The modpost, with the -d option given, generates per-module .ns_deps
files.

Kbuild generates per-module .mod files to carry module information.
This is convenient because Make handles multiple jobs in parallel
when the -j option is given.

On the other hand, the modpost always runs as a single thread.
I do not see a strong reason to produce separate .ns_deps files.

This commit changes the modpost to generate just one file,
modules.nsdeps, each line of which has the following format:

  <module_name>: <list of missing namespaces>

Please note it contains *missing* namespaces instead of required ones.
So, modules.nsdeps is empty if the namespace dependency is all good.

This will work more efficiently because spatch will no longer process
already imported namespaces. I removed the '(if needed)' from the
nsdeps log since spatch is invoked only when needed.

This also solves the stale .ns_deps problem reported by Jessica Yu:

  https://lkml.org/lkml/2019/10/28/467Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: NJessica Yu <jeyu@kernel.org>
Acked-by: NJessica Yu <jeyu@kernel.org>
Reviewed-by: NMatthias Maennich <maennich@google.com>
Tested-by: NMatthias Maennich <maennich@google.com>

buf_write() allocates memory. Free it.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

'make nsdeps' invokes the modpost three times at most; before linking
vmlinux, before building modules, and finally for generating .ns_deps
files. Running the modpost again and again is not efficient.

The last two can be unified. When the -d option is given, the modpost
still does the usual job, and in addition, generates .ns_deps files.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: NMatthias Maennich <maennich@google.com>
Reviewed-by: NMatthias Maennich <maennich@google.com>

Since commit 040fcc81 ("kbuild: improved modversioning support for
external modules"), the external module build reads Module.symvers in
the directory of the module itself, then dumps symbols back into it.
It accumulates stale symbols in the file when you build an external
module incrementally.

The idea behind it was, as the commit log explained, you can copy
Modules.symvers from one module to another when you need to pass symbol
information between two modules. However, the manual copy of the file
sounds questionable to me, and containing stale symbols is a downside.

Some time later, commit 0d96fb20 ("kbuild: Add new Kbuild variable
KBUILD_EXTRA_SYMBOLS") introduced a saner approach.

So, this commit removes the former one. Going forward, the external
module build dumps symbols into Module.symvers to be carried via
KBUILD_EXTRA_SYMBOLS, but never reads it automatically.

With the -I option removed, there is no one to set the external_module
flag unless KBUILD_EXTRA_SYMBOLS is passed. Now the -i option does it
instead.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

The introduction of Symbol Namespaces changed the naming schema of the
__ksymtab entries from __kysmtab__symbol to __ksymtab_NAMESPACE.symbol.

That caused some breakages in tools that depend on the name layout in
either the binaries(vmlinux,*.ko) or in System.map. E.g. kmod's depmod
would not be able to read System.map without a patch to support symbol
namespaces. A warning reported by depmod for namespaced symbols would
look like

  depmod: WARNING: [...]/uas.ko needs unknown symbol usb_stor_adjust_quirks

In order to address this issue, revert to the original naming scheme and
rather read the __kstrtabns_<symbol> entries and their corresponding
values from __ksymtab_strings to update the namespace values for
symbols. After having read all symbols and handled them in
handle_modversions(), the symbols are created. In a second pass, read
the __kstrtabns_ entries and update the namespaces accordingly.

Fixes: 8651ec01 ("module: add support for symbol namespaces.")
Reported-by: NStefan Wahren <stefan.wahren@i2se.com>
Suggested-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NWill Deacon <will@kernel.org>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NMatthias Maennich <maennich@google.com>
Signed-off-by: NJessica Yu <jeyu@kernel.org>

Setting the symbol namespace of a symbol within sym_add_exported feels
displaced and lead to issues in the current implementation of symbol
namespaces. This patch makes updating the namespace an explicit call to
decouple it from adding a symbol to the export list.
Acked-by: NWill Deacon <will@kernel.org>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NMatthias Maennich <maennich@google.com>
Signed-off-by: NJessica Yu <jeyu@kernel.org>

Let the function 'sym_update_namespace' take care of updating the
namespace for a symbol. While this currently only replaces one single
location where namespaces are updated, in a following patch, this
function will get more call sites.

