While looking at the disassembly for the epoll stuff I noticed that this
expands to quite a lot of code that the compiler can't optimize out for
LP64 (because it doesn't know that the "copy the argument into a local
and then use the local" bit isn't important).
There are two obvious options here. Something like this:
```
int signalfd64(int fd, const sigset64_t* mask, int flags) {
return __signalfd4(fd, mask, sizeof(*mask), flags);
}
int signalfd(int fd, const sigset_t* mask, int flags) {
#if defined(__LP64__)
return signalfd64(fd, mask, flags);
#else
SigSetConverter set = {.sigset = *mask};
return signalfd64(fd, &set.sigset64, flags);
#endif
}
```
Or something like this:
```
int signalfd64(int fd, const sigset64_t* mask, int flags) {
return __signalfd4(fd, mask, sizeof(*mask), flags);
}
#if defined(__LP64__)
__strong_alias(signalfd, signalfd64);
#else
int signalfd(int fd, const sigset_t* mask, int flags) {
SigSetConverter set = {};
set.sigset = *mask;
return signalfd64(fd, &set.sigset64, flags);
}
#endif
```
The former is slightly more verbose, but seems a bit more obvious, so I
initially went with that. (The former is more verbose in the generated
code too, given that the latter expands to _no_ code, just another symbol
pointing to the same code address.)
Having done that, I realized that slight changes to the interface would
let clang optimize away most/all of the overhead for LP64 with the only
preprocessor hackery being in SigSetConverter itself.
I also pulled out the legacy bsd `int` conversions since they're only
used in two (secret!) functions, so it's clearer to just have a separate
union for them. While doing so, I suppressed those functions for
riscv64, since there's no reason to keep carrying that mistake forward.
posix_spawn() is another simple case that doesn't actually benefit from
SigSetConverter, so I've given that its own anonymous union too.
Test: treehugger
Change-Id: Iaf67486da40d40fc53ec69717c3492ab7ab81ad6
The obsolete mips header rides again!
The most interesting part of this change is that I've removed the hack
that meant that all system call wrappers starting with `__` defaulted to
being hidden symbols. That's no longer useful given our linker scripts,
and it actively got in the way here because the public libc symbol
actually starts with `__` in glibc, and it would be weird and annoying
for developers if we chose a different name.
Test: strace
Change-Id: I230479787895e8e34f566ade36346a8241eea998
Investigation shows that the symbols that claimed to have been in 32-bit
builds one API level earlier than in 64-bit builds actually weren't ---
everything was actually API level 22. This patch fixes the libc.map.txt
to match reality, and then simplifies the __INTRODUCED_IN()
incantations.
Investigation also shows that we have a bunch of unused #defines, so
this patch removes the ones that don't correspond to functions we
actually expose.
Test: treehugger
Change-Id: I540dd0d1d9561cac17c55eb68a07bed58dd718fa
* Rationale
The question often comes up of how to use multiple time zones in C code.
If you're single-threaded, you can just use setenv() to manipulate $TZ.
toybox does this, for example. But that's not thread-safe in two
distinct ways: firstly, getenv() is not thread-safe with respect to
modifications to the environment (and between the way putenv() is
specified and the existence of environ, it's not obvious how to fully
fix that), and secondly the _caller_ needs to ensure that no other
threads are using tzset() or any function that behaves "as if" tzset()
was called (which is neither easy to determine nor easy to ensure).
This isn't a bigger problem because most of the time the right answer
is to stop pretending that libc is at all suitable for any i18n, and
switch to icu4c instead. (The NDK icu4c headers do not include ucal_*,
so this is not a realistic option for most applications.)
But what if you're somewhere in between? Like the rust chrono library,
for example? What then?
Currently their "least worst" option is to reinvent the entire wheel and
read our tzdata files. Which isn't a great solution for anyone, for
obvious maintainability reasons.
So it's probably time we broke the catch-22 here and joined NetBSD in
offering a less broken API than standard C has for the last 40 years.
Sure, any would-be caller will have to have a separate "is this
Android?" and even "is this API level >= 35?" path, but that will fix
itself sometime in the 2030s when developers can just assume "yes, it
is", whereas if we keep putting off exposing anything, this problem
never gets solved.
