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Enze Li 95bb5b617b LoongArch: Get partial stack information when providing regs parameter
Currently, arch_stack_walk() can only get the full stack information
including NMI.  This is because the implementation of arch_stack_walk()
is forced to ignore the information passed by the regs parameter and use
the current stack information instead.

For some detection systems like KFENCE, only partial stack information
is needed.  In particular, the stack frame where the interrupt occurred.

To support KFENCE, this patch modifies the implementation of the
arch_stack_walk() function so that if this function is called with the
regs argument passed, it retains all the stack information in regs and
uses it to provide accurate information.

Before this patch:
[    1.531195 ] ==================================================================
[    1.531442 ] BUG: KFENCE: out-of-bounds read in stack_trace_save_regs+0x48/0x6c
[    1.531442 ]
[    1.531900 ] Out-of-bounds read at 0xffff800012267fff (1B left of kfence-#12):
[    1.532046 ]  stack_trace_save_regs+0x48/0x6c
[    1.532169 ]  kfence_report_error+0xa4/0x528
[    1.532276 ]  kfence_handle_page_fault+0x124/0x270
[    1.532388 ]  no_context+0x50/0x94
[    1.532453 ]  do_page_fault+0x1a8/0x36c
[    1.532524 ]  tlb_do_page_fault_0+0x118/0x1b4
[    1.532623 ]  test_out_of_bounds_read+0xa0/0x1d8
[    1.532745 ]  kunit_generic_run_threadfn_adapter+0x1c/0x28
[    1.532854 ]  kthread+0x124/0x130
[    1.532922 ]  ret_from_kernel_thread+0xc/0xa4
<snip>

After this patch:
[    1.320220 ] ==================================================================
[    1.320401 ] BUG: KFENCE: out-of-bounds read in test_out_of_bounds_read+0xa8/0x1d8
[    1.320401 ]
[    1.320898 ] Out-of-bounds read at 0xffff800012257fff (1B left of kfence-#10):
[    1.321134 ]  test_out_of_bounds_read+0xa8/0x1d8
[    1.321264 ]  kunit_generic_run_threadfn_adapter+0x1c/0x28
[    1.321392 ]  kthread+0x124/0x130
[    1.321459 ]  ret_from_kernel_thread+0xc/0xa4
<snip>

Suggested-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Enze Li <lienze@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-06 22:54:16 +08:00
Documentation LoongArch: Allow building with kcov coverage 2023-09-06 22:53:55 +08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
arch LoongArch: Get partial stack information when providing regs parameter 2023-09-06 22:54:16 +08:00
block Merge tag 'md-next-20230814-resend' into loongarch-next 2023-08-30 17:35:54 +08:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto crypto: fix uninit-value in af_alg_free_resources 2023-08-18 18:30:09 +08:00
drivers Merge tag 'md-next-20230814-resend' into loongarch-next 2023-08-30 17:35:54 +08:00
fs Merge tag 'md-next-20230814-resend' into loongarch-next 2023-08-30 17:35:54 +08:00
include raid6: Add LoongArch SIMD recovery implementation 2023-09-06 22:53:55 +08:00
init Kbuild updates for v6.5 2023-07-01 09:24:31 -07:00
io_uring io_uring/parisc: Adjust pgoff in io_uring mmap() for parisc 2023-08-08 12:37:01 -06:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel A last minute fix for a regression introduced in the v6.5 merge window. The 2023-08-26 10:34:29 -07:00
lib raid6: Add LoongArch SIMD recovery implementation 2023-09-06 22:53:55 +08:00
mm kfence: Defer the assignment of the local variable addr 2023-09-06 22:53:55 +08:00
net Networking fixes for 6.5-rc8, including fixes from wifi, can 2023-08-24 08:23:13 -07:00
rust rust: macros: vtable: fix `HAS_*` redefinition (`gen_const_name`) 2023-08-09 21:15:07 +02:00
samples samples: ftrace: Replace bti assembly with hint for older compiler 2023-08-21 22:03:58 -04:00
scripts Kbuild fixes for v6.5 (2nd) 2023-08-13 08:56:24 -07:00
security selinux/stable-6.5 PR 20230821 2023-08-22 10:38:29 -07:00
sound ASoC: Quirk for v6.5 2023-08-25 09:43:49 +02:00
tools Merge tag 'md-next-20230814-resend' into loongarch-next 2023-08-30 17:35:54 +08:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt KVM: Grab a reference to KVM for VM and vCPU stats file descriptors 2023-07-29 11:05:28 -04:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.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 Revert ".gitignore: ignore *.cover and *.mbx" 2023-07-04 15:05:12 -07:00
.mailmap mailmap: add entries for Simon Horman 2023-08-16 09:53:10 +01:00
.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 - Address -Wmissing-prototype warnings 2023-06-26 16:43:54 -07:00
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 sound fixes for 6.5 2023-08-25 08:48:14 -07:00
Makefile Linux 6.5 2023-08-27 14:49:51 -07:00
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.