- Remove the deprecated rule to build *.dtbo from *.dts
- Refactor section mismatch detection in modpost
- Fix bogus ARM section mismatch detections
- Fix error of 'make gtags' with O= option
- Add Clang's target triple to KBUILD_CPPFLAGS to fix a build error with
the latest LLVM version
- Rebuild the built-in initrd when KBUILD_BUILD_TIMESTAMP is changed
- Ignore more compiler-generated symbols for kallsyms
- Fix 'make local*config' to handle the ${CONFIG_FOO} form in Makefiles
- Enable more kernel-doc warnings with W=2
- Refactor <linux/export.h> by generating KSYMTAB data by modpost
- Deprecate <asm/export.h> and <asm-generic/export.h>
- Remove the EXPORT_DATA_SYMBOL macro
- Move the check for static EXPORT_SYMBOL back to modpost, which makes
the build faster
- Re-implement CONFIG_TRIM_UNUSED_KSYMS with one-pass algorithm
- Warn missing MODULE_DESCRIPTION when building modules with W=1
- Make 'make clean' robust against too long argument error
- Exclude more objects from GCOV to fix CFI failures with GCOV
- Allow 'make modules_install' to install modules.builtin and
modules.builtin.modinfo even when CONFIG_MODULES is disabled
- Include modules.builtin and modules.builtin.modinfo in the linux-image
Debian package even when CONFIG_MODULES is disabled
- Revive "Entering directory" logging for the latest Make version
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Merge tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Remove the deprecated rule to build *.dtbo from *.dts
- Refactor section mismatch detection in modpost
- Fix bogus ARM section mismatch detections
- Fix error of 'make gtags' with O= option
- Add Clang's target triple to KBUILD_CPPFLAGS to fix a build error
with the latest LLVM version
- Rebuild the built-in initrd when KBUILD_BUILD_TIMESTAMP is changed
- Ignore more compiler-generated symbols for kallsyms
- Fix 'make local*config' to handle the ${CONFIG_FOO} form in Makefiles
- Enable more kernel-doc warnings with W=2
- Refactor <linux/export.h> by generating KSYMTAB data by modpost
- Deprecate <asm/export.h> and <asm-generic/export.h>
- Remove the EXPORT_DATA_SYMBOL macro
- Move the check for static EXPORT_SYMBOL back to modpost, which makes
the build faster
- Re-implement CONFIG_TRIM_UNUSED_KSYMS with one-pass algorithm
- Warn missing MODULE_DESCRIPTION when building modules with W=1
- Make 'make clean' robust against too long argument error
- Exclude more objects from GCOV to fix CFI failures with GCOV
- Allow 'make modules_install' to install modules.builtin and
modules.builtin.modinfo even when CONFIG_MODULES is disabled
- Include modules.builtin and modules.builtin.modinfo in the
linux-image Debian package even when CONFIG_MODULES is disabled
- Revive "Entering directory" logging for the latest Make version
* tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (72 commits)
modpost: define more R_ARM_* for old distributions
kbuild: revive "Entering directory" for Make >= 4.4.1
kbuild: set correct abs_srctree and abs_objtree for package builds
scripts/mksysmap: Ignore prefixed KCFI symbols
kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb
kbuild: builddeb: always make modules_install, to install modules.builtin*
modpost: continue even with unknown relocation type
modpost: factor out Elf_Sym pointer calculation to section_rel()
modpost: factor out inst location calculation to section_rel()
kbuild: Disable GCOV for *.mod.o
kbuild: Fix CFI failures with GCOV
kbuild: make clean rule robust against too long argument error
script: modpost: emit a warning when the description is missing
kbuild: make modules_install copy modules.builtin(.modinfo)
linux/export.h: rename 'sec' argument to 'license'
modpost: show offset from symbol for section mismatch warnings
modpost: merge two similar section mismatch warnings
kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion
modpost: use null string instead of NULL pointer for default namespace
modpost: squash sym_update_namespace() into sym_add_exported()
...
- Adjust log levels for common messages. (Oleksandr Natalenko,
Alex Williamson)
- Support for dynamic MSI-X allocation. (Reinette Chatre)
- Enable and report PCIe AtomicOp Completer capabilities.
(Alex Williamson)
- Cleanup Kconfigs for vfio bus drivers. (Alex Williamson)
- Add support for CDX bus based devices. (Nipun Gupta)
- Fix race with concurrent mdev initialization. (Eric Farman)
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Merge tag 'vfio-v6.5-rc1' of https://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson:
- Adjust log levels for common messages (Oleksandr Natalenko, Alex
Williamson)
- Support for dynamic MSI-X allocation (Reinette Chatre)
- Enable and report PCIe AtomicOp Completer capabilities (Alex
Williamson)
- Cleanup Kconfigs for vfio bus drivers (Alex Williamson)
- Add support for CDX bus based devices (Nipun Gupta)
- Fix race with concurrent mdev initialization (Eric Farman)
* tag 'vfio-v6.5-rc1' of https://github.com/awilliam/linux-vfio:
vfio/mdev: Move the compat_class initialization to module init
vfio/cdx: add support for CDX bus
vfio/fsl: Create Kconfig sub-menu
vfio/platform: Cleanup Kconfig
vfio/pci: Cleanup Kconfig
vfio/pci-core: Add capability for AtomicOp completer support
vfio/pci: Also demote hiding standard cap messages
vfio/pci: Clear VFIO_IRQ_INFO_NORESIZE for MSI-X
vfio/pci: Support dynamic MSI-X
vfio/pci: Probe and store ability to support dynamic MSI-X
vfio/pci: Use bitfield for struct vfio_pci_core_device flags
vfio/pci: Update stale comment
vfio/pci: Remove interrupt context counter
vfio/pci: Use xarray for interrupt context storage
vfio/pci: Move to single error path
vfio/pci: Prepare for dynamic interrupt context storage
vfio/pci: Remove negative check on unsigned vector
vfio/pci: Consolidate irq cleanup on MSI/MSI-X disable
vfio/pci: demote hiding ecap messages to debug level
On CentOS 7, the following build error occurs.
