| Commit message (Expand) | Author | Age | Files | Lines |
|---|
| * | overhaul cancellation to fix resource leaks and dangerous behavior with signals•••this commit addresses two issues:
1. a race condition, whereby a cancellation request occurring after a
syscall returned from kernelspace but before the subsequent
CANCELPT_END would cause cancellable resource-allocating syscalls
(like open) to leak resources.
2. signal handlers invoked while the thread was blocked at a
cancellation point behaved as if asynchronous cancellation mode wer in
effect, resulting in potentially dangerous state corruption if a
cancellation request occurs.
the glibc/nptl implementation of threads shares both of these issues.
with this commit, both are fixed. however, cancellation points
encountered in a signal handler will not be acted upon if the signal
was received while the thread was already at a cancellation point.
they will of course be acted upon after the signal handler returns, so
in real-world usage where signal handlers quickly return, it should
not be a problem. it's possible to solve this problem too by having
sigaction() wrap all signal handlers with a function that uses a
pthread_cleanup handler to catch cancellation, patch up the saved
context, and return into the cancellable function that will catch and
act upon the cancellation. however that would be a lot of complexity
for minimal if any benefit...
| Rich Felker | 2011-03-24 | 1 | -1/+2 |
| * | global cleanup to use the new syscall interface | Rich Felker | 2011-03-20 | 1 | -22/+0 |
| * | syscall overhaul part two - unify public and internal syscall interface•••with this patch, the syscallN() functions are no longer needed; a
variadic syscall() macro allows syscalls with anywhere from 0 to 6
arguments to be made with a single macro name. also, manually casting
each non-integer argument with (long) is no longer necessary; the
casts are hidden in the macros.
some source files which depended on being able to define the old macro
SYSCALL_RETURNS_ERRNO have been modified to directly use __syscall()
instead of syscall(). references to SYSCALL_SIGSET_SIZE and SYSCALL_LL
have also been changed.
x86_64 has not been tested, and may need a follow-up commit to fix any
minor bugs/oversights.
| Rich Felker | 2011-03-19 | 1 | -0/+32 |
| * | remove comment cruft that got left behind in x86_64 syscall.s | Rich Felker | 2011-03-19 | 1 | -1/+0 |
| * | overhaul syscall interface•••this commit shuffles around the location of syscall definitions so
that we can make a syscall() library function with both SYS_* and
__NR_* style syscall names available to user applications, provides
the syscall() library function, and optimizes the code that performs
the actual inline syscalls in the library itself.
previously on i386 when built as PIC (shared library), syscalls were
incurring bus lock (lock prefix) overhead at entry and exit, due to
the way the ebx register was being loaded (xchg instruction with a
memory operand). now the xchg takes place between two registers.
further cleanup to arch/$(ARCH)/syscall.h is planned.
| Rich Felker | 2011-03-19 | 4 | -11/+46 |
| * | implement [v]swprintf | Rich Felker | 2011-03-18 | 1 | -1/+1 |
| * | implement robust mutexes•••some of this code should be cleaned up, e.g. using macros for some of
the bit flags, masks, etc. nonetheless, the code is believed to be
working and correct at this point.
| Rich Felker | 2011-03-17 | 1 | -0/+5 |
| * | reorder mutex struct fields to make room for pointers (upcoming robust mutexes)•••the layout has been chosen so that pointer slots 3 and 4 fit between
the integer slots on 32-bit archs, and come after the integer slots on
64-bit archs.
| Rich Felker | 2011-03-17 | 1 | -1/+3 |
| * | unify lock and owner fields of mutex structure•••this change is necessary to free up one slot in the mutex structure so
that we can use doubly-linked lists in the implementation of robust
mutexes.
| Rich Felker | 2011-03-17 | 1 | -1/+0 |
| * | implement flockfile api, rework stdio locking | Rich Felker | 2011-03-12 | 2 | -12/+11 |
| * | optimize pthread termination in the non-detached case•••we can avoid blocking signals by simply using a flag to mark that the
thread has exited and prevent it from getting counted in the rsyscall
signal-pingpong. this restores the original pthread create/join
throughput from before the sigprocmask call was added.
