2f31ad64a9
Before commit 3f388f28639f ("panic: dump registers on panic_on_warn"),
__warn() was calling show_regs() when regs was not NULL, and show_stack()
otherwise.
After that commit, show_stack() is called regardless of whether
show_regs() has been called or not, leading to duplicated Call Trace:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/nohash/8xx.c:186 mmu_mark_initmem_nx+0x24/0x94
CPU: 0 PID: 1 Comm: swapper Not tainted 5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty #4092
NIP: c00128b4 LR: c0010228 CTR: 00000000
REGS: c9023e40 TRAP: 0700 Not tainted (5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty)
MSR: 00029032 <EE,ME,IR,DR,RI> CR: 24000424 XER: 00000000
GPR00: c0010228 c9023ef8 c2100000 0074c000 ffffffff 00000000 c2151000 c07b3880
GPR08: ff000900 0074c000 c8000000 c33b53a8 24000822 00000000 c0003a20 00000000
GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
GPR24: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00800000
NIP [c00128b4] mmu_mark_initmem_nx+0x24/0x94
LR [c0010228] free_initmem+0x20/0x58
Call Trace:
free_initmem+0x20/0x58
kernel_init+0x1c/0x114
ret_from_kernel_thread+0x14/0x1c
Instruction dump:
7d291850 7d234b78 4e800020 9421ffe0 7c0802a6 bfc10018 3fe0c060 3bff0000
3fff4080 3bffffff 90010024 57ff0010 <0fe00000> 392001cd 7c3e0b78 953e0008
CPU: 0 PID: 1 Comm: swapper Not tainted 5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty #4092
Call Trace:
__warn+0x8c/0xd8 (unreliable)
report_bug+0x11c/0x154
program_check_exception+0x1dc/0x6e0
ret_from_except_full+0x0/0x4
--- interrupt: 700 at mmu_mark_initmem_nx+0x24/0x94
LR = free_initmem+0x20/0x58
free_initmem+0x20/0x58
kernel_init+0x1c/0x114
ret_from_kernel_thread+0x14/0x1c
---[ end trace 31702cd2a9570752 ]---
Only call show_stack() when regs is NULL.
Fixes: 3f388f28639f ("panic: dump registers on panic_on_warn")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lkml.kernel.org/r/e8c055458b080707f1bc1a98ff8bea79d0cec445.1604748361.git.christophe.leroy@csgroup.eu
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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.