linux-toradex.git/kernel/kallsyms.c, branch v5.12-rc5

kallsyms: only build {,module_}kallsyms_on_each_symbol when required

2021-02-08T11:24:04+00:00

kallsyms_on_each_symbol and module_kallsyms_on_each_symbol are only used
by the livepatching code, so don't build them if livepatching is not
enabled.

Reviewed-by: Miroslav Benes 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jessica Yu

kallsyms: refactor {,module_}kallsyms_on_each_symbol

2021-02-08T11:22:08+00:00

Require an explicit call to module_kallsyms_on_each_symbol to look
for symbols in modules instead of the call from kallsyms_on_each_symbol,
and acquire module_mutex inside of module_kallsyms_on_each_symbol instead
of leaving that up to the caller.  Note that this slightly changes the
behavior for the livepatch code in that the symbols from vmlinux are not
iterated anymore if objname is set, but that actually is the desired
behavior in this case.

Reviewed-by: Petr Mladek 
Acked-by: Miroslav Benes 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jessica Yu

treewide: Convert macro and uses of section(foo) to section("foo")

2020-10-25T21:51:49+00:00

Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.pl

Signed-off-by: Joe Perches 
Reviewed-by: Nick Desaulniers 
Reviewed-by: Miguel Ojeda 
Signed-off-by: Linus Torvalds

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva

Merge tag 'v5.8-rc7' into perf/core, to pick up fixes

2020-07-28T11:18:01+00:00

Signed-off-by: Ingo Molnar

kallsyms: Refactor kallsyms_show_value() to take cred

2020-07-08T22:59:57+00:00

In order to perform future tests against the cred saved during open(),
switch kallsyms_show_value() to operate on a cred, and have all current
callers pass current_cred(). This makes it very obvious where callers
are checking the wrong credential in their "read" contexts. These will
be fixed in the coming patches.

Additionally switch return value to bool, since it is always used as a
direct permission check, not a 0-on-success, negative-on-error style
function return.

Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook

ftrace: Add symbols for ftrace trampolines

2020-06-15T12:09:49+00:00

Symbols are needed for tools to describe instruction addresses. Pages
allocated for ftrace's purposes need symbols to be created for them.
Add such symbols to be visible via /proc/kallsyms.

Example on x86 with CONFIG_DYNAMIC_FTRACE=y

	# echo function > /sys/kernel/debug/tracing/current_tracer
	# cat /proc/kallsyms | grep '\[__builtin__ftrace\]'
	ffffffffc0238000 t ftrace_trampoline    [__builtin__ftrace]

Note: This patch adds "__builtin__ftrace" as a module name in /proc/kallsyms for
symbols for pages allocated for ftrace's purposes, even though "__builtin__ftrace"
is not a module.

Signed-off-by: Adrian Hunter 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20200512121922.8997-7-adrian.hunter@intel.com

kprobes: Add symbols for kprobe insn pages

2020-06-15T12:09:48+00:00

Symbols are needed for tools to describe instruction addresses. Pages
allocated for kprobe's purposes need symbols to be created for them.
Add such symbols to be visible via /proc/kallsyms.

Note: kprobe insn pages are not used if ftrace is configured. To see the
effect of this patch, the kernel must be configured with:

	# CONFIG_FUNCTION_TRACER is not set
	CONFIG_KPROBES=y

and for optimised kprobes:

	CONFIG_OPTPROBES=y

Example on x86:

	# perf probe __schedule
	Added new event:
	  probe:__schedule     (on __schedule)
	# cat /proc/kallsyms | grep '\[__builtin__kprobes\]'
	ffffffffc00d4000 t kprobe_insn_page     [__builtin__kprobes]
	ffffffffc00d6000 t kprobe_optinsn_page  [__builtin__kprobes]

Note: This patch adds "__builtin__kprobes" as a module name in
/proc/kallsyms for symbols for pages allocated for kprobes' purposes, even
though "__builtin__kprobes" is not a module.

Signed-off-by: Adrian Hunter 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Masami Hiramatsu 
Link: https://lkml.kernel.org/r/20200528080058.20230-1-adrian.hunter@intel.com

kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()

2020-04-07T17:43:44+00:00

kallsyms_lookup_name() and kallsyms_on_each_symbol() are exported to
modules despite having no in-tree users and being wide open to abuse by
out-of-tree modules that can use them as a method to invoke arbitrary
non-exported kernel functions.

Unexport kallsyms_lookup_name() and kallsyms_on_each_symbol().

Signed-off-by: Will Deacon 
Signed-off-by: Andrew Morton 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Masami Hiramatsu 
Reviewed-by: Quentin Perret 
Acked-by: Alexei Starovoitov 
Cc: Thomas Gleixner 
Cc: Frederic Weisbecker 
Cc: K.Prasad 
Cc: Miroslav Benes 
Cc: Petr Mladek 
Cc: Joe Lawrence 
Cc: Mathieu Desnoyers 
Link: http://lkml.kernel.org/r/20200221114404.14641-4-will@kernel.org
Signed-off-by: Linus Torvalds

Merge tag 'kbuild-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2020-02-10T00:05:50+00:00

Pull more Kbuild updates from Masahiro Yamada:

 - fix randconfig to generate a sane .config

 - rename hostprogs-y / always to hostprogs / always-y, which are more
   natual syntax.

 - optimize scripts/kallsyms

 - fix yes2modconfig and mod2yesconfig

 - make multiple directory targets ('make foo/ bar/') work

* tag 'kbuild-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: make multiple directory targets work
  kconfig: Invalidate all symbols after changing to y or m.
  kallsyms: fix type of kallsyms_token_table[]
  scripts/kallsyms: change table to store (strcut sym_entry *)
  scripts/kallsyms: rename local variables in read_symbol()
  kbuild: rename hostprogs-y/always to hostprogs/always-y
  kbuild: fix the document to use extra-y for vmlinux.lds
  kconfig: fix broken dependency in randconfig-generated .config