System.map shows that vmlinux contains several instances of
__static_call_return0():
c0004fc0 t __static_call_return0
c0011518 t __static_call_return0
c00d8160 t __static_call_return0
arch_static_call_transform() uses the middle one to check whether we are
setting a call to __static_call_return0 or not:
c0011520 <arch_static_call_transform>:
c0011520: 3d 20 c0 01 lis r9,-16383 <== r9 = 0xc001 << 16
c0011524: 39 29 15 18 addi r9,r9,5400 <== r9 += 0x1518
c0011528: 7c 05 48 00 cmpw r5,r9 <== r9 has value 0xc0011518 here
So if static_call_update() is called with one of the other instances of
__static_call_return0(), arch_static_call_transform() won't recognise it.
In order to work properly, global single instance of __static_call_return0() is required.
Fixes: 3f2a8fc4b1 ("static_call/x86: Add __static_call_return0()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/30821468a0e7d28251954b578e5051dc09300d04.1647258493.git.christophe.leroy@csgroup.eu
Current scheme of having userspace decompress kernel modules before
loading them into the kernel runs afoul of LoadPin security policy, as
it loses link between the source of kernel module on the disk and binary
blob that is being loaded into the kernel. To solve this issue let's
implement decompression in kernel, so that we can pass a file descriptor
of compressed module file into finit_module() which will keep LoadPin
happy.
To let userspace know what compression/decompression scheme kernel
supports it will create /sys/module/compression attribute. kmod can read
this attribute and decide if it can pass compressed file to
finit_module(). New MODULE_INIT_COMPRESSED_DATA flag indicates that the
kernel should attempt to decompress the data read from file descriptor
prior to trying load the module.
To simplify things kernel will only implement single decompression
method matching compression method selected when generating modules.
This patch implements gzip and xz; more can be added later,
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Pull tracing updates from Steven Rostedt:
- kprobes: Restructured stack unwinder to show properly on x86 when a
stack dump happens from a kretprobe callback.
- Fix to bootconfig parsing
- Have tracefs allow owner and group permissions by default (only
denying others). There's been pressure to allow non root to tracefs
in a controlled fashion, and using groups is probably the safest.
- Bootconfig memory managament updates.
- Bootconfig clean up to have the tools directory be less dependent on
changes in the kernel tree.
- Allow perf to be traced by function tracer.
- Rewrite of function graph tracer to be a callback from the function
tracer instead of having its own trampoline (this change will happen
on an arch by arch basis, and currently only x86_64 implements it).
- Allow multiple direct trampolines (bpf hooks to functions) be batched
together in one synchronization.
- Allow histogram triggers to add variables that can perform
calculations against the event's fields.
- Use the linker to determine architecture callbacks from the ftrace
trampoline to allow for proper parameter prototypes and prevent
warnings from the compiler.
- Extend histogram triggers to key off of variables.
- Have trace recursion use bit magic to determine preempt context over
if branches.
- Have trace recursion disable preemption as all use cases do anyway.
- Added testing for verification of tracing utilities.
- Various small clean ups and fixes.
* tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits)
tracing/histogram: Fix semicolon.cocci warnings
tracing/histogram: Fix documentation inline emphasis warning
tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together
tracing: Show size of requested perf buffer
bootconfig: Initialize ret in xbc_parse_tree()
ftrace: do CPU checking after preemption disabled
ftrace: disable preemption when recursion locked
tracing/histogram: Document expression arithmetic and constants
tracing/histogram: Optimize division by a power of 2
tracing/histogram: Covert expr to const if both operands are constants
tracing/histogram: Simplify handling of .sym-offset in expressions
tracing: Fix operator precedence for hist triggers expression
tracing: Add division and multiplication support for hist triggers
tracing: Add support for creating hist trigger variables from literal
selftests/ftrace: Stop tracing while reading the trace file by default
MAINTAINERS: Update KPROBES and TRACING entries
test_kprobes: Move it from kernel/ to lib/
docs, kprobes: Remove invalid URL and add new reference
samples/kretprobes: Fix return value if register_kretprobe() failed
lib/bootconfig: Fix the xbc_get_info kerneldoc
...
