Commit Graph

84 Commits

Author SHA1 Message Date
Rich Felker
006a75a997 move IPC_STAT definition to a new bits/ipcstat.h file
otherwise, 32-bit archs that could otherwise share the generic
bits/ipc.h would need to duplicate the struct ipc_perm definition,
obscuring the fact that it's the same. sysvipc is not widely used and
these headers are not commonly included, so there is no performance
gain to be had by limiting the number of indirectly included files
here.

files with the existing time32 definition of IPC_STAT are added to all
current 32-bit archs now, so that when it's changed the change will
show up as a change rather than addition of a new file where it's less
obvious that the value is changing vs the generic one that was used
before.
2019-08-02 00:08:23 -04:00
Rich Felker
2e554617e5 ioctl: add fallback for new time64 SIOCGSTAMP[NS]
without this, the SIOCGSTAMP and SIOCGSTAMPNS ioctl commands, for
obtaining timestamps, would stop working on pre-5.1 kernels after
time_t is switched to 64-bit and their values are changed to the new
time64 versions.

new code is written such that it's statically unreachable on 64-bit
archs, and on existing 32-bit archs until the macro values are changed
to activate 64-bit time_t.
2019-07-31 20:21:04 -04:00
Rich Felker
95ed26353c duplicate generic bits/msg.h for each arch using it, in prep to change 2019-07-29 18:22:33 -04:00
Rich Felker
6f2e5607d2 duplicate generic bits/sem.h for each arch using it, in prep to change 2019-07-29 18:07:23 -04:00
Rich Felker
01ae3fc6d4 decouple struct stat from kernel type
presently, all archs/ABIs have struct stat matching the kernel
stat[64] type, except mips/mipsn32/mips64 which do conversion hacks in
syscall_arch.h to work around bugs in the kernel type. this patch
completely decouples them and adds a translation step to the success
path of fstatat. at present, this is just a gratuitous copying, but it
opens up multiple possibilities for future support for 64-bit time_t
on 32-bit archs and for cleaned-up/unified ABIs.

for clarity, the mips hacks are not yet removed in this commit, so the
mips kstat structs still correspond to the output of the hacks in
their syscall_arch.h files, not the raw kernel type. a subsequent
commit will fix this.
2019-07-18 19:38:12 -04:00
Szabolcs Nagy
f3f96f2daa add new syscall numbers from linux v5.1
syscall numbers are now synced up across targets (starting from 403 the
numbers are the same on all targets other than an arch specific offset)

IPC syscalls sem*, shm*, msg* got added where they were missing (except
for semop: only semtimedop got added), the new semctl, shmctl, msgctl
imply IPC_64, see

  linux commit 0d6040d4681735dfc47565de288525de405a5c99
  arch: add split IPC system calls where needed

new 64bit time_t syscall variants got added on 32bit targets, see

  linux commit 48166e6ea47d23984f0b481ca199250e1ce0730a
  y2038: add 64-bit time_t syscalls to all 32-bit architectures

new async io syscalls got added, see

  linux commit 2b188cc1bb857a9d4701ae59aa7768b5124e262e
  Add io_uring IO interface

  linux commit edafccee56ff31678a091ddb7219aba9b28bc3cb
  io_uring: add support for pre-mapped user IO buffers

a new syscall got added that uses the fd of /proc/<pid> as a stable
handle for processes: allows sending signals without pid reuse issues,
intended to eventually replace rt_sigqueueinfo, kill, tgkill and
rt_tgsigqueueinfo, see

  linux commit 3eb39f47934f9d5a3027fe00d906a45fe3a15fad
  signal: add pidfd_send_signal() syscall

on some targets (arm, m68k, s390x, sh) some previously missing syscall
numbers got added as well.
2019-07-01 14:20:58 -04:00
Bobby Bingham
3517d74a5e move arch-invariant definitions out of bits/ioctl.h 2019-02-07 12:43:19 -05:00
Rich Felker
a4a3e4dbc0 make thread-pointer-loading asm non-volatile
this will allow the compiler to cache and reuse the result, meaning we
no longer have to take care not to load it more than once for the sake
of archs where the load may be expensive.

