The EXPORT_SYMBOL_NS() and EXPORT_SYMBOL_NS_GPL() macros can be used to
export a symbol to a specific namespace. There are no _GPL_FUTURE and
_UNUSED variants because these are currently unused, and I'm not sure
they are necessary.
I didn't add EXPORT_SYMBOL_NS() for ASM exports; this patch sets the
namespace of ASM exports to NULL by default. In case of relative
references, it will be relocatable to NULL. If there's a need, this
should be pretty easy to add.
A module that wants to use a symbol exported to a namespace must add a
MODULE_IMPORT_NS() statement to their module code; otherwise, modpost
will complain when building the module, and the kernel module loader
will emit an error and fail when loading the module.
MODULE_IMPORT_NS() adds a modinfo tag 'import_ns' to the module. That
tag can be observed by the modinfo command, modpost and kernel/module.c
at the time of loading the module.
The ELF symbols are renamed to include the namespace with an asm label;
for example, symbol 'usb_stor_suspend' in namespace USB_STORAGE becomes
'usb_stor_suspend.USB_STORAGE'. This allows modpost to do namespace
checking, without having to go through all the effort of parsing ELF and
relocation records just to get to the struct kernel_symbols.
On x86_64 I saw no difference in binary size (compression), but at
runtime this will require a word of memory per export to hold the
namespace. An alternative could be to store namespaced symbols in their
own section and use a separate 'struct namespaced_kernel_symbol' for
that section, at the cost of making the module loader more complex.
Co-developed-by: Martijn Coenen <maco@android.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Adding DEFINE_SRCU() or DEFINE_STATIC_SRCU() to a loadable module requires
that the size of the reserved region be increased, which is not something
we want to be doing all that often. One approach would be to require
that loadable modules define an srcu_struct and invoke init_srcu_struct()
from their module_init function and cleanup_srcu_struct() from their
module_exit function. However, this is more than a bit user unfriendly.
This commit therefore creates an ___srcu_struct_ptrs linker section,
and pointers to srcu_struct structures created by DEFINE_SRCU() and
DEFINE_STATIC_SRCU() within a module are placed into that module's
___srcu_struct_ptrs section. The required init_srcu_struct() and
cleanup_srcu_struct() functions are then automatically invoked as needed
when that module is loaded and unloaded, thus allowing modules to continue
to use DEFINE_SRCU() and DEFINE_STATIC_SRCU() while avoiding the need
to increase the size of the reserved region.
Many of the algorithms and some of the code was cheerfully cherry-picked
from other code making use of linker sections, perhaps most notably from
tracepoints. All bugs are nevertheless the sole property of the author.
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
[ paulmck: Use __section() and use "default" in srcu_module_notify()'s
"switch" statement as suggested by Joel Fernandes. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Tested-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Summary of modules changes for the 5.2 merge window:
- Use a separate table to store symbol types instead of
hijacking fields in struct Elf_Sym
- Trivial code cleanups
Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull modules updates from Jessica Yu:
- Use a separate table to store symbol types instead of hijacking
fields in struct Elf_Sym
- Trivial code cleanups
* tag 'modules-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
module: add stubs for within_module functions
kallsyms: store type information in its own array
vmlinux.lds.h: drop unused __vermagic
Pull intgrity updates from James Morris:
"This contains just three patches, the remainder were either included
in other pull requests (eg. audit, lockdown) or will be upstreamed via
other subsystems (eg. kselftests, Power).
Included here is one bug fix, one documentation update, and extending
the x86 IMA arch policy rules to coordinate the different kernel
module signature verification methods"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
doc/kernel-parameters.txt: Deprecate ima_appraise_tcb
x86/ima: add missing include
x86/ima: require signed kernel modules
- allow users to invoke 'make' out of the source tree
- refactor scripts/mkmakefile
- deprecate KBUILD_SRC, which was used to track the source tree
location for O= build.
- fix recordmcount.pl in case objdump output is localized
- turn unresolved symbols in external modules to errors from warnings
by default; pass KBUILD_MODPOST_WARN=1 to get them back to warnings
- generate modules.builtin.modinfo to collect .modinfo data from
built-in modules
- misc Makefile cleanups
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Merge tag 'kbuild-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- allow users to invoke 'make' out of the source tree
- refactor scripts/mkmakefile
- deprecate KBUILD_SRC, which was used to track the source tree
location for O= build.
- fix recordmcount.pl in case objdump output is localized
- turn unresolved symbols in external modules to errors from warnings
by default; pass KBUILD_MODPOST_WARN=1 to get them back to warnings
- generate modules.builtin.modinfo to collect .modinfo data from
built-in modules
- misc Makefile cleanups
* tag 'kbuild-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (21 commits)
.gitignore: add more all*.config patterns
moduleparam: Save information about built-in modules in separate file
Remove MODULE_ALIAS() calls that take undefined macro
.gitignore: add leading and trailing slashes to generated directories
scripts/tags.sh: fix direct execution of scripts/tags.sh
scripts: override locale from environment when running recordmcount.pl
samples: kobject: allow CONFIG_SAMPLE_KOBJECT to become y
samples: seccomp: turn CONFIG_SAMPLE_SECCOMP into a bool option
kbuild: move Documentation to vmlinux-alldirs
kbuild: move samples/ to KBUILD_VMLINUX_OBJS
modpost: make KBUILD_MODPOST_WARN also configurable for external modules
kbuild: check arch/$(SRCARCH)/include/generated before out-of-tree build
kbuild: remove unneeded dependency for include/config/kernel.release
memory: squash drivers/memory/Makefile.asm-offsets
kbuild: use $(srctree) instead of KBUILD_SRC to check out-of-tree build
kbuild: mkmakefile: generate a simple wrapper of top Makefile
kbuild: mkmakefile: do not check the generated Makefile marker
kbuild: allow Kbuild to start from any directory
kbuild: pass $(MAKECMDGOALS) to sub-make as is
kbuild: fix warning "overriding recipe for target 'Makefile'"
...
Problem:
When a kernel module is compiled as a separate module, some important
information about the kernel module is available via .modinfo section of
the module. In contrast, when the kernel module is compiled into the
kernel, that information is not available.
Information about built-in modules is necessary in the following cases:
1. When it is necessary to find out what additional parameters can be
passed to the kernel at boot time.
2. When you need to know which module names and their aliases are in
the kernel. This is very useful for creating an initrd image.
Proposal:
The proposed patch does not remove .modinfo section with module
information from the vmlinux at the build time and saves it into a
separate file after kernel linking. So, the kernel does not increase in
size and no additional information remains in it. Information is stored
in the same format as in the separate modules (null-terminated string
array). Because the .modinfo section is already exported with a separate
modules, we are not creating a new API.
