Merge "libc: Provide ucontext_t/mcontext_t/<sys/ucontext.h>"

1 files changed, 141 insertions, 0 deletions

diff --git a/libc/arch-mips/include/machine/ucontext.h b/libc/arch-mips/include/machine/ucontext.h
new file mode 100644
index 0000000..df3b64b
--- /dev/null
+++ b/libc/arch-mips/include/machine/ucontext.h
@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#ifndef _ARCH_MIPS_SYS_UCONTEXT_H_
+#define _ARCH_MIPS_SYS_UCONTEXT_H_
+
+#include <signal.h>
+#include <stdint.h>
+
+__BEGIN_DECLS
+
+/* Technical note:
+ *
+ * On MIPS, there are differences in the way GLibc and the Linux kernel declare
+ * ucontext_t:
+ *
+ *  - The kernel implements 'uc_mcontext' with a 'struct sigcontext',
+ *    while GLibc defines 'mcontext_t' in a binary-compatible way
+ *    (same size, same binary layout), but with different field naming/access
+ *    convention.
+ *
+ *    The biggest difference is the naming of the fields. The kernel uses
+ *    a 'sc_' prefix (e.g. "sc_gregs[]"), while GLibc does not ("gregs[]").
+ *
+ *    For maximum portability of existing client code, this header follows
+ *    the GLibc convention. Client code, and the C library, should never
+ *    try to include <asm/ucontext.h>
+ *
+ *  Apart from that, all floating point state is stored in uc_mcontext
+ *  in the same way, which is much simpler than ARM and x86 schemes for it.
+ *  As such, there is no _libc_fpstate.
+ *
+ *  Reference source files:
+ *    $KERNEL/arch/mips/include/asm/sigcontext.h
+ *    $KERNEL/arch/mips/include/asm/ucontext.h
+ *
+ *    $GLIBC/sysdeps/unix/sysv/linux/mips/getcontext.S
+ *    $GLIBC/sysdeps/unix/sysv/linux/mips/setcontext.S
+ *    $GLIBC/sysdeps/unix/sysv/linux/mips/sys/ucontext.h
+ */
+
+/* First, the kernel-compatible version, for reference. */
+typedef struct __kernel_ucontext {
+  unsigned long              uc_flags;
+  struct __kernel_ucontext*  uc_link;
+  stack_t                    uc_stack;
+  struct sigcontext          uc_mcontext;
+  __kernel_sigset_t          uc_sigmask;
+} __kernel_ucontext_t;
+
+/* Second, the GLibc-compatible version */
+
+__extension__ /* Required to build in ANSI C mode */
+typedef unsigned long long greg_t;
+
+#define NGREG   32
+#define NFPREG  32
+
+typedef greg_t  gregset_t[NGREG];
+
+typedef struct fpregset {
+  union {
+    double fp_dregs[NFPREG];
+    struct {
+      float     _fp_fregs;
+      unsigned  _fp_pad;
+    } fp_fregs[NFPREG];
+  } fp_r;
+} fpregset_t;
+
+#ifndef _MIPS_SIM
+#error "_MIPS_SIM should be defined by your Android MIPS toolchain!"
+#endif
+
+#ifndef _OABI32
+#error "_OABI32 should be defined by your Android MIPS toolchain!"
+#endif
+
+#if _MIPS_SIM != _OABI32
+#error "Only _OABI32 is supported on Android MIPS!"
+#endif
+
+typedef struct {
+  unsigned   regmask;
+  unsigned   status;
+  greg_t     pc;
+  gregset_t  gregs;
+  fpregset_t fpregs;
+  unsigned   fp_owned;
+  unsigned   fpc_csr;
+  unsigned   fpc_eir;
+  unsigned   used_math;
+  unsigned   dsp;
+  greg_t     mdhi;
+  greg_t     mdlo;
+  unsigned   hi1;
+  unsigned   lo1;
+  unsigned   hi2;
+  unsigned   lo2;
+  unsigned   hi3;
+  unsigned   lo3;
+} mcontext_t;
+
+typedef struct ucontext {
+  uint32_t          uc_flags;
+  struct ucontext*  uc_link;
+  stack_t           uc_stack;
+  mcontext_t        uc_mcontext;
+  /* Only expose the signals in Bionic's 32-bit sigset_t.
+   * The _unused field is required padding from the kernel. */
+  sigset_t          uc_sigmask;
+  char _unused[sizeof(__kernel_sigset_t) - sizeof(sigset_t)];
+} ucontext_t;
+
+__END_DECLS
+
+#endif /* _ARCH_MIPS_SYS_UCONTEXT_H_ */