depends on commit 1c84c99913 for
correctness, since otherwise the compiler could hoist loads during
stage 3 of dynamic linking before the initial thread-pointer setup.
2018-10-16 14:11:46 -04:00
Szabolcs Nagy
5ef60206ff add arm and sh bits/ptrace.h
These should have been added in commit
df6d9450ea
that added target specific PTRACE_ macros, but somehow got missed.
2018-09-20 17:56:29 -04:00
Rich Felker
b6e59cd925 apply hidden visibility to sigreturn code fragments
these were overlooked in the declarations overhaul work because they
are not properly declared, and the current framework even allows their
declared types to vary by arch. at some point this should be cleaned
up, but I'm not sure what the right way would be.
2018-09-12 14:34:34 -04:00
Rich Felker
9b95fd0944 define and use internal macros for hidden visibility, weak refs
this cleans up what had become widespread direct inline use of "GNU C"
style attributes directly in the source, and lowers the barrier to
increased use of hidden visibility, which will be useful to recovering
some of the efficiency lost when the protected visibility hack was
dropped in commit dc2f368e56, especially
on archs where the PLT ABI is costly.
2018-09-05 14:05:14 -04:00
Rich Felker
35cd7c0950 fix async thread cancellation on sh-fdpic
if __cp_cancel was reached via __syscall_cp, r12 will necessarily
still contain a GOT pointer (for libc.so or for the static-linked main
program) valid for entering __cancel. however, in the case of async
cancellation, r12 may contain any scratch value; it's not necessarily
even a valid GOT pointer for the code that was interrupted.

unlike in commit 0ec49dab67 where the
corresponding issue was fixed for powerpc64, there is fundamentally no
way for fdpic code to recompute its GOT pointer. so a new mechanism is
introduced for cancel_handler to write a GOT register value into the
interrupted context on archs where it is needed.
2018-08-29 14:01:46 -04:00
Rich Felker
0cd2be2314 work around broken kernel struct ipc_perm on some big endian archs
the mode member of struct ipc_perm is specified by POSIX to have type
mode_t, which is uniformly defined as unsigned int. however, Linux
defines it with type __kernel_mode_t, and defines __kernel_mode_t as
unsigned short on some archs. since there is a subsequent padding
field, treating it as a 32-bit unsigned int works on little endian
archs, but the order is backwards on big endian archs with the
erroneous definition.

since multiple archs are affected, remedy the situation with fixup
code in the affected functions (shmctl, semctl, and msgctl) rather
than repeating the same shims in syscall_arch.h for every affected
arch.
2018-06-20 00:07:09 -04:00
Szabolcs Nagy
610c5a8524 fix TLS layout of TLS variant I when there is a gap above TP
In TLS variant I the TLS is above TP (or above a fixed offset from TP)
but on some targets there is a reserved gap above TP before TLS starts.

This matters for the local-exec tls access model when the offsets of
TLS variables from the TP are hard coded by the linker into the
executable, so the libc must compute these offsets the same way as the
linker.  The tls offset of the main module has to be

	alignup(GAP_ABOVE_TP, main_tls_align).

If there is no TLS in the main module then the gap can be ignored
since musl does not use it and the tls access models of shared
libraries are not affected.

The previous setup only worked if (tls_align & -GAP_ABOVE_TP) == 0
(i.e. TLS did not require large alignment) because the gap was
treated as a fixed offset from TP.  Now the TP points at the end
of the pthread struct (which is aligned) and there is a gap above
it (which may also need alignment).

