I tried building using a freshly built Make (4.2.1-69-g8a731d1), but
already the objtool build broke with
orc_dump.c: In function ‘orc_dump’:
orc_dump.c:106:2: error: ‘elf_getshnum’ is deprecated [-Werror=deprecated-declarations]
if (elf_getshdrnum(elf, &nr_sections)) {
Turns out that with that new Make, the backslash was not removed, so cpp
didn't see a #include directive, grep found nothing, and
-DLIBELF_USE_DEPRECATED was wrongly put in CFLAGS.
Now, that new Make behaviour is documented in their NEWS file:
* WARNING: Backward-incompatibility!
Number signs (#) appearing inside a macro reference or function invocation
no longer introduce comments and should not be escaped with backslashes:
thus a call such as:
foo := $(shell echo '#')
is legal. Previously the number sign needed to be escaped, for example:
foo := $(shell echo '\#')
Now this latter will resolve to "\#". If you want to write makefiles
portable to both versions, assign the number sign to a variable:
C := \#
foo := $(shell echo '$C')
This was claimed to be fixed in 3.81, but wasn't, for some reason.
To detect this change search for 'nocomment' in the .FEATURES variable.
This also fixes up the two make-cmd instances to replace # with $(pound)
rather than with \#. There might very well be other places that need
similar fixup in preparation for whatever future Make release contains
the above change, but at least this builds an x86_64 defconfig with the
new make.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=197847
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tidy the naming convention for compat syscall subs. Hints which describe
the purpose of the stub go in front and receive a double underscore to
denote that they are generated on-the-fly by the COMPAT_SYSCALL_DEFINEx()
macro.
For the generic case, this means:
t kernel_waitid # common C function (see kernel/exit.c)
__do_compat_sys_waitid # inlined helper doing the actual work
# (takes original parameters as declared)
T __se_compat_sys_waitid # sign-extending C function calling inlined
# helper (takes parameters of type long,
# casts them to unsigned long and then to
# the declared type)
T compat_sys_waitid # alias to __se_compat_sys_waitid()
# (taking parameters as declared), to
# be included in syscall table
For x86, the naming is as follows:
t kernel_waitid # common C function (see kernel/exit.c)
__do_compat_sys_waitid # inlined helper doing the actual work
# (takes original parameters as declared)
t __se_compat_sys_waitid # sign-extending C function calling inlined
# helper (takes parameters of type long,
# casts them to unsigned long and then to
# the declared type)
T __ia32_compat_sys_waitid # IA32_EMULATION 32-bit-ptregs -> C stub,
# calls __se_compat_sys_waitid(); to be
# included in syscall table
T __x32_compat_sys_waitid # x32 64-bit-ptregs -> C stub, calls
# __se_compat_sys_waitid(); to be included
# in syscall table
If only one of IA32_EMULATION and x32 is enabled, __se_compat_sys_waitid()
may be inlined into the stub __{ia32,x32}_compat_sys_waitid().
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180409105145.5364-3-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tidy the naming convention for compat syscall subs. Hints which describe
the purpose of the stub go in front and receive a double underscore to
denote that they are generated on-the-fly by the SYSCALL_DEFINEx() macro.
For the generic case, this means (0xffffffff prefix removed):
810f08d0 t kernel_waitid # common C function (see kernel/exit.c)
<inline> __do_sys_waitid # inlined helper doing the actual work
# (takes original parameters as declared)
810f1aa0 T __se_sys_waitid # sign-extending C function calling inlined
# helper (takes parameters of type long;
# casts them to the declared type)
810f1aa0 T sys_waitid # alias to __se_sys_waitid() (taking
# parameters as declared), to be included
# in syscall table
For x86, the naming is as follows:
810efc70 t kernel_waitid # common C function (see kernel/exit.c)
<inline> __do_sys_waitid # inlined helper doing the actual work
# (takes original parameters as declared)
810efd60 t __se_sys_waitid # sign-extending C function calling inlined
# helper (takes parameters of type long;
# casts them to the declared type)
810f1140 T __ia32_sys_waitid # IA32_EMULATION 32-bit-ptregs -> C stub,
# calls __se_sys_waitid(); to be included
# in syscall table
810f1110 T sys_waitid # x86 64-bit-ptregs -> C stub, calls
# __se_sys_waitid(); to be included in
# syscall table
For x86, sys_waitid() will be re-named to __x64_sys_waitid in a follow-up
patch.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180409105145.5364-2-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull leaking-addresses updates from Tobin Harding:
"This set represents improvements to the scripts/leaking_addresses.pl
script.
