| Commit message (Expand) | Author | Age | Files | Lines |
|---|
| * | fix build regression in aarch64 sigsetjmp•••at least some assembler versions do not accept the register name lr.
use the name x30 instead.
| Rich Felker | 2015-04-24 | 1 | -2/+2 |
| * | fix build regression in sh-nofpu subarch due to missing symbol•••commit 646cb9a4a04e5ed78e2dd928bf9dc6e79202f609 switched sigsetjmp to
use the new hidden ___setjmp symbol for setjmp, but the nofpu variant
of setjmp.s was not updated to match.
| Rich Felker | 2015-04-24 | 1 | -0/+3 |
| * | fix misalignment of dtv in static-linked programs with odd-sized TLS•••both static and dynamic linked versions of the __copy_tls function
have a hidden assumption that the alignment of the beginning or end of
the memory passed is suitable for storing an array of pointers for the
dtv. pthread_create satisfies this requirement except when
libc.tls_size is misaligned, which cannot happen with dynamic linking
due to way update_tls_size computes the total size, but could happen
with static linking and odd-sized TLS.
| Rich Felker | 2015-04-23 | 1 | -1/+2 |
| * | remove dead store from static __init_tls•••commit dab441aea240f3b7c18a26d2ef51979ea36c301c, which made thread
pointer init mandatory for all programs, rendered this store obsolete
by removing the early-return path for static programs with no TLS.
| Rich Felker | 2015-04-23 | 1 | -2/+0 |
| * | make __init_tp function static when static linking•••this slightly reduces the code size cost of TLS/thread-pointer for
static linking since __init_tp can be inlined into its only caller and
removed. this is analogous to the handling of __init_libc in
__libc_start_main, where the function only has external linkage when
it needs to be called from the dynamic linker.
| Rich Felker | 2015-04-23 | 1 | -0/+3 |
| * | fix regression in x86_64 math asm with old binutils•••the implicit-operand form of fucomip is rejected by binutils 2.19 and
perhaps other versions still in use. writing both operands explicitly
fixes the issue. there is no change to the resulting output.
commit a732e80d33b4fd6f510f7cec4f5573ef5d89bc4e was the source of this
regression.
| Rich Felker | 2015-04-23 | 2 | -6/+6 |
| * | minor optimization to pthread_spin_trylock•••use CAS instead of swap since it's lighter for most archs, and keep
EBUSY in the lock value so that the old value obtained by CAS can be
used directly as the return value for pthread_spin_trylock.
| Rich Felker | 2015-04-22 | 2 | -2/+4 |
| * | optimize spin lock not to dirty cache line while spinning | Rich Felker | 2015-04-22 | 1 | -1/+1 |
| * | in visibility preinclude, remove overrides for stdin/stdout/stderr•••the motivation for this change is that the extra declaration (with or
without visibility) using "struct _IO_FILE" instead of "FILE" seems to
trigger a bug in gcc 3.x where it considers the types mismatched.
however, this change also results in slightly better code and it is
valid because (1) these three objects are constant, and (2) applying
the & operator to any of them is invalid C, since they are not even
specified to be objects. thus it does not matter if the application
and libc see different addresses for them, as long as the (initial,
unchanging) value is seen the same by both.
| Rich Felker | 2015-04-22 | 1 | -3/+0 |
| * | fix inconsistent visibility for __hwcap and __sysinfo symbols•••these are used as hidden by asm files (and such use is the whole
reason they exist), but their actual definitions were not hidden.
| Rich Felker | 2015-04-22 | 2 | -5/+3 |
| * | remove additional libc struct accessor cruft•••commit f9cccfc16e58b39ee381fbdfb8688db3bb8e3555 left behind the part
in libc.c; remove it too.
| Rich Felker | 2015-04-22 | 1 | -12/+0 |
| * | remove useless visibility application from static-linking-only code•••part of the goal here is to eliminate use of the ATTR_LIBC_VISIBILITY
macro outside of libc.h, since it was never intended to be 'public'.
| Rich Felker | 2015-04-22 | 2 | -3/+2 |
| * | remove libc.h dependency from otherwise-independent multibyte code | Rich Felker | 2015-04-22 | 1 | -2/+4 |
| * | remove cruft for libc struct accessor function and broken visibility•••these were hacks to work around toolchains that could not properly
optimize PIC accesses based on visibility and would generate GOT
lookups even for hidden data, which broke the old dynamic linker.
since commit f3ddd173806fd5c60b3f034528ca24542aecc5b9 it no longer
matters; the dynamic linker does not assume accessibility of this data
until stage 3.