The fix required changing TP_ADJ and __pthread_self on affected
targets (aarch64, arm and sh) and in the tlsdesc asm the offset to
access the dtv changed too.
2018-06-02 19:38:44 -04:00
Rich Felker
c9c2cd3e69 reverse definition dependency between PAGESIZE and PAGE_SIZE
PAGESIZE is actually the version defined in POSIX base, with PAGE_SIZE
being in the XSI option. use PAGESIZE as the underlying definition to
facilitate making exposure of PAGE_SIZE conditional.
2018-03-10 17:47:14 -05:00
Szabolcs Nagy
754f66afb7 ioctl TIOCGPTPEER from linux v4.13
added for safe opening of peer end of pty in a mount namespace.
new in linux commit c6325179238f1d4683edbec53d8322575d76d7e2
2017-11-05 18:41:22 -05:00
Szabolcs Nagy
cc08669380 add SIOCGSTAMPNS socket ioctl macro to ioctl.h
it is defined in linux asm/sockios.h since commit
ae40eb1ef30ab4120bd3c8b7e3da99ee53d27a23 (linux v2.6.22)
but was missing from musl by accident.

in musl the sockios macros are exposed in sys/ioctl.h together
with other ioctl requests instead of in sys/socket.h because of
namespace rules. (glibc has them in sys/socket.h under _GNU_SOURCE.)
2017-08-29 19:48:37 -04:00
Thomas Petazzoni
1698fe6cdc fix build failure for sh4a due to missing colon in asm statement
Due to a missing ":" in an asm() statement, the "memory" clobber is
considered by gcc as an input operand and not a clobber, which causes a
build failure.
2017-08-11 21:06:57 -04:00
Szabolcs Nagy
fe39aaae0e add bits/hwcap.h and include it in sys/auxv.h
aarch64, arm, mips, mips64, mipsn32, powerpc, powerpc64 and sh have
cpu feature bits defined in linux for AT_HWCAP auxv entry, so expose
those in sys/auxv.h

it seems the mips hwcaps were never exposed to userspace neither
by linux nor by glibc, but that's most likely an oversight.
2016-10-20 01:28:25 -04:00
Szabolcs Nagy
189acc705e add sh syscall numbers from linux v4.8
sh was updated in linux commit 74bdaa611fa69368fb4032ad437af073d31116bd
to have numbers for new syscalls.
2016-10-20 01:27:24 -04:00
Rich Felker
7cc3a28eed fix pread/pwrite syscall calling convention on sh
despite sh not generally using register-pair alignment for 64-bit
syscall arguments, there are arch-specific versions of the syscall
entry points for pread and pwrite which include a dummy argument for
alignment before the 64-bit offset argument.
2016-08-11 18:36:46 -04:00
Rich Felker
befa5866ee make brace placement in public header struct definitions consistent
placing the opening brace on the same line as the struct keyword/tag
is the style I prefer and seems to be the prevailing practice in more
recent additions.

these changes were generated by the command:

find include/ arch/*/bits -name '*.h' \
-exec sed -i '/^struct [^;{]*$/{N;s/\n/ /;}' {} +

and subsequently checked by hand to ensure that the regex did not pick
up any false positives.
2016-07-03 15:02:25 -04:00
Szabolcs Nagy
6fce6ca129 remove termios2 related ioctls from sh ioctl.h
musl does not define these on other targets either.
2016-07-03 14:54:35 -04:00
Szabolcs Nagy
5ce901279e add missing TIOC* macros to ioctl.h
these are defined in linux asm/ioctls.h.
(powerpc64 and powerpc bits/ioctl.h are now identical)
2016-07-03 14:54:34 -04:00
Szabolcs Nagy
8735a921d0 add missing SIOCSIFNAME from linux/sockios.h to ioctl.h
glibc ioctl.h has it too.
2016-07-03 14:54:33 -04:00
Szabolcs Nagy
2df9ae9161 remove ioctl macros that were removed from linux uapi
TIOCTTYGSTRUCT, TIOCGHAYESESP, TIOCSHAYESESP and TIOCM_MODEM_BITS
were removed from the linux uapi and not present in glibc ioctl.h
2016-07-03 14:54:33 -04:00
Bobby Bingham
63e3a1661f deduplicate __NR_* and SYS_* syscall number definitions 2016-05-12 00:34:05 -05:00
Szabolcs Nagy
e9f1c7981a deduplicate bits/mman.h
currently five targets use the same mman.h constants and the rest
share most constants too, so move them to sys/mman.h before the
bits/mman.h include where the differences can be corrected by
redefinition of the macros.