It can be easily read in the userspace:
$ tr '\0' '\n' < modules.builtin.modinfo
ext4.softdep=pre: crc32c
ext4.license=GPL
ext4.description=Fourth Extended Filesystem
ext4.author=Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others
ext4.alias=fs-ext4
ext4.alias=ext3
ext4.alias=fs-ext3
ext4.alias=ext2
ext4.alias=fs-ext2
md_mod.alias=block-major-9-*
md_mod.alias=md
md_mod.description=MD RAID framework
md_mod.license=GPL
md_mod.parmtype=create_on_open:bool
md_mod.parmtype=start_dirty_degraded:int
...
Co-Developed-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Signed-off-by: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Provide stubs for within_module_core(), within_module_init(), and
within_module() to prevent build errors when !CONFIG_MODULES.
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kbuild test robot <lkp@intel.com>
Link: https://marc.info/?l=linux-mm&m=155384681109231&w=2
Signed-off-by: Tri Vo <trong@android.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
When a module is loaded, its symbols' Elf_Sym information is stored
in a symtab. Further, type information is also captured. Since
Elf_Sym has no type field, historically the st_info field has been
hijacked for storing type: st_info was overwritten.
commit 5439c985c5 ("module: Overwrite
st_size instead of st_info") changes that practice, as its one-liner
indicates. Unfortunately, this change overwrites symbol size,
information that a tool like DTrace expects to find.
Allocate a typetab array to store type information so that no Elf_Sym
field needs to be overwritten.
Fixes: 5439c985c5 ("module: Overwrite st_size instead of st_info")
Signed-off-by: Eugene Loh <eugene.loh@oracle.com>
Reviewed-by: Nick Alcock <nick.alcock@oracle.com>
[jeyu: renamed typeoff -> typeoffs ]
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Have the IMA architecture specific policy require signed kernel modules
on systems with secure boot mode enabled; and coordinate the different
signature verification methods, so only one signature is required.
Requiring appended kernel module signatures may be configured, enabled
on the boot command line, or with this patch enabled in secure boot
mode. This patch defines set_module_sig_enforced().
To coordinate between appended kernel module signatures and IMA
signatures, only define an IMA MODULE_CHECK policy rule if
CONFIG_MODULE_SIG is not enabled. A custom IMA policy may still define
and require an IMA signature.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Implement the ability for filesystems to log error, warning and
informational messages through the fs_context. These can be extracted by
userspace by reading from an fd created by fsopen().
Error messages are prefixed with "e ", warnings with "w " and informational
messages with "i ".
Inside the kernel, formatted messages are malloc'd but unformatted messages
are not copied if they're either in the core .rodata section or in the
.rodata section of the filesystem module pinned by fs_context::fs_type.
The messages are only good till the fs_type is released.
Note that the logging object is shared between duplicated fs_context
structures. This is so that such as NFS which do a mount within a mount
can get at least some of the errors from the inner mount.
Five logging functions are provided for this:
(1) void logfc(struct fs_context *fc, const char *fmt, ...);
This logs a message into the context. If the buffer is full, the
earliest message is discarded.
(2) void errorf(fc, fmt, ...);
This wraps logfc() to log an error.
(3) void invalf(fc, fmt, ...);
This wraps errorf() and returns -EINVAL for convenience.
(4) void warnf(fc, fmt, ...);
This wraps logfc() to log a warning.
(5) void infof(fc, fmt, ...);
This wraps logfc() to log an informational message.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
and more translations. There's also some LICENSES adjustments from
Thomas.
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Merge tag 'docs-5.1' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"A fairly routine cycle for docs - lots of typo fixes, some new
documents, and more translations. There's also some LICENSES
adjustments from Thomas"
* tag 'docs-5.1' of git://git.lwn.net/linux: (74 commits)
docs: Bring some order to filesystem documentation
Documentation/locking/lockdep: Drop last two chars of sample states
doc: rcu: Suspicious RCU usage is a warning
docs: driver-api: iio: fix errors in documentation
Documentation/process/howto: Update for 4.x -> 5.x versioning
docs: Explicitly state that the 'Fixes:' tag shouldn't split lines
doc: security: Add kern-doc for lsm_hooks.h
doc: sctp: Merge and clean up rst files
Docs: Correct /proc/stat path
scripts/spdxcheck.py: fix C++ comment style detection
doc: fix typos in license-rules.rst
Documentation: fix admin-guide/README.rst minimum gcc version requirement
doc: process: complete removal of info about -git patches
doc: translations: sync translations 'remove info about -git patches'
perf-security: wrap paragraphs on 72 columns
perf-security: elaborate on perf_events/Perf privileged users
perf-security: document collected perf_events/Perf data categories
perf-security: document perf_events/Perf resource control
sysfs.txt: add note on available attribute macros
docs: kernel-doc: typo "if ... if" -> "if ... is"
...
The upcoming GCC 9 release extends the -Wmissing-attributes warnings
(enabled by -Wall) to C and aliases: it warns when particular function
attributes are missing in the aliases but not in their target.
In particular, it triggers for all the init/cleanup_module
aliases in the kernel (defined by the module_init/exit macros),
ending up being very noisy.
These aliases point to the __init/__exit functions of a module,
which are defined as __cold (among other attributes). However,
the aliases themselves do not have the __cold attribute.
Since the compiler behaves differently when compiling a __cold
function as well as when compiling paths leading to calls
to __cold functions, the warning is trying to point out
the possibly-forgotten attribute in the alias.
In order to keep the warning enabled, we decided to silence
this case. Ideally, we would mark the aliases directly
as __init/__exit. However, there are currently around 132 modules
in the kernel which are missing __init/__exit in their init/cleanup
functions (either because they are missing, or for other reasons,
e.g. the functions being called from somewhere else); and
a section mismatch is a hard error.
A conservative alternative was to mark the aliases as __cold only.
However, since we would like to eventually enforce __init/__exit
to be always marked, we chose to use the new __copy function
attribute (introduced by GCC 9 as well to deal with this).
With it, we copy the attributes used by the target functions
into the aliases. This way, functions that were not marked
as __init/__exit won't have their aliases marked either,
and therefore there won't be a section mismatch.
Note that the warning would go away marking either the extern
declaration, the definition, or both. However, we only mark
the definition of the alias, since we do not want callers
(which only see the declaration) to be compiled as if the function
was __cold (and therefore the paths leading to those calls
would be assumed to be unlikely).
