:22:40 -08:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto crypto: scomp - fix req->dst buffer overflow 2023-12-29 11:25:56 +08:00
Documentation bpf, docs: Clarify which legacy packet instructions existed 2024-02-01 11:32:13 +01:00
drivers bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
fs bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
include bpf: Preserve boundaries and track scalars on narrowing fill 2024-02-02 13:22:14 -08:00
init init: Kconfig: Disable -Wstringop-overflow for GCC-11 2024-01-21 17:45:31 -06:00
io_uring for-6.8/io_uring-2024-01-18 2024-01-18 18:17:57 -08:00
ipc shm: Slim down dependencies 2023-12-20 19:26:31 -05:00
kernel bpf: Handle scalar spill vs all MISC in stacksafe() 2024-02-02 13:22:14 -08:00
lib RISC-V Patches for the 6.8 Merge Window, Part 4 2024-01-20 11:06:04 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm vfs-6.8.netfs 2024-01-19 09:10:23 -08:00
net bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
rust rust: phy: use VTABLE_DEFAULT_ERROR 2024-01-27 14:28:00 +00:00
samples samples/cgroup: add .gitignore file for generated samples 2024-01-24 11:52:40 -08:00
scripts bpf: Generate const static pointers for kernel helpers 2024-01-29 16:46:12 -08:00
security bpf-next-for-netdev 2024-01-26 21:08:22 -08:00
sound sound fixes for 6.8-rc1 2024-01-19 12:30:29 -08:00
tools selftests/bpf: Add test cases for narrowing fill 2024-02-02 13:22:14 -08:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt Generic: 2024-01-17 13:03:37 -08:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.mailmap Char/Misc and other Driver changes for 6.8-rc1 2024-01-17 16:47:17 -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 Including fixes from bpf and netfilter. 2024-01-18 17:33:50 -08:00
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 bpf-next-for-netdev 2024-01-26 21:08:22 -08:00
Makefile init: Kconfig: Disable -Wstringop-overflow for GCC-11 2024-01-21 17:45:31 -06:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.