If the timestamp of the .config file is updated, config_data.gz is
regenerated, then vmlinux is re-linked. This occurs even if the content
of the .config has not changed at all.
This issue was mitigated by commit 67424f61f8 ("kconfig: do not write
.config if the content is the same"); Kconfig does not update the
.config when it ends up with the identical configuration.
The issue is remaining when the .config is created by *_defconfig with
some config fragment(s) applied on top.
This is typical for powerpc and mips, where several *_defconfig targets
are constructed by using merge_config.sh.
One workaround is to have the copy of the .config. The filechk rule
updates the copy, kernel/config_data, by checking the content instead
of the timestamp.
With this commit, the second run with the same configuration avoids
the needless rebuilds.
$ make ARCH=mips defconfig all
[ snip ]
$ make ARCH=mips defconfig all
*** Default configuration is based on target '32r2el_defconfig'
Using ./arch/mips/configs/generic_defconfig as base
Merging arch/mips/configs/generic/32r2.config
Merging arch/mips/configs/generic/el.config
Merging ./arch/mips/configs/generic/board-boston.config
Merging ./arch/mips/configs/generic/board-ni169445.config
Merging ./arch/mips/configs/generic/board-ocelot.config
Merging ./arch/mips/configs/generic/board-ranchu.config
Merging ./arch/mips/configs/generic/board-sead-3.config
Merging ./arch/mips/configs/generic/board-xilfpga.config
#
# configuration written to .config
#
SYNC include/config/auto.conf
CALL scripts/checksyscalls.sh
CALL scripts/atomic/check-atomics.sh
CHK include/generated/compile.h
CHK include/generated/autoksyms.h
Reported-by: Elliot Berman <eberman@codeaurora.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This change adds support for Clang’s forward-edge Control Flow
Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler
injects a runtime check before each indirect function call to ensure
the target is a valid function with the correct static type. This
restricts possible call targets and makes it more difficult for
an attacker to exploit bugs that allow the modification of stored
function pointers. For more details, see:
https://clang.llvm.org/docs/ControlFlowIntegrity.html
Clang requires CONFIG_LTO_CLANG to be enabled with CFI to gain
visibility to possible call targets. Kernel modules are supported
with Clang’s cross-DSO CFI mode, which allows checking between
independently compiled components.
With CFI enabled, the compiler injects a __cfi_check() function into
the kernel and each module for validating local call targets. For
cross-module calls that cannot be validated locally, the compiler
calls the global __cfi_slowpath_diag() function, which determines
the target module and calls the correct __cfi_check() function. This
patch includes a slowpath implementation that uses __module_address()
to resolve call targets, and with CONFIG_CFI_CLANG_SHADOW enabled, a
shadow map that speeds up module look-ups by ~3x.
Clang implements indirect call checking using jump tables and
offers two methods of generating them. With canonical jump tables,
the compiler renames each address-taken function to <function>.cfi
and points the original symbol to a jump table entry, which passes
__cfi_check() validation. This isn’t compatible with stand-alone
assembly code, which the compiler doesn’t instrument, and would
result in indirect calls to assembly code to fail. Therefore, we
default to using non-canonical jump tables instead, where the compiler
generates a local jump table entry <function>.cfi_jt for each
address-taken function, and replaces all references to the function
with the address of the jump table entry.
Note that because non-canonical jump table addresses are local
to each component, they break cross-module function address
equality. Specifically, the address of a global function will be
different in each module, as it's replaced with the address of a local
jump table entry. If this address is passed to a different module,
it won’t match the address of the same function taken there. This
may break code that relies on comparing addresses passed from other
components.
CFI checking can be disabled in a function with the __nocfi attribute.