The function signature is intentionally close to sym_update_crc and
taking the name by char* seems like unnecessary work as the symbol has
to be looked up again. In a later patch of this series, this concern
will be addressed.

This function ensures that symbol::namespace is either NULL or has a
valid non-empty value. Previously, the empty string was considered 'no
namespace' as well and this lead to confusion.
Acked-by: NWill Deacon <will@kernel.org>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NMatthias Maennich <maennich@google.com>
Signed-off-by: NJessica Yu <jeyu@kernel.org>

Currently, external module builds produce tons of false-positives:

  WARNING: module <mod> uses symbol <sym> from namespace <ns>, but does not import it.

Here, the <ns> part shows a random string.

When you build external modules, the symbol info of vmlinux and
in-kernel modules are read from $(objtree)/Module.symvers, but
read_dump() is buggy in multiple ways:

[1] When the modpost is run for vmlinux and in-kernel modules,
sym_extract_namespace() allocates memory for the namespace. On the
other hand, read_dump() does not, then sym->namespace will point to
somewhere in the line buffer of get_next_line(). The data in the
buffer will be replaced soon, and sym->namespace will end up with
pointing to unrelated data. As a result, check_exports() will show
random strings in the warning messages.

[2] When there is no namespace, sym_extract_namespace() returns NULL.
On the other hand, read_dump() sets namespace to an empty string "".
(but, it will be later replaced with unrelated data due to bug [1].)
The check_exports() shows a warning unless exp->namespace is NULL,
so every symbol read from read_dump() emits the warning, which is
mostly false positive.

To address [1], sym_add_exported() calls strdup() for s->namespace.
The namespace from sym_extract_namespace() must be freed to avoid
memory leak.

For [2], I changed the if-conditional in check_exports().

This commit also fixes sym_add_exported() to set s->namespace correctly
when the symbol is preloaded.
Reviewed-by: NMatthias Maennich <maennich@google.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NJessica Yu <jeyu@kernel.org>

Currently, EXPORT_SYMBOL_NS(_GPL) constructs the kernel symbol as
follows:

  __ksymtab_SYMBOL.NAMESPACE

The sym_extract_namespace() in modpost allocates memory for the part
SYMBOL.NAMESPACE when '.' is contained. One problem is that the pointer
returned by strdup() is lost because the symbol name will be copied to
malloc'ed memory by alloc_symbol(). No one will keep track of the
pointer of strdup'ed memory.

sym->namespace still points to the NAMESPACE part. So, you can free it
with complicated code like this:

   free(sym->namespace - strlen(sym->name) - 1);

It complicates memory free.

To fix it elegantly, I swapped the order of the symbol and the
namespace as follows:

  __ksymtab_NAMESPACE.SYMBOL

then, simplified sym_extract_namespace() so that it allocates memory
only for the NAMESPACE part.

I prefer this order because it is intuitive and also matches to major
languages. For example, NAMESPACE::NAME in C++, MODULE.NAME in Python.
Reviewed-by: NMatthias Maennich <maennich@google.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NJessica Yu <jeyu@kernel.org>

Johannes Berg reports lots of modpost warnings on ARCH=um builds:

WARNING: "rename" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "lseek" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "ftruncate64" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "getuid" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "lseek64" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "unlink" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "pwrite64" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "close" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "opendir" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "pread64" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "syscall" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "readdir" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "readdir64" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "futimes" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "__lxstat" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "write" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "closedir" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "__xstat" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "fsync" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "__lxstat64" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "__fxstat64" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "telldir" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "printf" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "readlink" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "__sprintf_chk" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "link" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "rmdir" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "fdatasync" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "truncate" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "statfs" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "__errno_location" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "__xmknod" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "open64" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "truncate64" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "open" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "read" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "chown" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "chmod" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "utime" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "fchmod" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "seekdir" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "ioctl" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "dup2" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "statfs64" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "utimes" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "mkdir" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "fchown" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "__guard" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "symlink" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "access" [vmlinux] is a static EXPORT_SYMBOL
WARNING: "__stack_smash_handler" [vmlinux] is a static EXPORT_SYMBOL

When you run "make", the modpost is run twice; before linking vmlinux,
and before building modules. All the warnings above are from the second
modpost.

