1 files changed, 48 insertions, 101 deletions

diff --git a/arch/x86/um/os-Linux/registers.c b/arch/x86/um/os-Linux/registers.c
index 28775f55bde2..eb1cdadc8a61 100644
--- a/arch/x86/um/os-Linux/registers.c
+++ b/arch/x86/um/os-Linux/registers.c
@@ -5,6 +5,7 @@
  */
 
 #include <errno.h>
+#include <stdlib.h>
 #include <sys/ptrace.h>
 #ifdef __i386__
 #include <sys/user.h>
@@ -14,127 +15,73 @@
 #include <sys/uio.h>
 #include <asm/sigcontext.h>
 #include <linux/elf.h>
+#include <registers.h>
+#include <sys/mman.h>
 
-int have_xstate_support;
+static unsigned long ptrace_regset;
+unsigned long host_fp_size;
 
-int save_i387_registers(int pid, unsigned long *fp_regs)
-{
-	if (ptrace(PTRACE_GETFPREGS, pid, 0, fp_regs) < 0)
-		return -errno;
-	return 0;
-}
-
-int save_fp_registers(int pid, unsigned long *fp_regs)
+int get_fp_registers(int pid, unsigned long *regs)
 {
-#ifdef PTRACE_GETREGSET
-	struct iovec iov;
+	struct iovec iov = {
+		.iov_base = regs,
+		.iov_len = host_fp_size,
+	};
 
-	if (have_xstate_support) {
-		iov.iov_base = fp_regs;
-		iov.iov_len = sizeof(struct _xstate);
-		if (ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov) < 0)
-			return -errno;
-		return 0;
-	} else
-#endif
-		return save_i387_registers(pid, fp_regs);
-}
-
-int restore_i387_registers(int pid, unsigned long *fp_regs)
-{
-	if (ptrace(PTRACE_SETFPREGS, pid, 0, fp_regs) < 0)
+	if (ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov) < 0)
 		return -errno;
 	return 0;
 }
 
-int restore_fp_registers(int pid, unsigned long *fp_regs)
-{
-#ifdef PTRACE_SETREGSET
-	struct iovec iov;
-
-	if (have_xstate_support) {
-		iov.iov_base = fp_regs;
-		iov.iov_len = sizeof(struct _xstate);
-		if (ptrace(PTRACE_SETREGSET, pid, NT_X86_XSTATE, &iov) < 0)
-			return -errno;
-		return 0;
-	} else
-#endif
-		return restore_i387_registers(pid, fp_regs);
-}
-
-#ifdef __i386__
-int have_fpx_regs = 1;
-int save_fpx_registers(int pid, unsigned long *fp_regs)
+int put_fp_registers(int pid, unsigned long *regs)
 {
-	if (ptrace(PTRACE_GETFPXREGS, pid, 0, fp_regs) < 0)
-		return -errno;
-	return 0;
-}
+	struct iovec iov = {
+		.iov_base = regs,
+		.iov_len = host_fp_size,
+	};
 
-int restore_fpx_registers(int pid, unsigned long *fp_regs)
-{
-	if (ptrace(PTRACE_SETFPXREGS, pid, 0, fp_regs) < 0)
+	if (ptrace(PTRACE_SETREGSET, pid, ptrace_regset, &iov) < 0)
 		return -errno;
 	return 0;
 }
 
-int get_fp_registers(int pid, unsigned long *regs)
+int arch_init_registers(int pid)
 {
-	if (have_fpx_regs)
-		return save_fpx_registers(pid, regs);
-	else
-		return save_fp_registers(pid, regs);
-}
-
-int put_fp_registers(int pid, unsigned long *regs)
-{
-	if (have_fpx_regs)
-		return restore_fpx_registers(pid, regs);
-	else
-		return restore_fp_registers(pid, regs);
-}
-
-void arch_init_registers(int pid)
-{
-	struct user_fpxregs_struct fpx_regs;
-	int err;
-
-	err = ptrace(PTRACE_GETFPXREGS, pid, 0, &fpx_regs);
-	if (!err)
-		return;
-
-	if (errno != EIO)
-		panic("check_ptrace : PTRACE_GETFPXREGS failed, errno = %d",
-		      errno);
-
-	have_fpx_regs = 0;
-}
+	struct iovec iov = {
+		/* Just use plenty of space, it does not cost us anything */
+		.iov_len = 2 * 1024 * 1024,
+	};
+	int ret;
+
+	iov.iov_base = mmap(NULL, iov.iov_len, PROT_WRITE | PROT_READ,
+			    MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+	if (iov.iov_base == MAP_FAILED)
+		return -ENOMEM;
+
+	/* GDB has x86_xsave_length, which uses x86_cpuid_count */
+	ptrace_regset = NT_X86_XSTATE;
+	ret = ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov);
+	if (ret)
+		ret = -errno;
+
+	if (ret == -ENODEV) {
+#ifdef CONFIG_X86_32
+		ptrace_regset = NT_PRXFPREG;
 #else
+		ptrace_regset = NT_PRFPREG;
+#endif
+		iov.iov_len = 2 * 1024 * 1024;
+		ret = ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov);
+		if (ret)
+			ret = -errno;
+	}
 
-int get_fp_registers(int pid, unsigned long *regs)
-{
-	return save_fp_registers(pid, regs);
-}
-
-int put_fp_registers(int pid, unsigned long *regs)
-{
-	return restore_fp_registers(pid, regs);
-}
+	munmap(iov.iov_base, 2 * 1024 * 1024);
 
-void arch_init_registers(int pid)
-{
-#ifdef PTRACE_GETREGSET
-	struct _xstate fp_regs;
-	struct iovec iov;
+	host_fp_size = iov.iov_len;
 
-	iov.iov_base = &fp_regs;
-	iov.iov_len = sizeof(struct _xstate);
-	if (ptrace(PTRACE_GETREGSET, pid, NT_X86_XSTATE, &iov) == 0)
-		have_xstate_support = 1;
-#endif
+	return ret;
 }
-#endif
 
 unsigned long get_thread_reg(int reg, jmp_buf *buf)
 {