scripts/mod/modpost.c: In function 'addend_arm_rel':
scripts/mod/modpost.c:1312:7: error: 'R_ARM_MOVW_ABS_NC' undeclared (first use in this function); did you mean 'R_ARM_THM_ABS5'?
case R_ARM_MOVW_ABS_NC:
^~~~~~~~~~~~~~~~~
R_ARM_THM_ABS5
scripts/mod/modpost.c:1312:7: note: each undeclared identifier is reported only once for each function it appears in
scripts/mod/modpost.c:1313:7: error: 'R_ARM_MOVT_ABS' undeclared (first use in this function); did you mean 'R_ARM_THM_ABS5'?
case R_ARM_MOVT_ABS:
^~~~~~~~~~~~~~
R_ARM_THM_ABS5
scripts/mod/modpost.c:1326:7: error: 'R_ARM_THM_MOVW_ABS_NC' undeclared (first use in this function); did you mean 'R_ARM_THM_ABS5'?
case R_ARM_THM_MOVW_ABS_NC:
^~~~~~~~~~~~~~~~~~~~~
R_ARM_THM_ABS5
scripts/mod/modpost.c:1327:7: error: 'R_ARM_THM_MOVT_ABS' undeclared (first use in this function); did you mean 'R_ARM_THM_ABS5'?
case R_ARM_THM_MOVT_ABS:
^~~~~~~~~~~~~~~~~~
R_ARM_THM_ABS5
Fixes: 12ca2c67d7 ("modpost: detect section mismatch for R_ARM_{MOVW_ABS_NC,MOVT_ABS}")
Fixes: cd1824fb7a ("modpost: detect section mismatch for R_ARM_THM_{MOVW_ABS_NC,MOVT_ABS}")
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently, unknown relocation types are just skipped.
The value of r_addend is only needed to get the symbol name in case
is_valid_name(elf, sym) returns false.
Even if we do not know how to calculate r_addend, we should continue.
At worst, we will get "(unknown)" as the symbol name, but it is better
than failing to detect section mismatches.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pass the Elf_Sym pointer to addend_arm_rel() as well as to
check_section_mismatch().
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
All the addend_*_rel() functions calculate the instruction location in
the same way.
Factor out the similar code to the caller. Squash reloc_location() too.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Emit a warning when the mod description is missed and only
when the W=1 is enabled.
Reported-by: Roland Kletzing <devzero@web.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=10770
Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Tested-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Currently, modpost only shows the symbol names and section names, so it
repeats the same message if there are multiple relocations in the same
symbol. It is common the relocation spans across multiple instructions.
It is better to show the offset from the symbol.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
In case of section mismatch, modpost shows slightly different messages.
For extable section mismatch:
"%s(%s+0x%lx): Section mismatch in reference to the %s:%s\n"
For the other cases:
"%s: section mismatch in reference: %s (section: %s) -> %s (section: %s)\n"
They are similar. Merge them.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
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.
Linus stated negative opinions about this slowness in commits:
- 5cf0fd591f ("Kbuild: disable TRIM_UNUSED_KSYMS option")
- a555bdd0c5 ("Kbuild: enable TRIM_UNUSED_KSYMS again, with some guarding")
We can do this better now. The final data structures of EXPORT_SYMBOL
are generated by the modpost stage, so modpost can selectively emit
KSYMTAB entries that are really used by modules.
Commit f73edc8951 ("kbuild: unify two modpost invocations") is another
ground-work to do this in a one-pass algorithm. With the list of modules,
modpost sets sym->used if it is used by a module. modpost emits KSYMTAB
only for symbols with sym->used==true.
BTW, Nicolas explained why the trimming was implemented with recursion:
https://lore.kernel.org/all/2o2rpn97-79nq-p7s2-nq5-8p83391473r@syhkavp.arg/
Actually, we never achieved that level of optimization where the chain
reaction of trimming comes into play because:
- CONFIG_LTO_CLANG cannot remove any unused symbols
- CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is enabled only for vmlinux,
but not modules
If deeper trimming is required, we need to revisit this, but I guess
that is unlikely to happen.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The default namespace is the null string, "".
When set, the null string "" is converted to NULL:
s->namespace = namespace[0] ? NOFAIL(strdup(namespace)) : NULL;
When printed, the NULL pointer is get back to the null string:
sym->namespace ?: ""
This saves 1 byte memory allocated for "", but loses the readability.
In kernel-space, we strive to save memory, but modpost is a userspace
tool used to build the kernel. On modern systems, such small piece of
memory is not a big deal.
Handle the namespace string as is.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Pass a set of the name, license, and namespace to sym_add_exported().
sym_update_namespace() is unneeded.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Commit 31cb50b559 ("kbuild: check static EXPORT_SYMBOL* by script
instead of modpost") moved the static EXPORT_SYMBOL* check from the
mostpost to a shell script because I thought it must be checked per
compilation unit to avoid false negatives.
