Attachment 290461 Details for Bug 254024 – Jermey's vm86 patch backport for RHEL5-58

[patch] Jermey's vm86 patch backport for RHEL5-58

backport-jermey-vm86-changes-v2.patch (text/plain), 10.37 KB, created by Vivek Goyal on 2007-12-27 22:45:13 UTC

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Creator: Vivek Goyal

Created: 2007-12-27 22:45:13 UTC

Size: 10.37 KB

patch

obsolete

>
>---
>
>
>Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
>---
>
> arch/i386/kernel/vm86.c |  110 ++++++++++++++++++++++++++++++------------------
> include/asm-i386/vm86.h |   17 -------
> 2 files changed, 71 insertions(+), 56 deletions(-)
>
>diff -puN arch/i386/kernel/vm86.c~backport-jermey-vm86-changes arch/i386/kernel/vm86.c
>--- linux-2.6.18.i386-el5.58-vivek/arch/i386/kernel/vm86.c~backport-jermey-vm86-changes	2007-12-27 16:17:47.000000000 -0500
>+++ linux-2.6.18.i386-el5.58-vivek-root/arch/i386/kernel/vm86.c	2007-12-27 17:25:24.000000000 -0500
>@@ -43,6 +43,7 @@
> #include <linux/highmem.h>
> #include <linux/ptrace.h>
> #include <linux/audit.h>
>+#include <linux/stddef.h>
> 
> #include <asm/uaccess.h>
> #include <asm/io.h>
>@@ -72,10 +73,10 @@
> /*
>  * 8- and 16-bit register defines..
>  */
>-#define AL(regs)	(((unsigned char *)&((regs)->eax))[0])
>-#define AH(regs)	(((unsigned char *)&((regs)->eax))[1])
>-#define IP(regs)	(*(unsigned short *)&((regs)->eip))
>-#define SP(regs)	(*(unsigned short *)&((regs)->esp))
>+#define AL(regs)       (((unsigned char *)&((regs)->pt.eax))[0])
>+#define AH(regs)       (((unsigned char *)&((regs)->pt.eax))[1])
>+#define IP(regs)       (*(unsigned short *)&((regs)->pt.eip))
>+#define SP(regs)       (*(unsigned short *)&((regs)->pt.esp))
> 
> /*
>  * virtual flags (16 and 32-bit versions)
>@@ -89,10 +90,37 @@
> #define SAFE_MASK	(0xDD5)
> #define RETURN_MASK	(0xDFF)
> 
>-#define VM86_REGS_PART2 orig_eax
>-#define VM86_REGS_SIZE1 \
>-        ( (unsigned)( & (((struct kernel_vm86_regs *)0)->VM86_REGS_PART2) ) )
>-#define VM86_REGS_SIZE2 (sizeof(struct kernel_vm86_regs) - VM86_REGS_SIZE1)
>+/* convert kernel_vm86_regs to vm86_regs */
>+static int copy_vm86_regs_to_user(struct vm86_regs __user *user,
>+                                 const struct kernel_vm86_regs *regs)
>+{
>+       int ret = 0;
>+
>+       /* kernel_vm86_regs is missing xfs, so copy everything up to
>+          (but not including) xgs, and then rest after xgs. */
>+       ret += copy_to_user(user, regs, offsetof(struct kernel_vm86_regs, pt.orig_eax));
>+       ret += copy_to_user(&user->orig_eax, &regs->pt.orig_eax,
>+                           sizeof(struct kernel_vm86_regs) -
>+                           offsetof(struct kernel_vm86_regs, pt.orig_eax));
>+
>+       return ret;
>+}
>+
>+/* convert vm86_regs to kernel_vm86_regs */
>+static int copy_vm86_regs_from_user(struct kernel_vm86_regs *regs,
