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authorWaldemar Brodkorb <wbx@uclibc-ng.org>2016-04-23 10:17:56 (GMT)
committerWaldemar Brodkorb <wbx@uclibc-ng.org>2016-04-26 17:41:08 (GMT)
commit2b3cdadee36b0445ed799932358dd94a1e839b46 (patch)
tree88120c5bcbf0a5420b3407bc5b0ccc1f0eae1456 /libc
parentf1dcb9beedc5d05238e90cfbad026736d6efe891 (diff)
sparc: add deprecated context switching functions
Ported over from glibc mostly without changes. Lightly tested with mongrel2 in qemu-system-sparc.
Diffstat (limited to 'libc')
-rw-r--r--libc/sysdeps/linux/sparc/Makefile.arch3
-rw-r--r--libc/sysdeps/linux/sparc/getcontext.S84
-rw-r--r--libc/sysdeps/linux/sparc/makecontext.c92
-rw-r--r--libc/sysdeps/linux/sparc/setcontext.S118
-rw-r--r--libc/sysdeps/linux/sparc/swapcontext.S118
-rw-r--r--libc/sysdeps/linux/sparc/ucontext_i.sym61
6 files changed, 476 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/sparc/Makefile.arch b/libc/sysdeps/linux/sparc/Makefile.arch
index 0173eff..92ea7d9 100644
--- a/libc/sysdeps/linux/sparc/Makefile.arch
+++ b/libc/sysdeps/linux/sparc/Makefile.arch
@@ -13,6 +13,9 @@ SSRC-y := \
SSRC-$(if $(UCLIBC_HAS_THREADS_NATIVE),,y) += fork.S vfork.S clone.S
+CSRC-$(UCLIBC_HAS_CONTEXT_FUNCS) += makecontext.c
+SSRC-$(UCLIBC_HAS_CONTEXT_FUNCS) += getcontext.S setcontext.S swapcontext.S
+
# check weather __LONG_DOUBLE_128__ is defined (long double support)
UCLIBC_SPARC_HAS_LONG_DOUBLE=$(shell if [ "x`$(CC) -E -dM -xc /dev/null 2>&1 | grep __LONG_DOUBLE_128__`" != "x" ]; then echo "y"; fi)
ifeq ($(UCLIBC_SPARC_HAS_LONG_DOUBLE),y)
diff --git a/libc/sysdeps/linux/sparc/getcontext.S b/libc/sysdeps/linux/sparc/getcontext.S
new file mode 100644
index 0000000..615a2c1
--- /dev/null
+++ b/libc/sysdeps/linux/sparc/getcontext.S
@@ -0,0 +1,84 @@
+/* Save current context.
+ Copyright (C) 2008-2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by David S. Miller <davem@davemloft.net>, 2008.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+#include "ucontext_i.h"
+
+/* int __getcontext (ucontext_t *ucp)
+
+ Saves the machine context in UCP such that when it is activated,
+ it appears as if __getcontext() returned again.