Additionally, CFI can be disabled for an entire compilation unit by
filtering out CC_FLAGS_CFI.
By default, CFI failures result in a kernel panic to stop a potential
exploit. CONFIG_CFI_PERMISSIVE enables a permissive mode, where the
kernel prints out a rate-limited warning instead, and allows execution
to continue. This option is helpful for locating type mismatches, but
should only be enabled during development.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-2-samitolvanen@google.com
Both KCOV and UBSAN use compiler instrumentation. If UBSAN detects a bug
in KCOV, it may cause infinite recursion via printk and other common
functions. We already don't instrument KCOV with KASAN/KCSAN for this
reason, don't instrument it with UBSAN as well.
As a side effect this also resolves the following gcc warning:
conflicting types for built-in function '__sanitizer_cov_trace_switch';
expected 'void(long unsigned int, void *)'
[-Wbuiltin-declaration-mismatch]
It's only reported when kcov.c is compiled with any of the sanitizers
enabled. Size of the arguments is correct, it's just that gcc uses 'long'
on 64-bit arches and 'long long' on 32-bit arches, while kernel type is
always 'long long'.
Link: https://lkml.kernel.org/r/20201209100152.2492072-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: Marco Elver <elver@google.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull ACPI updates from Rafael Wysocki:
"These update the ACPICA code in the kernel to upstream revision
20201113, fix and clean up some resources manipulation code, extend
the enumeration and gpio-line-names property documentation, clean up
the handling of _DEP during device enumeration, add a new backlight
DMI quirk, clean up transaction handling in the EC driver and make
some assorted janitorial changes.
Specifics:
- Update ACPICA code in the kernel to upstream revision 20201113 with
changes as follows:
* Add 5 new UUIDs to the known UUID table (Bob Moore)
* Remove extreaneous "the" in comments (Colin Ian King)
* Add function trace macros to improve debugging (Erik Kaneda)
* Fix interpreter memory leak (Erik Kaneda)
* Handle "orphan" _REG for GPIO OpRegions (Hans de Goede)
- Introduce resource_union() and resource_intersection() helpers and
clean up some resource-manipulation code with the help of them
(Andy Shevchenko)
- Revert problematic commit related to the handling of resources in
the ACPI core (Daniel Scally)
- Extend the ACPI device enumeration documentation and the
gpio-line-names _DSD property documentation, clean up the latter
(Flavio Suligoi)
- Clean up _DEP handling during device enumeration, modify the list
of _DEP exceptions and the handling of it and fix up terminology
related to _DEP (Hans de Goede, Rafael Wysocki)
- Eliminate in_interrupt() usage from the ACPI EC driver (Sebastian
Andrzej Siewior)
- Clean up the advance_transaction() routine and related code in the
ACPI EC driver (Rafael Wysocki)
- Add new backlight quirk for GIGABYTE GB-BXBT-2807 (Jasper St
Pierre)
- Make assorted janitorial changes in several ACPI-related pieces of
code (Hanjun Guo, Jason Yan, Punit Agrawal)"
* tag 'acpi-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (40 commits)
ACPI: scan: Fix up _DEP-related terminology with supplier/consumer
ACPI: scan: Drop INT3396 from acpi_ignore_dep_ids[]
ACPI: video: Add DMI quirk for GIGABYTE GB-BXBT-2807
Revert "ACPI / resources: Use AE_CTRL_TERMINATE to terminate resources walks"
ACPI: scan: Add PNP0D80 to the _DEP exceptions list
ACPI: scan: Call acpi_get_object_info() from acpi_add_single_object()
ACPI: scan: Add acpi_info_matches_hids() helper
ACPICA: Update version to 20201113
ACPICA: Interpreter: fix memory leak by using existing buffer
ACPICA: Add function trace macros to improve debugging
ACPICA: Also handle "orphan" _REG methods for GPIO OpRegions
ACPICA: Remove extreaneous "the" in comments
ACPICA: Add 5 new UUIDs to the known UUID table
resource: provide meaningful MODULE_LICENSE() in test suite
ASoC: Intel: catpt: Replace open coded variant of resource_intersection()
ACPI: processor: Drop duplicate setting of shared_cpu_map
ACPI: EC: Clean up status flags checks in advance_transaction()
ACPI: EC: Untangle error handling in advance_transaction()
ACPI: EC: Simplify error handling in advance_transaction()
ACPI: EC: Rename acpi_ec_is_gpe_raised()
...
