summaryrefslogtreecommitdiff
path: root/libc/sysdeps/linux/powerpc/sys/ucontext.h
diff options
context:
space:
mode:
Diffstat (limited to 'libc/sysdeps/linux/powerpc/sys/ucontext.h')
-rw-r--r--libc/sysdeps/linux/powerpc/sys/ucontext.h144
1 files changed, 140 insertions, 4 deletions
diff --git a/libc/sysdeps/linux/powerpc/sys/ucontext.h b/libc/sysdeps/linux/powerpc/sys/ucontext.h
index 07f0933ff..9eb50aa96 100644
--- a/libc/sysdeps/linux/powerpc/sys/ucontext.h
+++ b/libc/sysdeps/linux/powerpc/sys/ucontext.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1998, 1999, 2002, 2004, 2005 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -26,7 +26,110 @@
included in <signal.h>. */
#include <bits/sigcontext.h>
-typedef struct sigcontext mcontext_t;
+#if __WORDSIZE == 32
+
+/* Number of general registers. */
+# define NGREG 48
+
+/* Container for all general registers. */
+typedef unsigned long gregset_t[NGREG];
+
+/* Container for floating-point registers and status */
+typedef struct _libc_fpstate
+{
+ double fpregs[32];
+ double fpscr;
+ unsigned int _pad[2];
+} fpregset_t;
+
+/* Container for Altivec/VMX registers and status.
+ Needs to be aligned on a 16-byte boundary. */
+typedef struct _libc_vrstate
+{
+ unsigned int vrregs[32][4];
+ unsigned int vrsave;
+ unsigned int _pad[2];
+ unsigned int vscr;
+} vrregset_t;
+
+/* Context to describe whole processor state. */
+typedef struct
+{
+ gregset_t gregs;
+ fpregset_t fpregs;
+ vrregset_t vrregs __attribute__((__aligned__(16)));
+} mcontext_t;
+
+#else
+
+/* For 64-bit kernels with Altivec support, a machine context is exactly
+ * a sigcontext. For older kernel (without Altivec) the sigcontext matches
+ * the mcontext upto but not including the v_regs field. For kernels that
+ * don't AT_HWCAP or return AT_HWCAP without PPC_FEATURE_HAS_ALTIVEC the
+ * v_regs field may not exit and should not be referenced. The v_regd field
+ * can be refernced safely only after verifying that PPC_FEATURE_HAS_ALTIVEC
+ * is set in AT_HWCAP. */
+
+/* Number of general registers. */
+# define NGREG 48 /* includes r0-r31, nip, msr, lr, etc. */
+# define NFPREG 33 /* includes fp0-fp31 &fpscr. */
+# define NVRREG 34 /* includes v0-v31, vscr, & vrsave in split vectors */
+
+typedef unsigned long gregset_t[NGREG];
+typedef double fpregset_t[NFPREG];
+
+/* Container for Altivec/VMX Vector Status and Control Register. Only 32-bits
+ but can only be copied to/from a 128-bit vector register. So we allocated
+ a whole quadword speedup save/restore. */
+typedef struct _libc_vscr
+{
+ unsigned int __pad[3];
+ unsigned int vscr_word;
+} vscr_t;
+
+/* Container for Altivec/VMX registers and status.
+ Must to be aligned on a 16-byte boundary. */
+typedef struct _libc_vrstate
+{
+ unsigned int vrregs[32][4];
+ vscr_t vscr;
+ unsigned int vrsave;
+ unsigned int __pad[3];
+} vrregset_t __attribute__((__aligned__(16)));
+
+typedef struct {
+ unsigned long __unused[4];
+ int signal;
+ int __pad0;
+ unsigned long handler;
+ unsigned long oldmask;
+ struct pt_regs *regs;
+ gregset_t gp_regs;
+ fpregset_t fp_regs;
+/*
+ * To maintain compatibility with current implementations the sigcontext is
+ * extended by appending a pointer (v_regs) to a quadword type (elf_vrreg_t)
+ * followed by an unstructured (vmx_reserve) field of 69 doublewords. This
+ * allows the array of vector registers to be quadword aligned independent of
+ * the alignment of the containing sigcontext or ucontext. It is the
+ * responsibility of the code setting the sigcontext to set this pointer to
+ * either NULL (if this processor does not support the VMX feature) or the
+ * address of the first quadword within the allocated (vmx_reserve) area.
+ *
+ * The pointer (v_regs) of vector type (elf_vrreg_t) is essentually
+ * an array of 34 quadword entries. The entries with
+ * indexes 0-31 contain the corresponding vector registers. The entry with
+ * index 32 contains the vscr as the last word (offset 12) within the
+ * quadword. This allows the vscr to be stored as either a quadword (since
+ * it must be copied via a vector register to/from storage) or as a word.
+ * The entry with index 33 contains the vrsave as the first word (offset 0)
+ * within the quadword.
+ */
+ vrregset_t *v_regs;
+ long vmx_reserve[NVRREG+NVRREG+1];
+} mcontext_t;
+
+#endif
/* Userlevel context. */
typedef struct ucontext
@@ -34,8 +137,41 @@ typedef struct ucontext
unsigned long int uc_flags;
struct ucontext *uc_link;
stack_t uc_stack;
- mcontext_t uc_mcontext;
- __sigset_t uc_sigmask;
+#if __WORDSIZE == 32
+ /*
+ * These fields are set up this way to maximize source and
+ * binary compatibility with code written for the old
+ * ucontext_t definition, which didn't include space for the
+ * registers.
+ *
+ * Different versions of the kernel have stored the registers on
+ * signal delivery at different offsets from the ucontext struct.
+ * Programs should thus use the uc_mcontext.uc_regs pointer to
+ * find where the registers are actually stored. The registers
+ * will be stored within the ucontext_t struct but not necessarily
+ * at a fixed address. As a side-effect, this lets us achieve
+ * 16-byte alignment for the register storage space if the
+ * Altivec registers are to be saved, without requiring 16-byte
+ * alignment on the whole ucontext_t.
+ *
+ * The uc_mcontext.regs field is included for source compatibility
+ * with programs written against the older ucontext_t definition,
+ * and its name should therefore not change. The uc_pad field
+ * is for binary compatibility with programs compiled against the
+ * old ucontext_t; it ensures that uc_mcontext.regs and uc_sigmask
+ * are at the same offset as previously.
+ */
+ int uc_pad[7];
+ union uc_regs_ptr {
+ struct pt_regs *regs;
+ mcontext_t *uc_regs;
+ } uc_mcontext;
+ sigset_t uc_sigmask;
+ char uc_reg_space[sizeof(mcontext_t) + 12]; /* last for extensibility */
+#else /* 64-bit */
+ sigset_t uc_sigmask;
+ mcontext_t uc_mcontext; /* last for extensibility */
+#endif
} ucontext_t;
#endif /* sys/ucontext.h */