+
+ This implementation is intended to be used for *synchronous* context
+ switches only. Therefore, it does not have to save anything
+ other than the PRESERVED state. */
+
+
+ENTRY(__getcontext)
+ save %sp, -112, %sp
+ st %g0, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_PSR]
+
+ /* In reality, we only use the GREG_PC value when setting
+ or swapping contexts. But we fill in NPC for completeness. */
+ add %i7, 8, %o0
+ st %o0, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_PC]
+ add %o0, 4, %o0
+ st %o0, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_NPC]
+
+ rd %y, %o1
+ st %o1, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_Y]
+
+ st %g1, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G1]
+ st %g2, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G2]
+ st %g3, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G3]
+ st %g4, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G4]
+ st %g5, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G5]
+ st %g6, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G6]
+ st %g7, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G7]
+
+ mov SIG_BLOCK, %o0
+ clr %o1
+ add %i0, UC_SIGMASK, %o2
+ mov 8, %o3
+ mov __NR_rt_sigprocmask, %g1
+ ta 0x10
+
+ /* Zero, success, return value. */
+ st %g0, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O0]
+ st %i1, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O1]
+ st %i2, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O2]
+ st %i3, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O3]
+ st %i4, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O4]
+ st %i5, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O5]
+ st %i6, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O6]
+ st %i7, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O7]
+
+ st %g0, [%i0 + UC_MCONTEXT + MC_GWINS]
+
+ /* Do not save FPU state, it is volatile across calls. */
+ stb %g0, [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_EN]
+
+ st %g0, [%i0 + UC_MCONTEXT + MC_XRS + XRS_ID]
+ st %g0, [%i0 + UC_MCONTEXT + MC_XRS + XRS_PTR]
+ jmpl %i7 + 8, %g0
+ restore %g0, %g0, %o0
+END(__getcontext)
+
+weak_alias (__getcontext, getcontext)
diff --git a/libc/sysdeps/linux/sparc/makecontext.c b/libc/sysdeps/linux/sparc/makecontext.c
new file mode 100644
index 0000000..3a9f70c
--- /dev/null
+++ b/libc/sysdeps/linux/sparc/makecontext.c
@@ -0,0 +1,92 @@
+/* Create new context.
+ Copyright (C) 2008-2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by David S. Miller <davem@davemloft.net>, 2008.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <ucontext.h>
+
+/* Sets up the outgoing arguments and the program counter for a user
+ context for the requested function call.
+
+ Returning to the correct parent context is pretty simple on
+ Sparc. We only need to link up the register windows correctly.
+ Since global registers are clobbered by calls, we need not be
+ concerned about those, and thus is all could be worked out without
+ using a trampoline.
+
+ Except that we must deal with the signal mask, thus a trampoline
+ is unavoidable. 32-bit stackframe layout:
+ +-----------------------------------------+
+ | 7th and further parameters |
+ +-----------------------------------------+
+ | backup storage for initial 6 parameters |
+ +-----------------------------------------+
+ | struct return pointer |
+ +-----------------------------------------+
+ | 8 incoming registers |
+ +-----------------------------------------+
+ | 8 local registers |
+ %sp --> +-----------------------------------------+
+
+*/
+
+void
+__makecontext (ucontext_t *ucp, void (*func) (void), int argc, ...)
+{
+ extern void __start_context (void);
+ unsigned long int *sp;
+ va_list ap;
+ int i;
+
+ sp = (unsigned long int *) (ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size);
+ sp -= 16 + 7 + argc;
+ sp = (unsigned long int *) (((uintptr_t) sp) & ~(8 - 1));
+
+ for (i = 0; i < 8; i++)
+ sp[i + 8] = ucp->uc_mcontext.gregs[REG_O0 + i];
+
+ /* The struct return pointer is essentially unused, so we can
+ place the link there. */
+ sp[16] = (unsigned long int) ucp->uc_link;
+
+ va_start (ap, argc);
+
+ /* Fill in outgoing arguments, including those which will
+ end up being passed on the stack. */
+ for (i = 0; i < argc; i++)
+ {
+ unsigned long int arg = va_arg (ap, unsigned long int);
+ if (i < 6)
+ ucp->uc_mcontext.gregs[REG_O0 + i] = arg;
+ else
+ sp[i + 23 - 6] = arg;
+ }
+
+ va_end (ap);
+
+ ucp->uc_mcontext.gregs[REG_O6] = (unsigned long int) sp;
+
+ ucp->uc_mcontext.gregs[REG_O7] = ((unsigned long int) __start_context) - 8;
+
+ ucp->uc_mcontext.gregs[REG_PC] = (unsigned long int) func;
+ ucp->uc_mcontext.gregs[REG_nPC] = ucp->uc_mcontext.gregs[REG_PC] + 4;
+}
+
+weak_alias (__makecontext, makecontext)
diff --git a/libc/sysdeps/linux/sparc/setcontext.S b/libc/sysdeps/linux/sparc/setcontext.S
new file mode 100644
index 0000000..f9da215
--- /dev/null
+++ b/libc/sysdeps/linux/sparc/setcontext.S
@@ -0,0 +1,118 @@
+/* Install given context.
