linux-toradex.git/scripts/mod/modpost.c, branch v5.1-rc1

modpost: always show verbose warning for section mismatch

2019-03-13T17:39:09+00:00

Unless CONFIG_DEBUG_SECTION_MISMATCH is enabled, modpost only shows
the number of section mismatches.

If you want to know the symbols causing the issue, you need to rebuild
with CONFIG_DEBUG_SECTION_MISMATCH. It is tedious.

I think it is fine to show annoying warning when a new section mismatch
comes in.

Signed-off-by: Masahiro Yamada

x86, modpost: Replace last remnants of RETPOLINE with CONFIG_RETPOLINE

2019-01-09T09:35:56+00:00

Commit

  4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")

replaced the RETPOLINE define with CONFIG_RETPOLINE checks. Remove the
remaining pieces.

 [ bp: Massage commit message. ]

Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")
Signed-off-by: WANG Chao 
Signed-off-by: Borislav Petkov 
Reviewed-by: Zhenzhong Duan 
Reviewed-by: Masahiro Yamada 
Cc: "H. Peter Anvin" 
Cc: Andi Kleen 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Daniel Borkmann 
Cc: David Woodhouse 
Cc: Geert Uytterhoeven 
Cc: Jessica Yu 
Cc: Jiri Kosina 
Cc: Kees Cook 
Cc: Konrad Rzeszutek Wilk 
Cc: Luc Van Oostenryck 
Cc: Michal Marek 
Cc: Miguel Ojeda 
Cc: Peter Zijlstra 
Cc: Tim Chen 
Cc: Vasily Gorbik 
Cc: linux-kbuild@vger.kernel.org
Cc: srinivas.eeda@oracle.com
Cc: stable 
Cc: x86-ml 
Link: https://lkml.kernel.org/r/20181210163725.95977-1-chao.wang@ucloud.cn

modpost: move unresolved symbol checks to check_exports()

2018-12-01T13:21:59+00:00

This will fit better in check_exports() than add_versions().

Signed-off-by: Masahiro Yamada

modpost: merge module iterations

2018-12-01T13:21:58+00:00

Probably, this is just a matter of the order of error/warning
messages. Merge the two for-loops.

Signed-off-by: Masahiro Yamada

modpost: refactor seen flag clearing in add_depends()

2018-12-01T13:21:58+00:00

You do not need to iterate over all modules for resetting ->seen flag
because add_depends() is only interested in modules that export symbols
referenced from the given 'mod'.

This also avoids shadowing the 'modules' parameter of add_depends().

Signed-off-by: Masahiro Yamada

modpost: skip ELF local symbols during section mismatch check

2018-12-01T13:21:56+00:00

During development of a serial console driver with a gcc 8.2.0
toolchain for RISC-V, the following modpost warning appeared:

----
WARNING: vmlinux.o(.data+0x19b10): Section mismatch in reference from the variable .LANCHOR1 to the function .init.text:sifive_serial_console_setup()
The variable .LANCHOR1 references
the function __init sifive_serial_console_setup()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console
----

".LANCHOR1" is an ELF local symbol, automatically created by gcc's section
anchor generation code:

https://gcc.gnu.org/onlinedocs/gccint/Anchored-Addresses.html

https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/varasm.c;h=cd9591a45617464946dcf9a126dde277d9de9804;hb=9fb89fa845c1b2e0a18d85ada0b077c84508ab78#l7473

This was verified by compiling the kernel with -fno-section-anchors
and observing that the ".LANCHOR1" ELF local symbol disappeared, and
modpost no longer warned about the section mismatch.  The serial
driver code idiom triggering the warning is standard Linux serial
driver practice that has a specific whitelist inclusion in modpost.c.

I'm neither a modpost nor an ELF expert, but naively, it doesn't seem
useful for modpost to report section mismatch warnings caused by ELF
local symbols by default.  Local symbols have compiler-generated
names, and thus bypass modpost's whitelisting algorithm, which relies
on the presence of a non-autogenerated symbol name.  This increases
the likelihood that false positive warnings will be generated (as in
the above case).

Thus, disable section mismatch reporting on ELF local symbols.  The
rationale here is similar to that of commit 2e3a10a1551d ("ARM: avoid
ARM binutils leaking ELF local symbols") and of similar code already
present in modpost.c:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/mod/modpost.c?h=v4.19-rc4&id=7876320f88802b22d4e2daf7eb027dd14175a0f8#n1256

This third version of the patch implements a suggestion from Masahiro
Yamada  to restructure the code as an
additional pattern matching step inside secref_whitelist(), and
further improves the patch description.

Signed-off-by: Paul Walmsley 
Signed-off-by: Paul Walmsley 
Acked-by: Sam Ravnborg 
Signed-off-by: Masahiro Yamada

modpost: drop unused command line switches

2018-11-21T14:57:33+00:00

Drop modpost command line switches that are no longer used by
makefile.modpost, upon request from Sam Ravnborg ,
who wrote:

    modpost is not supposed to be used outside the kernel build. [...]
    I checked if there were any options supported by modpost that
    was not configurable in Makefile.modpost.
    And I could see that the -M and -K options in getopt() were leftovers.
    The code that used these option was dropped in:
    commit a8773769d1a1 ("Kbuild: clear marker out of modpost")

    Could you add a patch that delete these on top of what you already have.

https://lore.kernel.org/lkml/20181020140835.GA3351@ravnborg.org/

Suggested-by: Sam Ravnborg 
Signed-off-by: Paul Walmsley 
Signed-off-by: Paul Walmsley 
Acked-by: Sam Ravnborg 
Signed-off-by: Masahiro Yamada

modpost: validate symbol names also in find_elf_symbol

2018-11-21T14:57:32+00:00

If an ARM mapping symbol shares an address with a valid symbol,
find_elf_symbol can currently return the mapping symbol instead, as the
symbol is not validated. This can result in confusing warnings:

  WARNING: vmlinux.o(.text+0x18f4028): Section mismatch in reference
  from the function set_reset_devices() to the variable .init.text:$x.0

This change adds a call to is_valid_name to find_elf_symbol, similarly
to how it's already used in find_elf_symbol2.

Signed-off-by: Sami Tolvanen 
Signed-off-by: Masahiro Yamada

scripts: modpost: check memory allocation results

2018-08-22T14:21:40+00:00

Fix missing error check for memory allocation functions in
scripts/mod/modpost.c.

Fixes kernel bugzilla #200319:
https://bugzilla.kernel.org/show_bug.cgi?id=200319

Signed-off-by: Randy Dunlap 
Cc: Yuexing Wang 
Signed-off-by: Masahiro Yamada

kbuild: Add build salt to the kernel and modules

2018-07-17T16:18:05+00:00

In Fedora, the debug information is packaged separately (foo-debuginfo) and
can be installed separately. There's been a long standing issue where only
one version of a debuginfo info package can be installed at a time. There's
been an effort for Fedora for parallel debuginfo to rectify this problem.

Part of the requirement to allow parallel debuginfo to work is that build ids
are unique between builds. The existing upstream rpm implementation ensures
this by re-calculating the build-id using the version and release as a
seed. This doesn't work 100% for the kernel because of the vDSO which is
its own binary and doesn't get updated when embedded.

Fix this by adding some data in an ELF note for both the kernel and modules.
The data is controlled via a Kconfig option so distributions can set it
to an appropriate value to ensure uniqueness between builds.

Suggested-by: Masahiro Yamada 
Signed-off-by: Laura Abbott 
Signed-off-by: Masahiro Yamada