| Rich Felker | 2011-03-10 | 1 | -0/+1 |
| * | fix and optimize non-default-type mutex behavior•••problem 1: mutex type from the attribute was being ignored by
pthread_mutex_init, so recursive/errorchecking mutexes were never
being used at all.
problem 2: ownership of recursive mutexes was not being enforced at
unlock time.
| Rich Felker | 2011-03-08 | 1 | -0/+1 |
| * | use the selected clock from the condattr for pthread_cond_timedwait | Rich Felker | 2011-03-07 | 1 | -0/+1 |
| * | various changes in preparation for dynamic linking support•••prefer using visibility=hidden for __libc internal data, rather than
an accessor function, if the compiler has visibility.
optimize with -O3 for PIC targets (shared library). without heavy
inlining, reloading the GOT register in small functions kills
performance. 20-30% size increase for a single libc.so is not a big
deal, compared to comparaible size increase in every static binaries.
use -Bsymbolic-functions, not -Bsymbolic. global variables are subject
to COPY relocations, and thus binding their addresses in the library
at link time will cause library functions to read the wrong (original)
copies instead of the copies made in the main program's bss section.
add entry point, _start, for dynamic linker.
| Rich Felker | 2011-02-24 | 2 | -5/+13 |
| * | use an accessor function for __libc data pointer when compiled as PIC•••prior to this change, a large portion of libc was unusable prior to
relocation by the dynamic linker, due to dependence on the global data
in the __libc structure and the need to obtain its address through the
GOT. with this patch, the accessor function __libc_loc is now able to
obtain the address of __libc via PC-relative addressing without using
the GOT. this means the majority of libc functionality is now
accessible right away.
naturally, the above statements all depend on having an architecture
where PC-relative addressing and jumps/calls are feasible, and a
compiler that generates the appropriate code.
| Rich Felker | 2011-02-20 | 2 | -4/+19 |
| * | add pthread_atfork interface•••note that this presently does not handle consistency of the libc's own
global state during forking. as per POSIX 2008, if the parent process
was threaded, the child process may only call async-signal-safe
functions until one of the exec-family functions is called, so the
current behavior is believed to be conformant even if non-ideal. it
may be improved at some later time.
| Rich Felker | 2011-02-18 | 1 | -0/+1 |
| * | reorganize pthread data structures and move the definitions to alltypes.h•••this allows sys/types.h to provide the pthread types, as required by
POSIX. this design also facilitates forcing ABI-compatible sizes in
the arch-specific alltypes.h, while eliminating the need for
developers changing the internals of the pthread types to poke around
with arch-specific headers they may not be able to test.
| Rich Felker | 2011-02-17 | 1 | -0/+19 |
| * | move arch-specific internal headers into place | Rich Felker | 2011-02-15 | 4 | -637/+0 |
| * | finish unifying thread register handling in preparation for porting | Rich Felker | 2011-02-15 | 1 | -8/+2 |
| * | begin unifying clone/thread management interface in preparation for porting | Rich Felker | 2011-02-15 | 1 | -5/+3 |
| * | cleaning up syscalls in preparation for x86_64 port•••- hide all the legacy xxxxxx32 name cruft in syscall.h so the actual
source files can be clean and uniform across all archs.
- cleanup llseek/lseek and mmap2/mmap handling for 32/64 bit systems
- alternate implementation for nice if the target lacks nice syscall
| Rich Felker | 2011-02-13 | 1 | -9/+40 |
| * | ensure that the compiler doesn't try to reorder around atomic ops | Rich Felker | 2011-02-12 | 1 | -13/+13 |
| * | initial check-in, version 0.5.0 | Rich Felker | 2011-02-12 | 11 | -0/+852 |