| Rich Felker | 2015-04-22 | 2 | -18/+0 |
| * | fix duplocale clobbering of new locale struct with memcpy of old•••when the non-stub duplocale code was added as part of the locale
framework in commit 0bc03091bb674ebb9fa6fe69e4aec1da3ac484f2, the old
code to memcpy the old locale object to the new one was left behind.
the conditional for the memcpy no longer makes sense, because the
conditions are now always-true when it's reached, and the memcpy is
wrong because it clobbers the new->messages_name pointer setup just
above.
since the messages_name and ctype_utf8 members have already been
copied, all that remains is the cat[] array. these pointers are
volatile, so using memcpy to copy them is formally wrong; use a for
loop instead.
| Rich Felker | 2015-04-21 | 1 | -1/+2 |
| * | remove dead case for F_SETLKW in fcntl•••the first switch already returns in the F_SETLKW code path so it need
not be handled in the second switch. moreover the code in the second
switch is wrong for the F_SETLKW command: it's not cancellable.
| Rich Felker | 2015-04-21 | 1 | -1/+0 |
| * | fix mmap leak in sem_open failure path for link call•••the leak was found by static analysis (reported by Alexander Monakov),
not tested/observed, but seems to have occured both when failing due
to O_EXCL, and in a race condition with O_CREAT but not O_EXCL where a
semaphore by the same name was created concurrently.
| Rich Felker | 2015-04-21 | 1 | -0/+1 |
| * | remove always-true conditional in dynamic linker TLSDESC processing•••the allocating path which can fail is for dynamic TLS, which can only
occur at runtime, and the check for runtime was already made in the
outer conditional.
| Rich Felker | 2015-04-21 | 1 | -1/+1 |
| * | remove redundant code in do_dlsym function•••commit 637dd2d383cc1f63bf02a732f03786857b22c7bd introduced the checks
for RTLD_DEFAULT and RTLD_NEXT here, claiming they fixed a regression,
but the above conditional block clearly already covered these cases,
and removing the checks produces no difference in the generated code.
| Rich Felker | 2015-04-21 | 1 | -1/+1 |
| * | add optional global visibility override•••this is implemented via the build system and does not affect source
files. the idea is to use protected or hidden visibility to prevent
the compiler from pessimizing function calls within a shared (or
position-independent static) libc in the form of overhead setting up
for a call through the PLT. the ld-time symbol binding via the
-Bsymbolic-functions option already optimized out the PLT itself, but
not the code in the caller needed to support a call through the PLT.
on some archs this overhead can be substantial; on others it's
trivial.
| Rich Felker | 2015-04-19 | 1 | -0/+40 |
| * | remove invalid PLT calls from or1k asm•••analogous to commit 646cb9a4a04e5ed78e2dd928bf9dc6e79202f609 for sh.
| Rich Felker | 2015-04-19 | 2 | -3/+7 |
| * | remove possible-textrels from powerpc asm•••these are perfectly fine with ld-time symbol binding, but otherwise
result in textrels. they cannot be replaced with @PLT jump targets
because the PLT thunks require a GOT register to be setup, so use a
hidden alias instead.
| Rich Felker | 2015-04-19 | 2 | -2/+6 |
| * | remove invalid PLT calls from microblaze asm•••analogous to commit 646cb9a4a04e5ed78e2dd928bf9dc6e79202f609 for sh.
| Rich Felker | 2015-04-19 | 2 | -2/+6 |
| * | remove invalid PLT calls from sh asm•••these are perfectly fine with ld-time symbol binding, but if the calls
go through a PLT thunk, they are invalid because the caller does not
setup a GOT register. use a hidden alias to bypass the issue.
| Rich Felker | 2015-04-19 | 2 | -2/+6 |
| * | remove potentially PIC-incompatible relocations from x86_64 and x32 asm•••analogous to commit 8ed66ecbcba1dd0f899f22b534aac92a282f42d5 for i386.
| Rich Felker | 2015-04-18 | 6 | -7/+11 |
| * | remove the last of possible-textrels from i386 asm•••none of these are actual textrels because of ld-time binding performed
by -Bsymbolic-functions, but I'm changing them with the goal of making
ld-time binding purely an optimization rather than relying on it for
semantic purposes.
in the case of memmove's call to memcpy, making it explicit that the
memmove asm is assuming the forward-copying behavior of the memcpy asm
is desirable anyway; in case memcpy is ever changed, the semantic
mismatch would be apparent while editing memmcpy.s.
| Rich Felker | 2015-04-18 | 6 | -4/+16 |
| * | make dlerror state and message thread-local and dynamically-allocated•••this fixes truncation of error messages containing long pathnames or
symbol names.
the dlerror state was previously required by POSIX to be global. the
resolution of bug 97 relaxed the requirements to allow thread-safe
implementations of dlerror with thread-local state and message buffer.