Pull Kbuild updates from Masahiro Yamada:
- Support 'make compile_commands.json' to generate the compilation
database more easily, avoiding stale entries
- Support 'make clang-analyzer' and 'make clang-tidy' for static checks
using clang-tidy
- Preprocess scripts/modules.lds.S to allow CONFIG options in the
module linker script
- Drop cc-option tests from compiler flags supported by our minimal
GCC/Clang versions
- Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y
- Use sha1 build id for both BFD linker and LLD
- Improve deb-pkg for reproducible builds and rootless builds
- Remove stale, useless scripts/namespace.pl
- Turn -Wreturn-type warning into error
- Fix build error of deb-pkg when CONFIG_MODULES=n
- Replace 'hostname' command with more portable 'uname -n'
- Various Makefile cleanups
* tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
kbuild: Use uname for LINUX_COMPILE_HOST detection
kbuild: Only add -fno-var-tracking-assignments for old GCC versions
kbuild: remove leftover comment for filechk utility
treewide: remove DISABLE_LTO
kbuild: deb-pkg: clean up package name variables
kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n
kbuild: enforce -Werror=return-type
scripts: remove namespace.pl
builddeb: Add support for all required debian/rules targets
builddeb: Enable rootless builds
builddeb: Pass -n to gzip for reproducible packages
kbuild: split the build log of kallsyms
kbuild: explicitly specify the build id style
scripts/setlocalversion: make git describe output more reliable
kbuild: remove cc-option test of -Werror=date-time
kbuild: remove cc-option test of -fno-stack-check
kbuild: remove cc-option test of -fno-strict-overflow
kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles
kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan
kbuild: do not create built-in objects for external module builds
...
This change removes all instances of DISABLE_LTO from
Makefiles, as they are currently unused, and the preferred
method of disabling LTO is to filter out the flags instead.
Note added by Masahiro Yamada:
DISABLE_LTO was added as preparation for GCC LTO, but GCC LTO was
not pulled into the mainline. (https://lkml.org/lkml/2014/4/8/272)
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull RCU changes from Ingo Molnar:
- Debugging for smp_call_function()
- RT raw/non-raw lock ordering fixes
- Strict grace periods for KASAN
- New smp_call_function() torture test
- Torture-test updates
- Documentation updates
- Miscellaneous fixes
[ This doesn't actually pull the tag - I've dropped the last merge from
the RCU branch due to questions about the series. - Linus ]
* tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits)
smp: Make symbol 'csd_bug_count' static
kernel/smp: Provide CSD lock timeout diagnostics
smp: Add source and destination CPUs to __call_single_data
rcu: Shrink each possible cpu krcp
rcu/segcblist: Prevent useless GP start if no CBs to accelerate
torture: Add gdb support
rcutorture: Allow pointer leaks to test diagnostic code
rcutorture: Hoist OOM registry up one level
refperf: Avoid null pointer dereference when buf fails to allocate
rcutorture: Properly synchronize with OOM notifier
rcutorture: Properly set rcu_fwds for OOM handling
torture: Add kvm.sh --help and update help message
rcutorture: Add CONFIG_PROVE_RCU_LIST to TREE05
torture: Update initrd documentation
rcutorture: Replace HTTP links with HTTPS ones
locktorture: Make function torture_percpu_rwsem_init() static
torture: document --allcpus argument added to the kvm.sh script
rcutorture: Output number of elapsed grace periods
rcutorture: Remove KCSAN stubs
rcu: Remove unused "cpu" parameter from rcu_report_qs_rdp()
...