+ Copyright (C) 2008-2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by David S. Miller <davem@davemloft.net>, 2008.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+#include "ucontext_i.h"
+
+#define ST_FLUSH_WINDOWS 3
+
+/* int __setcontext (const ucontext_t *ucp)
+
+ Restores the machine context in UCP and thereby resumes execution
+ in that context.
+
+ This implementation is intended to be used for *synchronous* context
+ switches only. Therefore, it does not have to restore anything
+ other than the PRESERVED state. */
+
+ENTRY(__setcontext)
+ save %sp, -112, %sp
+
+ mov SIG_SETMASK, %o0
+ add %i0, UC_SIGMASK, %o1
+ clr %o2
+ mov 8, %o3
+ mov __NR_rt_sigprocmask, %g1
+ ta 0x10
+
+ /* This is a bit on the expensive side, and we could optimize
+ the unwind similar to how the 32-bit sparc longjmp code
+ does if performance of this routine really matters. */
+ ta ST_FLUSH_WINDOWS
+
+ ldub [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_EN], %g1
+ cmp %g1, 0
+ be 1f
+ nop
+ ld [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_FSR], %fsr
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D0], %f0
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D2], %f2
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D4], %f4
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D6], %f6
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D8], %f8
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D10], %f10
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D12], %f12
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D14], %f14
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D16], %f16
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D18], %f18
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D20], %f20
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D22], %f22
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D24], %f24
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D26], %f26
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D28], %f28
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D30], %f30
+1:
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_Y], %g1
+ wr %g1, 0x0, %y
+
+ /* We specifically do not restore %g1 since we need it here as
+ a temporary. */
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G2], %g2
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G3], %g3
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G4], %g4
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G5], %g5
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G6], %g6
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G7], %g7
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O1], %i1
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O2], %i2
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O3], %i3
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O4], %i4
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O5], %i5
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O6], %i6
+ restore
+ ld [%o0 + UC_MCONTEXT + MC_GREGS + GREG_O7], %o7
+ ld [%o0 + UC_MCONTEXT + MC_GREGS + GREG_PC], %g1
+ jmpl %g1, %g0
+ ld [%o0 + UC_MCONTEXT + MC_GREGS + GREG_O0], %o0
+END(__setcontext)
+
+weak_alias (__setcontext, setcontext)
+
+/* This is the helper code which gets called if a function which is
+ registered with 'makecontext' returns. In this case we have to
+ install the context listed in the uc_link element of the context
+ 'makecontext' manipulated at the time of the 'makecontext' call.
+ If the pointer is NULL the process must terminate. */
+
+ENTRY(__start_context)
+ ld [%sp + (16 * 4)], %g1
+ cmp %g1, 0
+ be,a 1f
+ clr %o0
+ call __setcontext
+ mov %g1, %o0
+ /* If this returns (which can happen if the syscall fails) we'll
+ exit the program with the return error value (-1). */
+1: call HIDDEN_JUMPTARGET(exit)
+ nop
+ /* The 'exit' call should never return. In case it does cause
+ the process to terminate. */
+ unimp
+END(__start_context)
diff --git a/libc/sysdeps/linux/sparc/swapcontext.S b/libc/sysdeps/linux/sparc/swapcontext.S
new file mode 100644
index 0000000..7dc7e2e
--- /dev/null
+++ b/libc/sysdeps/linux/sparc/swapcontext.S
@@ -0,0 +1,118 @@
+/* Save current context and install the given one.