>+                                   const struct vm86_regs __user *user,
>+                                   unsigned extra)
>+{
>+       int ret = 0;
>+
>+       ret += copy_from_user(regs, user, offsetof(struct kernel_vm86_regs, pt.orig_eax));
>+       ret += copy_from_user(&regs->pt.orig_eax, &user->orig_eax,
>+                             sizeof(struct kernel_vm86_regs) -
>+                             offsetof(struct kernel_vm86_regs, pt.orig_eax) +
>+                             extra);
>+
>+       return ret;
>+}
> 
> struct pt_regs * FASTCALL(save_v86_state(struct kernel_vm86_regs * regs));
> struct pt_regs * fastcall save_v86_state(struct kernel_vm86_regs * regs)
>@@ -114,10 +142,8 @@ struct pt_regs * fastcall save_v86_state
> 		printk("no vm86_info: BAD\n");
> 		do_exit(SIGSEGV);
> 	}
>-	set_flags(regs->eflags, VEFLAGS, VIF_MASK | current->thread.v86mask);
>-	tmp = copy_to_user(&current->thread.vm86_info->regs,regs, VM86_REGS_SIZE1);
>-	tmp += copy_to_user(&current->thread.vm86_info->regs.VM86_REGS_PART2,
>-		&regs->VM86_REGS_PART2, VM86_REGS_SIZE2);
>+	set_flags(regs->pt.eflags, VEFLAGS, VIF_MASK | current->thread.v86mask);
>+	tmp = copy_vm86_regs_to_user(&current->thread.vm86_info->regs,regs);
> 	tmp += put_user(current->thread.screen_bitmap,&current->thread.vm86_info->screen_bitmap);
> 	if (tmp) {
> 		printk("vm86: could not access userspace vm86_info\n");
>@@ -189,9 +215,10 @@ asmlinkage int sys_vm86old(struct pt_reg
> 	tsk = current;
> 	if (tsk->thread.saved_esp0)
> 		goto out;
>-	tmp  = copy_from_user(&info, v86, VM86_REGS_SIZE1);
>-	tmp += copy_from_user(&info.regs.VM86_REGS_PART2, &v86->regs.VM86_REGS_PART2,
>-		(long)&info.vm86plus - (long)&info.regs.VM86_REGS_PART2);
>+	tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs,
>+					offsetof(struct kernel_vm86_struct, vm86plus) -
>+					sizeof(info.regs));
>+
> 	ret = -EFAULT;
> 	if (tmp)
> 		goto out;
>@@ -239,9 +266,10 @@ asmlinkage int sys_vm86(struct pt_regs r
> 	if (tsk->thread.saved_esp0)
> 		goto out;
> 	v86 = (struct vm86plus_struct __user *)regs.ecx;
>-	tmp  = copy_from_user(&info, v86, VM86_REGS_SIZE1);
>-	tmp += copy_from_user(&info.regs.VM86_REGS_PART2, &v86->regs.VM86_REGS_PART2,
>-		(long)&info.regs32 - (long)&info.regs.VM86_REGS_PART2);
>+	tmp = copy_vm86_regs_from_user(&info.regs, &v86->regs,
>+					offsetof(struct kernel_vm86_struct, regs32) -
>+					sizeof(info.regs));
>+
> 	ret = -EFAULT;
> 	if (tmp)
> 		goto out;
>@@ -264,8 +292,8 @@ static void do_sys_vm86(struct kernel_vm
> /*
>  * make sure the vm86() system call doesn't try to do anything silly
>  */
>-	info->regs.__null_ds = 0;
>-	info->regs.__null_es = 0;
>+	info->regs.pt.xds = 0;
>+	info->regs.pt.xes = 0;
> 
> /* we are clearing fs,gs later just before "jmp resume_userspace",
>  * because starting with Linux 2.1.x they aren't no longer saved/restored
>@@ -276,10 +304,10 @@ static void do_sys_vm86(struct kernel_vm
