Boot on parisc has been broken for some time:
[...]
Run /init as init process
process '/usr/bin/sh' started with executable stack
Loading, please wait...
Starting systemd-udevd version 254.1-3
Backtrace:
[<0000000040433d0c>] kmalloc_trace+0x3c/0x50
[<00000000402fceb4>] do_init_module+0xa4/0x4d0
[<00000000402ff130>] load_module+0xe48/0x1028
[<00000000402ff6ec>] __do_sys_finit_module+0x104/0x168
[<00000000402ff7bc>] sys_finit_module+0x2c/0x40
[<0000000040203e5c>] syscall_exit+0x0/0x10
Page fault: bad address: Code=6 (Instruction TLB miss fault) at addr 37dd3fa10c0
CPU: 1 PID: 825 Comm: (udev-worker) Not tainted 6.4.0-rc2+ #14
Hardware name: 9000/785/C8000
YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001001101111100001111 Not tainted
r00-03 000000ff0804df0f 37dd3fa10c6712d0 000000000816704c 0000000053390520
r04-07 0000000008161000 00000000081611c0 00000000520915a0 00000000411d8000
r08-11 0000000000000000 000000004115ad88 0000000053390240 0000000000000000
r12-15 00000000081631b8 0000000053390370 00000000410b9e40 0000000008165174
r16-19 0000000000000000 0000000000000000 0000000053390288 0000000008169000
r20-23 000000005381b0b0 000000000eaaa000 00000000533904c8 0000000000000001
r24-27 0000000000000cc0 0000000000000000 0000000008165290 081a024770650030
r28-31 0000000000000000 0000000053390570 00000000533905a0 0000000008167000
sr00-03 00000000000c3800 0000000000000000 0000000000000000 00000000000c6400
sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000
IASQ: 0000000037dd3fa1 0000000037dd3fa1 IAOQ: 37dd3fa10c6712d0 37dd3fa10c6712d4
IIR: 43ffff80 ISR: 0000000040ca43a0 IOR: 0000000040c8c040
CPU: 1 CR30: 00000000520915a0 CR31: ffffffffffffffff
ORIG_R28: 000000000800000e
IAOQ[0]: 0x37dd3fa10c6712d0
IAOQ[1]: 0x37dd3fa10c6712d4
RP(r2): usb_common_init+0x2c/0xfe0 [usb_common]
Backtrace:
[<0000000040433d0c>] kmalloc_trace+0x3c/0x50
[<00000000402fceb4>] do_init_module+0xa4/0x4d0
[<00000000402ff130>] load_module+0xe48/0x1028
[<00000000402ff6ec>] __do_sys_finit_module+0x104/0x168
[<00000000402ff7bc>] sys_finit_module+0x2c/0x40
[<0000000040203e5c>] syscall_exit+0x0/0x10
Kernel panic - not syncing: Page fault: bad address
I bisected this to the following commit:
dave@atlas:~/linux/linux$ git bisect good
ddb5cdbafaaad6b99d7007ae1740403124502d03 is the first bad commit
commit ddb5cdbafaaad6b99d7007ae1740403124502d03
Author: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Date: Mon Jun 12 00:50:52 2023 +0900
kbuild: generate KSYMTAB entries by modpost
Commit 7b4537199a4a ("kbuild: link symbol CRCs at final link, removing
CONFIG_MODULE_REL_CRCS") made modpost output CRCs in the same way
whether the EXPORT_SYMBOL() is placed in *.c or *.S.
For further cleanups, this commit applies a similar approach to the
entire data structure of EXPORT_SYMBOL().
The EXPORT_SYMBOL() compilation is split into two stages.
When a source file is compiled, EXPORT_SYMBOL() will be converted into
a dummy symbol in the .export_symbol section.
For example,
EXPORT_SYMBOL(foo);
EXPORT_SYMBOL_NS_GPL(bar, BAR_NAMESPACE);
will be encoded into the following assembly code:
.section ".export_symbol","a"
__export_symbol_foo:
.asciz "" /* license */
.asciz "" /* name space */
.balign 8
.quad foo /* symbol reference */
.previous
.section ".export_symbol","a"
__export_symbol_bar:
.asciz "GPL" /* license */
.asciz "BAR_NAMESPACE" /* name space */
.balign 8
.quad bar /* symbol reference */
.previous
They are mere markers to tell modpost the name, license, and namespace
of the symbols. They will be dropped from the final vmlinux and modules
because the *(.export_symbol) will go into /DISCARD/ in the linker script.