Pull networking updates from Jakub Kicinski:
- Add redirect_neigh() BPF packet redirect helper, allowing to limit
stack traversal in common container configs and improving TCP
back-pressure.
Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain.
- Expand netlink policy support and improve policy export to user
space. (Ge)netlink core performs request validation according to
declared policies. Expand the expressiveness of those policies
(min/max length and bitmasks). Allow dumping policies for particular
commands. This is used for feature discovery by user space (instead
of kernel version parsing or trial and error).
- Support IGMPv3/MLDv2 multicast listener discovery protocols in
bridge.
- Allow more than 255 IPv4 multicast interfaces.
- Add support for Type of Service (ToS) reflection in SYN/SYN-ACK
packets of TCPv6.
- In Multi-patch TCP (MPTCP) support concurrent transmission of data on
multiple subflows in a load balancing scenario. Enhance advertising
addresses via the RM_ADDR/ADD_ADDR options.
- Support SMC-Dv2 version of SMC, which enables multi-subnet
deployments.
- Allow more calls to same peer in RxRPC.
- Support two new Controller Area Network (CAN) protocols - CAN-FD and
ISO 15765-2:2016.
- Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit
kernel problem.
- Add TC actions for implementing MPLS L2 VPNs.
- Improve nexthop code - e.g. handle various corner cases when nexthop
objects are removed from groups better, skip unnecessary
notifications and make it easier to offload nexthops into HW by
converting to a blocking notifier.
- Support adding and consuming TCP header options by BPF programs,
opening the doors for easy experimental and deployment-specific TCP
option use.
- Reorganize TCP congestion control (CC) initialization to simplify
life of TCP CC implemented in BPF.
- Add support for shipping BPF programs with the kernel and loading
them early on boot via the User Mode Driver mechanism, hence reusing
all the user space infra we have.
- Support sleepable BPF programs, initially targeting LSM and tracing.
- Add bpf_d_path() helper for returning full path for given 'struct
path'.
- Make bpf_tail_call compatible with bpf-to-bpf calls.
- Allow BPF programs to call map_update_elem on sockmaps.
- Add BPF Type Format (BTF) support for type and enum discovery, as
well as support for using BTF within the kernel itself (current use
is for pretty printing structures).
- Support listing and getting information about bpf_links via the bpf
syscall.
- Enhance kernel interfaces around NIC firmware update. Allow
specifying overwrite mask to control if settings etc. are reset
during update; report expected max time operation may take to users;
support firmware activation without machine reboot incl. limits of
how much impact reset may have (e.g. dropping link or not).
- Extend ethtool configuration interface to report IEEE-standard
counters, to limit the need for per-vendor logic in user space.
- Adopt or extend devlink use for debug, monitoring, fw update in many
drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw, mv88e6xxx,
dpaa2-eth).
- In mlxsw expose critical and emergency SFP module temperature alarms.
Refactor port buffer handling to make the defaults more suitable and
support setting these values explicitly via the DCBNL interface.
- Add XDP support for Intel's igb driver.
- Support offloading TC flower classification and filtering rules to
mscc_ocelot switches.
- Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as
fixed interval period pulse generator and one-step timestamping in
dpaa-eth.
- Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3)
offload.
- Add Lynx PHY/PCS MDIO module, and convert various drivers which have
this HW to use it. Convert mvpp2 to split PCS.
- Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as
7-port Mediatek MT7531 IP.
- Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver,
and wcn3680 support in wcn36xx.
- Improve performance for packets which don't require much offloads on
recent Mellanox NICs by 20% by making multiple packets share a
descriptor entry.
- Move chelsio inline crypto drivers (for TLS and IPsec) from the
crypto subtree to drivers/net. Move MDIO drivers out of the phy
directory.