Link: https://lore.kernel.org/lkml/20190123173707.GA16603@gmail.com/
Link: https://lore.kernel.org/lkml/20190206175627.GA20399@gmail.com/
Suggested-by: Martin Sebor <msebor@gcc.gnu.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
The original MODULE_LICENSE string for kernel modules licensed under the
GPL v2 (only / or later) was simply "GPL", which was - and still is -
completely sufficient for the purpose of module loading and checking
whether the module is free software or proprietary.
In January 2003 this was changed with commit 3344ea3ad4b7 ("[PATCH]
MODULE_LICENSE and EXPORT_SYMBOL_GPL support"). This commit can be found in
the history git repository which holds the 1:1 import of Linus' bitkeeper
repository:
https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=3344ea3ad4b7c302c846a680dbaeedf96ed45c02
The main intention of the patch was to refuse linking proprietary modules
against symbols exported with EXPORT_SYMBOL_GPL() at module load time.
As a completely undocumented side effect it also introduced the distinction
between "GPL" and "GPL v2" MODULE_LICENSE() strings:
* "GPL" [GNU Public License v2 or later]
* "GPL v2" [GNU Public License v2]
* "GPL and additional rights" [GNU Public License v2 rights and more]
* "Dual BSD/GPL" [GNU Public License v2
* or BSD license choice]
* "Dual MPL/GPL" [GNU Public License v2
* or Mozilla license choice]
This distinction was and still is wrong in several aspects:
1) It broke all modules which were using the "GPL" string in the
MODULE_LICENSE() already and were licensed under GPL v2 only.
A quick license scan over the tree at that time shows that at least 480
out of 1484 modules have been affected by this change back then. The
number is probably way higher as this was just a quick check for
clearly identifiable license information.
There was exactly ONE instance of a "GPL v2" module license string in
the kernel back then - drivers/net/tulip/xircom_tulip_cb.c which
otherwise had no license information at all. There is no indication
that the change above is any way related to this driver. The change
happend with the 2.4.11 release which was on Oct. 9 2001 - so quite
some time before the above commit. Unfortunately there is no trace on
the intertubes to any discussion of this.
2) The dual licensed strings became ill defined as well because following
the "GPL" vs. "GPL v2" distinction all dual licensed (or additional
rights) MODULE_LICENSE strings would either require those dual licensed
modules to be licensed under GPL v2 or later or just be unspecified for
the dual licensing case. Neither choice is coherent with the GPL
distinction.
Due to the lack of a proper changelog and no real discussion on the patch
submission other than a few implementation details, it's completely unclear
why this distinction was introduced at all. Other than the comment in the
module header file exists no documentation for this at all.
From a license compliance and license scanning POV this distinction is a
total nightmare.
As of 5.0-rc2 2873 out of 9200 instances of MODULE_LICENSE() strings are
conflicting with the actual license in the source code (either SPDX or
license boilerplate/reference). A comparison between the scan of the
history tree and a scan of current Linus tree shows to the extent that the
git rename detection over Linus tree grafted with the history tree is
halfways complete that almost none of the files which got broken in 2003
have been cleaned up vs. the MODULE_LICENSE string. So subtracting those
480 known instances from the conflicting 2800 of today more than 25% of the
module authors got it wrong and it's a high propability that a large
portion of the rest just got it right by chance.
There is no value for the module loader to convey the detailed license
information as the only decision to be made is whether the module is free
software or not.
The "and additional rights", "BSD" and "MPL" strings are not conclusive
license information either. So there is no point in trying to make the GPL
part conclusive and exact. As shown above it's already non conclusive for
dual licensing and incoherent with a large portion of the module source.
As an unintended side effect this distinction causes a major headache for
license compliance, license scanners and the ongoing effort to clean up the
license mess of the kernel.
Therefore remove the well meant, but ill defined, distinction between "GPL"
and "GPL v2" and document that:
- "GPL" and "GPL v2" both express that the module is licensed under GPLv2
(without a distinction of 'only' and 'or later') and is therefore kernel
license compliant.
- None of the MODULE_LICENSE strings can be used for expressing or
determining the exact license
- Their sole purpose is to decide whether the module is free software or
not.
Add a MODULE_LICENSE subsection to the license rule documentation as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Acked-by: Joe Perches <joe@perches.com>
[jc: Did s/merily/merely/ ]
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".
The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:
#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
# define HAVE_JUMP_LABEL
#endif
We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.
Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Pull networking updates from David Miller:
1) New ipset extensions for matching on destination MAC addresses, from
Stefano Brivio.
2) Add ipv4 ttl and tos, plus ipv6 flow label and hop limit offloads to
nfp driver. From Stefano Brivio.
3) Implement GRO for plain UDP sockets, from Paolo Abeni.
4) Lots of work from Michał Mirosław to eliminate the VLAN_TAG_PRESENT
bit so that we could support the entire vlan_tci value.
5) Rework the IPSEC policy lookups to better optimize more usecases,
from Florian Westphal.
6) Infrastructure changes eliminating direct manipulation of SKB lists
wherever possible, and to always use the appropriate SKB list
helpers. This work is still ongoing...
7) Lots of PHY driver and state machine improvements and
simplifications, from Heiner Kallweit.
8) Various TSO deferral refinements, from Eric Dumazet.
9) Add ntuple filter support to aquantia driver, from Dmitry Bogdanov.
10) Batch dropping of XDP packets in tuntap, from Jason Wang.
11) Lots of cleanups and improvements to the r8169 driver from Heiner
Kallweit, including support for ->xmit_more. This driver has been
getting some much needed love since he started working on it.
12) Lots of new forwarding selftests from Petr Machata.
13) Enable VXLAN learning in mlxsw driver, from Ido Schimmel.
14) Packed ring support for virtio, from Tiwei Bie.
15) Add new Aquantia AQtion USB driver, from Dmitry Bezrukov.
16) Add XDP support to dpaa2-eth driver, from Ioana Ciocoi Radulescu.
17) Implement coalescing on TCP backlog queue, from Eric Dumazet.
18) Implement carrier change in tun driver, from Nicolas Dichtel.
19) Support msg_zerocopy in UDP, from Willem de Bruijn.
20) Significantly improve garbage collection of neighbor objects when
the table has many PERMANENT entries, from David Ahern.
21) Remove egdev usage from nfp and mlx5, and remove the facility
completely from the tree as it no longer has any users. From Oz
Shlomo and others.
22) Add a NETDEV_PRE_CHANGEADDR so that drivers can veto the change and
therefore abort the operation before the commit phase (which is the
NETDEV_CHANGEADDR event). From Petr Machata.
23) Add indirect call wrappers to avoid retpoline overhead, and use them
in the GRO code paths. From Paolo Abeni.
24) Add support for netlink FDB get operations, from Roopa Prabhu.