I came up with an idea to do this in modpost, against combined ELF
files. The relocation entries in ELF will find the correct exported
symbol even if there exist symbols with the same name in different
compilation units.
Again, the same sample code.
Makefile:
obj-y += foo1.o foo2.o
foo1.c:
#include <linux/export.h>
static void foo(void) {}
EXPORT_SYMBOL(foo);
foo2.c:
void foo(void) {}
Then, modpost can catch it correctly.
MODPOST Module.symvers
ERROR: modpost: vmlinux: local symbol 'foo' was exported
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Commit 7b4537199a ("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 22823ab419 ("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 8651ec01da ("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@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
vfio-cdx driver enables IOCTLs for user space to query
MMIO regions for CDX devices and mmap them. This change
also adds support for reset of CDX devices. With VFIO
enabled on CDX devices, user-space applications can also
exercise DMA securely via IOMMU on these devices.
This change adds the VFIO CDX driver and enables the following
ioctls for CDX devices:
- VFIO_DEVICE_GET_INFO:
- VFIO_DEVICE_GET_REGION_INFO
- VFIO_DEVICE_RESET
Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Tested-by: Nikhil Agarwal <nikhil.agarwal@amd.com>
Link: https://lore.kernel.org/r/20230531124557.11009-1-nipun.gupta@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Commits ffb1b4a410 ("x86/unwind/orc: Add 'signal' field to ORC
metadata") and fb799447ae ("x86,objtool: Split UNWIND_HINT_EMPTY in
two") changed the ORC format. Although ORC is internal to the kernel,
it's the only way for external tools to get reliable kernel stack traces
on x86-64. In particular, the drgn debugger [1] uses ORC for stack
unwinding, and these format changes broke it [2]. As the drgn
maintainer, I don't care how often or how much the kernel changes the
ORC format as long as I have a way to detect the change.
It suffices to store a version identifier in the vmlinux and kernel
module ELF files (to use when parsing ORC sections from ELF), and in
kernel memory (to use when parsing ORC from a core dump+symbol table).
Rather than hard-coding a version number that needs to be manually
bumped, Peterz suggested hashing the definitions from orc_types.h. If
there is a format change that isn't caught by this, the hashing script
can be updated.
This patch adds an .orc_header allocated ELF section containing the
20-byte hash to vmlinux and kernel modules, along with the corresponding
__start_orc_header and __stop_orc_header symbols in vmlinux.
1: https://github.com/osandov/drgn
2: https://github.com/osandov/drgn/issues/303
Fixes: ffb1b4a410 ("x86/unwind/orc: Add 'signal' field to ORC metadata")
Fixes: fb799447ae ("x86,objtool: Split UNWIND_HINT_EMPTY in two")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lkml.kernel.org/r/aef9c8dc43915b886a8c48509a12ec1b006ca1ca.1686690801.git.osandov@osandov.com
The > comparison should be >= to prevent an out of bounds array
access.
Fixes: 52dc0595d5 ("modpost: handle relocations mismatch in __ex_table.")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
"No build warning" is a strong requirement these days, so you must fix
all issues before enabling a new warning flag.
We often add a new warning to W=1 first so that the kbuild test robot
blocks new breakages.
This commit allows modpost to show extra warnings only when W=1
(or KBUILD_EXTRA_WARN=1) is given.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
For ARM, modpost fails to detect some types of section mismatches.
[test code]
.section .init.data,"aw"
bar:
.long 0
.section .data,"aw"
.globl foo
foo:
.long bar - .
It is apparently a bad reference, but modpost does not report anything.
The test code above produces the following relocations.
Relocation section '.rel.data' at offset 0xe8 contains 1 entry:
Offset Info Type Sym.Value Sym. Name
00000000 00000403 R_ARM_REL32 00000000 .init.data
Currently, R_ARM_REL32 is just skipped.
Handle it like R_ARM_ABS32.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
addend_arm_rel() processes R_ARM_THM_CALL, R_ARM_THM_JUMP24,
R_ARM_THM_JUMP19 in a wrong way.
Here, test code.
[test code for R_ARM_THM_JUMP24]
.section .init.text,"ax"
bar:
bx lr
.section .text,"ax"
.globl foo
foo:
b bar
[test code for R_ARM_THM_CALL]
.section .init.text,"ax"
bar:
bx lr
.section .text,"ax"
.globl foo
foo:
push {lr}
bl bar
pop {pc}
If you compile it with CONFIG_THUMB2_KERNEL=y, modpost will show the
symbol name, (unknown).
WARNING: modpost: vmlinux.o: section mismatch in reference: foo (section: .text) -> (unknown) (section: .init.text)
(You need to use GNU linker instead of LLD to reproduce it.)
Fix the code to make modpost show the correct symbol name. I checked
arch/arm/kernel/module.c to learn the encoding of R_ARM_THM_CALL and
R_ARM_THM_JUMP24. The module does not support R_ARM_THM_JUMP19, but
I checked its encoding in ARM ARM.
The '+4' is the compensation for pc-relative instruction. It is
documented in "ELF for the Arm Architecture" [1].
"If the relocation is pc-relative then compensation for the PC bias
(the PC value is 8 bytes ahead of the executing instruction in Arm
state and 4 bytes in Thumb state) must be encoded in the relocation
by the object producer."
[1]: https://github.com/ARM-software/abi-aa/blob/main/aaelf32/aaelf32.rst
Fixes: c9698e5cd6 ("ARM: 7964/1: Detect section mismatches in thumb relocations")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When CONFIG_THUMB2_KERNEL is enabled, modpost fails to detect some
types of section mismatches.
