diff options
Diffstat (limited to 'lib/libc/i386/gen/getcontextx.c')
-rw-r--r-- | lib/libc/i386/gen/getcontextx.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/lib/libc/i386/gen/getcontextx.c b/lib/libc/i386/gen/getcontextx.c new file mode 100644 index 0000000..de0a1a3 --- /dev/null +++ b/lib/libc/i386/gen/getcontextx.c @@ -0,0 +1,133 @@ +/* + * Copyright (c) 2011 Konstantin Belousov <kib@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. 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 AUTHOR ``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 AUTHOR 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. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <sys/ucontext.h> +#include <errno.h> +#include <stdarg.h> +#include <stdlib.h> +#include <machine/npx.h> +#include <machine/specialreg.h> +#include <machine/sysarch.h> + +static int xstate_sz = -1; + +size_t +__getcontextx_size(void) +{ + u_int p[4]; + int cpuid_supported; + + if (xstate_sz == -1) { + __asm __volatile( + " pushfl\n" + " popl %%eax\n" + " movl %%eax,%%ecx\n" + " xorl $0x200000,%%eax\n" + " pushl %%eax\n" + " popfl\n" + " pushfl\n" + " popl %%eax\n" + " xorl %%eax,%%ecx\n" + " je 1f\n" + " movl $1,%0\n" + " jmp 2f\n" + "1: movl $0,%0\n" + "2:\n" + : "=r" (cpuid_supported) : : "eax", "ecx"); + if (cpuid_supported) { + __asm __volatile( + " pushl %%ebx\n" + " cpuid\n" + " movl %%ebx,%1\n" + " popl %%ebx\n" + : "=a" (p[0]), "=r" (p[1]), "=c" (p[2]), "=d" (p[3]) + : "0" (0x0)); + if ((p[2] & CPUID2_OSXSAVE) != 0) { + __asm __volatile( + " pushl %%ebx\n" + " cpuid\n" + " movl %%ebx,%1\n" + " popl %%ebx\n" + : "=a" (p[0]), "=r" (p[1]), "=c" (p[2]), + "=d" (p[3]) + : "0" (0xd), "2" (0x0)); + xstate_sz = p[1] - sizeof(struct savexmm); + } else + xstate_sz = 0; + } else + xstate_sz = 0; + } + + return (sizeof(ucontext_t) + xstate_sz); +} + +int +__fillcontextx(char *ctx) +{ + struct i386_get_xfpustate xfpu; + ucontext_t *ucp; + + ucp = (ucontext_t *)ctx; + if (getcontext(ucp) == -1) + return (-1); + if (xstate_sz != 0) { + xfpu.addr = (char *)(ucp + 1); + xfpu.len = xstate_sz; + if (sysarch(I386_GET_XFPUSTATE, &xfpu) == -1) + return (-1); + ucp->uc_mcontext.mc_xfpustate = (__register_t)xfpu.addr; + ucp->uc_mcontext.mc_xfpustate_len = xstate_sz; + ucp->uc_mcontext.mc_flags |= _MC_HASFPXSTATE; + } else { + ucp->uc_mcontext.mc_xfpustate = 0; + ucp->uc_mcontext.mc_xfpustate_len = 0; + } + return (0); +} + +__weak_reference(__getcontextx, getcontextx); + +ucontext_t * +__getcontextx(void) +{ + char *ctx; + int error; + + ctx = malloc(__getcontextx_size()); + if (ctx == NULL) + return (NULL); + if (__fillcontextx(ctx) == -1) { + error = errno; + free(ctx); + errno = error; + return (NULL); + } + return ((ucontext_t *)ctx); +} |