25) Support bloom filter in mlxsw driver, from Nir Dotan.
26) Add SKB extension infrastructure. This consolidates the handling of
the auxiliary SKB data used by IPSEC and bridge netfilter, and is
designed to support the needs to MPTCP which could be integrated in
the future.
27) Lots of XDP TX optimizations in mlx5 from Tariq Toukan.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1845 commits)
net: dccp: fix kernel crash on module load
drivers/net: appletalk/cops: remove redundant if statement and mask
bnx2x: Fix NULL pointer dereference in bnx2x_del_all_vlans() on some hw
net/net_namespace: Check the return value of register_pernet_subsys()
net/netlink_compat: Fix a missing check of nla_parse_nested
ieee802154: lowpan_header_create check must check daddr
net/mlx4_core: drop useless LIST_HEAD
mlxsw: spectrum: drop useless LIST_HEAD
net/mlx5e: drop useless LIST_HEAD
iptunnel: Set tun_flags in the iptunnel_metadata_reply from src
net/mlx5e: fix semicolon.cocci warnings
staging: octeon: fix build failure with XFRM enabled
net: Revert recent Spectre-v1 patches.
can: af_can: Fix Spectre v1 vulnerability
packet: validate address length if non-zero
nfc: af_nfc: Fix Spectre v1 vulnerability
phonet: af_phonet: Fix Spectre v1 vulnerability
net: core: Fix Spectre v1 vulnerability
net: minor cleanup in skb_ext_add()
net: drop the unused helper skb_ext_get()
...
Distributions build drivers as modules, including network and filesystem
drivers which export numerous tracepoints. This enables
bpf(BPF_RAW_TRACEPOINT_OPEN) to attach to those tracepoints.
Signed-off-by: Matt Mullins <mmullins@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Thumb-2 functions have the lowest bit set in the symbol value in the
symtab. When kallsyms are generated for the vmlinux, the kallsyms are
generated from the output of nm, and nm clears the lowest bit.
$ arm-linux-gnueabihf-readelf -a vmlinux | grep show_interrupts
95947: 8015dc89 686 FUNC GLOBAL DEFAULT 2 show_interrupts
$ arm-linux-gnueabihf-nm vmlinux | grep show_interrupts
8015dc88 T show_interrupts
$ cat /proc/kallsyms | grep show_interrupts
8015dc88 T show_interrupts
However, for modules, the kallsyms uses the values in the symbol table
without modification, so for functions in modules, the lowest bit is set
in kallsyms.
$ arm-linux-gnueabihf-readelf -a drivers/net/tun.ko | grep tun_get_socket
333: 00002d4d 36 FUNC GLOBAL DEFAULT 1 tun_get_socket
$ arm-linux-gnueabihf-nm drivers/net/tun.ko | grep tun_get_socket
00002d4c T tun_get_socket
$ cat /proc/kallsyms | grep tun_get_socket
7f802d4d t tun_get_socket [tun]
Because of this, the symbol+offset of the crashing instruction shown in
oopses is incorrect when the crash is in a module. For example, given a
tun_get_socket which starts like this,
00002d4c <tun_get_socket>:
2d4c: 6943 ldr r3, [r0, #20]
2d4e: 4a07 ldr r2, [pc, #28]
2d50: 4293 cmp r3, r2
a crash when tun_get_socket is called with NULL results in:
PC is at tun_xdp+0xa3/0xa4 [tun]
pc : [<7f802d4c>]
As can be seen, the "PC is at" line reports the wrong symbol name, and
the symbol+offset will point to the wrong source line if it is passed to
gdb.
To solve this, add a way for archs to fixup the reading of these module
kallsyms values, and use that to clear the lowest bit for function
symbols on Thumb-2.
After the fix:
# cat /proc/kallsyms | grep tun_get_socket
7f802d4c t tun_get_socket [tun]
PC is at tun_get_socket+0x0/0x24 [tun]
pc : [<7f802d4c>]
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Pull security subsystem updates from James Morris:
"In this patchset, there are a couple of minor updates, as well as some
reworking of the LSM initialization code from Kees Cook (these prepare
the way for ordered stackable LSMs, but are a valuable cleanup on
their own)"
* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
LSM: Don't ignore initialization failures
LSM: Provide init debugging infrastructure
LSM: Record LSM name in struct lsm_info
LSM: Convert security_initcall() into DEFINE_LSM()
vmlinux.lds.h: Move LSM_TABLE into INIT_DATA
LSM: Convert from initcall to struct lsm_info
LSM: Remove initcall tracing
LSM: Rename .security_initcall section to .lsm_info
vmlinux.lds.h: Avoid copy/paste of security_init section
LSM: Correctly announce start of LSM initialization
security: fix LSM description location
keys: Fix the use of the C++ keyword "private" in uapi/linux/keyctl.h
seccomp: remove unnecessary unlikely()
security: tomoyo: Fix obsolete function
security/capabilities: remove check for -EINVAL
commit 46e0c9be20 ("kernel: tracepoints: add support for relative
references") changes the layout of the __tracepoint_ptrs section on
architectures supporting relative references. However, it does so
without turning struct tracepoint * const into const int elsewhere in
the tracepoint code, which has the following side-effect:
Setting mod->num_tracepoints is done in by module.c:
mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
sizeof(*mod->tracepoints_ptrs),
&mod->num_tracepoints);
Basically, since sizeof(*mod->tracepoints_ptrs) is a pointer size
(rather than sizeof(int)), num_tracepoints is erroneously set to half the
size it should be on 64-bit arch. So a module with an odd number of
tracepoints misses the last tracepoint due to effect of integer
division.
So in the module going notifier:
for_each_tracepoint_range(mod->tracepoints_ptrs,
mod->tracepoints_ptrs + mod->num_tracepoints,
tp_module_going_check_quiescent, NULL);
the expression (mod->tracepoints_ptrs + mod->num_tracepoints) actually
evaluates to something within the bounds of the array, but miss the
last tracepoint if the number of tracepoints is odd on 64-bit arch.
Fix this by introducing a new typedef: tracepoint_ptr_t, which
is either "const int" on architectures that have PREL32 relocations,
or "struct tracepoint * const" on architectures that does not have
this feature.
Also provide a new tracepoint_ptr_defer() static inline to
encapsulate deferencing this type rather than duplicate code and
ugly idefs within the for_each_tracepoint_range() implementation.
This issue appears in 4.19-rc kernels, and should ideally be fixed
before the end of the rc cycle.