[test code]
#include <linux/init.h>
int __initdata foo;
int get_foo(void) { return foo; }
It is apparently a bad reference, but modpost does not report anything.
The test code above produces the following relocations.
Relocation section '.rel.text' at offset 0x1e8 contains 2 entries:
Offset Info Type Sym.Value Sym. Name
00000000 0000052f R_ARM_THM_MOVW_AB 00000000 .LANCHOR0
00000004 00000530 R_ARM_THM_MOVT_AB 00000000 .LANCHOR0
Currently, R_ARM_THM_MOVW_ABS_NC and R_ARM_THM_MOVT_ABS are just skipped.
Add code to handle them. I checked arch/arm/kernel/module.c to learn
how the offset is encoded in the instruction.
One more thing to note for Thumb instructions - the st_value is an odd
value, so you need to mask the bit 0 to get the offset. Otherwise, you
will get an off-by-one error in the nearest symbol look-up.
It is documented in "ELF for the ARM Architecture" [1]:
In addition to the normal rules for symbol values the following rules
shall also apply to symbols of type STT_FUNC:
* If the symbol addresses an Arm instruction, its value is the
address of the instruction (in a relocatable object, the offset
of the instruction from the start of the section containing it).
* If the symbol addresses a Thumb instruction, its value is the
address of the instruction with bit zero set (in a relocatable
object, the section offset with bit zero set).
* For the purposes of relocation the value used shall be the address
of the instruction (st_value & ~1).
[1]: https://github.com/ARM-software/abi-aa/blob/main/aaelf32/aaelf32.rst
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
find_fromsym() and find_tosym() are similar - both of them iterate
in the .symtab section and return the nearest symbol.
The difference between them is that find_tosym() allows a negative
distance, but the distance must be less than 20.
Factor out the common part into find_nearest_sym().
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
For ARM defconfig (i.e. multi_v7_defconfig), modpost fails to detect
some types of section mismatches.
[test code]
#include <linux/init.h>
int __initdata foo;
int get_foo(void) { return foo; }
It is apparently a bad reference, but modpost does not report anything.
The test code above produces the following relocations.
Relocation section '.rel.text' at offset 0x200 contains 2 entries:
Offset Info Type Sym.Value Sym. Name
00000000 0000062b R_ARM_MOVW_ABS_NC 00000000 .LANCHOR0
00000004 0000062c R_ARM_MOVT_ABS 00000000 .LANCHOR0
Currently, R_ARM_MOVW_ABS_NC and R_ARM_MOVT_ABS are just skipped.
Add code to handle them. I checked arch/arm/kernel/module.c to learn
how the offset is encoded in the instruction.
The referenced symbol in relocation might be a local anchor.
If is_valid_name() returns false, let's search for a better symbol name.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
addend_arm_rel() processes R_ARM_PC24, R_ARM_CALL, R_ARM_JUMP24 in a
wrong way.
Here, test code.
[test code for R_ARM_JUMP24]
.section .init.text,"ax"
bar:
bx lr
.section .text,"ax"
.globl foo
foo:
b bar
[test code for R_ARM_CALL]
.section .init.text,"ax"
bar:
bx lr
.section .text,"ax"
.globl foo
foo:
push {lr}
bl bar
pop {pc}
If you compile it with ARM multi_v7_defconfig, modpost will show the
symbol name, (unknown).
WARNING: modpost: vmlinux.o: section mismatch in reference: foo (section: .text) -> (unknown) (section: .init.text)
(You need to use GNU linker instead of LLD to reproduce it.)
Fix the code to make modpost show the correct symbol name.
I imported (with adjustment) sign_extend32() from include/linux/bitops.h.
The '+8' is the compensation for pc-relative instruction. It is
documented in "ELF for the Arm Architecture" [1].
"If the relocation is pc-relative then compensation for the PC bias
(the PC value is 8 bytes ahead of the executing instruction in Arm
state and 4 bytes in Thumb state) must be encoded in the relocation
by the object producer."
[1]: https://github.com/ARM-software/abi-aa/blob/main/aaelf32/aaelf32.rst
Fixes: 56a974fa2d ("kbuild: make better section mismatch reports on arm")
Fixes: 6e2e340b59 ("ARM: 7324/1: modpost: Fix section warnings for ARM for many compilers")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
addend_arm_rel() processes R_ARM_ABS32 in a wrong way.
Here, test code.
[test code 1]
#include <linux/init.h>
int __initdata foo;
int get_foo(void) { return foo; }
If you compile it with ARM versatile_defconfig, modpost will show the
symbol name, (unknown).
WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> (unknown) (section: .init.data)
(You need to use GNU linker instead of LLD to reproduce it.)
If you compile it for other architectures, modpost will show the correct
symbol name.
WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> foo (section: .init.data)
For R_ARM_ABS32, addend_arm_rel() sets r->r_addend to a wrong value.
I just mimicked the code in arch/arm/kernel/module.c.
However, there is more difficulty for ARM.
Here, test code.
[test code 2]
#include <linux/init.h>
int __initdata foo;
int get_foo(void) { return foo; }
int __initdata bar;
int get_bar(void) { return bar; }
With this commit applied, modpost will show the following messages
for ARM versatile_defconfig:
WARNING: modpost: vmlinux.o: section mismatch in reference: get_foo (section: .text) -> foo (section: .init.data)
WARNING: modpost: vmlinux.o: section mismatch in reference: get_bar (section: .text) -> foo (section: .init.data)
The reference from 'get_bar' to 'foo' seems wrong.
