mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC][PATCH v2 09/22] x86: switch save_v86_state() to unsafe_put_user()
Date: Fri, 27 Mar 2020 02:31:52 +0000	[thread overview]
Message-ID: <20200327023205.881896-9-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200327023205.881896-1-viro@ZenIV.linux.org.uk>

From: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/x86/kernel/vm86_32.c | 61 +++++++++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 31 deletions(-)

diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index 49b37eb01e99..47a8676c7395 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -98,7 +98,6 @@ void save_v86_state(struct kernel_vm86_regs *regs, int retval)
 	struct task_struct *tsk = current;
 	struct vm86plus_struct __user *user;
 	struct vm86 *vm86 = current->thread.vm86;
-	long err = 0;
 
 	/*
 	 * This gets called from entry.S with interrupts disabled, but
@@ -114,37 +113,30 @@ void save_v86_state(struct kernel_vm86_regs *regs, int retval)
 	set_flags(regs->pt.flags, VEFLAGS, X86_EFLAGS_VIF | vm86->veflags_mask);
 	user = vm86->user_vm86;
 
-	if (!access_ok(user, vm86->vm86plus.is_vm86pus ?
+	if (!user_access_begin(user, vm86->vm86plus.is_vm86pus ?
 		       sizeof(struct vm86plus_struct) :
-		       sizeof(struct vm86_struct))) {
-		pr_alert("could not access userspace vm86 info\n");
-		do_exit(SIGSEGV);
-	}
-
-	put_user_try {
-		put_user_ex(regs->pt.bx, &user->regs.ebx);
-		put_user_ex(regs->pt.cx, &user->regs.ecx);
-		put_user_ex(regs->pt.dx, &user->regs.edx);
-		put_user_ex(regs->pt.si, &user->regs.esi);
-		put_user_ex(regs->pt.di, &user->regs.edi);
-		put_user_ex(regs->pt.bp, &user->regs.ebp);
-		put_user_ex(regs->pt.ax, &user->regs.eax);
-		put_user_ex(regs->pt.ip, &user->regs.eip);
-		put_user_ex(regs->pt.cs, &user->regs.cs);
-		put_user_ex(regs->pt.flags, &user->regs.eflags);
-		put_user_ex(regs->pt.sp, &user->regs.esp);
-		put_user_ex(regs->pt.ss, &user->regs.ss);
-		put_user_ex(regs->es, &user->regs.es);
-		put_user_ex(regs->ds, &user->regs.ds);
-		put_user_ex(regs->fs, &user->regs.fs);
-		put_user_ex(regs->gs, &user->regs.gs);
-
-		put_user_ex(vm86->screen_bitmap, &user->screen_bitmap);
-	} put_user_catch(err);
-	if (err) {
-		pr_alert("could not access userspace vm86 info\n");
-		do_exit(SIGSEGV);
-	}
+		       sizeof(struct vm86_struct)))
+		goto Efault;
+
+	unsafe_put_user(regs->pt.bx, &user->regs.ebx, Efault_end);
+	unsafe_put_user(regs->pt.cx, &user->regs.ecx, Efault_end);
+	unsafe_put_user(regs->pt.dx, &user->regs.edx, Efault_end);
+	unsafe_put_user(regs->pt.si, &user->regs.esi, Efault_end);
+	unsafe_put_user(regs->pt.di, &user->regs.edi, Efault_end);
+	unsafe_put_user(regs->pt.bp, &user->regs.ebp, Efault_end);
+	unsafe_put_user(regs->pt.ax, &user->regs.eax, Efault_end);
+	unsafe_put_user(regs->pt.ip, &user->regs.eip, Efault_end);
+	unsafe_put_user(regs->pt.cs, &user->regs.cs, Efault_end);
+	unsafe_put_user(regs->pt.flags, &user->regs.eflags, Efault_end);
+	unsafe_put_user(regs->pt.sp, &user->regs.esp, Efault_end);
+	unsafe_put_user(regs->pt.ss, &user->regs.ss, Efault_end);
+	unsafe_put_user(regs->es, &user->regs.es, Efault_end);
+	unsafe_put_user(regs->ds, &user->regs.ds, Efault_end);
+	unsafe_put_user(regs->fs, &user->regs.fs, Efault_end);
+	unsafe_put_user(regs->gs, &user->regs.gs, Efault_end);
+	unsafe_put_user(vm86->screen_bitmap, &user->screen_bitmap, Efault_end);
+
+	user_access_end();
 