The major improvement is that with this set applied the script
actually runs in a reasonable amount of time (less than a minute on a
standard stock Ubuntu user desktop). Also, we have a second maintainer
now and a tree hosted on kernel.org
We do a few code clean ups. We fix the command help output. Handling
of the vsyscall address range is fixed to check the whole range
instead of just the start/end addresses. We add support for 5 page
table levels (suggested on LKML). We use a system command to get the
machine architecture instead of using Perl. Calling this command for
every regex comparison is what previously choked the script, caching
the result of this call gave the major speed improvement. We add
support for scanning 32-bit kernels using the user/kernel memory
split. Path skipping code refactored and simplified (meaning easier
script configuration). We remove version numbering. We add a variable
name to improve readability of a regex and finally we check filenames
for leaking addresses.
Currently script scans /proc/PID for all PID. With this set applied we
only scan for PID==1. It was observed that on an idle system files
under /proc/PID are predominantly the same for all processes. Also it
was noted that the script does not scan _all_ the kernel since it only
scans active processes. Scanning only for PID==1 makes explicit the
inherent flaw in the script that the scan is only partial and also
speeds things up"
* tag 'leaks-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tobin/leaks:
MAINTAINERS: Update LEAKING_ADDRESSES
leaking_addresses: check if file name contains address
leaking_addresses: explicitly name variable used in regex
leaking_addresses: remove version number
leaking_addresses: skip '/proc/1/syscall'
leaking_addresses: skip all /proc/PID except /proc/1
leaking_addresses: cache architecture name
leaking_addresses: simplify path skipping
leaking_addresses: do not parse binary files
leaking_addresses: add 32-bit support
leaking_addresses: add is_arch() wrapper subroutine
leaking_addresses: use system command to get arch
leaking_addresses: add support for 5 page table levels
leaking_addresses: add support for kernel config file
leaking_addresses: add range check for vsyscall memory
leaking_addresses: indent dependant options
leaking_addresses: remove command examples
leaking_addresses: remove mention of kptr_restrict
leaking_addresses: fix typo function not called
Pull general security layer updates from James Morris:
- Convert security hooks from list to hlist, a nice cleanup, saving
about 50% of space, from Sargun Dhillon.
- Only pass the cred, not the secid, to kill_pid_info_as_cred and
security_task_kill (as the secid can be determined from the cred),
from Stephen Smalley.
- Close a potential race in kernel_read_file(), by making the file
unwritable before calling the LSM check (vs after), from Kees Cook.
* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
security: convert security hooks to use hlist
exec: Set file unwritable before LSM check
usb, signal, security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill
Move debian/ directory generation out of builddeb to a new script,
mkdebian. The package build commands are kept in builddeb, which
is now an internal command called from debian/rules.
With these changes in place, we can now use dpkg-buildpackage from
deb-pkg and bindeb-pkg removing need for handrolled source/changes
generation.
This patch is based on the criticism of the current state of builddeb
discussed on:
https://patchwork.kernel.org/patch/9656403/
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
GNU Make automatically deletes intermediate files that are updated
in a chain of pattern rules.