I have no solution for this because it is true in assembly level.
In the following output, relocation at 0x1c is no longer associated
with 'bar'. The two relocation entries point to the same symbol, and
the offset to 'bar' is encoded in the instruction 'r0, [r3, #4]'.
Disassembly of section .text:
00000000 <get_foo>:
0: e59f3004 ldr r3, [pc, #4] @ c <get_foo+0xc>
4: e5930000 ldr r0, [r3]
8: e12fff1e bx lr
c: 00000000 .word 0x00000000
00000010 <get_bar>:
10: e59f3004 ldr r3, [pc, #4] @ 1c <get_bar+0xc>
14: e5930004 ldr r0, [r3, #4]
18: e12fff1e bx lr
1c: 00000000 .word 0x00000000
Relocation section '.rel.text' at offset 0x244 contains 2 entries:
Offset Info Type Sym.Value Sym. Name
0000000c 00000c02 R_ARM_ABS32 00000000 .init.data
0000001c 00000c02 R_ARM_ABS32 00000000 .init.data
When find_elf_symbol() gets into a situation where relsym->st_name is
zero, there is no guarantee to get the symbol name as written in C.
I am keeping the current logic because it is useful in many architectures,
but the symbol name is not always correct depending on the optimization.
I left some comments in find_tosym().
Fixes: 56a974fa2d ("kbuild: make better section mismatch reports on arm")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
There is no distinction between TEXT_TO_ANY_EXIT and DATA_TO_ANY_EXIT.
Just merge them.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
This check is unneeded. Without it, sec_name() will returns the null
string "", then section_mismatch() will return immediately.
Anyway, special section indices rarely appear in these loops.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
r_offset/r_addend holds the offset address from/to which a symbol is
referenced. It is unclear unless you are familiar with ELF.
Rename them to faddr, taddr, respectively. The prefix 'f' means 'from',
't' means 'to'.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
find_tosym() takes 'sym' and stores the return value to another
variable 'to'. You can use the same variable because we want to
replace the original one when appropriate.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
secref_whitelist() does not use the argument 'mismatch'.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
This reverts commit a4d26f1a09.
The variable 'fromsym' never starts with ".L" since commit 87e5b1e8f2
("module: Sync code of is_arm_mapping_symbol()").
In other words, Pattern 6 is now dead code.
Previously, the .LANCHOR1 hid the symbols listed in Pattern 2.
87e5b1e8f2 provided a better solution.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
find_elf_symbol() and find_elf_symbol2() are not good names.
Rename them to find_tosym(), find_fromsym(), respectively.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
find_elf_symbol2() converts the section index to the section name,
then compares the two strings in each iteration. This is slow.
It is faster to compare the section indices (i.e. integers) directly.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
default_mismatch_handler() does not need to compute 'tosec' because
it is calculated by the caller.
Pass it down to default_mismatch_handler() instead of calling
sec_name() twice.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Merging these two reduces several lines of code. The extable section
mismatch is already distinguished by EXTABLE_TO_NON_TEXT.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
SHF_EXECINSTR is a bit flag (#define SHF_EXECINSTR 0x4).
Compare the masked flag to '!= 0'.
There is no good reason to stop modpost immediately even if a special
section index is given. You will get a section mismatch error anyway.
Also, change the return type to bool.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
report_sec_mismatch() and default_mismatch_handler() are small enough
to be merged together.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Collect relevant code into one place to clarify all the cases are
covered by 'if () ... else if ... else ...'.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
This is the last user of get_pretty_name() - it is just used to
distinguish whether the symbol is a function or not. It is not
valuable information.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
report_extable_warnings() prints "from" in a pretty form, but we know
it is always located in the __ex_table section, i.e. a collection of
struct exception_table_entry.
It is very likely to fail to get the symbol name and ends up with
meaningless message:
... in reference from the (unknown reference) (unknown) to ...
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
find_extable_entry_size() is completely broken. It has awesome comments
about how to calculate sizeof(struct exception_table_entry).
It was based on these assumptions:
- struct exception_table_entry has two fields
- both of the fields have the same size
Then, we came up with this equation:
(offset of the second field) * 2 == (size of struct)
It was true for all architectures when commit 52dc0595d5 ("modpost:
handle relocations mismatch in __ex_table.") was applied.
Our mathematics broke when commit 548acf1923 ("x86/mm: Expand the
exception table logic to allow new handling options") introduced the
third field.
Now, the definition of exception_table_entry is highly arch-dependent.
For x86, sizeof(struct exception_table_entry) is apparently 12, but
find_extable_entry_size() sets extable_entry_size to 8.
I could fix it, but I do not see much value in this code.
extable_entry_size is used just for selecting a slightly different
error message.
If the first field ("insn") references to a non-executable section,
The relocation at %s+0x%lx references
section "%s" which is not executable, IOW
it is not possible for the kernel to fault
at that address. Something is seriously wrong
and should be fixed.
If the second field ("fixup") references to a non-executable section,
The relocation at %s+0x%lx references
section "%s" which is not executable, IOW
the kernel will fault if it ever tries to
jump to it. Something is seriously wrong
and should be fixed.
Merge the two error messages rather than adding even more complexity.
Change fatal() to error() to make it continue running and catch more
possible errors.