- Clean up a lot of W=1 warnings, reportedly the actively developed
subsections of networking drivers should now build W=1 warning free.
- Make sure drivers don't use in_interrupt() to dynamically adapt their
code. Convert tasklets to use new tasklet_setup API (sadly this
conversion is not yet complete).
* tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2583 commits)
Revert "bpfilter: Fix build error with CONFIG_BPFILTER_UMH"
net, sockmap: Don't call bpf_prog_put() on NULL pointer
bpf, selftest: Fix flaky tcp_hdr_options test when adding addr to lo
bpf, sockmap: Add locking annotations to iterator
netfilter: nftables: allow re-computing sctp CRC-32C in 'payload' statements
net: fix pos incrementment in ipv6_route_seq_next
net/smc: fix invalid return code in smcd_new_buf_create()
net/smc: fix valid DMBE buffer sizes
net/smc: fix use-after-free of delayed events
bpfilter: Fix build error with CONFIG_BPFILTER_UMH
cxgb4/ch_ipsec: Replace the module name to ch_ipsec from chcr
net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info
bpf: Fix register equivalence tracking.
rxrpc: Fix loss of final ack on shutdown
rxrpc: Fix bundle counting for exclusive connections
netfilter: restore NF_INET_NUMHOOKS
ibmveth: Identify ingress large send packets.
ibmveth: Switch order of ibmveth_helper calls.
cxgb4: handle 4-tuple PEDIT to NAT mode translation
selftests: Add VRF route leaking tests
...
Add infrastructure for an arch-specific CONFIG_HAVE_STATIC_CALL_INLINE
option, which is a faster version of CONFIG_HAVE_STATIC_CALL. At
runtime, the static call sites are patched directly, rather than using
the out-of-line trampolines.
Compared to out-of-line static calls, the performance benefits are more
modest, but still measurable. Steven Rostedt did some tracepoint
measurements:
https://lkml.kernel.org/r/20181126155405.72b4f718@gandalf.local.home
This code is heavily inspired by the jump label code (aka "static
jumps"), as some of the concepts are very similar.
For more details, see the comments in include/linux/static_call.h.
[peterz: simplified interface; merged trampolines]
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20200818135804.684334440@infradead.org
This commit adds an smp_call_function() torture test that repeatedly
invokes this function and complains if things go badly awry.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Add kernel module with user mode driver that populates bpffs with
BPF iterators.
$ mount bpffs /my/bpffs/ -t bpf
$ ls -la /my/bpffs/
total 4
drwxrwxrwt 2 root root 0 Jul 2 00:27 .
drwxr-xr-x 19 root root 4096 Jul 2 00:09 ..
-rw------- 1 root root 0 Jul 2 00:27 maps.debug
-rw------- 1 root root 0 Jul 2 00:27 progs.debug
The user mode driver will load BPF Type Formats, create BPF maps, populate BPF
maps, load two BPF programs, attach them to BPF iterators, and finally send two
bpf_link IDs back to the kernel.
The kernel will pin two bpf_links into newly mounted bpffs instance under
names "progs.debug" and "maps.debug". These two files become human readable.
$ cat /my/bpffs/progs.debug
id name attached
11 dump_bpf_map bpf_iter_bpf_map
12 dump_bpf_prog bpf_iter_bpf_prog
27 test_pkt_access
32 test_main test_pkt_access test_pkt_access
33 test_subprog1 test_pkt_access_subprog1 test_pkt_access
34 test_subprog2 test_pkt_access_subprog2 test_pkt_access
35 test_subprog3 test_pkt_access_subprog3 test_pkt_access
36 new_get_skb_len get_skb_len test_pkt_access
37 new_get_skb_ifindex get_skb_ifindex test_pkt_access
38 new_get_constant get_constant test_pkt_access
The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about
all BPF programs currently loaded in the system. This information is unstable
and will change from kernel to kernel as ".debug" suffix conveys.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200819042759.51280-4-alexei.starovoitov@gmail.com
Pull ptrace regset updates from Al Viro:
"Internal regset API changes:
- regularize copy_regset_{to,from}_user() callers
- switch to saner calling conventions for ->get()
- kill user_regset_copyout()
The ->put() side of things will have to wait for the next cycle,
unfortunately.