Example 1) %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
Example 2) %.o <- %.c <- %.c_shipped
A couple of makefiles mark such targets as .PRECIOUS to prevent Make
from deleting them, but the correct way is to use .SECONDARY.
.SECONDARY
Prerequisites of this special target are treated as intermediate
files but are never automatically deleted.
.PRECIOUS
When make is interrupted during execution, it may delete the target
file it is updating if the file was modified since make started.
If you mark the file as precious, make will never delete the file
if interrupted.
Both can avoid deletion of intermediate files, but the difference is
the behavior when Make is interrupted; .SECONDARY deletes the target,
but .PRECIOUS does not.
The use of .PRECIOUS is relatively rare since we do not want to keep
partially constructed (possibly corrupted) targets.
Another difference is that .PRECIOUS works with pattern rules whereas
.SECONDARY does not.
.PRECIOUS: $(obj)/%.lex.c
works, but
.SECONDARY: $(obj)/%.lex.c
has no effect. However, for the reason above, I do not want to use
.PRECIOUS which could cause obscure build breakage.
The targets specified as .SECONDARY must be explicit. $(targets)
contains all targets that need to include .*.cmd files. So, the
intermediates you want to keep are mostly in there. Therefore, mark
$(targets) as .SECONDARY. It means primary targets are also marked
as .SECONDARY, but I do not see any drawback for this.
I replaced some .SECONDARY / .PRECIOUS markers with 'targets'. This
will make Kbuild search for non-existing .*.cmd files, but this is
not a noticeable performance issue.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Frank Rowand <frowand.list@gmail.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Our convention is to distinguish file types by suffixes with a period
as a separator.
*-asn1.[ch] is a different pattern from other generated sources such
as *.lex.c, *.tab.[ch], *.dtb.S, etc. More confusing, files with
'-asn1.[ch]' are generated files, but '_asn1.[ch]' are checked-in
files:
net/netfilter/nf_conntrack_h323_asn1.c
include/linux/netfilter/nf_conntrack_h323_asn1.h
include/linux/sunrpc/gss_asn1.h
Rename generated files to *.asn1.[ch] for consistency.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Another common pattern that consists of chained commands is to compile
a DTB as binary data into the kernel image or a module. It is used in
several places in the source tree. Support it in the core Makefile.
$(call if_changed,dt_S_dtb) is more suitable than $(call cmd,dt_S_dtb)
in case cmd_dt_S_dtb is changed in the future.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Frank Rowand <frowand.list@gmail.com>
Files generated by if_changed* must be added to 'targets' to include
*.cmd files. Otherwise, they would be regenerated every time.
The build system automatically adds objects to 'targets' where
appropriate, such as obj-y, extra-y, etc. but does nothing for
intermediate files. So, each Makefile needs to add them by itself.
There are some common cases where objects are generated by chained
rules. Lexers and parsers are compiled like follows:
%.lex.o <- %.lex.c <- %.l
%.tab.o <- %.tab.c <- %.y
They are common patterns, so it is reasonable to take care of them
in the core Makefile instead of requiring each Makefile to do so.
At this moment, you cannot delete 'target += zconf.lex.c' in the
Kconfig Makefile because zconf.lex.c is included from zconf.tab.c
instead of being compiled separately. It should be deleted after
Kconfig is more refactored.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Frank Rowand <frowand.list@gmail.com>
Now that the kernel build supports flex and bison, remove the _shipped
files and generate them during the build instead.
There are no more shipped lexer and parser, so I ripped off the rules
in scripts/Malefile.lib that were used for REGENERATE_PARSERS.
The genksyms parser has ambiguous grammar, which would emit warnings:
scripts/genksyms/parse.y: warning: 9 shift/reduce conflicts [-Wconflicts-sr]
scripts/genksyms/parse.y: warning: 5 reduce/reduce conflicts [-Wconflicts-rr]
They are normally suppressed, but displayed when W=1 is given.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Files suffixed by .lex.c, .tab.[ch] are generated lexers, parsers,
respectively. Clean them up globally from the top Makefile.