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Link: http://lkml.kernel.org/r/20181013191050.22389-1-mathieu.desnoyers@efficios.com
Link: http://lkml.kernel.org/r/20180704083651.24360-7-ard.biesheuvel@linaro.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morris <james.morris@microsoft.com>
Cc: James Morris <jmorris@namei.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In preparation for doing more interesting LSM init probing, this converts
the existing initcall system into an explicit call into a function pointer
from a section-collected struct lsm_info array.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
With the special case handling for Blackfin and Metag was removed by
commit 94e58e0ac3 ("export.h: remove code for prefixing symbols with
underscore"), VMLINUX_SYMBOL_STR() is now equivalent to __stringify().
Replace the remaining usages to prepare for the entire removal of
VMLINUX_SYMBOL_STR().
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Make module_is_live return bool due to this particular function only using
either one or zero as its return value.
No functional change.
Link: http://lkml.kernel.org/r/1513266622-15860-6-git-send-email-baiyaowei@cmss.chinamobile.com
Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull printk updates from Petr Mladek:
- Add a console_msg_format command line option:
The value "default" keeps the old "[time stamp] text\n" format. The
value "syslog" allows to see the syslog-like "<log
level>[timestamp] text" format.
This feature was requested by people doing regression tests, for
example, 0day robot. They want to have both filtered and full logs
at hands.
- Reduce the risk of softlockup:
Pass the console owner in a busy loop.
This is a new approach to the old problem. It was first proposed by
Steven Rostedt on Kernel Summit 2017. It marks a context in which
the console_lock owner calls console drivers and could not sleep.
On the other side, printk() callers could detect this state and use
a busy wait instead of a simple console_trylock(). Finally, the
console_lock owner checks if there is a busy waiter at the end of
the special context and eventually passes the console_lock to the
waiter.
The hand-off works surprisingly well and helps in many situations.
Well, there is still a possibility of the softlockup, for example,
when the flood of messages stops and the last owner still has too
much to flush.
There is increasing number of people having problems with
printk-related softlockups. We might eventually need to get better
solution. Anyway, this looks like a good start and promising
direction.
- Do not allow to schedule in console_unlock() called from printk():
This reverts an older controversial commit. The reschedule helped
to avoid softlockups. But it also slowed down the console output.
This patch is obsoleted by the new console waiter logic described
above. In fact, the reschedule made the hand-off less effective.
- Deprecate "%pf" and "%pF" format specifier:
It was needed on ia64, ppc64 and parisc64 to dereference function
descriptors and show the real function address. It is done
transparently by "%ps" and "pS" format specifier now.
Sergey Senozhatsky found that all the function descriptors were in
a special elf section and could be easily detected.
- Remove printk_symbol() API:
It has been obsoleted by "%pS" format specifier, and this change
helped to remove few continuous lines and a less intuitive old API.
- Remove redundant memsets:
Sergey removed unnecessary memset when processing printk.devkmsg
command line option.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits)
printk: drop redundant devkmsg_log_str memsets
printk: Never set console_may_schedule in console_trylock()
printk: Hide console waiter logic into helpers
printk: Add console owner and waiter logic to load balance console writes
kallsyms: remove print_symbol() function
checkpatch: add pF/pf deprecation warning
symbol lookup: introduce dereference_symbol_descriptor()
parisc64: Add .opd based function descriptor dereference
powerpc64: Add .opd based function descriptor dereference
ia64: Add .opd based function descriptor dereference
sections: split dereference_function_descriptor()
openrisc: Fix conflicting types for _exext and _stext
lib: do not use print_symbol()
irq debug: do not use print_symbol()
sysfs: do not use print_symbol()
drivers: do not use print_symbol()
x86: do not use print_symbol()
unicore32: do not use print_symbol()
sh: do not use print_symbol()
mn10300: do not use print_symbol()
...
Pull networking updates from David Miller:
1) Significantly shrink the core networking routing structures. Result
of http://vger.kernel.org/~davem/seoul2017_netdev_keynote.pdf
2) Add netdevsim driver for testing various offloads, from Jakub
Kicinski.
3) Support cross-chip FDB operations in DSA, from Vivien Didelot.
4) Add a 2nd listener hash table for TCP, similar to what was done for
UDP. From Martin KaFai Lau.
5) Add eBPF based queue selection to tun, from Jason Wang.
6) Lockless qdisc support, from John Fastabend.
7) SCTP stream interleave support, from Xin Long.
8) Smoother TCP receive autotuning, from Eric Dumazet.
9) Lots of erspan tunneling enhancements, from William Tu.
10) Add true function call support to BPF, from Alexei Starovoitov.
11) Add explicit support for GRO HW offloading, from Michael Chan.
12) Support extack generation in more netlink subsystems. From Alexander
Aring, Quentin Monnet, and Jakub Kicinski.
13) Add 1000BaseX, flow control, and EEE support to mvneta driver. From
Russell King.
14) Add flow table abstraction to netfilter, from Pablo Neira Ayuso.
15) Many improvements and simplifications to the NFP driver bpf JIT,
from Jakub Kicinski.
16) Support for ipv6 non-equal cost multipath routing, from Ido
Schimmel.
17) Add resource abstration to devlink, from Arkadi Sharshevsky.
18) Packet scheduler classifier shared filter block support, from Jiri
Pirko.
19) Avoid locking in act_csum, from Davide Caratti.
20) devinet_ioctl() simplifications from Al viro.
21) More TCP bpf improvements from Lawrence Brakmo.
22) Add support for onlink ipv6 route flag, similar to ipv4, from David
Ahern.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1925 commits)
tls: Add support for encryption using async offload accelerator
ip6mr: fix stale iterator
net/sched: kconfig: Remove blank help texts
openvswitch: meter: Use 64-bit arithmetic instead of 32-bit
tcp_nv: fix potential integer overflow in tcpnv_acked
r8169: fix RTL8168EP take too long to complete driver initialization.
qmi_wwan: Add support for Quectel EP06
rtnetlink: enable IFLA_IF_NETNSID for RTM_NEWLINK
ipmr: Fix ptrdiff_t print formatting
ibmvnic: Wait for device response when changing MAC
qlcnic: fix deadlock bug
tcp: release sk_frag.page in tcp_disconnect
ipv4: Get the address of interface correctly.
net_sched: gen_estimator: fix lockdep splat
net: macb: Handle HRESP error
net/mlx5e: IPoIB, Fix copy-paste bug in flow steering refactoring
ipv6: addrconf: break critical section in addrconf_verify_rtnl()
ipv6: change route cache aging logic
i40e/i40evf: Update DESC_NEEDED value to reflect larger value
bnxt_en: cleanup DIM work on device shutdown
...
Pull x86/pti updates from Thomas Gleixner:
"Another set of melted spectrum related changes:
- Code simplifications and cleanups for RSB and retpolines.
- Make the indirect calls in KVM speculation safe.