this fixes two minor bugs: POSIX_MADV_DONTNEED was wrong on most
targets (it should be the same as MADV_DONTNEED), and sh defined
the x86-only MAP_32BIT mmap flag.
2016-03-18 22:40:28 -04:00
Rich Felker
4dfac11538 deduplicate the bulk of the arch bits headers
all bits headers that were identical for a number of 'clean' archs are
moved to the new arch/generic tree. in addition, a few headers that
differed only cosmetically from the new generic version are removed.

additional deduplication may be possible in mman.h and in several
headers (limits.h, posix.h, stdint.h) that mostly depend on whether
the arch is 32- or 64-bit, but they are left alone for now because
greater gains are likely possible with more invasive changes to header
logic, which is beyond the scope of this commit.
2016-01-27 21:52:14 -05:00
Szabolcs Nagy
789ff6a9f8 add MCL_ONFAULT and MLOCK_ONFAULT mlockall and mlock2 flags
they lock faulted pages into memory (useful when a small part of a
large mapped file needs efficient access), new in linux v4.4, commit
b0f205c2a3082dd9081f9a94e50658c5fa906ff1

MLOCK_* is not in the POSIX reserved namespace for sys/mman.h
2016-01-26 18:31:05 -05:00
Rich Felker
4de1bc1164 remove sh port's __fpscr_values source file
commit f3ddd17380, the dynamic linker
bootstrap overhaul, silently disabled the definition of __fpscr_values
in this file since libc.so's copy of __fpscr_values now comes from
crt_arch.h, the same place the public definition in the main program's
crt1.o ultimately comes from. remove this file which is no longer in
use.
2016-01-22 03:50:58 +00:00
Rich Felker
007907a93c move sh port's __shcall internal function from arch/sh/src to src tree 2016-01-22 03:50:08 +00:00
Rich Felker
230bfe1a7d move sh __unmapself code from arch/sh/src to main src tree 2016-01-22 03:46:00 +00:00
Rich Felker
61b1e75f7d overhaul sh atomics for new atomics framework, add j-core cas.l backend
sh needs runtime-selected atomic backends since there are a number of
supported models that use non-forwards-compatible (non-smp-compatible)
atomic mechanisms. previously, the code paths for this were highly
inefficient since they involved C function calls with multiple
branches in the callee and heavy spills in the caller. the new code
performs calls the runtime-selected asm fragment from inline asm with
extremely minimal clobbers, rather than using a function call.

for the sh4a case where the atomic mechanism is known and there is no
forward-compatibility issue, the movli.l and movco.l instructions are
provided as a_ll and a_sc, allowing the new shared atomic.h to
generate efficient inline versions of all the basic atomic operations
without needing a cas loop.
2016-01-21 19:43:04 +00:00
Rich Felker
1315596b51 refactor internal atomic.h
rather than having each arch provide its own atomic.h, there is a new
shared atomic.h in src/internal which pulls arch-specific definitions
from arc/$(ARCH)/atomic_arch.h. the latter can be extremely minimal,
defining only a_cas or new ll/sc type primitives which the shared
atomic.h will use to construct everything else.

this commit avoids making heavy changes to the individual archs'
atomic implementations. definitions which are identical or
near-identical to what the new shared atomic.h would produce have been
removed, but otherwise the changes made are just hooking up the
arch-specific files to the new infrastructure. major changes to take
advantage of the new system will come in subsequent commits.
2016-01-21 19:08:54 +00:00
Rich Felker
9439ebd766 fix dynamic loader library mapping for nommu systems
on linux/nommu, non-writable private mappings of files may actually
use memory shared with other processes or the fs cache. the old nommu
loader code (used when mmap with MAP_FIXED fails) simply wrote over
top of the original file mapping, possibly clobbering this shared
memory. no such breakage was observed in practice, but it should have
been possible.

