now that commit f7f1079796 removed the
legacy i386 conditional definition, va_list is in no way
arch-specific, and has no reason to be in the future. move it to the
shared part of alltypes.h.in
commit ab3eb89a8b removed it as part of
correcting the mcontext_t definition, but there is still code using
struct sigcontext and expecting the member names present in it, most
notably libgcc_eh. almost all such usage is incorrect, but bring back
struct sigcontext at least for now so as not to introduce regressions.
in order for sys/procfs.h (provided by sys/user.h) to be useful, it
needs to match the API its consumers (gdb, etc.) expect, including the
member names established by glibc.
this partly reverts commit 29e8737f81,
which partly reverted d493206de7,
eliminating struct user_fpregs_struct which seems to have had no
precedent and using union __riscv_mc_fp_state for elf_fpregset_t. this
requires indirect inclusion of signal.h to make union
__riscv_mc_fp_state visible, but being that these are nonstandard
"junk" headers with no official restrictions on what they can pull in,
that's no big deal.
split off and expanded from patch by Khem Raj.
the top-level mcontext_t member names were namespace-violating in
standards profiles before, and nested-level member names (some of them
single-letter) were egregiously bad namespace impositions even in
non-strict profiles. moreover, they mismatched those used in the
public API first defined in glibc, breaking any code making use of
them.
unlike most archs, the public API used in glibc for riscv mcontext_t
members was designed to be namespace-safe, so we can and should expose
the members regardless of feature test macros. only the typedefs for
greg_t, gregset_t, and fpregset_t need to be protected behind FTMs.
the struct tags for mcontext_t and ucontext_t are also changed. for
mcontext_t this is necessary to make the common definition across
profiles namespace-safe. for ucontext_t, it's just a matter of
matching the tag from the glibc-defined API.
these changes are split off and expanded from a patch by Khem Raj.
The operand sepcifiers in a_cas and a_cas_p for riscv64 were incorrect:
there's a backwards branch in the routine, so despite tmp being written
at the end of the assembly fragment it cannot be allocated in one of the
input registers because the input values may be needed for another trip
around the loop.
For code that follows the guaranteed forward progress requirements, the
backwards branch is rarely taken: SiFive's hardware only fails a store
conditional on execptional cases (ie, instruction cache misses inside
the loop), and until recently a bug in QEMU allowed back-to-back
store conditionals to succeed. The bug has been fixed in the latest
QEMU release, but it turns out that the fix caused this latent bug in
musl to manifest.
new mount api syscalls were added, same numers on all targets, see
linux commit a07b20004793d8926f78d63eb5980559f7813404
vfs: syscall: Add open_tree(2) to reference or clone a mount
linux commit 2db154b3ea8e14b04fee23e3fdfd5e9d17fbc6ae
vfs: syscall: Add move_mount(2) to move mounts around
linux commit 24dcb3d90a1f67fe08c68a004af37df059d74005
vfs: syscall: Add fsopen() to prepare for superblock creation
linux commit ecdab150fddb42fe6a739335257949220033b782
vfs: syscall: Add fsconfig() for configuring and managing a context
linux commit 93766fbd2696c2c4453dd8e1070977e9cd4e6b6d
vfs: syscall: Add fsmount() to create a mount for a superblock
linux commit cf3cba4a429be43e5527a3f78859b1bfd9ebc5fb
vfs: syscall: Add fspick() to select a superblock for reconfiguration
linux commit 9c8ad7a2ff0bfe58f019ec0abc1fb965114dde7d
uapi, x86: Fix the syscall numbering of the mount API syscalls [ver #2]
linux commit d8076bdb56af5e5918376cd1573a6b0007fc1a89
uapi: Wire up the mount API syscalls on non-x86 arches [ver #2]
the contents conflicted with asm/ptrace.h. glibc does not provide
anything in user.h for riscv, so software cannot be depending on it.
simplified from patch submitted by Baruch Siach.
