linux.git/scripts/mksysmap, branch v6.18.21

modpost: Create modalias for builtin modules

2025-09-24T16:10:45+00:00

For some modules, modalias is generated using the modpost utility and
the section is added to the module file.

When a module is added inside vmlinux, modpost does not generate
modalias for such modules and the information is lost.

As a result kmod (which uses modules.builtin.modinfo in userspace)
cannot determine that modalias is handled by a builtin kernel module.

$ cat /sys/devices/pci0000:00/0000:00:14.0/modalias
pci:v00008086d0000A36Dsv00001043sd00008694bc0Csc03i30

$ modinfo xhci_pci
name:           xhci_pci
filename:       (builtin)
license:        GPL
file:           drivers/usb/host/xhci-pci
description:    xHCI PCI Host Controller Driver

Missing modalias "pci:v*d*sv*sd*bc0Csc03i30*" which will be generated by
modpost if the module is built separately.

To fix this it is necessary to generate the same modalias for vmlinux as
for the individual modules. Fortunately '.vmlinux.export.o' is already
generated from which '.modinfo' can be extracted in the same way as for
vmlinux.o.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Alexey Gladkov 
Tested-by: Stephen Rothwell 
Reviewed-by: Nicolas Schier 
Link: https://patch.msgid.link/28d4da3b0e3fc8474142746bcf469e03752c3208.1758182101.git.legion@kernel.org
Signed-off-by: Nathan Chancellor

kbuild: keep .modinfo section in vmlinux.unstripped

2025-09-24T16:10:44+00:00

Keep the .modinfo section during linking, but strip it from the final
vmlinux.

Adjust scripts/mksysmap to exclude modinfo symbols from kallsyms.

This change will allow the next commit to extract the .modinfo section
from the vmlinux.unstripped intermediate.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Alexey Gladkov 
Reviewed-by: Nicolas Schier 
Link: https://patch.msgid.link/aaf67c07447215463300fccaa758904bac42f992.1758182101.git.legion@kernel.org
Signed-off-by: Nathan Chancellor

scripts/mksysmap: Fix escape chars '$'

2024-12-28T14:23:52+00:00

Commit b18b047002b7 ("kbuild: change scripts/mksysmap into sed script")
changed the invocation of the script, to call sed directly without
shell.

That means, the current extra escape that was added in:
commit ec336aa83162 ("scripts/mksysmap: Fix badly escaped '$'")
for the shell is not correct any more, at the moment the stack traces
for nvhe are corrupted:
[   22.840904] kvm [190]:  [] __kvm_nvhe_$x.220+0x58/0x9c
[   22.842913] kvm [190]:  [] __kvm_nvhe_$x.9+0x44/0x50
[   22.844112] kvm [190]:  [] __kvm_nvhe___skip_pauth_save+0x4/0x4

With this patch:
[   25.793513] kvm [192]: nVHE call trace:
[   25.794141] kvm [192]:  [] __kvm_nvhe_hyp_panic+0xb0/0xf4
[   25.796590] kvm [192]:  [] __kvm_nvhe_handle_trap+0xe4/0x188
[   25.797553] kvm [192]:  [] __kvm_nvhe___skip_pauth_save+0x4/0x4

Fixes: b18b047002b7 ("kbuild: change scripts/mksysmap into sed script")
Signed-off-by: Mostafa Saleh 
Reviewed-by: Nathan Chancellor 
Signed-off-by: Masahiro Yamada

kbuild: change scripts/mksysmap into sed script

2024-05-29T07:40:03+00:00

The previous commit removed the subshell execution from scripts/mksysmap,
which is now simple enough to become a sed script.

Signed-off-by: Masahiro Yamada

kbuild: avoid unneeded kallsyms step 3

2024-05-29T07:40:03+00:00

Since commit 951bcae6c5a0 ("kallsyms: Avoid weak references for kallsyms
symbols"), the kallsyms step 3 always occurs.

You can compare the build logs.

[Before 951bcae6c5a0]

  $ git checkout 951bcae6c5a0^
  $ make defconfig all
       [ snip ]
    LD      .tmp_vmlinux.kallsyms1
    NM      .tmp_vmlinux.kallsyms1.syms
    KSYMS   .tmp_vmlinux.kallsyms1.S
    AS      .tmp_vmlinux.kallsyms1.S
    LD      .tmp_vmlinux.kallsyms2
    NM      .tmp_vmlinux.kallsyms2.syms
    KSYMS   .tmp_vmlinux.kallsyms2.S
    AS      .tmp_vmlinux.kallsyms2.S
    LD      vmlinux

[After 951bcae6c5a0]

  $ git checkout 951bcae6c5a0
  $ make defconfig all
       [ snip ]
    LD      .tmp_vmlinux.kallsyms1
    NM      .tmp_vmlinux.kallsyms1.syms
    KSYMS   .tmp_vmlinux.kallsyms1.S
    AS      .tmp_vmlinux.kallsyms1.S
    LD      .tmp_vmlinux.kallsyms2
    NM      .tmp_vmlinux.kallsyms2.syms
    KSYMS   .tmp_vmlinux.kallsyms2.S
    AS      .tmp_vmlinux.kallsyms2.S
    LD      .tmp_vmlinux.kallsyms3             # should not happen
    NM      .tmp_vmlinux.kallsyms3.syms        # should not happen
    KSYMS   .tmp_vmlinux.kallsyms3.S           # should not happen
    AS      .tmp_vmlinux.kallsyms3.S           # should not happen
    LD      vmlinux

The resulting vmlinux is correct, but it always requires an additional
linking step.