(No-one's bothered to try to implement the std::chrono::time_zone
functionality in libc++ yet, but they'll face a similar problem if/when
they do.)
* Implementation
The good news is that tzcode already implements these functions, so
there's relatively little here.
I've chosen not to expose `struct state` because `struct __timezone_t`
makes for clearer error messages, given that compiler diagnostics will
show the underlying type name (`struct __timezone_t*`) rather than the
typedef name (`timezone_t`) that's used in calling code.
I've moved us over to FreeBSD's wcsftime() rather than keep the OpenBSD
one building --- I've long wanted to only have one implementation here,
and FreeBSD is already doing the "convert back and forth, calling the
non-wide function in the middle" dance that I'd hoped to get round to
doing myself someday. This should mean that our strftime() and
wcsftime() behaviors can't easily diverge in future, plus macOS/iOS are
mostly FreeBSD, so any bugs will likely be interoperable with the other
major mobile operating system, so there's something nice for everyone
there!
The FreeBSD wcsftime() implementation includes a wcsftime_l()
implementation, so that's one stub we can remove. The flip side of that
is that it uses mbsrtowcs_l() and wcsrtombs_l() which we didn't
previously have. So expose those as aliases of mbsrtowcs() and
wcsrtombs().
Bug: https://github.com/chronotope/chrono/issues/499
Test: treehugger
Change-Id: Iee1b9d763ead15eef3d2c33666b3403b68940c3c
Nothing to see here --- you'll want to keep using POSIX clock_gettime()
and clock_getres() instead. But portable code might use this eventually,
and it's trivial, so let's add it anyway.
(The whole "zero as an error return" precluding the direct use of
Linux's CLOCK_ constants is what really makes this a terrible API ---
we're going to have to add explicit translation any time they add a
new base.)
Test: treehugger
Change-Id: Iddb6cbe67b67b2b10fdd8b5ee654896d23deee47
The recent header nullability additions and the corresponding source
cleanup made me notice that we're missing a couple of actions that most
of the other implementations have. They've also been added to the _next_
revision of POSIX, unchanged except for the removal of the `_np` suffix.
They're trivial to implement, the testing is quite simple too, and
if they're going to be in POSIX soon, having them accessible in older
versions of Android via __RENAME() seems useful. (No-one else has shipped
the POSIX names yet.)
Bug: http://b/152414297
Test: treehugger
Change-Id: I0d2a1e47fbd2e826cff9c45038928aa1b6fcce59
These APIs are exposed in the on-device libc.so's .dynsym table from R
and up (e.g. _Unwind_xxx@@LIBC_R), but they were only available in the
APEX and LLNDK stubs. Expose the symbols from the NDK stubs too so that
the LLVM toolchain build can build a libc++.so that imports the
unwinder from libc.so. (The platform/APEX libc++.so will become a
toolchain prebuilt.)
Eventually this change will also allows apps to use the unwinder from
libc.so rather than linking libunwind.a statically.
Bug: http://b/175635923
Test: treehugger
Change-Id: I7ba9cef9a4727b49dd717e25a0321bf2889694de
These have been aliases for strtoll() and strtoull() since L, by
accident. We've never exposed them in the headers, and they're unused by
any apps. Let's fix the inconsistency between libc.so and its headers by
removing the aliases.
Bug: https://github.com/android/ndk/issues/1803
Test: treehugger
Change-Id: I87de7831c04b3e450a44e9f0386cacb73793e393
We added this symbol somewhat inconsistently, with arm and x86-64 in one
release and arm64 in another. It doesn't really matter where we add
riscv64 (since there was no riscv64 at either of these now-historical
API levels), so arbitrarily go with the majority.
Signed-off-by: Mao Han <han_mao@linux.alibaba.com>
Signed-off-by: Xia Lifang <lifang_xia@linux.alibaba.com>
Signed-off-by: Chen Guoyin <chenguoyin.cgy@linux.alibaba.com>
Signed-off-by: Wang Chen <wangchen20@iscas.ac.cn>
Signed-off-by: Lu Xufan <luxufan@iscas.ac.cn>
Test: treehugger
Change-Id: I1ef1e0ebdbece728aaef52c08ee57cca1197cb95
The alternative would be to define an "lp64" shorthand like we have for
SYSCALLS.TXT, but since this functionality is only used by bionic and
old frameworks code to document historical oddities, it's unclear that
it's worth implementing. We shouldn't ever need architecture-specific
annotations again in future.