Rename user registers struct definitions to avoid conflict with the
asm/ptrace.h kernel header that defines the same structs. Use the
__riscv_mc prefix as glibc does.
commit f3f96f2daa added these for the
rest of the archs, but the patch it corresponded to missed riscv64
since riscv64 was not yet upstream at the time. this caused commit
dfc81828f7 to break riscv64 build, due
to a wrong assumption that SYS_statx was unconditionally defined.
these differ from generic only in using endian-matched padding with a
short __ipc_perm_seq field in place of the int field in generic. this
is not a documented public interface anyway, and the original intent
was to use int here. some ports just inadvertently slipped in the
kernel short+padding form.
the definition of the IPC_64 macro controls the interface between libc
and the kernel through syscalls; it's not a public API. the meaning is
rather obscure. long ago, Linux's sysvipc *id_ds structures used
16-bit uids/gids and wrong types for a few other fields. this was in
the libc5 era, before glibc. the IPC_64 flag (64 is a misnomer; it's
more like 32) tells the kernel to use the modern[-ish] versions of the
structures.
the definition of IPC_64 has nothing to do with whether the arch is
32- or 64-bit. rather, due to either historical accident or
intentional obnoxiousness, the kernel only accepts and masks off the
0x100 IPC_64 flag conditional on CONFIG_ARCH_WANT_IPC_PARSE_VERSION,
i.e. for archs that want to provide, or that accidentally provided,
both. for archs which don't define this option, no masking is
performed and commands with the 0x100 bit set will fail as invalid. so
ultimately, the definition is just a matter of matching an arbitrary
switch defined per-arch in the kernel.
some of these were not exact duplicates, but had gratuitously
different naming for padding, or omitted the endian checks because the
arch is fixed-endian.
various padding fields in the generic bits/sem.h were defined in terms
of time_t as a cheap hack standing in for "kernel long", to allow x32
to use the generic version of the file. this was a really bad idea, as
it ended up getting copied into lots of arch-specific versions of the
bits file, and is a blocker to changing time_t to 64-bit on 32-bit
archs.
this commit adds an x32-specific version of the header, and changes
padding type back from time_t to long (currently the same type on all
archs but x32) in the generic header and all the others the hack got
copied into.
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.
the "A" constraint is simply for an address expression that's a single
register, but it's not yet supported by clang, and has no advantage
here over just using a register operand for the address. the latter is
actually preferable in the a_cas_p case because it avoids aliasing an
lvalue onto the memory.
most egregious problem was the lack of memory clobber and lack of
volatile asm; this made the atomics memory barriers but not compiler
barriers. use of "+r" rather than "=r" for a clobbered temp was also
wrong, since the initial value is indeterminate.
having "+r"(a0) is redundant with "0"(a0) in syscalls with at least 1
arg, which is arguably a constraint violation (clang treats it as
such), and an invalid input with indeterminate value in the 0-arg
case. use the "=r"(a0) form instead.
this was apparently copied from x86_64; it's not part of the kernel
API for riscv64. this change eliminates the need for a
riscv64-specific bits header and lets it use the generic one.
Author: Alex Suykov <alex.suykov@gmail.com>
Author: Aric Belsito <lluixhi@gmail.com>
Author: Drew DeVault <sir@cmpwn.com>
Author: Michael Clark <mjc@sifive.com>
Author: Michael Forney <mforney@mforney.org>
Author: Stefan O'Rear <sorear2@gmail.com>
This port has involved the work of many people over several years. I
have tried to ensure that everyone with substantial contributions has
been credited above; if any omissions are found they will be noted
later in an update to the authors/contributors list in the COPYRIGHT
file.
The version committed here comes from the riscv/riscv-musl repo's
commit 3fe7e2c75df78eef42dcdc352a55757729f451e2, with minor changes by
me for issues found during final review:
- a_ll/a_sc atomics are removed (according to the ISA spec, lr/sc
are not safe to use in separate inline asm fragments)
- a_cas[_p] is fixed to be a memory barrier
- the call from the _start assembly into the C part of crt1/ldso is
changed to allow for the possibility that the linker does not place
them nearby each other.
- DTP_OFFSET is defined correctly so that local-dynamic TLS works
- reloc.h LDSO_ARCH logic is simplified and made explicit.
- unused, non-functional crti/n asm files are removed.
- an empty .sdata section is added to crt1 so that the
__global_pointer reference is resolvable.
- indentation style errors in some asm files are fixed.
