Jason Baron
e1452b607c
livepatch: Add atomic replace ...
Sometimes we would like to revert a particular fix. Currently, this
is not easy because we want to keep all other fixes active and we
could revert only the last applied patch.
One solution would be to apply new patch that implemented all
the reverted functions like in the original code. It would work
as expected but there will be unnecessary redirections. In addition,
it would also require knowing which functions need to be reverted at
build time.
Another problem is when there are many patches that touch the same
functions. There might be dependencies between patches that are
not enforced on the kernel side. Also it might be pretty hard to
actually prepare the patch and ensure compatibility with the other
patches.
Atomic replace && cumulative patches:
A better solution would be to create cumulative patch and say that
it replaces all older ones.
This patch adds a new "replace" flag to struct klp_patch. When it is
enabled, a set of 'nop' klp_func will be dynamically created for all
functions that are already being patched but that will no longer be
modified by the new patch. They are used as a new target during
the patch transition.
The idea is to handle Nops' structures like the static ones. When
the dynamic structures are allocated, we initialize all values that
are normally statically defined.
The only exception is "new_func" in struct klp_func. It has to point
to the original function and the address is known only when the object
(module) is loaded. Note that we really need to set it. The address is
used, for example, in klp_check_stack_func().
Nevertheless we still need to distinguish the dynamically allocated
structures in some operations. For this, we add "nop" flag into
struct klp_func and "dynamic" flag into struct klp_object. They
need special handling in the following situations:
+ The structures are added into the lists of objects and functions
immediately. In fact, the lists were created for this purpose.
+ The address of the original function is known only when the patched
object (module) is loaded. Therefore it is copied later in
klp_init_object_loaded().
+ The ftrace handler must not set PC to func->new_func. It would cause
infinite loop because the address points back to the beginning of
the original function.
+ The various free() functions must free the structure itself.
Note that other ways to detect the dynamic structures are not considered
safe. For example, even the statically defined struct klp_object might
include empty funcs array. It might be there just to run some callbacks.
Also note that the safe iterator must be used in the free() functions.
Otherwise already freed structures might get accessed.
Special callbacks handling:
The callbacks from the replaced patches are _not_ called by intention.
It would be pretty hard to define a reasonable semantic and implement it.
It might even be counter-productive. The new patch is cumulative. It is
supposed to include most of the changes from older patches. In most cases,
it will not want to call pre_unpatch() post_unpatch() callbacks from
the replaced patches. It would disable/break things for no good reasons.
Also it should be easier to handle various scenarios in a single script
in the new patch than think about interactions caused by running many
scripts from older patches. Not to say that the old scripts even would
not expect to be called in this situation.
Removing replaced patches:
One nice effect of the cumulative patches is that the code from the
older patches is no longer used. Therefore the replaced patches can
be removed. It has several advantages:
+ Nops' structs will no longer be necessary and might be removed.
This would save memory, restore performance (no ftrace handler),
allow clear view on what is really patched.
+ Disabling the patch will cause using the original code everywhere.
Therefore the livepatch callbacks could handle only one scenario.
Note that the complication is already complex enough when the patch
gets enabled. It is currently solved by calling callbacks only from
the new cumulative patch.
+ The state is clean in both the sysfs interface and lsmod. The modules
with the replaced livepatches might even get removed from the system.
Some people actually expected this behavior from the beginning. After all
a cumulative patch is supposed to "completely" replace an existing one.
It is like when a new version of an application replaces an older one.
This patch does the first step. It removes the replaced patches from
the list of patches. It is safe. The consistency model ensures that
they are no longer used. By other words, each process works only with
the structures from klp_transition_patch.
The removal is done by a special function. It combines actions done by
__disable_patch() and klp_complete_transition(). But it is a fast
track without all the transaction-related stuff.