>  * has set it up safely, so this makes sure interrupt etc flags are
>  * inherited from protected mode.
>  */
>- 	VEFLAGS = info->regs.eflags;
>-	info->regs.eflags &= SAFE_MASK;
>-	info->regs.eflags |= info->regs32->eflags & ~SAFE_MASK;
>-	info->regs.eflags |= VM_MASK;
>+	VEFLAGS = info->regs.pt.eflags;
>+	info->regs.pt.eflags &= SAFE_MASK;
>+	info->regs.pt.eflags |= info->regs32->eflags & ~SAFE_MASK;
>+	info->regs.pt.eflags |= VM_MASK;
> 
> 	switch (info->cpu_type) {
> 		case CPU_286:
>@@ -318,19 +346,19 @@ static void do_sys_vm86(struct kernel_vm
> 	tsk->thread.screen_bitmap = info->screen_bitmap;
> 	if (info->flags & VM86_SCREEN_BITMAP)
> 		mark_screen_rdonly(tsk->mm);
>-	__asm__ __volatile__("xorl %eax,%eax; movl %eax,%fs; movl %eax,%gs\n\t");
>-	__asm__ __volatile__("movl %%eax, %0\n" :"=r"(eax));
> 
> 	/*call audit_syscall_exit since we do not exit via the normal paths */
> 	if (unlikely(current->audit_context))
>-		audit_syscall_exit(AUDITSC_RESULT(eax), eax);
>+		audit_syscall_exit(AUDITSC_RESULT(0), 0);
> 
> 	__asm__ __volatile__(
> 		"movl %0,%%esp\n\t"
> 		"movl %1,%%ebp\n\t"
>+		"mov  %2, %%fs\n\t"
>+		"mov  %3, %%gs\n\t"
> 		"jmp resume_userspace"
> 		: /* no outputs */
>-		:"r" (&info->regs), "r" (task_thread_info(tsk)));
>+		:"r" (&info->regs), "r" (task_thread_info(tsk)), "r" (0), "r" (0));
> 	/* we never return here */
> }
> 
>@@ -360,12 +388,12 @@ static inline void clear_IF(struct kerne
> 
> static inline void clear_TF(struct kernel_vm86_regs * regs)
> {
>-	regs->eflags &= ~TF_MASK;
>+	regs->pt.eflags &= ~TF_MASK;
> }
> 
> static inline void clear_AC(struct kernel_vm86_regs * regs)
> {
>-	regs->eflags &= ~AC_MASK;
>+	regs->pt.eflags &= ~AC_MASK;
> }
> 
> /* It is correct to call set_IF(regs) from the set_vflags_*
>@@ -382,7 +410,7 @@ static inline void clear_AC(struct kerne
> static inline void set_vflags_long(unsigned long eflags, struct kernel_vm86_regs * regs)
> {
> 	set_flags(VEFLAGS, eflags, current->thread.v86mask);
>-	set_flags(regs->eflags, eflags, SAFE_MASK);
>+	set_flags(regs->pt.eflags, eflags, SAFE_MASK);
> 	if (eflags & IF_MASK)
> 		set_IF(regs);
> 	else
>@@ -392,7 +420,7 @@ static inline void set_vflags_long(unsig
> static inline void set_vflags_short(unsigned short flags, struct kernel_vm86_regs * regs)
> {
> 	set_flags(VFLAGS, flags, current->thread.v86mask);
>-	set_flags(regs->eflags, flags, SAFE_MASK);
>+	set_flags(regs->pt.eflags, flags, SAFE_MASK);
> 	if (flags & IF_MASK)
> 		set_IF(regs);
> 	else
>@@ -401,7 +429,7 @@ static inline void set_vflags_short(unsi
> 
> static inline unsigned long get_vflags(struct kernel_vm86_regs * regs)
> {
>-	unsigned long flags = regs->eflags & RETURN_MASK;
>+	unsigned long flags = regs->pt.eflags & RETURN_MASK;
> 
> 	if (VEFLAGS & VIF_MASK)
> 		flags |= IF_MASK;
>@@ -505,7 +533,7 @@ static void do_int(struct kernel_vm86_re
> 	unsigned long __user *intr_ptr;