Fixes: 548acf1923 ("x86/mm: Expand the exception table logic to allow new handling options")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The section mismatch check relies on the relocation entries.
For REL, the addend value is implicit, so we need some code to compute
it. Currently, EM_386, EM_ARM, and EM_MIPS are supported. This commit
makes sure we covered all the cases.
I believe the other architectures use RELA, where the explicit r_addend
field exists.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The summary of the changes for this pull requests is:
* Song Liu's new struct module_memory replacement
* Nick Alcock's MODULE_LICENSE() removal for non-modules
* My cleanups and enhancements to reduce the areas where we vmalloc
module memory for duplicates, and the respective debug code which
proves the remaining vmalloc pressure comes from userspace.
Most of the changes have been in linux-next for quite some time except
the minor fixes I made to check if a module was already loaded
prior to allocating the final module memory with vmalloc and the
respective debug code it introduces to help clarify the issue. Although
the functional change is small it is rather safe as it can only *help*
reduce vmalloc space for duplicates and is confirmed to fix a bootup
issue with over 400 CPUs with KASAN enabled. I don't expect stable
kernels to pick up that fix as the cleanups would have also had to have
been picked up. Folks on larger CPU systems with modules will want to
just upgrade if vmalloc space has been an issue on bootup.
Given the size of this request, here's some more elaborate details
on this pull request.
The functional change change in this pull request is the very first
patch from Song Liu which replaces the struct module_layout with a new
struct module memory. The old data structure tried to put together all
types of supported module memory types in one data structure, the new
one abstracts the differences in memory types in a module to allow each
one to provide their own set of details. This paves the way in the
future so we can deal with them in a cleaner way. If you look at changes
they also provide a nice cleanup of how we handle these different memory
areas in a module. This change has been in linux-next since before the
merge window opened for v6.3 so to provide more than a full kernel cycle
of testing. It's a good thing as quite a bit of fixes have been found
for it.
Jason Baron then made dynamic debug a first class citizen module user by
using module notifier callbacks to allocate / remove module specific
dynamic debug information.
Nick Alcock has done quite a bit of work cross-tree to remove module
license tags from things which cannot possibly be module at my request
so to:
a) help him with his longer term tooling goals which require a
deterministic evaluation if a piece a symbol code could ever be
part of a module or not. But quite recently it is has been made
clear that tooling is not the only one that would benefit.
Disambiguating symbols also helps efforts such as live patching,
kprobes and BPF, but for other reasons and R&D on this area
is active with no clear solution in sight.
b) help us inch closer to the now generally accepted long term goal
of automating all the MODULE_LICENSE() tags from SPDX license tags
In so far as a) is concerned, although module license tags are a no-op
for non-modules, tools which would want create a mapping of possible
modules can only rely on the module license tag after the commit
8b41fc4454 ("kbuild: create modules.builtin without Makefile.modbuiltin
or tristate.conf"). Nick has been working on this *for years* and
AFAICT I was the only one to suggest two alternatives to this approach
for tooling. The complexity in one of my suggested approaches lies in
that we'd need a possible-obj-m and a could-be-module which would check
if the object being built is part of any kconfig build which could ever
lead to it being part of a module, and if so define a new define
-DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've
suggested would be to have a tristate in kconfig imply the same new
-DPOSSIBLE_MODULE as well but that means getting kconfig symbol names
mapping to modules always, and I don't think that's the case today. I am
not aware of Nick or anyone exploring either of these options. Quite
recently Josh Poimboeuf has pointed out that live patching, kprobes and
BPF would benefit from resolving some part of the disambiguation as
well but for other reasons. The function granularity KASLR (fgkaslr)
patches were mentioned but Joe Lawrence has clarified this effort has
been dropped with no clear solution in sight [1].
In the meantime removing module license tags from code which could never
be modules is welcomed for both objectives mentioned above. Some
developers have also welcomed these changes as it has helped clarify
when a module was never possible and they forgot to clean this up,
and so you'll see quite a bit of Nick's patches in other pull
requests for this merge window. I just picked up the stragglers after
rc3. LWN has good coverage on the motivation behind this work [2] and
the typical cross-tree issues he ran into along the way. The only
concrete blocker issue he ran into was that we should not remove the
MODULE_LICENSE() tags from files which have no SPDX tags yet, even if
they can never be modules. Nick ended up giving up on his efforts due
to having to do this vetting and backlash he ran into from folks who
really did *not understand* the core of the issue nor were providing
any alternative / guidance. I've gone through his changes and dropped
the patches which dropped the module license tags where an SPDX
license tag was missing, it only consisted of 11 drivers. To see
if a pull request deals with a file which lacks SPDX tags you
can just use:
./scripts/spdxcheck.py -f \
$(git diff --name-only commid-id | xargs echo)
You'll see a core module file in this pull request for the above,
but that's not related to his changes. WE just need to add the SPDX
license tag for the kernel/module/kmod.c file in the future but
it demonstrates the effectiveness of the script.
Most of Nick's changes were spread out through different trees,
and I just picked up the slack after rc3 for the last kernel was out.
Those changes have been in linux-next for over two weeks.
The cleanups, debug code I added and final fix I added for modules
were motivated by David Hildenbrand's report of boot failing on
a systems with over 400 CPUs when KASAN was enabled due to running
out of virtual memory space. Although the functional change only
consists of 3 lines in the patch "module: avoid allocation if module is
already present and ready", proving that this was the best we can
do on the modules side took quite a bit of effort and new debug code.
