From a78ff1112263fdd871d3506dbcff44f6f12e8423 Mon Sep 17 00:00:00 2001
From: Eli Cooper <elicooper@gmx.com>
Date: Sun, 20 Mar 2016 00:58:41 +0800
Subject: [PATCH] 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: Eli Cooper <elicooper@gmx.com>
---
arch/um/include/shared/registers.h | 2 ++
arch/um/kernel/process.c | 2 +-
arch/x86/um/os-Linux/registers.c | 49 +++++++++++++++++++++++++--
arch/x86/um/ptrace_32.c | 5 +--
arch/x86/um/ptrace_64.c | 16 ++++-----
arch/x86/um/shared/sysdep/ptrace_64.h | 4 +--
6 files changed, 62 insertions(+), 16 deletions(-)
diff --git a/arch/um/include/shared/registers.h b/arch/um/include/shared/registers.h
index f5b76355ad71a..a74449b5b0e31 100644
--- a/arch/um/include/shared/registers.h
+++ b/arch/um/include/shared/registers.h
@@ -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);
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 48af59aae129d..d55a473dca4a3 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -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);
}
diff --git a/arch/x86/um/os-Linux/registers.c b/arch/x86/um/os-Linux/registers.c
index 41bfe84e11ab0..00f54a91bb4b0 100644
--- a/arch/x86/um/os-Linux/registers.c
+++ b/arch/x86/um/os-Linux/registers.c
@@ -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)
diff --git a/arch/x86/um/ptrace_32.c b/arch/x86/um/ptrace_32.c
index 47c78d5e5c320..ebd4dd6ef73b0 100644
--- a/arch/x86/um/ptrace_32.c
+++ b/arch/x86/um/ptrace_32.c
@@ -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);
}
diff --git a/arch/x86/um/ptrace_64.c b/arch/x86/um/ptrace_64.c
index a629694ee750f..faab418876ce7 100644
--- a/arch/x86/um/ptrace_64.c
+++ b/arch/x86/um/ptrace_64.c
@@ -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,
diff --git a/arch/x86/um/shared/sysdep/ptrace_64.h b/arch/x86/um/shared/sysdep/ptrace_64.h
index 919789f1071e4..0dc223aa1c2db 100644
--- a/arch/x86/um/shared/sysdep/ptrace_64.h
+++ b/arch/x86/um/shared/sysdep/ptrace_64.h
@@ -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
--
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