From a78ff1112263fdd871d3506dbcff44f6f12e8423 Mon Sep 17 00:00:00 2001 From: Eli Cooper 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 --- 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 f5b76355ad71..a74449b5b0e3 100644 --- a/arch/um/include/shared/registers.h +++ b/arch/um/include/shared/registers.h @@ -9,6 +9,8 @@ #include #include +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 48af59aae129..d55a473dca4a 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 41bfe84e11ab..00f54a91bb4b 100644 --- a/arch/x86/um/os-Linux/registers.c +++ b/arch/x86/um/os-Linux/registers.c @@ -11,21 +11,56 @@ #endif #include #include +#include +#include +#include -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 47c78d5e5c32..ebd4dd6ef73b 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 a629694ee750..faab418876ce 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 919789f1071e..0dc223aa1c2d 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 -- 2.20.1