the new code starts by mapping anonymous writable memory on archs that
might support nommu, then maps load segments over top of it, falling
back to read if MAP_FIXED fails. we use an anonymous map rather than a
writable file map to avoid reading more data from disk than needed.
since pages cannot be loaded lazily on fault, in case of large
data/bss, mapping the full file may read a lot of data that will
subsequently be thrown away when processing additional LOAD segments.
as a result, we cannot skip the first LOAD segment when operating in
this mode.

these changes affect only non-FDPIC nommu support.
2015-11-11 17:40:27 -05:00
Rich Felker
4fcb48275a generalize sh entry point asm not to assume call dests fit in 12 bits
this assumption is borderline-unsafe to begin with, and fails badly
with -ffunction-sections since the linker can move the callee
arbitrarily far away when it lies in a different section.
2015-11-02 18:11:36 -05:00
Rich Felker
cb1bf2f321 properly access mcontext_t program counter in cancellation handler
using the actual mcontext_t definition rather than an overlaid pointer
array both improves correctness/readability and eliminates some ugly
hacks for archs with 64-bit registers bit 32-bit program counter.

also fix UB due to comparison of pointers not in a common array
object.
2015-11-02 12:41:49 -05:00
Rich Felker
b61df2294f fix signal return for sh/fdpic
the restorer function pointer provided in the kernel sigaction
structure is interpreted by the kernel as a raw code address, not a
function descriptor.

this commit moves the declarations of the __restore and __restore_rt
symbols to ksigaction.h so that arch versions of the file can override
them, and introduces a version for sh which declares them as objects
rather than functions.

an alternate solution would have been defining SA_RESTORER to 0 so
that the functions are not used, but this both requires executable
stack (since the sh kernel does not have a vdso page with permanent
restorer functions) and crashes on qemu user-level emulation.
2015-09-23 18:33:49 +00:00
Rich Felker
e9e770dfd6 have sh/fdpic entry point set fdpic personality if needed
the entry point code supports being loaded by a loader which is not
fdpic-aware (in practice, either kernel with mmu or qemu without fdpic
support). this mostly just works, but signal handling will wrongly use
a function descriptor address as a code address if the personality is
not adjusted to fdpic.

ideally this code could be placed with sigaction so that it's not
needed except if/when a signal handler is installed. however,
personality is incorrectly maintained per-thread by the kernel, rather
than per-process, so it's necessary to correct the personality before
any threads are started. also, in order to skip the personality
syscall when an fdpic-aware loader is used, we need to be able to
detect how the program was loaded, and this information is only
readily available at the entry point.
2015-09-22 20:51:59 +00:00
Rich Felker
eaf7ab6e24 add real fdpic loading of shared libraries
previously, the normal ELF library loading code was used even for
fdpic, so only the kernel-loaded dynamic linker and main app could
benefit from separate placement of segments and shared text.
2015-09-22 19:12:48 +00:00
Rich Felker
7f9086df95 size-optimize sh/fdpic dynamic entry point
the __fdpic_fixup code is not needed for ET_DYN executables, which
instead use reloctions, so we can omit it from the dynamic linker and
static-pie entry point and save some code size.
2015-09-22 04:14:07 +00:00
Rich Felker
cab2b1f9d7 work around breakage in sh/fdpic __unmapself function
the C implementation of __unmapself used for potentially-nommu sh
assumed CRTJMP takes a function descriptor rather than a code address;
however, the actual dynamic linker needs a code address, and so commit
7a9669e977 changed the definition of the
macro in reloc.h. this commit puts the old macro back in a place where
it only affects __unmapself.

this is an ugly workaround and should be cleaned up at some point, but
at least it's well isolated.
2015-09-22 04:10:42 +00:00
Rich Felker
7a9669e977 add general fdpic support in dynamic linker and arch support for sh
at this point not all functionality is complete. the dynamic linker
itself, and main app if it is also loaded by the kernel, take
advantage of fdpic and do not need constant displacement between
segments, but additional libraries loaded by the dynamic linker follow
normal ELF semantics for mapping still. this fully works, but does not
admit shared text on nommu.

in terms of actual functional correctness, dlsym's results are
presently incorrect for function symbols, RTLD_NEXT fails to identify
the caller correctly, and dladdr fails almost entirely.