| Rich Felker | 2015-04-18 | 3 | -32/+65 |
| * | add missing 'void' in prototypes of internal pthread functions | Alexander Monakov | 2015-04-18 | 1 | -6/+6 |
| * | math: fix pow(+-0,-inf) not to raise divbyzero flag•••this reverts the commit f29fea00b5bc72d4b8abccba2bb1e312684d1fce
which was based on a bug in C99 and POSIX and did not match IEEE-754
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1515.pdf
| Szabolcs Nagy | 2015-04-18 | 3 | -3/+3 |
| * | apply hidden visibility to tlsdesc accessor functions•••these functions are never called directly; only their addresses are
used, so PLT indirections should never happen unless a broken
application tries to redefine them, but it's still best to make them
hidden.
| Rich Felker | 2015-04-17 | 5 | -0/+10 |
| * | comment fixes in aarch64 tlsdesc asm | Szabolcs Nagy | 2015-04-17 | 1 | -4/+4 |
| * | ensure debugger hook for dynamic linker does not point to a PLT slot•••this change is made in preparation to support linking without
-Bsymbolic-functions.
| Rich Felker | 2015-04-17 | 1 | -2/+4 |
| * | fix mips fesetenv(FE_DFL_ENV) again•••commit 5fc1487832e16aa2119e735a388d5f36c8c139e2 attempted to fix it,
but neglected the fact that mips has branch delay slots.
| Rich Felker | 2015-04-17 | 1 | -0/+1 |
| * | fix PLT call offset in sh dlsym asm•••the braf instruction's destination register is an offset from the
address of the braf instruction plus 4 (or equivalently, the address
of the next instruction after the delay slot). the code for dlsym was
incorrectly computing the offset to pass using the address of the
delay slot itself. in other places, a label was placed after the delay
slot, but I find this confusing. putting the label on the branch
instruction itself, and manually adding 4, makes it more clear which
branch the offset in the constant pool goes with.
| Rich Felker | 2015-04-17 | 1 | -3/+3 |
| * | fix sh build regressions in asm•••even hidden functions need @PLT symbol references; otherwise an
absolute address is produced instead of a PC-relative one.
| Rich Felker | 2015-04-17 | 2 | -2/+2 |
| * | fix sh __set_thread_area uninitialized return value•••this caused the dynamic linker/startup code to abort when r0 happened
to contain a negative value.
| Rich Felker | 2015-04-17 | 1 | -1/+2 |
| * | redesign sigsetjmp so that signal mask is restored after longjmp•••the conventional way to implement sigsetjmp is to save the signal mask
then tail-call to setjmp; siglongjmp then restores the signal mask and
calls longjmp. the problem with this approach is that a signal already
pending, or arriving between unmasking of signals and restoration of
the saved stack pointer, will have its signal handler run on the stack
that was active before siglongjmp was called. this can lead to
unbounded stack usage when siglongjmp is used to leave a signal
handler.
in the new design, sigsetjmp saves its own return address inside the
extended part of the sigjmp_buf (outside the __jmp_buf part used by
setjmp) then calls setjmp to save a jmp_buf inside its own execution.
it then tail-calls to __sigsetjmp_tail, which uses the return value of
setjmp to determine whether to save the current signal mask or restore
a previously-saved mask.
as an added bonus, this design makes it so that siglongjmp and longjmp
are identical. this is useful because the __longjmp_chk function we
need to add for ABI-compatibility assumes siglongjmp and longjmp are
the same, but for different reasons -- it was designed assuming either
can access a flag just past the __jmp_buf indicating whether the
signal masked was saved, and act on that flag. however, early versions
of musl did not have space past the __jmp_buf for the non-sigjmp_buf
version of jmp_buf, so our setjmp cannot store such a flag without
risking clobbering memory on (very) old binaries.
| Rich Felker | 2015-04-17 | 12 | -133/+177 |
| * | use hidden __tls_get_new for tls/tlsdesc lookup fallback cases•••previously, the dynamic tlsdesc lookup functions and the i386
special-ABI ___tls_get_addr (3 underscores) function called
__tls_get_addr when the slot they wanted was not already setup;
__tls_get_addr would then in turn also see that it's not setup and
call __tls_get_new.
calling __tls_get_new directly is both more efficient and avoids the
issue of calling a non-hidden (public API/ABI) function from asm.
for the special i386 function, a weak reference to __tls_get_new is
used since this function is not defined when static linking (the code
path that needs it is unreachable in static-linked programs).
| Rich Felker | 2015-04-14 | 4 | -5/+13 |
| * | cleanup use of visibility attributes in pthread_cancel.c•••applying the attribute to a weak_alias macro was a hack. instead use a
separate declaration to apply the visibility, and consolidate
declarations together to avoid having visibility mess all over the
file.