 	preempt_disable();
 	tsk->thread.sp0 = vm86->saved_sp0;
@@ -159,6 +151,13 @@ void save_v86_state(struct kernel_vm86_regs *regs, int retval)
 	lazy_load_gs(vm86->regs32.gs);
 
 	regs->pt.ax = retval;
+	return;
+
+Efault_end:
+	user_access_end();
+Efault:
+	pr_alert("could not access userspace vm86 info\n");
+	do_exit(SIGSEGV);
 }
 
 static void mark_screen_rdonly(struct mm_struct *mm)
-- 
2.11.0


  parent reply	other threads:[~2020-03-27  2:33 UTC|newest]

Thread overview: 71+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-23 18:36 [RFC][PATCHSET] x86 uaccess cleanups Al Viro
2020-03-23 18:37 ` [RFC][PATCH 01/22] x86 user stack frame reads: switch to explicit __get_user() Al Viro
2020-03-23 18:37   ` [RFC][PATCH 02/22] x86 kvm page table walks: " Al Viro
2020-03-23 18:38   ` [RFC][PATCH 03/22] x86: switch sigframe sigset handling to explict __get_user()/__put_user() Al Viro
2020-03-23 18:38   ` [RFC][PATCH 04/22] x86: get rid of small constant size cases in raw_copy_{to,from}_user() Al Viro
2020-03-23 18:38   ` [RFC][PATCH 05/22] vm86: get rid of get_user_ex() use Al Viro
2020-03-23 18:38   ` [RFC][PATCH 06/22] x86: get rid of get_user_ex() in ia32_restore_sigcontext() Al Viro
2020-03-23 18:38   ` [RFC][PATCH 07/22] x86: get rid of get_user_ex() in restore_sigcontext() Al Viro
2020-03-23 18:38   ` [RFC][PATCH 08/22] x86: kill get_user_{try,catch,ex} Al Viro
2020-03-23 18:38   ` [RFC][PATCH 09/22] x86: switch save_v86_state() to unsafe_put_user() Al Viro
2020-03-23 18:38   ` [RFC][PATCH 10/22] x86: switch setup_sigcontext() " Al Viro
2020-03-23 18:38   ` [RFC][PATCH 11/22] x86: switch ia32_setup_sigcontext() " Al Viro
2020-03-23 18:38   ` [RFC][PATCH 12/22] x86: get rid of put_user_try in {ia32,x32}_setup_rt_frame() Al Viro
2020-03-23 18:38   ` [RFC][PATCH 13/22] x86: ia32_setup_sigcontext(): lift user_access_{begin,end}() into the callers Al Viro
2020-03-23 18:53     ` Linus Torvalds
2020-03-23 21:42       ` Al Viro
2020-03-23 18:38   ` [RFC][PATCH 14/22] x86: ia32_setup_frame(): consolidate uaccess areas Al Viro
2020-03-23 18:38   ` [RFC][PATCH 15/22] x86: ia32_setup_rt_frame(): " Al Viro
2020-03-23 18:38   ` [RFC][PATCH 16/22] x86: get rid of put_user_try in __setup_rt_frame() (both 32bit and 64bit) Al Viro
2020-03-23 18:38   ` [RFC][PATCH 17/22] x86: setup_sigcontext(): list user_access_{begin,end}() into callers Al Viro
2020-03-23 18:56     ` Linus Torvalds
2020-03-23 18:38   ` [RFC][PATCH 18/22] x86: __setup_frame(): consolidate uaccess areas Al Viro
2020-03-23 18:38   ` [RFC][PATCH 19/22] x86: __setup_rt_frame(): " Al Viro
2020-03-23 18:38   ` [RFC][PATCH 20/22] x86: x32_setup_rt_frame(): " Al Viro
2020-03-23 18:38   ` [RFC][PATCH 21/22] x86: unsafe_put_... macros for sigcontext and sigmask Al Viro
2020-03-23 18:38   ` [RFC][PATCH 22/22] kill uaccess_try() Al Viro
2020-03-24 15:15   ` [RFC][PATCH 01/22] x86 user stack frame reads: switch to explicit __get_user() Peter Zijlstra
2020-03-28 10:48   ` Ingo Molnar
2020-03-28 11:59     ` Al Viro
2020-03-29  9:26       ` Ingo Molnar
2020-03-29 16:50         ` Andy Lutomirski
2020-03-29 17:05           ` Linus Torvalds
2020-03-29 17:41           ` David Laight
2020-03-29 17:56             ` Linus Torvalds