The balance is about -1KLoC and replacements for ->get() instances are
a lot saner"
* 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
regset: kill user_regset_copyout{,_zero}()
regset(): kill ->get_size()
regset: kill ->get()
csky: switch to ->regset_get()
xtensa: switch to ->regset_get()
parisc: switch to ->regset_get()
nds32: switch to ->regset_get()
nios2: switch to ->regset_get()
hexagon: switch to ->regset_get()
h8300: switch to ->regset_get()
openrisc: switch to ->regset_get()
riscv: switch to ->regset_get()
c6x: switch to ->regset_get()
ia64: switch to ->regset_get()
arc: switch to ->regset_get()
arm: switch to ->regset_get()
sh: convert to ->regset_get()
arm64: switch to ->regset_get()
mips: switch to ->regset_get()
sparc: switch to ->regset_get()
...
Pull generic kernel entry/exit code from Thomas Gleixner:
"Generic implementation of common syscall, interrupt and exception
entry/exit functionality based on the recent X86 effort to ensure
correctness of entry/exit vs RCU and instrumentation.
As this functionality and the required entry/exit sequences are not
architecture specific, sharing them allows other architectures to
benefit instead of copying the same code over and over again.
This branch was kept standalone to allow others to work on it. The
conversion of x86 comes in a seperate pull request which obviously is
based on this branch"
* tag 'core-entry-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
entry: Correct __secure_computing() stub
entry: Correct 'noinstr' attributes
entry: Provide infrastructure for work before transitioning to guest mode
entry: Provide generic interrupt entry/exit code
entry: Provide generic syscall exit function
entry: Provide generic syscall entry functionality
seccomp: Provide stub for __secure_computing()
Pull execve updates from Eric Biederman:
"During the development of v5.7 I ran into bugs and quality of
implementation issues related to exec that could not be easily fixed
because of the way exec is implemented. So I have been diggin into
exec and cleaning up what I can.
This cycle I have been looking at different ideas and different
implementations to see what is possible to improve exec, and cleaning
the way exec interfaces with in kernel users. Only cleaning up the
interfaces of exec with rest of the kernel has managed to stabalize
and make it through review in time for v5.9-rc1 resulting in 2 sets of
changes this cycle.
- Implement kernel_execve
- Make the user mode driver code a better citizen
With kernel_execve the code size got a little larger as the copying of
parameters from userspace and copying of parameters from userspace is
now separate. The good news is kernel threads no longer need to play
games with set_fs to use exec. Which when combined with the rest of
Christophs set_fs changes should security bugs with set_fs much more
difficult"
* 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (23 commits)
exec: Implement kernel_execve
exec: Factor bprm_stack_limits out of prepare_arg_pages
exec: Factor bprm_execve out of do_execve_common
exec: Move bprm_mm_init into alloc_bprm
exec: Move initialization of bprm->filename into alloc_bprm
exec: Factor out alloc_bprm
exec: Remove unnecessary spaces from binfmts.h
umd: Stop using split_argv
umd: Remove exit_umh
bpfilter: Take advantage of the facilities of struct pid
exit: Factor thread_group_exited out of pidfd_poll
umd: Track user space drivers with struct pid
bpfilter: Move bpfilter_umh back into init data
exec: Remove do_execve_file
umh: Stop calling do_execve_file
umd: Transform fork_usermode_blob into fork_usermode_driver
umd: Rename umd_info.cmdline umd_info.driver_name
umd: For clarity rename umh_info umd_info
umh: Separate the user mode driver and the user mode helper support
umh: Remove call_usermodehelper_setup_file.
...