- Whitelist CPUs which are known not to speculate from Meltdown and
prepare for the new CPUID flag which tells the kernel that a CPU is
not affected.
- A less rigorous variant of the module retpoline check which merily
warns when a non-retpoline protected module is loaded and reflects
that fact in the sysfs file.
- Prepare for Indirect Branch Prediction Barrier support.
- Prepare for exposure of the Speculation Control MSRs to guests, so
guest OSes which depend on those "features" can use them. Includes
a blacklist of the broken microcodes. The actual exposure of the
MSRs through KVM is still being worked on"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/speculation: Simplify indirect_branch_prediction_barrier()
x86/retpoline: Simplify vmexit_fill_RSB()
x86/cpufeatures: Clean up Spectre v2 related CPUID flags
x86/cpu/bugs: Make retpoline module warning conditional
x86/bugs: Drop one "mitigation" from dmesg
x86/nospec: Fix header guards names
x86/alternative: Print unadorned pointers
x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support
x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes
x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown
x86/msr: Add definitions for new speculation control MSRs
x86/cpufeatures: Add AMD feature bits for Speculation Control
x86/cpufeatures: Add Intel feature bits for Speculation Control
x86/cpufeatures: Add CPUID_7_EDX CPUID leaf
module/retpoline: Warn about missing retpoline in module
KVM: VMX: Make indirect call speculation safe
KVM: x86: Make indirect calls in emulator speculation safe
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: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas 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
Add injectable error types for each error-injectable function.
One motivation of error injection test is to find software flaws,
mistakes or mis-handlings of expectable errors. If we find such
flaws by the test, that is a program bug, so we need to fix it.
But if the tester miss input the error (e.g. just return success
code without processing anything), it causes unexpected behavior
even if the caller is correctly programmed to handle any errors.
That is not what we want to test by error injection.
To clarify what type of errors the caller must expect for each
injectable function, this introduces injectable error types:
- EI_ETYPE_NULL : means the function will return NULL if it
fails. No ERR_PTR, just a NULL.
- EI_ETYPE_ERRNO : means the function will return -ERRNO
if it fails.
- EI_ETYPE_ERRNO_NULL : means the function will return -ERRNO
(ERR_PTR) or NULL.
ALLOW_ERROR_INJECTION() macro is expanded to get one of
NULL, ERRNO, ERRNO_NULL to record the error type for
each function. e.g.
ALLOW_ERROR_INJECTION(open_ctree, ERRNO)
This error types are shown in debugfs as below.
====
/ # cat /sys/kernel/debug/error_injection/list
open_ctree [btrfs] ERRNO
io_ctl_init [btrfs] ERRNO
====
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since error-injection framework is not limited to be used
by kprobes, nor bpf. Other kernel subsystems can use it
freely for checking safeness of error-injection, e.g.
livepatch, ftrace etc.
So this separate error-injection framework from kprobes.
Some differences has been made:
- "kprobe" word is removed from any APIs/structures.
- BPF_ALLOW_ERROR_INJECTION() is renamed to
ALLOW_ERROR_INJECTION() since it is not limited for BPF too.
- CONFIG_FUNCTION_ERROR_INJECTION is the config item of this
feature. It is automatically enabled if the arch supports
error injection feature for kprobe or ftrace etc.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
There are two format specifiers to print out a pointer in symbolic
format: '%pS/%ps' and '%pF/%pf'. On most architectures, the two
mean exactly the same thing, but some architectures (ia64, ppc64,
parisc64) use an indirect pointer for C function pointers, where
the function pointer points to a function descriptor (which in
turn contains the actual pointer to the code). The '%pF/%pf, when
used appropriately, automatically does the appropriate function
descriptor dereference on such architectures.
The "when used appropriately" part is tricky. Basically this is
a subtle ABI detail, specific to some platforms, that made it to
the API level and people can be unaware of it and miss the whole
"we need to dereference the function" business out. [1] proves
that point (note that it fixes only '%pF' and '%pS', there might
be '%pf' and '%ps' cases as well).
It appears that we can handle everything within the affected
arches and make '%pS/%ps' smart enough to retire '%pF/%pf'.
Function descriptors live in .opd elf section and all affected
arches (ia64, ppc64, parisc64) handle it properly for kernel
and modules. So we, technically, can decide if the dereference
is needed by simply looking at the pointer: if it belongs to
.opd section then we need to dereference it.
The kernel and modules have their own .opd sections, obviously,
that's why we need to split dereference_function_descriptor()
and use separate kernel and module dereference arch callbacks.
This patch does the first step, it
a) adds dereference_kernel_function_descriptor() function.
b) adds a weak alias to dereference_module_function_descriptor()
function.
So, for the time being, we will have:
1) dereference_function_descriptor()
A generic function, that simply dereferences the pointer. There is
bunch of places that call it: kgdbts, init/main.c, extable, etc.
2) dereference_kernel_function_descriptor()
A function to call on kernel symbols that does kernel .opd section
address range test.
3) dereference_module_function_descriptor()
A function to call on modules' symbols that does modules' .opd
section address range test.
[1] https://marc.info/?l=linux-kernel&m=150472969730573
Link: http://lkml.kernel.org/r/20171109234830.5067-2-sergey.senozhatsky@gmail.com
To: Fenghua Yu <fenghua.yu@intel.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Paul Mackerras <paulus@samba.org>
To: Michael Ellerman <mpe@ellerman.id.au>
To: James Bottomley <jejb@parisc-linux.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Tony Luck <tony.luck@intel.com> #ia64
Tested-by: Santosh Sivaraj <santosh@fossix.org> #powerpc
Tested-by: Helge Deller <deller@gmx.de> #parisc64
Signed-off-by: Petr Mladek <pmladek@suse.com>
Using BPF we can override kprob'ed functions and return arbitrary
values. Obviously this can be a bit unsafe, so make this feature opt-in
for functions. Simply tag a function with KPROBE_ERROR_INJECT_SYMBOL in
order to give BPF access to that function for error injection purposes.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A static variable sig_enforce is used as status var to indicate the real
value of CONFIG_MODULE_SIG_FORCE, once this one is set the var will hold
true, but if the CONFIG is not set the status var will hold whatever
value is present in the module.sig_enforce kernel cmdline param: true
when =1 and false when =0 or not present.
Considering this cmdline param take place over the CONFIG value when
it's not set, other places in the kernel could misbehave since they
would have only the CONFIG_MODULE_SIG_FORCE value to rely on. Exporting
this status var allows the kernel to rely in the effective value of
module signature enforcement, being it from CONFIG value or cmdline
param.