The offending symbols are defined not in vmlinux, but in the C library.
The first modpost is run against the relocatable vmlinux.o, and those
warnings are nicely suppressed because the SH_UNDEF entries from the
symbol table clear the ->is_static flag.

The second modpost is run against the executable vmlinux (+ modules),
where those symbols have been resolved, but the definitions do not
exist.

This commit fixes it in a straightforward way; suppress the static
EXPORT_SYMBOL warnings from "vmlinux".

Without this commit, we see valid warnings twice anyway. For example,
ARCH=arm64 defconfig shows the following warning twice:

WARNING: "HYPERVISOR_platform_op" [vmlinux] is a static EXPORT_SYMBOL_GPL

So, it is reasonable to suppress the second one.

Fixes: 15bfc234 ("modpost: check for static EXPORT_SYMBOL* functions")
Reported-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: NJohannes Berg <johannes@sipsolutions.net>
Tested-by: NDenis Efremov <efremov@linux.com>

Use the __section() shorthand. This avoids escaping double-quotes,
and improves the readability.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

This makes *.mod.c much more readable. I confirmed depmod still
produced the same modules.dep file.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

This patch adds an option to modpost to generate a <module>.ns_deps file
per module, containing the namespace dependencies for that module.

E.g. if the linked module my-module.ko would depend on the symbol
myfunc.MY_NS in the namespace MY_NS, the my-module.ns_deps file created
by modpost would contain the entry MY_NS to express the namespace
dependency of my-module imposed by using the symbol myfunc.

These files can subsequently be used by static analysis tools (like
coccinelle scripts) to address issues with missing namespace imports. A
later patch of this series will introduce such a script 'nsdeps' and a
corresponding make target to automatically add missing
MODULE_IMPORT_NS() definitions to the module's sources. For that it uses
the information provided in the generated .ns_deps files.
Co-developed-by: NMartijn Coenen <maco@android.com>
Signed-off-by: NMartijn Coenen <maco@android.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NMatthias Maennich <maennich@google.com>
Signed-off-by: NJessica Yu <jeyu@kernel.org>

Add support for symbols that are exported into namespaces. For that,
extract any namespace suffix from the symbol name. In addition, emit a
warning whenever a module refers to an exported symbol without
explicitly importing the namespace that it is defined in. This patch
consistently adds the namespace suffix to symbol names exported into
Module.symvers.

Example warning emitted by modpost in case of the above violation:

 WARNING: module ums-usbat uses symbol usb_stor_resume from namespace
 USB_STORAGE, but does not import it.
Co-developed-by: NMartijn Coenen <maco@android.com>
Signed-off-by: NMartijn Coenen <maco@android.com>
Reviewed-by: NJoel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NMatthias Maennich <maennich@google.com>
Signed-off-by: NJessica Yu <jeyu@kernel.org>

Add NOFAIL check for the strndup call, because the function
allocates memory and can return NULL. All calls to strdup in
modpost are checked with NOFAIL.
Signed-off-by: NDenis Efremov <efremov@linux.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

This patch adds a check to warn about static EXPORT_SYMBOL* functions
during the modpost. In most of the cases, a static symbol marked for
exporting is an odd combination that should be fixed either by deleting
the exporting mark or by removing the static attribute and adding the
appropriate declaration to headers.