Some of the final host programs those lexer/parser are linked into
are necessary for building external modules, but the intermediates
are unneeded. They can be cleaned away by 'make clean' instead of
'make mrproper'.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Frank Rowand <frowand.list@gmail.com>
These patterns are common to host programs that require lexer and parser.
Move them to the top .gitignore.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Frank Rowand <frowand.list@gmail.com>
Sometimes files may be created by using output from printk. As the scan
traverses the directory tree we should parse each path name and check if
it is leaking an address.
Add check for leaking address on each path name.
Suggested-by: Tycho Andersen <tycho@tycho.ws>
Acked-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Currently sub routine may_leak_address() is checking regex against Perl
special variable $_ which is _fortunately_ being set correctly in a loop
before this sub routine is called. We already have declared a variable
to hold this value '$line' we should use it.
Use $line in regex match instead of implicit $_
Signed-off-by: Tobin C. Harding <me@tobin.cc>
We have git now, we don't need a version number. This was originally
added because leaking_addresses.pl shamelessly (and mindlessly) copied
checkpatch.pl
Remove version number from script.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
The pointers listed in /proc/1/syscall are user pointers, and negative
syscall args will show up like kernel addresses.
For example
/proc/31808/syscall: 0 0x3 0x55b107a38180 0x2000 0xffffffffffffffb0 \
0x55b107a302d0 0x55b107a38180 0x7fffa313b8e8 0x7ff098560d11
Skip parsing /proc/1/syscall
Suggested-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: Tobin C. Harding <me@tobin.cc>
When the system is idle it is likely that most files under /proc/PID
will be identical for various processes. Scanning _all_ the PIDs under
/proc is unnecessary and implies that we are thoroughly scanning /proc.
This is _not_ the case because there may be ways userspace can trigger
creation of /proc files that leak addresses but were not present during
a scan. For these two reasons we should exclude all PID directories
under /proc except '1/'
Exclude all /proc/PID except /proc/1.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Currently we are repeatedly calling `uname -m`. This is causing the
script to take a long time to run (more than 10 seconds to parse
/proc/kallsyms). We can use Perl state variables to cache the result of
the first call to `uname -m`. With this change in place the script
scans the whole kernel in under a minute.
Cache machine architecture in state variable.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Currently script has multiple configuration arrays. This is confusing,
evident by the fact that a bunch of the entries are in the wrong place.
We can simplify the code by just having a single array for absolute
paths to skip and a single array for file names to skip wherever they
appear in the scanned directory tree. There are also currently multiple
subroutines to handle the different arrays, we can reduce these to a
single subroutine also.
Simplify the path skipping code.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Currently script parses binary files. Since we are scanning for
readable kernel addresses there is no need to parse binary files. We
can use Perl to check if file is binary and skip parsing it if so.
Do not parse binary files.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Currently script only supports x86_64 and ppc64. It would be nice to be
able to scan 32-bit machines also. We can add support for 32-bit
architectures by modifying how we check for false positives, taking
advantage of the page offset used by the kernel, and using the correct
regular expression.
Support for 32-bit machines is enabled by the observation that the kernel
addresses on 32-bit machines are larger [in value] than the page offset.
We can use this to filter false positives when scanning the kernel for
leaking addresses.
Programmatic determination of the running architecture is not
immediately obvious (current 32-bit machines return various strings from
`uname -m`). We therefore provide a flag to enable scanning of 32-bit
kernels. Also we can check the kernel config file for the offset and if
not found default to 0xc0000000. A command line option to parse in the
page offset is also provided. We do automatically detect architecture
if running on ix86.
Add support for 32-bit kernels. Add a command line option for page
offset.
Suggested-by: Kaiwan N Billimoria <kaiwan.billimoria@gmail.com>
Signed-off-by: Tobin C. Harding <me@tobin.cc>