2020-03-29 18:03               ` David Laight
2020-03-29 18:16                 ` Linus Torvalds
2020-03-29 18:32                   ` David Laight
2020-03-29 18:55                     ` Linus Torvalds
2020-03-29 21:21                   ` Andy Lutomirski
2020-03-29 22:06                     ` Linus Torvalds
2020-03-29 22:12                       ` Linus Torvalds
2020-03-29 18:16               ` Al Viro
2020-03-29 18:19                 ` Linus Torvalds
2020-03-29 17:57         ` Al Viro
2020-03-30 15:54           ` David Laight
2020-03-23 19:16 ` [RFC][PATCHSET] x86 uaccess cleanups Linus Torvalds
2020-03-27  2:24 ` [RFC][PATCHSET v2] " Al Viro
2020-03-27  2:26   ` Al Viro
2020-03-27  2:30     ` Al Viro
2020-03-27  2:31       ` [RFC][PATCH v2 01/22] x86 user stack frame reads: switch to explicit __get_user() Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 02/22] x86 kvm page table walks: " Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 03/22] x86: switch sigframe sigset handling to explict __get_user()/__put_user() Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 04/22] x86: get rid of small constant size cases in raw_copy_{to,from}_user() Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 05/22] vm86: get rid of get_user_ex() use Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 06/22] x86: get rid of get_user_ex() in ia32_restore_sigcontext() Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 07/22] x86: get rid of get_user_ex() in restore_sigcontext() Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 08/22] x86: kill get_user_{try,catch,ex} Al Viro
2020-03-27  2:31         ` Al Viro [this message]
2020-03-27  2:31         ` [RFC][PATCH v2 10/22] x86: switch setup_sigcontext() to unsafe_put_user() Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 11/22] x86: switch ia32_setup_sigcontext() " Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 12/22] x86: get rid of put_user_try in {ia32,x32}_setup_rt_frame() Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 13/22] x86: ia32_setup_sigcontext(): lift user_access_{begin,end}() into the callers Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 14/22] x86: ia32_setup_frame(): consolidate uaccess areas Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 15/22] x86: ia32_setup_rt_frame(): " Al Viro
2020-03-27  2:31         ` [RFC][PATCH v2 16/22] x86: get rid of put_user_try in __setup_rt_frame() (both 32bit and 64bit) Al Viro
2020-03-27  2:32         ` [RFC][PATCH v2 17/22] x86: setup_sigcontext(): list user_access_{begin,end}() into callers Al Viro
2020-03-27  2:32         ` [RFC][PATCH v2 18/22] x86: __setup_frame(): consolidate uaccess areas Al Viro
2020-03-27  2:32         ` [RFC][PATCH v2 19/22] x86: __setup_rt_frame(): " Al Viro
2020-03-27  2:32         ` [RFC][PATCH v2 20/22] x86: x32_setup_rt_frame(): " Al Viro
2020-03-27  2:32         ` [RFC][PATCH v2 21/22] x86: unsafe_put-style macro for sigmask Al Viro
2020-03-27  2:32         ` [RFC][PATCH v2 22/22] kill uaccess_try() Al Viro

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200327023205.881896-9-viro@ZenIV.linux.org.uk \
    --to=viro@zeniv.linux.org.uk \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

Powered by JetHome