with the dynamic linker entry point working, support for static pie is
automatically included, but linking the main application as ET_DYN
(pie) probably does not make sense for fdpic anyway. ET_EXEC is
equally relocatable but more efficient at representing relocations.
2015-09-22 03:54:42 +00:00
Rich Felker
d4c82d05b8 add sh fdpic subarch variants
with this commit it should be possible to produce a working
static-linked fdpic libc and application binaries for sh.

the changes in reloc.h are largely unused at this point since dynamic
linking is not supported, but the CRTJMP macro is used one place
outside of dynamic linking, in __unmapself.
2015-09-12 03:23:49 +00:00
Rich Felker
4ccc1a01e0 add fdpic version of entry point code for sh
this version of the entry point is only suitable for static linking in
ET_EXEC form. neither dynamic linking nor pie is supported yet. at
some point in the future the fdpic and non-fdpic versions of this code
may be unified but for now it's easiest to work with them separately.
2015-09-12 03:18:08 +00:00
Rich Felker
234c58467c make sh clone asm fdpic-compatible
clone calls back to a function pointer provided by the caller, which
will actually be a pointer to a function descriptor on fdpic. the
obvious solution is to have a separate version of clone for fdpic, but
I have taken a simpler approach to go around the problem. instead of
calling the pointed-to function from asm, a direct call is made to an
internal C function which then calls the pointed-to function. this
lets the C compiler generate the appropriate calling convention for an
indirect call with no need for ABI-specific assembly.
2015-09-12 02:55:28 +00:00
Rich Felker
10d0268ccf switch to using trap number 31 for syscalls on sh
nominally the low bits of the trap number on sh are the number of
syscall arguments, but they have never been used by the kernel, and
some code making syscalls does not even know the number of arguments
and needs to pass an arbitrary high number anyway.

sh3/sh4 traditionally used the trap range 16-31 for syscalls, but part
of this range overlapped with hardware exceptions/interrupts on sh2
hardware, so an incompatible range 32-47 was chosen for sh2.

using trap number 31 everywhere, since it's in the existing sh3/sh4
range and does not conflict with sh2 hardware, is a proposed
unification of the kernel syscall convention that will allow binaries
to be shared between sh2 and sh3/sh4. if this is not accepted into the
kernel, we can refit the sh2 target with runtime selection mechanisms
for the trap number, but doing so would be invasive and would entail
non-trivial overhead.
2015-06-16 15:25:02 +00:00
Rich Felker
3366a99b17 switch sh port's __unmapself to generic version when running on sh2/nommu
due to the way the interrupt and syscall trap mechanism works,
userspace on sh2 must never set the stack pointer to an invalid value.
thus, the approach used on most archs, where __unmapself executes with
no stack for the interval between SYS_munmap and SYS_exit, is not
viable on sh2.

in order not to pessimize sh3/sh4, the sh asm version of __unmapself
is not removed. instead it's renamed and redirected through code that
calls either the generic (safe) __unmapself or the sh3/sh4 asm,
depending on compile-time and run-time conditions.
2015-06-16 14:55:06 +00:00
Rich Felker
f9d84554ba add support for sh2 interrupt-masking-based atomics to sh port
the sh2 target is being considered an ISA subset of sh3/sh4, in the
sense that binaries built for sh2 are intended to be usable on later
cpu models/kernels with mmu support. so rather than hard-coding
sh2-specific atomics, the runtime atomic selection mechanisms that was
already in place has been extended to add sh2 atomics.

at this time, the sh2 atomics are not SMP-compatible; since the ISA
lacks actual atomic operations, the new code instead masks interrupts
for the duration of the atomic operation, producing an atomic result
on single-core. this is only possible because the kernel/hardware does
not impose protections against userspace doing so. additional changes
will be needed to support future SMP systems.

care has been taken to avoid producing significant additional code
size in the case where it's known at compile-time that the target is
not sh2 and does not need sh2-specific code.
2015-06-16 14:38:41 +00:00