Signed-off-by: Jason Baron <jbaron@akamai.com>
[pmladek@suse.com: Split, reuse existing code, simplified]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2019-01-11 20:51:24 +01:00
dmaengine-4.21-rc1
2019-01-01 15:45:48 -08:00
Char/Misc driver patches for 4.21-rc1
2018-12-28 20:54:57 -08:00
This is the bulk of GPIO changes for the v4.21 kernel series:
2018-12-28 20:00:21 -08:00
irqchip: Add driver for Cirrus Logic Madera codecs
2018-12-18 14:06:56 +00:00
power supply and reset changes for the v4.21 series
2018-12-28 20:22:45 -08:00
4.21 merge window pull request
2018-12-28 14:57:10 -08:00
MMC core:
2018-12-28 16:52:18 -08:00
Char/Misc driver patches for 4.21-rc1
2018-12-28 20:54:57 -08:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
2018-12-20 18:20:26 -08:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
2019-01-03 12:53:47 -08:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
2019-01-02 18:56:59 -08:00
power supply and reset changes for the v4.21 series
2018-12-28 20:22:45 -08:00
fork: fix some -Wmissing-prototypes warnings
2019-01-04 13:13:47 -08:00
MMC core:
2018-12-28 16:52:18 -08:00
NFS client updates for Linux 4.21
2019-01-02 16:35:23 -08:00
- Improve the over-current handling for imx
2018-12-17 13:58:44 +01:00
Device properties framework updates for 4.21-rc1
2018-12-25 15:01:46 -08:00
misc: cardreader: add new Alcor Micro Cardreader PCI driver
2018-12-17 08:26:24 +01:00
writeback: don't decrement wb->refcnt if !wb->bdi
2018-12-28 12:11:46 -08:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2019-01-05 13:18:59 -08:00
blkcg: clean up blkg_tryget_closest()
2018-12-21 08:47:05 -07:00
block: make request_to_qc_t public
2018-12-18 17:50:47 +01:00
block: make request_to_qc_t public
2018-12-18 17:50:47 +01:00
SCSI misc on 20181224
2018-12-28 14:48:06 -08:00
bpf: prevent out of bounds speculation on pointer arithmetic
2019-01-02 16:01:24 -08:00
bpf: enable cgroup local storage map pretty print with kind_flag
2018-12-18 01:11:59 +01:00
build_bug.h: remove most of dummy BUILD_BUG_ON stubs for Sparse
2019-01-04 13:13:45 -08:00
Merge branches 'clk-imx7ulp', 'clk-imx6-fixes', 'clk-imx-fixes', 'clk-imx8qxp' and 'clk-imx8mq' into clk-next
2018-12-14 13:34:47 -08:00
y2038: signal: Add compat_sys_rt_sigtimedwait_time64
2018-12-18 16:13:04 +01:00
kasan: add CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS
2018-12-28 12:11:43 -08:00
kasan: add CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS
2018-12-28 12:11:43 -08:00
Revert "x86/objtool: Use asm macros to work around GCC inlining bugs"
2018-12-19 12:00:23 +01:00
kasan: add CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS
2018-12-28 12:11:43 -08:00
include/linux/compiler_types.h: don't pollute userspace with macro definitions
2018-12-14 16:57:16 +01:00
cred: allow get_cred() and put_cred() to be given NULL.