> 	unsigned long segoffs;
> 
>-	if (regs->cs == BIOSSEG)
>+	if (regs->pt.xcs == BIOSSEG)
> 		goto cannot_handle;
> 	if (is_revectored(i, &KVM86->int_revectored))
> 		goto cannot_handle;
>@@ -517,9 +545,9 @@ static void do_int(struct kernel_vm86_re
> 	if ((segoffs >> 16) == BIOSSEG)
> 		goto cannot_handle;
> 	pushw(ssp, sp, get_vflags(regs), cannot_handle);
>-	pushw(ssp, sp, regs->cs, cannot_handle);
>+	pushw(ssp, sp, regs->pt.xcs, cannot_handle);
> 	pushw(ssp, sp, IP(regs), cannot_handle);
>-	regs->cs = segoffs >> 16;
>+	regs->pt.xcs = segoffs >> 16;
> 	SP(regs) -= 6;
> 	IP(regs) = segoffs & 0xffff;
> 	clear_TF(regs);
>@@ -536,7 +564,7 @@ int handle_vm86_trap(struct kernel_vm86_
> 	if (VMPI.is_vm86pus) {
> 		if ( (trapno==3) || (trapno==1) )
> 			return_to_32bit(regs, VM86_TRAP + (trapno << 8));
>-		do_int(regs, trapno, (unsigned char __user *) (regs->ss << 4), SP(regs));
>+		do_int(regs, trapno, (unsigned char __user *) (regs->pt.xss << 4), SP(regs));
> 		return 0;
> 	}
> 	if (trapno !=1)
>@@ -565,10 +593,10 @@ void handle_vm86_fault(struct kernel_vm8
> 		handle_vm86_trap(regs, 0, 1); \
> 	return; } while (0)
> 
>-	orig_flags = *(unsigned short *)&regs->eflags;
>+	orig_flags = *(unsigned short *)&regs->pt.eflags;
> 
>-	csp = (unsigned char __user *) (regs->cs << 4);
>-	ssp = (unsigned char __user *) (regs->ss << 4);
>+	csp = (unsigned char __user *) (regs->pt.xcs << 4);
>+	ssp = (unsigned char __user *) (regs->pt.xss << 4);
> 	sp = SP(regs);
> 	ip = IP(regs);
> 
>@@ -655,7 +683,7 @@ void handle_vm86_fault(struct kernel_vm8
> 			SP(regs) += 6;
> 		}
> 		IP(regs) = newip;
>-		regs->cs = newcs;
>+		regs->pt.xcs = newcs;
> 		CHECK_IF_IN_TRAP;
> 		if (data32) {
> 			set_vflags_long(newflags, regs);
>diff -puN include/asm-i386/vm86.h~backport-jermey-vm86-changes include/asm-i386/vm86.h
>--- linux-2.6.18.i386-el5.58-vivek/include/asm-i386/vm86.h~backport-jermey-vm86-changes	2007-12-27 16:17:47.000000000 -0500
>+++ linux-2.6.18.i386-el5.58-vivek-root/include/asm-i386/vm86.h	2007-12-27 16:17:47.000000000 -0500
>@@ -68,6 +68,7 @@
>  * done a translation of "SAVE_ALL" from vm86 mode. The real kernel layout
>  * is 'kernel_vm86_regs' (see below).
>  */
>+#include <asm/ptrace.h>
> 
> struct vm86_regs {
> /*
>@@ -150,21 +151,7 @@ struct kernel_vm86_regs {
> /*
>  * normal regs, with special meaning for the segment descriptors..
>  */
>-	long ebx;
>-	long ecx;
>-	long edx;
>-	long esi;
>-	long edi;
>-	long ebp;
>-	long eax;
>-	long __null_ds;
>-	long __null_es;
>-	long orig_eax;
>-	long eip;
>-	unsigned short cs, __csh;
>-	long eflags;
>-	long esp;
>-	unsigned short ss, __ssh;
>+	struct pt_regs pt;
> /*
>  * these are specific to v86 mode:
>  */
>_

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Attachments on bug 254024: 206251 | 289391 | 289411 | 289806 | 289807 | 290180 | 290181 | 290211 | 290212 | 290461 | 290688 | 291734 | 292069