Signed-off-by: Bruno E. O. Meneguele <brdeoliv@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
MODULE_DEVICE_TABLE(type, name) creates an alias of type 'extern const
typeof(name)'. If 'name' is already constant the 'const' attribute is
specified twice, which is not allowed in C89 (see discussion at
https://lkml.org/lkml/2017/5/23/1440). Since the kernel is built with
-std=gnu89 clang generates warnings like this:
drivers/thermal/x86_pkg_temp_thermal.c:509:1: warning: duplicate 'const'
declaration specifier
[-Wduplicate-decl-specifier]
MODULE_DEVICE_TABLE(x86cpu, pkg_temp_thermal_ids);
^
./include/linux/module.h:212:8: note: expanded from macro 'MODULE_DEVICE_TABLE'
extern const typeof(name) __mod_##type##__##name##_device_table
Remove the const attribute from the alias to avoid the duplicate
specifier. After all it is only an alias and the attribute shouldn't
have any effect.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
randstruct plugin, including the task_struct.
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Merge tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull structure randomization updates from Kees Cook:
"Now that IPC and other changes have landed, enable manual markings for
randstruct plugin, including the task_struct.
This is the rest of what was staged in -next for the gcc-plugins, and
comes in three patches, largest first:
- mark "easy" structs with __randomize_layout
- mark task_struct with an optional anonymous struct to isolate the
__randomize_layout section
- mark structs to opt _out_ of automated marking (which will come
later)
And, FWIW, this continues to pass allmodconfig (normal and patched to
enable gcc-plugins) builds of x86_64, i386, arm64, arm, powerpc, and
s390 for me"
* tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
randstruct: opt-out externally exposed function pointer structs
task_struct: Allow randomized layout
randstruct: Mark various structs for randomization
This marks many critical kernel structures for randomization. These are
structures that have been targeted in the past in security exploits, or
contain functions pointers, pointers to function pointer tables, lists,
workqueues, ref-counters, credentials, permissions, or are otherwise
sensitive. This initial list was extracted from Brad Spengler/PaX Team's
code in the last public patch of grsecurity/PaX based on my understanding
of the code. Changes or omissions from the original code are mine and
don't reflect the original grsecurity/PaX code.
Left out of this list is task_struct, which requires special handling
and will be covered in a subsequent patch.
Signed-off-by: Kees Cook <keescook@chromium.org>
Each module has a list of enum's its contributing to the
enum map, rename that entry to reflect its use by more than
enums.
Link: http://lkml.kernel.org/r/20170531215653.3240-4-jeremy.linton@arm.com
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Each enum is loaded into the trace_enum_map, as we
are now using this for more than enums rename it.
Link: http://lkml.kernel.org/r/20170531215653.3240-3-jeremy.linton@arm.com
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Summary of modules changes for the 4.12 merge window:
- Minor code cleanups
- Fix section alignment for .init_array
Signed-off-by: Jessica Yu <jeyu@redhat.com>
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Merge tag 'modules-for-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull modules updates from Jessica Yu:
- Minor code cleanups
- Fix section alignment for .init_array
* tag 'modules-for-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
kallsyms: Use bounded strnchr() when parsing string
module: Unify the return value type of try_module_get
module: set .init_array alignment to 8
The prototypes of try_module_get are different with different macro.
When enable module and module unload, it returns bool, but others not.
Make the return type for try_module_get consistent across all module
config options.
Signed-off-by: Gao Feng <fgao@ikuai8.com>
[jeyu: slightly amended changelog to make it clearer]
Signed-off-by: Jessica Yu <jeyu@redhat.com>
If a PER_CPU struct which contains a spin_lock is statically initialized
via:
DEFINE_PER_CPU(struct foo, bla) = {
.lock = __SPIN_LOCK_UNLOCKED(bla.lock)
};
then lockdep assigns a seperate key to each lock because the logic for
assigning a key to statically initialized locks is to use the address as
the key. With per CPU locks the address is obvioulsy different on each CPU.
That's wrong, because all locks should have the same key.
To solve this the following modifications are required:
1) Extend the is_kernel/module_percpu_addr() functions to hand back the
canonical address of the per CPU address, i.e. the per CPU address
minus the per CPU offset.
2) Check the lock address with these functions and if the per CPU check
matches use the returned canonical address as the lock key, so all per
CPU locks have the same key.
3) Move the static_obj(key) check into look_up_lock_class() so this check
can be avoided for statically initialized per CPU locks. That's
required because the canonical address fails the static_obj(key) check
for obvious reasons.
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ Merged Dan's fixups for !MODULES and !SMP into this patch. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Murphy <dmurphy@ti.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170227143736.pectaimkjkan5kow@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Summary of modules changes for the 4.11 merge window:
- A few small code cleanups
- Add modules git tree url to MAINTAINERS
Signed-off-by: Jessica Yu <jeyu@redhat.com>
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Merge tag 'modules-for-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull modules updates from Jessica Yu:
"Summary of modules changes for the 4.11 merge window:
- A few small code cleanups
- Add modules git tree url to MAINTAINERS"
* tag 'modules-for-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
MAINTAINERS: add tree for modules
module: fix memory leak on early load_module() failures
module: Optimize search_module_extables()
modules: mark __inittest/__exittest as __maybe_unused
livepatch/module: print notice of TAINT_LIVEPATCH
module: Drop redundant declaration of struct module
CONFIG_SET_MODULE_RONX to the more sensible CONFIG_STRICT_KERNEL_RWX and
CONFIG_STRICT_MODULE_RWX.
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Merge tag 'rodata-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull rodata updates from Kees Cook:
"This renames the (now inaccurate) DEBUG_RODATA and related
SET_MODULE_RONX configs to the more sensible STRICT_KERNEL_RWX and
STRICT_MODULE_RWX"
* tag 'rodata-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
arch: Rename CONFIG_DEBUG_RODATA and CONFIG_DEBUG_MODULE_RONX
arch: Move CONFIG_DEBUG_RODATA and CONFIG_SET_MODULE_RONX to be common
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Merge tag 'extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
Pull exception table module split from Paul Gortmaker:
"Final extable.h related changes.
This completes the separation of exception table content from the
module.h header file. This is achieved with the final commit that
removes the one line back compatible change that sourced extable.h
into the module.h file.
The commits are unchanged since January, with the exception of a
couple Acks that came in for the last two commits a bit later. The
changes have been in linux-next for quite some time[1] and have got
widespread arch coverage via toolchains I have and also from
additional ones the kbuild bot has.
Maintaners of the various arch were Cc'd during the postings to
lkml[2] and informed that the intention was to take the remaining arch
specific changes and lump them together with the final two non-arch
specific changes and submit for this merge window.