Signed-off-by: Mao Han <han_mao@linux.alibaba.com>
Signed-off-by: Xia Lifang <lifang_xia@linux.alibaba.com>
Signed-off-by: Chen Guoyin <chenguoyin.cgy@linux.alibaba.com>
Signed-off-by: Wang Chen <wangchen20@iscas.ac.cn>
Signed-off-by: Lu Xufan <luxufan@iscas.ac.cn>
Test: treehugger
Change-Id: Id64b1746e7490b2d7ad3e4627e9908c28f8f23ba
At the time I added <stdio_ext.h>, I just added what was on the man
page (which matched glibc), not realizing that musl and glibc had
slightly different functionality in their headers.
The toybox maintainer came up with a legitimate use case for this, for
which there is no portable workaround, so I'm adding it here. I'm not
adding the other functions that are in musl but not glibc for lack of a
motivating use case.
Bug: http://lists.landley.net/htdig.cgi/toybox-landley.net/2022-April/020864.html
Test: treehugger
Change-Id: I073baa86ff0271064d4e2f20a584d38787ead6b0
See:
https://man7.org/linux/man-pages/man2/close_range.2.html
Note: 'man close_range' documents 'flags' as unsigned int,
while glibc unistd.h as just 'int'. Picking 'int' to match glibc,
though it probably doesn't matter.
BYPASS_INCLUSIVE_LANGUAGE_REASON=man is a cli command
Test: TreeHugger
Bug: 229913920
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I1e2d1c8edc2ea28922d60f3ce3e534a784622cd1
Mbstowcs and wcstombs cannot get correct return value when called in the environment below api 21, and need to raise the API level to solve the problem.
Test: None
fix bug 1108 https://github.com/android/ndk/issues/1108
Change-Id: Iabcf1bff0be087288646687732ef68870630b48a
They're in glibc, though not in musl.
Also add basic doc comments to the whole of <sys/uio.h>.
Bug: http://b/203002492
Test: treehugger
Change-Id: Ic607f7f349e5b7c9bf66c25b7bd68f827da530d6
Also delete some fdsan code that attempts to check for the post-fork
state, but never will, because we update the cached pid upon fork.
Bug: http://b/174542867
Test: /data/nativetest64/bionic-unit-tests/bionic-unit-tests
Test: treehugger
Change-Id: I9b748dac9de9b4c741897d93e64d31737e52bf8e
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
This is already covered by the existing test by virtue of being used for
all threads.
Bug: http://b/168258494
Test: treehugger
Change-Id: I5c872fd7f30a4c79de1d70e7702f4b12d4e94cd3
(Based on proposal at https://sourceware.org/glibc/wiki/ThreadPropertiesAPI)
This includes API to:
- locate static and dynamic TLS
- register thread-exit and dynamic TLS creation/destruction callbacks
Change-Id: Icd9d29a5b2f47495395645e19d3b2c96826f19c8
POSIX added these GNU extensions for issue 8.
I've made these always inline without the usual "until API level X"
proviso because they're single instructions that the compiler can inline
and there's really no point providing these if they add function call
overhead --- everyone should just use __builtin_ffs() and friends
instead in that case.
Bug: https://austingroupbugs.net/view.php?id=617
Test: treehugger
Change-Id: I33fc4b8648ea25917329e81c1b4c60eb9a66d667
This function will be used by Scudo and GWP-ASan to efficiently collect
stack traces for frames built with frame pointers.
Bug: 135634846
Bug: 135772972
Change-Id: Ic63efdbafe11dfbb1226b5b4b403d53c4dbf28f3
Merged-In: Ic63efdbafe11dfbb1226b5b4b403d53c4dbf28f3
Add a hook that's called upon file descriptor creation to libc, and a
library that uses it to capture backtraces for file descriptor creation,
to make it easier to hunt down file descriptor leaks.
Currently, this doesn't capture all of the ways of creating a file
descriptor, but completeness isn't required for this to be useful as
long as leaked file descriptors are created with a function that is
tracked. The primary unhandled case is binder, which receives file
descriptors as a payload in a not-trivially-parsable byte blob, but
there's a chance that the leak we're currently trying to track down
isn't of a file descriptor received over binder, so leave that for
later.
