Commit graph

12 commits

Author SHA1 Message Date
Ryan Prichard
7752bcb234 Move the abort message to libc_shared_globals
__libc_shared_globals() is available in dynamic modules as soon as
relocation has finished (i.e. after ifuncs run). Before ifuncs have run,
the android_set_abort_message() function already doesn't work because it
calls public APIs via the PLT. (If this matters, we can use a static
bool variable to enable android_set_abort_message after libc
initialization).

__libc_shared_globals() is hidden, so it's available in the linker
immediately (i.e. before relocation). TLS memory (e.g. errno) currently
isn't accessible until after relocation, but a later patch fixes that.

Bug: none
Test: bionic unit tests
Change-Id: Ied4433758ed2da9ee404c6158e319cf502d05a53
2018-11-28 14:26:14 -08:00
Ryan Prichard
abf736a780 Expose libc_shared_globals to libc.so with symbol
Previously, the address of the global variable was communicated from the
dynamic linker to libc.so using a field of KernelArgumentBlock, which is
communicated using the TLS_SLOT_BIONIC_PREINIT slot.

As long as this function isn't called during relocations (i.e. while
executing an ifunc), it always return a non-NULL value. If it's called
before its PLT entry is relocated, I expect a crash.

I removed the __libc_init_shared_globals function. It's currently empty,
and I don't think there's one point in libc's initialization where
shared globals should be initialized.

Bug: http://b/25751302
Test: bionic unit tests
Change-Id: I614d25e7ef5e0d2ccc40d5c821dee10f1ec61c2e
2018-11-28 14:26:14 -08:00
Elliott Hughes
5e62b34c0d Clean up bionic_macros.h a bit.
Use <android-base/macros.h> instead where possible, and move the bionic
macros out of the way of the libbase ones. Yes, there are folks who manage
to end up with both included at once (thanks OpenGL!), and cleaning that
up doesn't seem nearly as practical as just making this change.

Bug: N/A
Test: builds
Change-Id: I23fc544f39d5addf81dc61471771a5438778895b
2018-10-25 11:00:00 -07:00
Yi Kong
32bc0fcf69 Modernize codebase by replacing NULL with nullptr
Fixes -Wzero-as-null-pointer-constant warning.

Test: m
Bug: 68236239
Change-Id: I5b4123bc6709641315120a191e36cc57541349b2
2018-08-02 18:09:44 -07:00
Josh Gao
f6e5b58260 Introduce api to track fd ownership in libc.
Add two functions to allow objects that own a file descriptor to
enforce that only they can close their file descriptor.

Use them in FILE* and DIR*.

Bug: http://b/110100358
Test: bionic_unit_tests
Test: aosp/master boots without errors
Test: treehugger
Change-Id: Iecd6e8b26c62217271e0822dc3d2d7888b091a45
2018-07-19 14:28:54 -07:00
Elliott Hughes
5cec377f49 Address a bunch of clang-tidy complaints.
There were a bunch more unreasonable/incorrect ones, but these ones
seemed legit. Nothing very interesting, though.

Bug: N/A
Test: ran tests, benchmarks
Change-Id: If66971194d4a7b4bf6d0251bedb88e8cdc88a76f
2018-01-19 15:56:12 -08:00
Elliott Hughes
63fbb233cb Tidy up KernelArgumentBlock::getauxval.
Correct the comment, and remove the unused functionality. getauxval(3) does
now set errno to let you know it failed to find anything, but since none of
this function's callers care anyway it seems safer to leave errno untouched
until we actually have a demonstrated need for it.

Bug: https://code.google.com/p/android/issues/detail?id=198111
Change-Id: I232a42dc5a02c8faab94c7d69bef610408276c23
2016-01-05 16:29:33 -08:00
Elliott Hughes
8eac9af24e Bring in google3-style DISALLOW_* macros.
I've been meaning to do this for a very long time...

Change-Id: Ia8c16eee7c026c3c9505399948485fb778fb0152
2014-05-09 19:12:08 -07:00
Elliott Hughes
0266ae5f88 Switch <elf.h> over to linux uapi under the covers.
Remove the linker's reliance on BSD cruft and use the glibc-style
ElfW macro. (Other code too, but the linker contains the majority
of the code that needs to work for Elf32 and Elf64.)

All platforms need dl_iterate_phdr_static, so it doesn't make sense
to have that part of the per-architecture configuration.

Bug: 12476126
Change-Id: I1d7f918f1303a392794a6cd8b3512ff56bd6e487
2014-02-10 18:22:24 -08:00
Elliott Hughes
c620059479 Remove 32-bit assumptions from the ELF code.
Change-Id: I2c1f3d34c33685799aade8866eec44479ff9f963
2013-09-30 18:43:46 -07:00
Elliott Hughes
0d787c1fa1 Make abort messages available to debuggerd.
This adds __libc_fatal, cleans up the internal logging code a bit more,
and switches suitable callers over to __libc_fatal. In addition to logging,
__libc_fatal stashes the message somewhere that the debuggerd signal handler
can find it before calling abort.

In the debuggerd signal handler, we pass this address to debuggerd so that
it can come back with ptrace to read the message and present it to the user.

Bug: 8531731
Change-Id: I416ec1da38a8a1b0d0a582ccd7c8aaa681ed4a29
2013-04-05 11:24:19 -07:00
Elliott Hughes
42b2c6a5ee Clean up the argc/argv/envp/auxv handling.
There's now only one place where we deal with this stuff, it only needs to
be parsed once by the dynamic linker (rather than by each recipient), and it's
now easier for us to get hold of auxv data early on.

Change-Id: I6314224257c736547aac2e2a650e66f2ea53bef5
2013-02-07 11:44:21 -08:00