2018-12-19 13:52:44 -05:00
crypto: skcipher - remove remnants of internal IV generators
2018-12-23 11:52:45 +08:00
driver core: Introduce device_iommu_mapped() function
2018-12-17 10:38:43 +01:00
DMA mapping updates for Linux 4.21
2018-12-28 14:12:21 -08:00
drbd: introduce P_ZEROES (REQ_OP_WRITE_ZEROES on the "wire")
2018-12-20 09:51:31 -07:00
Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2019-01-02 09:43:14 -08:00
binder: fix use-after-free due to ksys_close() during fdget()
2018-12-19 09:40:13 +01:00
bpf: enable access to ax register also from verifier rewrite
2019-01-02 16:01:24 -08:00
Fonts: New Terminus large console font
2018-12-19 10:42:08 +01:00
Merge branch 'akpm' (patches from Andrew)
2018-12-28 16:55:46 -08:00
Tracing changes for v4.21:
2018-12-31 11:46:59 -08:00
lib/genalloc.c: fix allocation of aligned buffer from non-aligned chunk
2019-01-04 13:13:46 -08:00
drbd: Avoid Clang warning about pointless switch statment
2018-12-20 09:51:31 -07:00
include/linux/gfp.h: fix typo
2018-12-28 12:11:52 -08:00
mm: convert totalram_pages and totalhigh_pages variables to atomic
2018-12-28 12:11:47 -08:00
mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
2018-12-28 12:11:52 -08:00
mm, thp, proc: report THP eligibility for each vma
2018-12-28 12:11:50 -08:00
hwmon: Introduce SENSOR_DEVICE_ATTR_{RO, RW, WO} and variants
2018-12-16 15:13:22 -08:00
mac80211: update HE operation fields to D3.0
2018-12-18 14:19:00 +01:00
net: unbreak CONFIG_RETPOLINE=n builds
2018-12-17 09:19:49 -08:00
genirq/affinity: Add is_managed to struct irq_affinity_desc
2018-12-19 11:32:08 +01:00
iommu: Consolitate ->add/remove_device() calls
2018-12-17 12:47:50 +01:00
genirq/core: Introduce struct irq_affinity_desc
2018-12-19 11:32:08 +01:00
genirq: Fix various typos in comments
2018-12-18 14:22:28 +01:00
genirq/core: Introduce struct irq_affinity_desc
2018-12-19 11:32:08 +01:00
kasan: add __must_check annotations to kasan hooks
2018-12-28 12:11:44 -08:00
kernel/sysctl: add panic_print into sysctl
2019-01-04 13:13:47 -08:00
Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-12-26 17:03:51 -08:00
kgdb/treewide: constify struct kgdb_arch arch_kgdb_ops
2018-12-30 08:33:06 +00:00
Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-12-26 17:03:51 -08:00
kvm: Change offset in kvm_write_guest_offset_cached to unsigned
2018-12-21 11:28:22 +01:00
LEDs for 4.21-rc1
2018-12-25 14:52:50 -08:00
scsi: flip the default on use_clustering
2018-12-18 23:13:12 -05:00
acpi/nfit, libnvdimm/security: add Intel DSM 1.8 master passphrase support
2018-12-21 12:44:41 -08:00
livepatch: Add atomic replace
2019-01-11 20:51:24 +01:00
LSM: new method: ->sb_add_mnt_opt()
2018-12-21 11:50:02 -05:00
mailbox: Support blocking transfers in atomic context
2018-12-21 22:31:26 -06:00
mailbox: Support blocking transfers in atomic context
2018-12-21 22:31:26 -06:00
mm/memblock.c: skip kmemleak for kasan_init()
2018-12-28 12:11:49 -08:00
mm, oom: add oom victim's memcg to the oom context information
2018-12-28 12:11:48 -08:00
include/linux/memory_hotplug.h: remove duplicate declaration of offline_pages()
2018-12-28 12:11:50 -08:00
mm/hmm: fix memremap.h, move dev_page_fault_t callback to hmm
2018-12-28 12:11:52 -08:00
mm: migrate: drop unused argument of migrate_page_move_mapping()
2018-12-28 12:11:51 -08:00
fs: don't open code lru_to_page()
2019-01-04 13:13:48 -08:00
fs: don't open code lru_to_page()
2019-01-04 13:13:48 -08:00
mm: introduce common STRUCT_PAGE_MAX_SHIFT define
2018-12-14 15:05:45 -08:00
mm/mmu_notifier: use structure for invalidate_range_start/end calls v2
2018-12-28 12:11:50 -08:00
mm, hotplug: move init_currently_empty_zone() under zone_span_lock protection
2018-12-28 12:11:49 -08:00
Add initial support for I3C along with 2 I3C master controller drivers.
2018-12-25 12:26:34 -08:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
2018-12-27 13:04:52 -08:00
vfs: Separate changing mount flags full remount
2018-12-20 16:32:56 +00:00
genirq/core: Introduce struct irq_affinity_desc
2018-12-19 11:32:08 +01:00
net: rtnetlink: support for fdb get
2018-12-16 14:42:34 -08:00
net: convert bridge_nf to use skb extension infrastructure
2018-12-19 11:21:37 -08:00
linux/netlink.h: drop unnecessary extern prefix
2018-12-20 16:43:54 -08:00
NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.