This check could help to detect the following problems:
1. 550113d4 ("i2c: add newly exported functions to the header, too")
2. 54638c6e ("net: phy: make exported variables non-static")
3. 98ef2046 ("mm: remove the exporting of totalram_pages")
4. 73df167c ("s390/zcrypt: remove the exporting of ap_query_configuration")
5. a57caf8c ("sunrpc/cache: remove the exporting of cache_seq_next")
6. e4e47306 ("crypto: skcipher - remove the exporting of skcipher_walk_next")
7. 14b4c48b ("gve: Remove the exporting of gve_probe")
8. 9b79ee97 ("scsi: libsas: remove the exporting of sas_wait_eh")
9. ...

The build time impact is very limited and is almost at the unnoticeable
level (< 1 sec).
Acked-by: NEmil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NDenis Efremov <efremov@linux.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Fix commit 56067812 ("kbuild: modversions: add infrastructure for
emitting relative CRCs") where CRCs are interpreted in host byte order
rather than proper kernel byte order. The bug is conditional on
CONFIG_MODULE_REL_CRCS.

For example, when loading a BE module into a BE kernel compiled with a LE
system, the error "disagrees about version of symbol module_layout" is
produced. A message such as "Found checksum D7FA6856 vs module 5668FAD7"
will be given with debug enabled, which indicates an obvious endian
problem within __kcrctab within the kernel image.

The general solution is to use the macro TO_NATIVE, as is done in
similar cases throughout modpost.c. With this correction it has been
verified that a BE kernel compiled with a LE system accepts BE modules.

This change has also been verified with a LE kernel compiled with a LE
system, in which case TO_NATIVE returns its value unmodified since the
byte orders match. This is by far the common case.

Fixes: 56067812 ("kbuild: modversions: add infrastructure for emitting relative CRCs")
Signed-off-by: NFredrik Noring <noring@nocrew.org>
Cc: stable@vger.kernel.org
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>

Commit

  4cd24de3 ("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: 4cd24de3 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support")
Signed-off-by: NWANG Chao <chao.wang@ucloud.cn>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NZhenzhong Duan <zhenzhong.duan@oracle.com>
Reviewed-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Kees Cook <keescook@chromium.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: linux-kbuild@vger.kernel.org
Cc: srinivas.eeda@oracle.com
Cc: stable <stable@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20181210163725.95977-1-chao.wang@ucloud.cn

This will fit better in check_exports() than add_versions().
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Probably, this is just a matter of the order of error/warning
messages. Merge the two for-loops.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>

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 2e3a10a1 ("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 <yamada.masahiro@socionext.com> to restructure the code as an
additional pattern matching step inside secref_whitelist(), and
further improves the patch description.
Signed-off-by: NPaul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Drop modpost command line switches that are no longer used by
makefile.modpost, upon request from Sam Ravnborg <sam@ravnborg.org>,
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 a8773769 ("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: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NPaul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: NPaul Walmsley <paul@pwsan.com>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

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: NSami Tolvanen <samitolvanen@google.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

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=200319Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Yuexing Wang <wangyxlandq@gmail.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

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: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NLaura Abbott <labbott@redhat.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Neither find_module() nor read_symbols() does change *modname.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

The second test of is_vmlinux() is redundant.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Currently, strstarts() is only used in export_from_secname().
Use it more widely to improve the code readability.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

get_(next_)modinfo takes a pointer and length pair of the .modinfo
section.  Instead, pass struct elf_info pointer to reduce the number
of function arguments.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX was selected by BLACKFIN, METAG.
They were removed by commit 4ba66a97 ("arch: remove blackfin port"),
commit bb6fb6df ("metag: Remove arch/metag/"), respectively.

No more architecture enables CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX,
hence VMLINUX_SYMBOL_STR(foo) can be simplify replaced with "foo".
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NSam Ravnborg <sam@ravnborg.org>

Remove the MN10300 arch as the hardware is defunct.
Suggested-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: Masahiro Yamada <yamada.masahiro@socionext.com>
cc: linux-am33-list@redhat.com
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

There's a risk that a kernel which has full retpoline mitigations becomes
vulnerable when a module gets loaded that hasn't been compiled with the
right compiler or the right option.

