Ard Biesheuvel
7290d58095
module: use relative references for __ksymtab entries ...
An ordinary arm64 defconfig build has ~64 KB worth of __ksymtab entries,
each consisting of two 64-bit fields containing absolute references, to
the symbol itself and to a char array containing its name, respectively.
When we build the same configuration with KASLR enabled, we end up with an
additional ~192 KB of relocations in the .init section, i.e., one 24 byte
entry for each absolute reference, which all need to be processed at boot
time.
Given how the struct kernel_symbol that describes each entry is completely
local to module.c (except for the references emitted by EXPORT_SYMBOL()
itself), we can easily modify it to contain two 32-bit relative references
instead. This reduces the size of the __ksymtab section by 50% for all
64-bit architectures, and gets rid of the runtime relocations entirely for
architectures implementing KASLR, either via standard PIE linking (arm64)
or using custom host tools (x86).
Note that the binary search involving __ksymtab contents relies on each
section being sorted by symbol name. This is implemented based on the
input section names, not the names in the ksymtab entries, so this patch
does not interfere with that.
Given that the use of place-relative relocations requires support both in
the toolchain and in the module loader, we cannot enable this feature for
all architectures. So make it dependent on whether
CONFIG_HAVE_ARCH_PREL32_RELOCATIONS is defined.
Link: http://lkml.kernel.org/r/20180704083651.24360-4-ard.biesheuvel@linaro.org
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Ingo Molnar <mingo@kernel.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: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
bpf: fix redirect to map under tail calls
2018-08-17 15:56:23 -07:00
kernfs: allow creating kernfs objects with arbitrary uid/gid
2018-07-20 23:44:35 -07:00
kconfig: tinyconfig: remove stale stack protector fixups
2018-06-15 07:15:28 +09:00
treewide: kzalloc() -> kcalloc()
2018-06-12 16:19:22 -07:00
kernel/dma: remove unsupported gfp_mask parameter from dma_alloc_from_contiguous()
2018-08-17 16:20:32 -07:00
Updates for v4.19:
2018-08-20 18:32:00 -07:00
gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT
2018-06-08 18:56:02 +09:00
Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 10:47:26 -07:00
Merge branch 'for-4.19/upstream' into for-linus
2018-08-20 18:33:50 +02:00
Updates for v4.19:
2018-08-20 18:32:00 -07:00
Power management updates for 4.19-rc1
2018-08-14 13:12:24 -07:00
drm pull for 4.19-rc1
2018-08-15 17:39:07 -07:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
Updates for v4.19:
2018-08-20 18:32:00 -07:00
Merge branch 'parisc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
2018-08-13 19:18:02 -07:00
Updates for v4.19:
2018-08-20 18:32:00 -07:00
kernel/acct.c: fix the acct->needcheck check in check_free_space()
2018-01-04 16:45:09 -08:00
kernel/async.c: revert "async: simplify lowest_in_progress()"
2018-02-06 18:32:44 -08:00
audit: use ktime_get_coarse_real_ts64() for timestamps
2018-07-17 14:45:08 -04:00
audit: track the owner of the command mutex ourselves
2018-02-23 11:22:22 -05:00
fsnotify: add fsnotify_add_inode_mark() wrappers
2018-05-18 14:58:22 +02:00
\n
2018-08-17 09:41:28 -07:00
audit: fix use-after-free in audit_add_watch
2018-07-18 11:43:36 -04:00
audit: rename FILTER_TYPE to FILTER_EXCLUDE
2018-06-19 10:39:54 -04:00
audit/stable-4.18 PR 20180814
2018-08-15 10:46:54 -07:00
time: Enable get/put_compat_itimerspec64 always
2018-06-24 14:39:47 +02:00
cpu/hotplug: Non-SMP machines do not make use of booted_once
2018-08-14 15:00:00 -07:00
kernel/crash_core.c: print timestamp using time64_t
2018-08-22 10:52:47 -07:00
delayacct: Use raw_spinlocks
2018-04-27 14:34:51 +02:00
proc: introduce proc_create_single{,_data}
2018-05-16 07:23:35 +02:00
proc: introduce proc_create_single{,_data}
2018-05-16 07:23:35 +02:00
kernel: use kernel_wait4() instead of sys_wait4()
2018-04-02 20:14:51 +02:00
extable: Make init_kernel_text() global
2018-02-21 16:54:06 +01:00
bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe
2018-06-21 12:33:19 +02:00
kernel/hung_task.c: allow to set checking interval separately from timeout
2018-08-22 10:52:47 -07:00
