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um: add extended processor state save/restore support

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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: Eli Cooper <elicooper@gmx.com>
This commit is contained in:
Eli Cooper 2016-03-20 00:58:41 +08:00 committed by Richard Weinberger
parent b6024b21fe
commit a78ff11122
6 changed files with 62 additions and 16 deletions
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2
arch/um/include/shared/registers.h
View File

@ -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);

2
arch/um/kernel/process.c
View File

@ -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);
}

49
arch/x86/um/os-Linux/registers.c
View File

@ -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)

5
arch/x86/um/ptrace_32.c
View File

@ -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);
}

16
arch/x86/um/ptrace_64.c
View File

@ -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,

4
arch/x86/um/shared/sysdep/ptrace_64.h
View File

@ -57,8 +57,6 @@
#define UPT_SYSCALL_ARG5(r) UPT_R8(r)
#define UPT_SYSCALL_ARG6(r) UPT_R9(r)
static inline void arch_init_registers(int pid)
{
}
extern void arch_init_registers(int pid);
#endif