Then, modpost extracts all the information about EXPORT_SYMBOL() from the
.export_symbol section, and generates the final C code:
KSYMTAB_FUNC(foo, "", "");
KSYMTAB_FUNC(bar, "_gpl", "BAR_NAMESPACE");
KSYMTAB_FUNC() (or KSYMTAB_DATA() if it is data) is expanded to struct
kernel_symbol that will be linked to the vmlinux or a module.
With this change, EXPORT_SYMBOL() works in the same way for *.c and *.S
files, providing the following benefits.
[1] Deprecate EXPORT_DATA_SYMBOL()
In the old days, EXPORT_SYMBOL() was only available in C files. To export
a symbol in *.S, EXPORT_SYMBOL() was placed in a separate *.c file.
arch/arm/kernel/armksyms.c is one example written in the classic manner.
Commit 22823ab419d8 ("EXPORT_SYMBOL() for asm") removed this limitation.
Since then, EXPORT_SYMBOL() can be placed close to the symbol definition
in *.S files. It was a nice improvement.
However, as that commit mentioned, you need to use EXPORT_DATA_SYMBOL()
for data objects on some architectures.
In the new approach, modpost checks symbol's type (STT_FUNC or not),
and outputs KSYMTAB_FUNC() or KSYMTAB_DATA() accordingly.
There are only two users of EXPORT_DATA_SYMBOL:
EXPORT_DATA_SYMBOL_GPL(empty_zero_page) (arch/ia64/kernel/head.S)
EXPORT_DATA_SYMBOL(ia64_ivt) (arch/ia64/kernel/ivt.S)
They are transformed as follows and output into .vmlinux.export.c
KSYMTAB_DATA(empty_zero_page, "_gpl", "");
KSYMTAB_DATA(ia64_ivt, "", "");
The other EXPORT_SYMBOL users in ia64 assembly are output as
KSYMTAB_FUNC().
EXPORT_DATA_SYMBOL() is now deprecated.
[2] merge <linux/export.h> and <asm-generic/export.h>
There are two similar header implementations:
include/linux/export.h for .c files
include/asm-generic/export.h for .S files
Ideally, the functionality should be consistent between them, but they
tend to diverge.
Commit 8651ec01daed ("module: add support for symbol namespaces.") did
not support the namespace for *.S files.
This commit shifts the essential implementation part to C, which supports
EXPORT_SYMBOL_NS() for *.S files.
<asm/export.h> and <asm-generic/export.h> will remain as a wrapper of
<linux/export.h> for a while.
They will be removed after #include <asm/export.h> directives are all
replaced with #include <linux/export.h>.
[3] Implement CONFIG_TRIM_UNUSED_KSYMS in one-pass algorithm (by a later commit)
When CONFIG_TRIM_UNUSED_KSYMS is enabled, Kbuild recursively traverses
the directory tree to determine which EXPORT_SYMBOL to trim. If an
EXPORT_SYMBOL turns out to be unused by anyone, Kbuild begins the
second traverse, where some source files are recompiled with their
EXPORT_SYMBOL() tuned into a no-op.
We can do this better now; modpost can selectively emit KSYMTAB entries
that are really used by modules.
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
arch/ia64/include/asm/Kbuild | 1 +
arch/ia64/include/asm/export.h | 3 --
include/asm-generic/export.h | 84 ++----------------------------
include/asm-generic/vmlinux.lds.h | 1 +
include/linux/export-internal.h | 49 ++++++++++++++++++
include/linux/export.h | 101 +++++++++++++++---------------------
include/linux/pm.h | 4 +-
kernel/module/internal.h | 12 +++++
scripts/Makefile.build | 8 ++-
scripts/check-local-export | 4 +-
scripts/mod/modpost.c | 106 ++++++++++++++++++++++++++------------
scripts/mod/modpost.h | 1 +
12 files changed, 190 insertions(+), 184 deletions(-)
delete mode 100644 arch/ia64/include/asm/export.h
Dave
--
John David Anglin dave.anglin@xxxxxxxx