+ Copyright (C) 2008-2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by David S. Miller <davem@davemloft.net>, 2008.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+#include "ucontext_i.h"
+
+#define ST_FLUSH_WINDOWS 3
+
+/* int __swapcontext (ucontext_t *oucp, const ucontext_t *ucp);
+
+ Saves the machine context in oucp such that when it is activated,
+ it appears as if __swapcontext() returned again, restores the
+ machine context in ucp and thereby resumes execution in that
+ context.
+
+ This implementation is intended to be used for *synchronous* context
+ switches only. Therefore, it does not have to save anything
+ other than the PRESERVED state. */
+
+ENTRY(__swapcontext)
+ save %sp, -112, %sp
+ ta ST_FLUSH_WINDOWS
+ st %g0, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_PSR]
+ add %i7, 8, %o0
+ st %o0, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_PC]
+ add %o0, 4, %o0
+ st %o0, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_NPC]
+ rd %y, %o1
+ st %o1, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_Y]
+ st %g1, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G1]
+ st %g2, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G2]
+ st %g3, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G3]
+ st %g4, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G4]
+ st %g5, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G5]
+ st %g6, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G6]
+ st %g7, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G7]
+ st %g0, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O0]
+ st %i1, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O1]
+ st %i2, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O2]
+ st %i3, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O3]
+ st %i4, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O4]
+ st %i5, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O5]
+ st %i6, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O6]
+ st %i7, [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O7]
+ st %g0, [%i0 + UC_MCONTEXT + MC_GWINS]
+ stb %g0, [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_EN]
+ st %g0, [%i0 + UC_MCONTEXT + MC_XRS + XRS_ID]
+ st %g0, [%i0 + UC_MCONTEXT + MC_XRS + XRS_PTR]
+
+ mov SIG_SETMASK, %o0
+ add %i1, UC_SIGMASK, %o1
+ add %i0, UC_SIGMASK, %o2
+ mov 8, %o3
+ mov __NR_rt_sigprocmask, %g1
+ ta 0x10
+
+ mov %i1, %i0
+ ldub [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_EN], %g1
+ cmp %g1, 0
+ be 1f
+ nop
+ ld [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_FSR], %fsr
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D0], %f0
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D2], %f2
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D4], %f4
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D6], %f6
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D8], %f8
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D10], %f10
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D12], %f12
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D14], %f14
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D16], %f16
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D18], %f18
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D20], %f20
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D22], %f22
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D24], %f24
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D26], %f26
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D28], %f28
+ ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D30], %f30