The ia64 diffstat stands out and probably warrants a mention. In an
earlier review, Al Viro made a valid comment that the original header
separation of content left something to be desired, and that it get
fixed as a part of this change, hence the larger diffstat"
* tag 'extable-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (21 commits)
module.h: remove extable.h include now users have migrated
core: migrate exception table users off module.h and onto extable.h
cris: migrate exception table users off module.h and onto extable.h
hexagon: migrate exception table users off module.h and onto extable.h
microblaze: migrate exception table users off module.h and onto extable.h
unicore32: migrate exception table users off module.h and onto extable.h
score: migrate exception table users off module.h and onto extable.h
metag: migrate exception table users off module.h and onto extable.h
arc: migrate exception table users off module.h and onto extable.h
nios2: migrate exception table users off module.h and onto extable.h
sparc: migrate exception table users onto extable.h
openrisc: migrate exception table users off module.h and onto extable.h
frv: migrate exception table users off module.h and onto extable.h
sh: migrate exception table users off module.h and onto extable.h
xtensa: migrate exception table users off module.h and onto extable.h
mn10300: migrate exception table users off module.h and onto extable.h
alpha: migrate exception table users off module.h and onto extable.h
arm: migrate exception table users off module.h and onto extable.h
m32r: migrate exception table users off module.h and onto extable.h
ia64: ensure exception table search users include extable.h
...
With hopefully most/all users of module.h that were looking for
exception table functions moved over to the new extable.h header,
we can remove the back-compat include that let us transition
without introducing build regressions.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Jessica Yu <jeyu@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Both of these options are poorly named. The features they provide are
necessary for system security and should not be considered debug only.
Change the names to CONFIG_STRICT_KERNEL_RWX and
CONFIG_STRICT_MODULE_RWX to better describe what these options do.
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
clang warns about unused inline functions by default:
arch/arm/crypto/aes-cipher-glue.c:68:1: warning: unused function '__inittest' [-Wunused-function]
arch/arm/crypto/aes-cipher-glue.c:69:1: warning: unused function '__exittest' [-Wunused-function]
As these appear in every single module, let's just disable the warnings by marking the
two functions as __maybe_unused.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jessica Yu <jeyu@redhat.com>
The modversion symbol CRCs are emitted as ELF symbols, which allows us
to easily populate the kcrctab sections by relying on the linker to
associate each kcrctab slot with the correct value.
This has a couple of downsides:
- Given that the CRCs are treated as memory addresses, we waste 4 bytes
for each CRC on 64 bit architectures,
- On architectures that support runtime relocation, a R_<arch>_RELATIVE
relocation entry is emitted for each CRC value, which identifies it
as a quantity that requires fixing up based on the actual runtime
load offset of the kernel. This results in corrupted CRCs unless we
explicitly undo the fixup (and this is currently being handled in the
core module code)
- Such runtime relocation entries take up 24 bytes of __init space
each, resulting in a x8 overhead in [uncompressed] kernel size for
CRCs.
Switching to explicit 32 bit values on 64 bit architectures fixes most
of these issues, given that 32 bit values are not treated as quantities
that require fixing up based on the actual runtime load offset. Note
that on some ELF64 architectures [such as PPC64], these 32-bit values
are still emitted as [absolute] runtime relocatable quantities, even if
the value resolves to a build time constant. Since relative relocations
are always resolved at build time, this patch enables MODULE_REL_CRCS on
powerpc when CONFIG_RELOCATABLE=y, which turns the absolute CRC
references into relative references into .rodata where the actual CRC
value is stored.
So redefine all CRC fields and variables as u32, and redefine the
__CRC_SYMBOL() macro for 64 bit builds to emit the CRC reference using
inline assembler (which is necessary since 64-bit C code cannot use
32-bit types to hold memory addresses, even if they are ultimately
resolved using values that do not exceed 0xffffffff). To avoid
potential problems with legacy 32-bit architectures using legacy
toolchains, the equivalent C definition of the kcrctab entry is retained
for 32-bit architectures.
Note that this mostly reverts commit d4703aefdb ("module: handle ppc64
relocating kcrctabs when CONFIG_RELOCATABLE=y")
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Struct module is already declared at the beginning of the file, no
need to declare it again.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 93c2e105f6 ("module: Optimize __module_address() using a latched RB-tree")
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jessica Yu <jeyu@redhat.com>
The commit 66cc69e34e ("Fix: module signature vs tracepoints:
add new TAINT_UNSIGNED_MODULE") updated module_taint_flags() to
potentially print one more character. But it did not increase the
size of the corresponding buffers in m_show() and print_modules().
We have recently done the same mistake when adding a taint flag
for livepatching, see
https://lkml.kernel.org/r/cfba2c823bb984690b73572aaae1db596b54a082.1472137475.git.jpoimboe@redhat.com
Also struct module uses an incompatible type for mod-taints flags.
It survived from the commit 2bc2d61a96 ("[PATCH] list module
taint flags in Oops/panic"). There was used "int" for the global taint
flags at these times. But only the global tain flags was later changed
to "unsigned long" by the commit 25ddbb18aa ("Make the taint
flags reliable").
This patch defines TAINT_FLAGS_COUNT that can be used to create
arrays and buffers of the right size. Note that we could not use
enum because the taint flag indexes are used also in assembly code.
Then it reworks the table that describes the taint flags. The TAINT_*
numbers can be used as the index. Instead, we add information
if the taint flag is also shown per-module.
Finally, it uses "unsigned long", bit operations, and the updated
taint_flags table also for mod->taints.
It is not optimal because only few taint flags can be printed by
module_taint_flags(). But better be on the safe side. IMHO, it is
not worth the optimization and this is a good compromise.
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: http://lkml.kernel.org/r/1474458442-21581-1-git-send-email-pmladek@suse.com
[jeyu@redhat.com: fix broken lkml link in changelog]
Signed-off-by: Jessica Yu <jeyu@redhat.com>
Matthias Maennich
Paul E. McKenney
Linus Torvalds
Alexey Gladkov
Tri Vo
Eugene Loh
Mimi Zohar
David Howells
Miguel Ojeda
Thomas Gleixner
WANG Chao
Masahiro Yamada
Matt Mullins
Vincent Whitchurch
Mathieu Desnoyers
Kees Cook
Yaowei Bai
Andi Kleen
Masami Hiramatsu
Sergey Senozhatsky
Josef Bacik
Bruno E. O. Meneguele
Matthias Kaehlcke
Jeremy Linton
Gao Feng
Paul Gortmaker
Laura Abbott
Arnd Bergmann
Ard Biesheuvel
Jean Delvare
Anson Jacob
Petr Mladek