The symbols produced by kallsyms are excluded from kallsyms itself
because they were previously missing in step 1. With those symbols
excluded, the symbol lists matched between step 1 and step 2,
eliminating the need for step 3. Now, this has a negative effect.

Since 951bcae6c5a0, the PROVIDE() directives provide the fallback
definitions, which are not trimmed from the sysbol list in step 1
because ${kallsymso_prev} is empty at this point.

In step 2, ${kallsymso_prev} is set, and the kallsyms_* symbols are
trimmed from the symbol list.

Due to the table size difference between step 1 and step 2 (the former
is larger due to the presence of kallsyms_*), step 3 is triggered.

Now that the kallsyms_* symbols are always linked, let's stop omitting
them from kallsyms. This avoids unnecessary step 3.

Fixes: 951bcae6c5a0 ("kallsyms: Avoid weak references for kallsyms symbols")
Signed-off-by: Masahiro Yamada

kallsyms: ignore ARMv4 thunks along with others

2024-02-15T13:44:56+00:00

lld is now able to build ARMv4 and ARMv4T kernels, which means it can
generate thunks for those (__ARMv4PILongThunk_*, __ARMv4PILongBXThunk_*)
that can interfere with kallsyms table generation since they do not get
ignore like the corresponding ARMv5+ ones are:

Inconsistent kallsyms data
Try "make KALLSYMS_EXTRA_PASS=1" as a workaround

Replace the hardcoded list of thunk symbols with a more general regex that
covers this one along with future symbols that follow the same pattern.

Fixes: 5eb6e280432d ("ARM: 9289/1: Allow pre-ARMv5 builds with ld.lld 16.0.0 and newer")
Fixes: efe6e3068067 ("kallsyms: fix nonconverging kallsyms table with lld")
Suggested-by: Masahiro Yamada 
Signed-off-by: Arnd Bergmann 
Reviewed-by: Ard Biesheuvel 
Signed-off-by: Masahiro Yamada

scripts/mksysmap: Ignore prefixed KCFI symbols

2023-06-26T23:35:43+00:00

The (relatively) new KCFI feature in LLVM/Clang encodes type information
for C functions by generating symbols named __kcfi_typeid_, which
can then be referenced from assembly. However, some custom build rules
(e.g. nVHE or early PIE on arm64) use objcopy to add a prefix to all the
symbols in their object files, making mksysmap's ignore filter miss
those KCFI symbols.

Therefore, explicitly list those twice-prefixed KCFI symbols as ignored.

Alternatively, this could also be achieved in a less verbose way by
ignoring any symbol containing the string "__kcfi_typeid_". However,
listing the combined prefixes explicitly saves us from running the small
risk of ignoring symbols that should be kept.

Signed-off-by: Pierre-Clément Tosi 
Reviewed-by: Sami Tolvanen 
Signed-off-by: Masahiro Yamada

scripts/mksysmap: Ignore __pi_ local arm64 symbols

2023-06-07T13:41:08+00:00

Similarly to "__kvm_nvhe_", filter out any local symbol that was
prefixed with "__pi_" (generated when CONFIG_RANDOMIZE_BASE=y) when
compiling System.map and in kallsyms.

Signed-off-by: Pierre-Clément Tosi 
Acked-by: Ard Biesheuvel 
Signed-off-by: Masahiro Yamada

scripts/mksysmap: Fix badly escaped '$'

2023-06-07T13:41:08+00:00

The backslash characters escaping '$' in the command to sed (intended to
prevent it from interpreting '$' as "end-of-line") are currently being
consumed by the Shell (where they mean that sh should not evaluate what
follows '$' as a variable name). This means that

    sed -e "/ \$/d"

executes the script

    / $/d

instead of the intended

    / \$/d

So escape twice in mksysmap any '$' that actually needs to reach sed
escaped so that the backslash survives the Shell.

Fixes: c4802044a0a7 ("scripts/mksysmap: use sed with in-line comments")
Fixes: 320e7c9d4494 ("scripts/kallsyms: move compiler-generated symbol patterns to mksysmap")
Signed-off-by: Pierre-Clément Tosi 
Signed-off-by: Masahiro Yamada

scripts/kallsyms: move compiler-generated symbol patterns to mksysmap

2023-04-17T02:03:56+00:00

scripts/kallsyms.c maintains compiler-generated symbols, but we end up
with something similar in scripts/mksysmap to avoid the "Inconsistent
kallsyms data" error. For example, commit c17a2538704f ("mksysmap: Fix
the mismatch of 'L0' symbols in System.map").

They were separately maintained prior to commit 94ff2f63d6a3 ("kbuild:
reuse mksysmap output for kallsyms").

Now that scripts/kallsyms.c parses the output of scripts/mksysmap,
it makes more sense to collect all the ignored patterns to mksysmap.

Signed-off-by: Masahiro Yamada 
Reviewed-by: Nick Desaulniers