+1:
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_Y], %g1
+ wr %g1, 0x0, %y
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G2], %g2
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G3], %g3
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G4], %g4
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G5], %g5
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G6], %g6
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G7], %g7
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O1], %i1
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O2], %i2
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O3], %i3
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O4], %i4
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O5], %i5
+ ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O6], %i6
+ restore
+ ld [%o0 + UC_MCONTEXT + MC_GREGS + GREG_O7], %o7
+ ld [%o0 + UC_MCONTEXT + MC_GREGS + GREG_PC], %g1
+ jmpl %g1, %g0
+ ld [%o0 + UC_MCONTEXT + MC_GREGS + GREG_O0], %o0
+END(__swapcontext)
+
+weak_alias (__swapcontext, swapcontext)
diff --git a/libc/sysdeps/linux/sparc/ucontext_i.sym b/libc/sysdeps/linux/sparc/ucontext_i.sym
new file mode 100644
index 0000000..544030c
--- /dev/null
+++ b/libc/sysdeps/linux/sparc/ucontext_i.sym
@@ -0,0 +1,61 @@
+#include <stddef.h>
+#include <signal.h>
+#include <sys/ucontext.h>
+
+--
+
+SIG_BLOCK
+SIG_SETMASK
+
+UC_FLAGS offsetof (ucontext_t, uc_flags)
+UC_LINK offsetof (ucontext_t, uc_link)
+UC_SIGMASK offsetof (ucontext_t, uc_sigmask)
+UC_STACK offsetof (ucontext_t, uc_stack)
+UC_MCONTEXT offsetof (ucontext_t, uc_mcontext)
+MC_GREGS offsetof (mcontext_t, gregs)
+MC_GWINS offsetof (mcontext_t, gwins)
+MC_FPREGS offsetof (mcontext_t, fpregs)
+MC_XRS offsetof (mcontext_t, xrs)
+MC_FILLER offsetof (mcontext_t, filler)
+GREG_PSR (REG_PSR * sizeof(greg_t))
+GREG_PC (REG_PC * sizeof(greg_t))
+GREG_NPC (REG_nPC * sizeof(greg_t))
+GREG_Y (REG_Y * sizeof(greg_t))
+GREG_G1 (REG_G1 * sizeof(greg_t))
+GREG_G2 (REG_G2 * sizeof(greg_t))
+GREG_G3 (REG_G3 * sizeof(greg_t))
+GREG_G4 (REG_G4 * sizeof(greg_t))
+GREG_G5 (REG_G5 * sizeof(greg_t))
+GREG_G6 (REG_G6 * sizeof(greg_t))
+GREG_G7 (REG_G7 * sizeof(greg_t))
+GREG_O0 (REG_O0 * sizeof(greg_t))
+GREG_O1 (REG_O1 * sizeof(greg_t))
+GREG_O2 (REG_O2 * sizeof(greg_t))
+GREG_O3 (REG_O3 * sizeof(greg_t))
+GREG_O4 (REG_O4 * sizeof(greg_t))
+GREG_O5 (REG_O5 * sizeof(greg_t))
+GREG_O6 (REG_O6 * sizeof(greg_t))
+GREG_O7 (REG_O7 * sizeof(greg_t))
+FPU_D0 offsetof (fpregset_t, fpu_fr.fpu_dregs[0])
+FPU_D2 offsetof (fpregset_t, fpu_fr.fpu_dregs[1])
+FPU_D4 offsetof (fpregset_t, fpu_fr.fpu_dregs[2])
+FPU_D6 offsetof (fpregset_t, fpu_fr.fpu_dregs[3])
+FPU_D8 offsetof (fpregset_t, fpu_fr.fpu_dregs[4])
+FPU_D10 offsetof (fpregset_t, fpu_fr.fpu_dregs[5])
+FPU_D12 offsetof (fpregset_t, fpu_fr.fpu_dregs[6])
+FPU_D14 offsetof (fpregset_t, fpu_fr.fpu_dregs[7])
+FPU_D16 offsetof (fpregset_t, fpu_fr.fpu_dregs[8])
+FPU_D18 offsetof (fpregset_t, fpu_fr.fpu_dregs[9])
+FPU_D20 offsetof (fpregset_t, fpu_fr.fpu_dregs[10])
+FPU_D22 offsetof (fpregset_t, fpu_fr.fpu_dregs[11])
+FPU_D24 offsetof (fpregset_t, fpu_fr.fpu_dregs[12])
+FPU_D26 offsetof (fpregset_t, fpu_fr.fpu_dregs[13])
+FPU_D28 offsetof (fpregset_t, fpu_fr.fpu_dregs[14])
+FPU_D30 offsetof (fpregset_t, fpu_fr.fpu_dregs[15])
+FPU_Q offsetof (fpregset_t, fpu_q)
+FPU_FSR offsetof (fpregset_t, fpu_fsr)
+FPU_QCNT offsetof (fpregset_t, fpu_qcnt)
+FPU_Q_ENTRY_SZ offsetof (fpregset_t, fpu_q_entrysize)
+FPU_EN offsetof (fpregset_t, fpu_en)
+XRS_ID offsetof (xrs_t, xrs_id)
+XRS_PTR offsetof (xrs_t, xrs_ptr)