| Rich Felker | 2015-04-14 | 1 | -8/+9 |
| * | fix inconsistent visibility for internal syscall symbols | Rich Felker | 2015-04-14 | 12 | -1/+16 |
| * | use hidden visibility for call from dlsym to internal __dlsym | Rich Felker | 2015-04-14 | 11 | -3/+14 |
| * | consistently use hidden visibility for cancellable syscall internals•••in a few places, non-hidden symbols were referenced from asm in ways
that assumed ld-time binding. while these is no semantic reason these
symbols need to be hidden, fixing the references without making them
hidden was going to be ugly, and hidden reduces some bloat anyway.
in the asm files, .global/.hidden directives have been moved to the
top to unclutter the actual code.
| Rich Felker | 2015-04-14 | 11 | -30/+96 |
| * | fix inconsistent visibility for internal __tls_get_new function•••at the point of call it was declared hidden, but the definition was
not hidden. for some toolchains this inconsistency produced textrels
without ld-time binding.
| Rich Felker | 2015-04-14 | 2 | -3/+3 |
| * | use hidden visibility for i386 asm-internal __vsyscall symbol•••otherwise the call instruction in the inline syscall asm results in
textrels without ld-time binding.
| Rich Felker | 2015-04-14 | 1 | -0/+2 |
| * | make _dlstart_c function use hidden visibility•••otherwise the call/jump from the crt_arch.h asm may not resolve
correctly without -Bsymbolic-functions.
| Rich Felker | 2015-04-14 | 1 | -0/+1 |
| * | remove initializers for decoded aux/dyn arrays in dynamic linker•••the zero initialization is redundant since decode_vec does its own
clearing, and it increases the risk that buggy compilers will generate
calls to memset. as long as symbols are bound at ld time, such a call
will not break anything, but it may be desirable to turn off ld-time
binding in the future.
| Rich Felker | 2015-04-13 | 1 | -5/+5 |
| * | allow libc itself to be built with stack protector enabled•••this was already essentially possible as a result of the previous
commits changing the dynamic linker/thread pointer bootstrap process.
this commit mainly adds build system infrastructure:
configure no longer attempts to disable stack protector. instead it
simply determines how so the makefile can disable stack protector for
a few translation units used during early startup.
stack protector is also disabled for memcpy and memset since compilers
(incorrectly) generate calls to them on some archs to implement
struct initialization and assignment, and such calls may creep into
early initialization.
no explicit attempt to enable stack protector is made by configure at
this time; any stack protector option supported by the compiler can be
passed to configure in CFLAGS, and if the compiler uses stack
protector by default, this default is respected.
| Rich Felker | 2015-04-13 | 1 | -0/+10 |
| * | remove remnants of support for running in no-thread-pointer mode•••since 1.1.0, musl has nominally required a thread pointer to be setup.
most of the remaining code that was checking for its availability was
doing so for the sake of being usable by the dynamic linker. as of
commit 71f099cb7db821c51d8f39dfac622c61e54d794c, this is no longer
necessary; the thread pointer is now valid before any libc code
(outside of dynamic linker bootstrap functions) runs.
this commit essentially concludes "phase 3" of the "transition path
for removing lazy init of thread pointer" project that began during
the 1.1.0 release cycle.
| Rich Felker | 2015-04-13 | 10 | -32/+13 |
| * | move thread pointer setup to beginning of dynamic linker stage 3•••this allows the dynamic linker itself to run with a valid thread
pointer, which is a prerequisite for stack protector on archs where
the ssp canary is stored in TLS. it will also allow us to remove some
remaining runtime checks for whether the thread pointer is valid.
as long as the application and its libraries do not require additional
size or alignment, this early thread pointer will be kept and reused
at runtime. otherwise, a new static TLS block is allocated after
library loading has finished and the thread pointer is switched over.
| Rich Felker | 2015-04-13 | 1 | -8/+23 |
| * | stabilize dynamic linker's layout of static TLS•••previously, the layout of the static TLS block was perturbed by the
size of the dtv; dtv size increasing from 0 to 1 perturbed both TLS
arch types, and the TLS-above-TP type's layout was perturbed by the
specific number of dtv slots (libraries with TLS). this behavior made
it virtually impossible to setup a tentative thread pointer address
before loading libraries and keep it unchanged as long as the
libraries' TLS size/alignment requirements fit.
the new code fixes the location of the dtv and pthread structure at
opposite ends of the static TLS block so that they will not move
unless size or alignment changes.
| Rich Felker | 2015-04-13 | 1 | -9/+6 |