To enable detection of that mismatch at module load time, add a module info
string "retpoline" at build time when the module was compiled with
retpoline support. This only covers compiled C source, but assembler source
or prebuilt object files are not checked.

If a retpoline enabled kernel detects a non retpoline protected module at
load time, print a warning and report it in the sysfs vulnerability file.

[ tglx: Massaged changelog ]
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: jeyu@kernel.org
Cc: arjan@linux.intel.com
Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org

The trailing semicolon is an empty statement that does no operation.
Removing it since it doesn't do anything.
Signed-off-by: NLuis de Bethencourt <luisbg@kernel.org>
Signed-off-by: NJessica Yu <jeyu@kernel.org>

Partially revert commit 2fa36568 ("kbuild: soften MODULE_LICENSE
check") so that modpost detects modules that do not have a
MODULE_LICENSE.

Sam's commit also changed the fatal error to a warning, which I am
leaving as is.

This gives advance notice of when a module has no license and will taint
the kernel if the module is loaded.

This produces the following warnings on x86_64 allmodconfig:

    MODPOST 6520 modules
  WARNING: modpost: missing MODULE_LICENSE() in drivers/auxdisplay/img-ascii-lcd.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/gpio/gpio-ath79.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/gpio/gpio-iop.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/iio/accel/kxsd9-i2c.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/iio/adc/qcom-vadc-common.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/media/platform/mtk-vcodec/mtk-vcodec-common.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/media/platform/soc_camera/soc_scale_crop.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/mtd/nand/denali_pci.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/net/phy/cortina.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/pinctrl/pxa/pinctrl-pxa2xx.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/power/reset/zx-reboot.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/rpmsg/qcom_glink_native.o
  WARNING: modpost: missing MODULE_LICENSE() in drivers/staging/comedi/drivers/ni_atmio.o
  WARNING: modpost: missing MODULE_LICENSE() in net/9p/9pnet_xen.o
  WARNING: modpost: missing MODULE_LICENSE() in sound/soc/codecs/snd-soc-pcm512x-spi.o
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is code duplication between sec_name() and sech_name().  Simplify
sec_name() by re-using sech_name().  Also, move them up to remove the
forward declaration of sec_name().

Link: http://lkml.kernel.org/r/1502248721-22009-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Module name has a limited length, but currently the build system
allows the build finishing even if the module name is too long.

  CC      /root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.o
 /root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.c:9:2:
 warning: initializer-string for array of chars is too long [enabled by default]
  .name = KBUILD_MODNAME,
  ^

but it's merely a warning.

This patch adds the check of the module name length in modpost and stops
the build properly.
Signed-off-by: NWanlong Gao <wanlong.gao@gmail.com>
Signed-off-by: NJessica Yu <jeyu@kernel.org>

Accessing the mod structure (e.g. for mod->name) prior to having completed
check_modstruct_version() can result in writing garbage to the error logs
if the layout of the mod structure loaded from disk doesn't match the
running kernel's mod structure layout. This kind of mismatch will become
much more likely if a kernel is built with different randomization seed
for the struct layout randomization plugin.

Instead, add and use a new modinfo string for logging the module name.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJessica Yu <jeyu@redhat.com>

The '__unreachable' and '__func_stack_frame_non_standard' sections are
only used at compile time.  They're discarded for vmlinux but they
should also be discarded for modules.

Since this is a recurring pattern, prefix the section names with
".discard.".  It's a nice convention and vmlinux.lds.h already discards
such sections.

Also remove the 'a' (allocatable) flag from the __unreachable section
since it doesn't make sense for a discarded section.
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: d1091c7f ("objtool: Improve detection of BUG() and other dead ends")
Link: http://lkml.kernel.org/r/20170301180444.lhd53c5tibc4ns77@trebleSigned-off-by: NIngo Molnar <mingo@kernel.org>