The initial cleanups I did on the modules side of things has been
in linux-next since around rc3 of the last kernel, the actual final
fix for and debug code however have only been in linux-next for about a
week or so but I think it is worth getting that code in for this merge
window as it does help fix / prove / evaluate the issues reported
with larger number of CPUs. Userspace is not yet fixed as it is taking
a bit of time for folks to understand the crux of the issue and find a
proper resolution. Worst come to worst, I have a kludge-of-concept [3]
of how to make kernel_read*() calls for modules unique / converge them,
but I'm currently inclined to just see if userspace can fix this
instead.
[0] https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/
[1] https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com
[2] https://lwn.net/Articles/927569/
[3] https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org
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Merge tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull module updates from Luis Chamberlain:
"The summary of the changes for this pull requests is:
- Song Liu's new struct module_memory replacement
- Nick Alcock's MODULE_LICENSE() removal for non-modules
- My cleanups and enhancements to reduce the areas where we vmalloc
module memory for duplicates, and the respective debug code which
proves the remaining vmalloc pressure comes from userspace.
Most of the changes have been in linux-next for quite some time except
the minor fixes I made to check if a module was already loaded prior
to allocating the final module memory with vmalloc and the respective
debug code it introduces to help clarify the issue. Although the
functional change is small it is rather safe as it can only *help*
reduce vmalloc space for duplicates and is confirmed to fix a bootup
issue with over 400 CPUs with KASAN enabled. I don't expect stable
kernels to pick up that fix as the cleanups would have also had to
have been picked up. Folks on larger CPU systems with modules will
want to just upgrade if vmalloc space has been an issue on bootup.
Given the size of this request, here's some more elaborate details:
The functional change change in this pull request is the very first
patch from Song Liu which replaces the 'struct module_layout' with a
new 'struct module_memory'. The old data structure tried to put
together all types of supported module memory types in one data
structure, the new one abstracts the differences in memory types in a
module to allow each one to provide their own set of details. This
paves the way in the future so we can deal with them in a cleaner way.
If you look at changes they also provide a nice cleanup of how we
handle these different memory areas in a module. This change has been
in linux-next since before the merge window opened for v6.3 so to
provide more than a full kernel cycle of testing. It's a good thing as
quite a bit of fixes have been found for it.
Jason Baron then made dynamic debug a first class citizen module user
by using module notifier callbacks to allocate / remove module
specific dynamic debug information.
Nick Alcock has done quite a bit of work cross-tree to remove module
license tags from things which cannot possibly be module at my request
so to:
a) help him with his longer term tooling goals which require a
deterministic evaluation if a piece a symbol code could ever be
part of a module or not. But quite recently it is has been made
clear that tooling is not the only one that would benefit.
Disambiguating symbols also helps efforts such as live patching,
kprobes and BPF, but for other reasons and R&D on this area is
active with no clear solution in sight.
b) help us inch closer to the now generally accepted long term goal
of automating all the MODULE_LICENSE() tags from SPDX license tags
In so far as a) is concerned, although module license tags are a no-op
for non-modules, tools which would want create a mapping of possible
modules can only rely on the module license tag after the commit
8b41fc4454 ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf").
Nick has been working on this *for years* and AFAICT I was the only
one to suggest two alternatives to this approach for tooling. The
complexity in one of my suggested approaches lies in that we'd need a
possible-obj-m and a could-be-module which would check if the object
being built is part of any kconfig build which could ever lead to it
being part of a module, and if so define a new define
-DPOSSIBLE_MODULE [0].
A more obvious yet theoretical approach I've suggested would be to
have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as
well but that means getting kconfig symbol names mapping to modules
always, and I don't think that's the case today. I am not aware of
Nick or anyone exploring either of these options. Quite recently Josh
Poimboeuf has pointed out that live patching, kprobes and BPF would
benefit from resolving some part of the disambiguation as well but for
other reasons. The function granularity KASLR (fgkaslr) patches were
mentioned but Joe Lawrence has clarified this effort has been dropped
with no clear solution in sight [1].
In the meantime removing module license tags from code which could
never be modules is welcomed for both objectives mentioned above. Some
developers have also welcomed these changes as it has helped clarify
when a module was never possible and they forgot to clean this up, and
so you'll see quite a bit of Nick's patches in other pull requests for
this merge window. I just picked up the stragglers after rc3. LWN has
good coverage on the motivation behind this work [2] and the typical
cross-tree issues he ran into along the way. The only concrete blocker
issue he ran into was that we should not remove the MODULE_LICENSE()
tags from files which have no SPDX tags yet, even if they can never be
modules. Nick ended up giving up on his efforts due to having to do
this vetting and backlash he ran into from folks who really did *not
understand* the core of the issue nor were providing any alternative /
guidance. I've gone through his changes and dropped the patches which
dropped the module license tags where an SPDX license tag was missing,
it only consisted of 11 drivers. To see if a pull request deals with a
file which lacks SPDX tags you can just use:
./scripts/spdxcheck.py -f \
$(git diff --name-only commid-id | xargs echo)
You'll see a core module file in this pull request for the above, but
that's not related to his changes. WE just need to add the SPDX
license tag for the kernel/module/kmod.c file in the future but it
demonstrates the effectiveness of the script.
Most of Nick's changes were spread out through different trees, and I
just picked up the slack after rc3 for the last kernel was out. Those
changes have been in linux-next for over two weeks.