Bug: http://b/140703823
Test: manual
Change-Id: I308a14c2e234cdba4207157b634ab6b8bc539dd9
(cherry picked from commit b7eccd4b15)
This supports the soong commit which causes most platform binaries to stop
statically linking against the unwinder implementation. The soong commit
message has more motivation for this change.
ARM32 uses LLVM libunwind, while all other platforms use libgcc as the
unwinder implementation. This matches the current choices of unwinders on
the various architectures, but means that apps which were directly linking
against the libc.so unwinder symbols on ARM32 are now using LLVM libunwind
instead of libgcc.
Set libc_headers sdk_version to 1 so that libunwind_llvm can depend on it,
and stop statically linking libunwind into libc_malloc_debug.
Bug: 144430859
Change-Id: I52c7f7893d93f500383aeb0b76086c3b6f1935a5
This commit removes several symbol versions (API 14 and 15) from
`libc.map.txt` because we no longer support NDK with those API levels.
This also matches the versioner annotations in the header files.
This commit also annotates twalk() with __INTRODUCED_IN(21). It was
accidentally removed in aosp/1157510.
Test: source development/vndk/tools/header-checker/android/envsetup.sh && \
source build/envsetup.sh && \
lunch aosp_arm64-userdebug && \
m versioner && \
./bionic/tools/versioner/run_tests.py
Change-Id: I211fe5b7b1b66793d5e76a8676f9d18825f96b5e
We have data that indicates that we no longer need to export the libgcc
unwinder's implementation detail symbols from libc.so, as well as the entire
unwinder interface from libm.so, so stop exporting them.
Bug: 144430859
Change-Id: Iebb591c4a121abe6368d9854ec96819abe70a006
The APIs that are tagged with # vndk are actually for LLNDK libraries.
Although LLNDK is part of VNDK, calling those APIs 'vndk' has given
users a wrong perception that the APIs don't need to be kept stable
because that's the norm for most of the VNDK libraries that are not
LLNDK.
In order to eliminate the misunderstanding, rename the tag to 'llndk' so
that people introducing new such API will realize what they are signing
themselves up for.
Bug: 143765505
Test: m
Merged-In: I56e49876410bd43723a80d0204a9aef21d20fca9
(cherry picked from commit 3e2cd44aa4)
Change-Id: I56e49876410bd43723a80d0204a9aef21d20fca9
As of I2037548cc2061e46c379931588194c21dfe234b4, these are no longer
used. Since they're new in R, we can remove them instead of keeping
backwards compat 'forever'. Take that opportunity now.
Bug: 141267932
Test: TreeHugger
Change-Id: I13f94cdcff6e75ad19b964be76445f113f79559b
These are old enough now that the latest devices will have kernels that
support them.
Also add basic doc comments to <sys/mman.h>.
Test: treehugger
Change-Id: I1b5ff5db0b6270f5c374287cac1d6a751a0259f5
This also adds _2-variants for these functions, for extra glorious
checking
Bug: 131861088
Test: mma
Change-Id: I80475ff4bb220c0c47894e9532426f53412f176f
Historical research (see bug) suggests that these functions were all in
22. The map file believed this with one (presumably typoed) exception,
but the header file didn't match the map file. It looks like the map was
correct (modulo the one typo), so fix up all the disagreement.
Bug: http://b/113618851
Test: treehugger
Change-Id: Ia579f4e6163206abfac79aa54dc98c792f00ee86
Add the malloc symbols used by libmemunreachable to the VNDK, and
make libc_malloc_debug_backtrace vendor_available.
Bug: 132302484
Test: m checkbuild
Change-Id: Ide555195afa084c13eaeaf0eab6ff90787b5f2d0
Added get_malloc_leak_info and free_malloc_leak_info for arm 32 bit
only so that the kindle app will continue to run.
Bug: 132175052
Test: Ran kindle app, read pdf file. Verified libKindleReaderJNI.so
Test: is loaded in memory properly.
Change-Id: Ib1ea3a37b3729f9bcc2739c5f3a584ea8f66d200
Merged-In: Ib1ea3a37b3729f9bcc2739c5f3a584ea8f66d200
(cherry picked from commit 235f35a266)
