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Commit a78ff111 authored by Eli Cooper's avatar Eli Cooper Committed by Richard Weinberger
Browse files

um: add extended processor state save/restore support 



This patch extends save_fp_registers() and restore_fp_registers() to use
PTRACE_GETREGSET and PTRACE_SETREGSET with the XSTATE note type, adding
support for new processor state extensions between context switches.

When the new ptrace requests are unavailable, it falls back to the old
PTRACE_GETFPREGS and PTRACE_SETFPREGS methods, which have been renamed to
save_i387_registers() and restore_i387_registers().

Now these functions expect *fp_regs to have the space of an _xstate struct.
Thus, this also makes ptrace in UML responde to PTRACE_GETFPREGS/_SETFPREG
requests with a user_i387_struct (thus independent from HOST_FP_SIZE), and
by calling save_i387_registers() and restore_i387_registers() instead of
the extended save_fp_registers() and restore_fp_registers() functions.

Signed-off-by: default avatarEli Cooper <elicooper@gmx.com>
parent b6024b21

arch/um/include/shared/registers.h

+2 −0
Original line number Diff line number Diff line
@@ -9,6 +9,8 @@ 
#include <sysdep/ptrace.h>

#include <sysdep/archsetjmp.h>



extern int save_i387_registers(int pid, unsigned long *fp_regs);

extern int restore_i387_registers(int pid, unsigned long *fp_regs);

extern int save_fp_registers(int pid, unsigned long *fp_regs);

extern int restore_fp_registers(int pid, unsigned long *fp_regs);

extern int save_fpx_registers(int pid, unsigned long *fp_regs);

arch/um/kernel/process.c

+1 −1
Original line number Diff line number Diff line
@@ -402,6 +402,6 @@ int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu) 
{

	int cpu = current_thread_info()->cpu;



	return save_fp_registers(userspace_pid[cpu], (unsigned long *) fpu);

	return save_i387_registers(userspace_pid[cpu], (unsigned long *) fpu);

}

arch/x86/um/os-Linux/registers.c

+47 −2
Original line number Diff line number Diff line
@@ -11,21 +11,56 @@ 
#endif

#include <longjmp.h>

#include <sysdep/ptrace_user.h>

#include <sys/uio.h>

#include <asm/sigcontext.h>

#include <linux/elf.h>



int save_fp_registers(int pid, unsigned long *fp_regs)

int have_xstate_support;



int save_i387_registers(int pid, unsigned long *fp_regs)

{

	if (ptrace(PTRACE_GETFPREGS, pid, 0, fp_regs) < 0)

		return -errno;

	return 0;

}



int restore_fp_registers(int pid, unsigned long *fp_regs)

int save_fp_registers(int pid, unsigned long *fp_regs)

{

	struct iovec iov;



	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 {

		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)

		return -errno;

	return 0;

}



int restore_fp_registers(int pid, unsigned long *fp_regs)

{

	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 {

		return restore_i387_registers(pid, fp_regs);

	}

}



#ifdef __i386__

int have_fpx_regs = 1;

int save_fpx_registers(int pid, unsigned long *fp_regs)
@@ -85,6 +120,16 @@ int put_fp_registers(int pid, unsigned long *regs) 
	return restore_fp_registers(pid, regs);

}



void arch_init_registers(int pid)

{

	struct _xstate fp_regs;

	struct iovec iov;



	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



unsigned long get_thread_reg(int reg, jmp_buf *buf)

arch/x86/um/ptrace_32.c

+3 −2
Original line number Diff line number Diff line
@@ -194,7 +194,8 @@ static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *c 
	int err, n, cpu = ((struct thread_info *) child->stack)->cpu;

	struct user_i387_struct fpregs;



	err = save_fp_registers(userspace_pid[cpu], (unsigned long *) &fpregs);

	err = save_i387_registers(userspace_pid[cpu],

				  (unsigned long *) &fpregs);

	if (err)

		return err;
@@ -214,7 +215,7 @@ static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *c 
	if (n > 0)

		return -EFAULT;



	return restore_fp_registers(userspace_pid[cpu],

	return restore_i387_registers(userspace_pid[cpu],

				    (unsigned long *) &fpregs);

}

arch/x86/um/ptrace_64.c

+8 −8
Original line number Diff line number Diff line
@@ -222,14 +222,14 @@ int is_syscall(unsigned long addr) 
static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)

{

	int err, n, cpu = ((struct thread_info *) child->stack)->cpu;

	long fpregs[HOST_FP_SIZE];

	struct user_i387_struct fpregs;



	BUG_ON(sizeof(*buf) != sizeof(fpregs));

	err = save_fp_registers(userspace_pid[cpu], fpregs);

	err = save_i387_registers(userspace_pid[cpu],

				  (unsigned long *) &fpregs);

	if (err)

		return err;



	n = copy_to_user(buf, fpregs, sizeof(fpregs));

	n = copy_to_user(buf, &fpregs, sizeof(fpregs));

	if (n > 0)

		return -EFAULT;
@@ -239,14 +239,14 @@ static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *c 
static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)

{

	int n, cpu = ((struct thread_info *) child->stack)->cpu;

	long fpregs[HOST_FP_SIZE];

	struct user_i387_struct fpregs;



	BUG_ON(sizeof(*buf) != sizeof(fpregs));

	n = copy_from_user(fpregs, buf, sizeof(fpregs));

	n = copy_from_user(&fpregs, buf, sizeof(fpregs));

	if (n > 0)

		return -EFAULT;



	return restore_fp_registers(userspace_pid[cpu], fpregs);

	return restore_i387_registers(userspace_pid[cpu],

				      (unsigned long *) &fpregs);

}



long subarch_ptrace(struct task_struct *child, long request,