The cleanups, debug code I added and final fix I added for modules
were motivated by David Hildenbrand's report of boot failing on a
systems with over 400 CPUs when KASAN was enabled due to running out
of virtual memory space. Although the functional change only consists
of 3 lines in the patch "module: avoid allocation if module is already
present and ready", proving that this was the best we can do on the
modules side took quite a bit of effort and new debug code.
The initial cleanups I did on the modules side of things has been in
linux-next since around rc3 of the last kernel, the actual final fix
for and debug code however have only been in linux-next for about a
week or so but I think it is worth getting that code in for this merge
window as it does help fix / prove / evaluate the issues reported with
larger number of CPUs. Userspace is not yet fixed as it is taking a
bit of time for folks to understand the crux of the issue and find a
proper resolution. Worst come to worst, I have a kludge-of-concept [3]
of how to make kernel_read*() calls for modules unique / converge
them, but I'm currently inclined to just see if userspace can fix this
instead"
Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0]
Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1]
Link: https://lwn.net/Articles/927569/ [2]
Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3]
* tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits)
module: add debugging auto-load duplicate module support
module: stats: fix invalid_mod_bytes typo
module: remove use of uninitialized variable len
module: fix building stats for 32-bit targets
module: stats: include uapi/linux/module.h
module: avoid allocation if module is already present and ready
module: add debug stats to help identify memory pressure
module: extract patient module check into helper
modules/kmod: replace implementation with a semaphore
Change DEFINE_SEMAPHORE() to take a number argument
module: fix kmemleak annotations for non init ELF sections
module: Ignore L0 and rename is_arm_mapping_symbol()
module: Move is_arm_mapping_symbol() to module_symbol.h
module: Sync code of is_arm_mapping_symbol()
scripts/gdb: use mem instead of core_layout to get the module address
interconnect: remove module-related code
interconnect: remove MODULE_LICENSE in non-modules
zswap: remove MODULE_LICENSE in non-modules
zpool: remove MODULE_LICENSE in non-modules
x86/mm/dump_pagetables: remove MODULE_LICENSE in non-modules
...
The L0 symbol is generated when build module on LoongArch, ignore it in
modpost and when looking at module symbols, otherwise we can not see the
expected call trace.
Now is_arm_mapping_symbol() is not only for ARM, in order to reflect the
reality, rename is_arm_mapping_symbol() to is_mapping_symbol().
This is related with commit c17a253870 ("mksysmap: Fix the mismatch of
'L0' symbols in System.map").
(1) Simple test case
[loongson@linux hello]$ cat hello.c
#include <linux/init.h>
#include <linux/module.h>
#include <linux/printk.h>
static void test_func(void)
{
pr_info("This is a test\n");
dump_stack();
}
static int __init hello_init(void)
{
pr_warn("Hello, world\n");
test_func();
return 0;
}
static void __exit hello_exit(void)
{
pr_warn("Goodbye\n");
}
module_init(hello_init);
module_exit(hello_exit);
MODULE_LICENSE("GPL");
[loongson@linux hello]$ cat Makefile
obj-m:=hello.o
ccflags-y += -g -Og
all:
make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) modules
clean:
make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) clean
(2) Test environment
system: LoongArch CLFS 5.5
https://github.com/sunhaiyong1978/CLFS-for-LoongArch/releases/tag/5.0
It needs to update grub to avoid booting error "invalid magic number".
kernel: 6.3-rc1 with loongson3_defconfig + CONFIG_DYNAMIC_FTRACE=y
(3) Test result
Without this patch:
[root@linux hello]# insmod hello.ko
[root@linux hello]# dmesg
...
Hello, world
This is a test
...
Call Trace:
[<9000000000223728>] show_stack+0x68/0x18c
[<90000000013374cc>] dump_stack_lvl+0x60/0x88
[<ffff800002050028>] L0\x01+0x20/0x2c [hello]
[<ffff800002058028>] L0\x01+0x20/0x30 [hello]
[<900000000022097c>] do_one_initcall+0x88/0x288
[<90000000002df890>] do_init_module+0x54/0x200
[<90000000002e1e18>] __do_sys_finit_module+0xc4/0x114
[<90000000013382e8>] do_syscall+0x7c/0x94
[<9000000000221e3c>] handle_syscall+0xbc/0x158
With this patch:
[root@linux hello]# insmod hello.ko
[root@linux hello]# dmesg
...
Hello, world
This is a test
...
Call Trace:
[<9000000000223728>] show_stack+0x68/0x18c
[<90000000013374cc>] dump_stack_lvl+0x60/0x88
[<ffff800002050028>] test_func+0x28/0x34 [hello]
[<ffff800002058028>] hello_init+0x28/0x38 [hello]
[<900000000022097c>] do_one_initcall+0x88/0x288
[<90000000002df890>] do_init_module+0x54/0x200
[<90000000002e1e18>] __do_sys_finit_module+0xc4/0x114
[<90000000013382e8>] do_syscall+0x7c/0x94
[<9000000000221e3c>] handle_syscall+0xbc/0x158
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Tested-by: Youling Tang <tangyouling@loongson.cn> # for LoongArch
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
In order to avoid duplicated code, move is_arm_mapping_symbol() to
include/linux/module_symbol.h, then remove is_arm_mapping_symbol()
in the other places.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
After commit 2e3a10a155 ("ARM: avoid ARM binutils leaking ELF local
symbols") and commit d6b732666a ("modpost: fix undefined behavior of
is_arm_mapping_symbol()"), many differences of is_arm_mapping_symbol()
exist in kernel/module/kallsyms.c and scripts/mod/modpost.c, just sync
the code to keep consistent.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