2018-12-19 13:52:46 -05:00
NFS/SUNRPC: don't lookup machine credential until rpcauth_bindcred().
2018-12-19 13:52:45 -05:00
NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.
2018-12-19 13:52:46 -05:00
Merge tag 'devicetree-for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
2018-12-28 20:08:34 -08:00
mm, oom: reorganize the oom report in dump_header
2018-12-28 12:11:48 -08:00
kasan, mm, arm64: tag non slab memory allocated via pagealloc
2018-12-28 12:11:44 -08:00
/proc/kpagecount: return 0 for special pages that are never mapped
2018-12-28 12:11:50 -08:00
mm: only report isolation failures when offlining memory
2018-12-28 12:11:46 -08:00
mm/pageblock: throw compile error if pageblock_bits cannot hold MIGRATE_TYPES
2018-12-28 12:11:51 -08:00
mm: put_and_wait_on_page_locked() while page is migrated
2018-12-28 12:11:48 -08:00
Char/Misc driver patches for 4.21-rc1
2018-12-28 20:54:57 -08:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
2018-12-27 13:04:52 -08:00
phy.h: fix obvious errors in doc and kerneldoc content
2018-12-27 16:29:31 -08:00
Fixed PHY: Add fixed_phy_change_carrier()
2018-12-17 11:24:32 -08:00
PM-runtime: Switch autosuspend over to using hrtimers
2018-12-19 10:31:50 +01:00
PM-runtime: Switch autosuspend over to using hrtimers
2018-12-19 10:31:50 +01:00
include/linux/printk.h: drop silly "static inline asmlinkage" from dump_stack()
2019-01-04 13:13:46 -08:00
ptr_ring: wrap back ->producer in __ptr_ring_swap_queue()
2019-01-01 11:58:33 -08:00
regmap: irq: add an option to clear status registers on unmask
2018-12-19 18:38:13 +00:00
Remove 'type' argument from access_ok() function
2019-01-03 18:57:57 -08:00
rtc: enforce rtc_timer_init private_data type
2018-12-18 22:53:29 +01:00
sbitmap: add helpers for add/del wait queue handling
2018-12-20 12:17:05 -07:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-12-26 14:56:10 -08:00
LSM: new method: ->sb_add_mnt_opt()
2018-12-21 11:50:02 -05:00
serial: 8250: Rate limit serial port rx interrupts during input overruns
2018-12-17 16:02:57 +01:00
for-4.21/block-20181221
2018-12-28 13:19:59 -08:00
bpf: sk_msg, fix socket data_ready events
2018-12-20 23:47:09 +01:00
A fairly normal cycle for documentation stuff. We have a new
2018-12-29 11:21:49 -08:00
mm: move obj_to_index to include/linux/slab_def.h
2018-12-28 12:11:44 -08:00
y2038: more syscalls and cleanups
2018-12-28 12:45:04 -08:00
string.h: Add str_has_prefix() helper function
2018-12-22 22:50:29 -05:00
mm/swap: use nr_node_ids for avail_lists in swap_info_struct
2018-12-28 12:11:47 -08:00
Merge branch 'next-seccomp' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2019-01-02 09:48:13 -08:00
timekeeping: remove timespec_add/timespec_del
2018-12-18 16:13:05 +01:00
timekeeping: remove obsolete time accessors
2018-12-18 16:13:05 +01:00
timekeeping: remove obsolete time accessors
2018-12-18 16:13:05 +01:00
bpf: support raw tracepoints in modules
2018-12-18 14:08:12 -08:00
make 'user_access_begin()' do 'access_ok()'
2019-01-04 12:56:09 -08:00
include/linux/vmstat.h: remove unused page state adjustment macro
2018-12-28 12:11:51 -08:00
Watchdog: remove outdated comment
2018-12-22 12:15:29 +01:00
xxHash: create arch dependent 32/64-bit xxhash()
2018-12-28 12:11:46 -08:00