PM / reboot: Eliminate race between reboot and suspend
2018-08-06 12:35:20 +02:00
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
kernel: make groups_sort calling a responsibility group_info allocators
2017-12-14 16:00:49 -08:00
kernel/hung_task.c: allow to set checking interval separately from timeout
2018-08-22 10:52:47 -07:00
memremap: split devm_memremap_pages() and memremap() infrastructure
2018-05-15 23:08:33 -07:00
irq/work: Improve the flag definitions
2018-01-08 19:43:15 +01:00
jump_label: Disable jump labels in __exit code
2018-03-20 08:57:17 +01:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
2018-02-01 13:36:15 -08:00
kconfig: include kernel/Kconfig.preempt from init/Kconfig
2018-08-02 08:06:54 +09:00
sched/core / kcov: avoid kcov_area during task switch
2018-06-15 07:55:24 +09:00
kexec: add call to LSM hook in original kexec_load syscall
2018-07-16 12:31:57 -07:00
kexec: yield to scheduler when loading kimage segments
2018-06-15 07:55:24 +09:00
treewide: Use array_size() in vzalloc()
2018-06-12 16:19:22 -07:00
kprobes: Replace %p with other pointer types
2018-06-21 17:33:42 +02:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
kbuild: move bin2c back to scripts/ from scripts/basic/
2018-07-18 01:18:05 +09:00
kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN
2018-08-17 16:20:30 -07:00
modsign: log module name in the event of an error
2018-07-02 11:36:17 +02:00
module: use relative references for __ksymtab entries
2018-08-22 10:52:47 -07:00
modsign: log module name in the event of an error
2018-07-02 11:36:17 +02:00
padata: add SPDX identifier
2018-01-05 18:43:00 +11:00
Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables
2018-06-14 12:21:18 +09:00
kernel/params.c: downgrade warning for unsafe parameters
2018-04-11 10:28:37 -07:00
xarray: add the xa_lock to the radix_tree_root
2018-04-11 10:28:39 -07:00
Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2018-04-03 19:15:32 -07:00
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
PM / reboot: Eliminate race between reboot and suspend
2018-08-06 12:35:20 +02:00
kernel/relay.c: change return type to vm_fault_t
2018-06-15 07:55:24 +09:00
libnvdimm for 4.18
2018-06-08 17:21:52 -07:00
rseq: uapi: Declare rseq_cs field as union, update includes
2018-07-10 22:18:52 +02:00
audit/stable-4.18 PR 20180605
2018-06-06 16:34:00 -07:00
signal: Remove no longer required irqsave/restore
2018-06-10 06:14:01 +02:00
cpu/hotplug: Fix SMT supported evaluation
2018-08-07 12:25:30 +02:00
smpboot: Remove cpumask from the API
2018-07-03 09:20:44 +02:00
nohz: Fix missing tick reprogram when interrupting an inline softirq
2018-08-03 15:52:10 +02:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-08-13 11:25:07 -07:00
sysinfo: Remove get_monotonic_boottime()
2018-06-19 09:56:27 +02:00
Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2018-06-10 10:17:09 -07:00
kernel/hung_task.c: allow to set checking interval separately from timeout
2018-08-22 10:52:47 -07:00
staging: irda: remove remaining remants of irda code removal
2018-04-16 11:26:49 +02:00
locking/barriers: Convert users of lockless_dereference() to READ_ONCE()
2017-12-17 13:57:15 +01:00
pids: introduce find_get_task_by_vpid() helper
2018-02-06 18:32:46 -08:00
kprobes: Remove jprobe API implementation
2018-06-21 12:33:05 +02:00
torture: Keep old-school dmesg format
2018-06-25 11:30:10 -07:00
tracepoints: Free early tracepoints after RCU is initialized
2018-08-10 15:32:53 -04:00
headers: untangle kmemleak.h from mm.h
2018-04-05 21:36:27 -07:00
fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers
2018-04-02 20:15:59 +02:00
kernel: provide ksys_*() wrappers for syscalls called by kernel/uid16.c
2018-04-02 20:15:30 +02:00
umh: fix race condition
2018-06-07 16:56:28 -04:00
userns: use irqsave variant of refcount_dec_and_lock()
2018-08-22 10:52:47 -07:00
treewide: kmalloc() -> kmalloc_array()
2018-06-12 16:19:22 -07:00
uts: create "struct uts_namespace" from kmem_cache
2018-04-11 10:28:35 -07:00
watchdog/softlockup: Fix cpu_stop_queue_work() double-queue bug
2018-07-15 23:51:19 +02:00
watchdog: Reduce message verbosity
2018-08-03 12:19:08 +02:00
treewide: kzalloc() -> kcalloc()
2018-06-12 16:19:22 -07:00
workqueue: Set worker->desc to workqueue name by default
2018-05-18 08:47:13 -07:00
7290d58095