A constructor or destructor function with an integral priority is
placed in an .init_array or .fini_array section with the priority
suffixed to the section name:
- __attribute__((constructor)) ==> .init_array
- __attribute__((constructor(42))) ==> .init_array.42
The suffixed init/fini sections appear before the unsuffixed sections,
so the prioritized functions appeared before the __{INIT,FINI}_ARRAY__
symbols and were dropped when the symbols were used.
The (static) linker doesn't recognize priority suffixes on
.preinit_array.
This bug affected .init_array and .fini_array for static executables.
For dynamic executables, only .fini_array was affected, because
.init_array is handled by the dynamic loader instead, which uses
DT_INIT_ARRAY[SZ]. For DSOs, neither is affected, because the two
sections are only handled by the dynamic loader.
This patch also fixes a minor inconsistency where dynamic init/preinit
were passed argc/argv/envp, but static were not.
Bug: http://b/170983066
Test: bionic-unit-tests
Change-Id: I0fffa776e5d9bdb6f8af06b4c1af148236742fef
Since (a) they're not a README.md and (b) they moved git project
recently, it's really hard to find these docs even if you know they
exist, which no-one does.
Test: N/A
Change-Id: Ic12e47ef5eb09e692ac0974b1d33bc5dc83d1028
The functions now read /etc/group and /etc/passwd on host machines.
Android-specific IDs are not recognized in the host.
getpwent and getgrent are still not working though. They require a
bigger refactoring to sequentially advance in the database files.
Bug: 171718702
Test: run assemble_cvd in aosp_cf_arm64_phone
Change-Id: Ie8da382a467bbd0bffac7b4b8592cd871db80181
/system/bin/sh exists only on Android. When Bionic is built for the
host, use the standard /bin/sh.
Bug: 159685774
Test: run aosp_cf_arm64_phone on rockpi4
Change-Id: Idf4028c134abc128f203fc4d3be591f06b8fe8ff
A lot of these benchmarks predate DoNotOptimize and rolled their own
hacks.
Bug: http://b/148307629
Test: ran benchmarks before & after and got similar results
Change-Id: If44699d261b687f6253af709edda58f4c90fb285
When an array element is added or removed, make only the relevant page
writable, rather than the entire array. The entire array is still made
writable during recompaction and expansion.
This change fixes most of a large regression in __cxa_atexit runtime
(blueline, taskset 10, performance governor, 100000 registrations,
times are in seconds)
- Q: _Exit=0.292380, exit=0.626801
- R: _Exit=28.435082, exit=95.785110
- new: _Exit=0.352285, exit=0.713893
Test: bionic unit tests
Test: adb shell taskset 10 \
/data/benchmarktest64/bionic-spawn-benchmarks/bionic-spawn-benchmarks \
--benchmark_filter='atexit' \
--benchmark_display_aggregates_only=true \
--benchmark_repetitions=10
Bug: http://b/168043760
Change-Id: I88cc15c29c9890b422b7f621f29f98a03ca1f886
Instead of assuming a module with the .llndk suffix exists, add an
llndk_stubs property to every cc_library module that has a
corresponding llndk_library. Also rename the llndk_library to have
an explicit .llndk suffix.
Bug: 170784825
Test: no changes to build.ninja (excluding comments) or Android-${TARGET_PRODUCT}.mk
Change-Id: Ib5453472a09ebc64818ceb69bcbe1184720ce86a
The benchmark calls __cxa_atexit 100000 times, then either exits early
without calling the destructors (_Exit) or exits normally, calling them
(exit).
Test: mmma bionic/benchmarks/spawn
Change-Id: I41fe702d6ef11acb7a1dec95bf546b5dc693bd4a
pthread_cond_pulse would unconditionally call futex, which meant that
a number of processes were spending a significant amount of time in
pthread_cond_broadcast and pthread_cond_signal when there were no
threads waiting on that pthread_cond_t.
This change adds a counter to the 64-bit pthread_cond_t struct and
only calls futex() in cases where there is a nonzero waiter count. The
32-bit pthread_cond_t is unchanged due to compatibility reasons.
Test: no pthread_cond_broadcast/signal stacks without try_to_wake_up
in SurfaceFlinger
bug: 168831708
Change-Id: I105e1345cd2a3a75f98cd0acf316e790ba1716f0
In order to disable memory initialization for a process, the following
command can be used:
android_mallopt(M_DISABLE_MEMORY_MITIGATIONS, nullptr, 0);
Since this is needed in vendor processes, this is exposing this
functionality to llndk. For convenience (and adding standard logging),
a helper function is being added into libcutils in order to use this,
w/o having to get into so many details.
Bug: 166675194
Test: use function from libcutils
Change-Id: Ia816089a9f3469c50c70afaa7244abeac5a51dcd
Introduce an android_mallopt(M_DISABLE_MEMORY_MITIGATIONS) API call
that may be used to disable zero- or pattern-init on non-MTE hardware,
or memory tagging on MTE hardware. The intent is that this function
may be called at any time, including when there are multiple threads
running.
Disabling zero- or pattern-init is quite trivial, we just need to set
a global variable to 0 via a Scudo API call (although there will be
some separate work required on the Scudo side to make this operation
thread-safe).
It is a bit more tricky to disable MTE across a process, because
the kernel does not provide an API for disabling tag checking in all
threads in a process, only per-thread. We need to send a signal to each
of the process's threads with a handler that issues the required prctl
call, and lock thread creation for the duration of the API call to
avoid races between thread enumeration and calls to pthread_create().
Bug: 135772972
Change-Id: I81ece86ace916eb6b435ab516cd431ec4b48a3bf
