From: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
To: Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Brian Gerst <brgerst@gmail.com>,
Chris Metcalf <cmetcalf@mellanox.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Liang Z Li <liang.z.li@intel.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Huang Rui <ray.huang@amd.com>, Jiri Slaby <jslaby@suse.cz>,
Jonathan Corbet <corbet@lwn.net>,
"Michael S. Tsirkin" <mst@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Vlastimil Babka <vbabka@suse.cz>, Chen Yucong <slaoub@gmail.com>,
Alexandre Julliard <julliard@winehq.org>,
Stas Sergeev <stsp@list.ru>, Fenghua Yu <fenghua.yu@intel.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Shuah Khan <shuah@kernel.org>,
linux-kernel@vger.kernel.org, x86@kernel.org,
linux-msdos@vger.kernel.org, wine-devel@winehq.org,
Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Subject: [v6 PATCH 18/21] x86/umip: Force a page fault when unable to copy emulated result to user
Date: Tue, 7 Mar 2017 16:32:51 -0800 [thread overview]
Message-ID: <20170308003254.27833-19-ricardo.neri-calderon@linux.intel.com> (raw)
In-Reply-To: <20170308003254.27833-1-ricardo.neri-calderon@linux.intel.com>
fixup_umip_exception will be called from do_general_protection. If the
former returns false, the latter will issue a SIGSEGV with SEND_SIG_PRIV.
However, when emulation is successful but the emulated result cannot be
copied to user space memory, it is more accurate to issue a SIGSEGV with
SEGV_MAPERR with the offending address. A new function is inspired in
force_sig_info_fault is introduced to model the page fault.
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
---
arch/x86/kernel/umip.c | 45 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 43 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c
index e64d8e5..bd06e26 100644
--- a/arch/x86/kernel/umip.c
+++ b/arch/x86/kernel/umip.c
@@ -163,6 +163,41 @@ static int __emulate_umip_insn(struct insn *insn, enum umip_insn umip_inst,
}
/**
+ * __force_sig_info_umip_fault - Force a SIGSEGV with SEGV_MAPERR
+ * @address: Address that caused the signal
+ * @regs: Register set containing the instruction pointer
+ *
+ * Force a SIGSEGV signal with SEGV_MAPERR as the error code. This function is
+ * intended to be used to provide a segmentation fault when the result of the
+ * UMIP emulation could not be copied to the user space memory.
+ *
+ * Return: none
+ */
+static void __force_sig_info_umip_fault(void __user *address,
+ struct pt_regs *regs)
+{
+ siginfo_t info;
+ struct task_struct *tsk = current;
+
+ if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV)) {
+ printk_ratelimited("%s[%d] umip emulation segfault ip:%lx sp:%lx error:%x in %lx\n",
+ tsk->comm, task_pid_nr(tsk), regs->ip,
+ regs->sp, X86_PF_USER | X86_PF_WRITE,
+ regs->ip);
+ }
+
+ tsk->thread.cr2 = (unsigned long)address;
+ tsk->thread.error_code = X86_PF_USER | X86_PF_WRITE;
+ tsk->thread.trap_nr = X86_TRAP_PF;
+
+ info.si_signo = SIGSEGV;
+ info.si_errno = 0;
+ info.si_code = SEGV_MAPERR;
+ info.si_addr = address;
+ force_sig_info(SIGSEGV, &info, tsk);
+}
+
+/**
* fixup_umip_exception - Fixup #GP faults caused by UMIP
* @regs: Registers as saved when entering the #GP trap
*
@@ -247,8 +282,14 @@ bool fixup_umip_exception(struct pt_regs *regs)
} else {
uaddr = insn_get_addr_ref(&insn, regs);
nr_copied = copy_to_user(uaddr, dummy_data, dummy_data_size);
- if (nr_copied > 0)
- return false;
+ if (nr_copied > 0) {
+ /*
+ * If copy fails, send a signal and tell caller that
+ * fault was fixed up
+ */
+ __force_sig_info_umip_fault(uaddr, regs);
+ return true;
+ }
}
/* increase IP to let the program keep going */
--
2.9.3
next prev parent reply other threads:[~2017-03-08 0:36 UTC|newest]
Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-08 0:32 [v6 PATCH 00/21] x86: Enable User-Mode Instruction Prevention Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 01/21] x86/mpx: Use signed variables to compute effective addresses Ricardo Neri
2017-04-11 21:56 ` Borislav Petkov
2017-04-26 1:40 ` Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 02/21] x86/mpx: Do not use SIB index if index points to R/ESP Ricardo Neri
2017-04-11 11:31 ` Borislav Petkov
2017-04-26 1:39 ` Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 03/21] x86/mpx: Do not use R/EBP as base in the SIB byte with Mod = 0 Ricardo Neri
2017-04-11 22:08 ` Borislav Petkov
2017-04-26 2:04 ` Ricardo Neri
2017-04-26 8:05 ` Borislav Petkov
2017-04-27 22:49 ` Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 04/21] x86/mpx, x86/insn: Relocate insn util functions to a new insn-kernel Ricardo Neri
2017-04-12 10:03 ` Borislav Petkov
2017-04-26 2:05 ` Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 05/21] x86/insn-eval: Add utility functions to get register offsets Ricardo Neri
2017-04-12 16:28 ` Borislav Petkov
2017-04-26 18:13 ` Ricardo Neri
2017-04-28 10:40 ` Borislav Petkov
2017-03-08 0:32 ` [v6 PATCH 06/21] x86/insn-eval: Add utility functions to get segment selector Ricardo Neri
2017-04-18 9:42 ` Borislav Petkov
2017-04-26 20:44 ` Ricardo Neri
2017-04-26 20:47 ` Ricardo Neri
2017-04-30 17:15 ` Borislav Petkov
2017-05-05 18:31 ` Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 07/21] x86/insn-eval: Add utility function to get segment descriptor Ricardo Neri
2017-04-19 10:26 ` Borislav Petkov
2017-04-26 21:51 ` Ricardo Neri
2017-05-04 11:02 ` Borislav Petkov
2017-05-12 2:13 ` Ricardo Neri
2017-05-15 17:27 ` Borislav Petkov
2017-03-08 0:32 ` [v6 PATCH 08/21] x86/insn-eval: Add utility function to get segment descriptor base address Ricardo Neri
2017-04-20 8:25 ` Borislav Petkov
2017-04-26 22:37 ` Ricardo Neri
2017-05-05 17:19 ` Borislav Petkov
2017-05-12 2:09 ` Ricardo Neri
2017-04-26 22:52 ` Ricardo Neri
2017-05-05 17:28 ` Borislav Petkov
2017-05-12 2:06 ` Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 09/21] x86/insn-eval: Add functions to get default operand and address sizes Ricardo Neri
2017-04-20 13:06 ` Borislav Petkov
2017-04-27 1:07 ` Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 10/21] x86/insn-eval: Do not use R/EBP as base if mod in ModRM is zero Ricardo Neri
2017-04-21 10:52 ` Borislav Petkov
2017-04-27 1:29 ` Ricardo Neri
2017-05-07 17:20 ` Borislav Petkov
2017-05-12 1:57 ` Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 11/21] insn/eval: Incorporate segment base in address computation Ricardo Neri
2017-04-21 14:55 ` Borislav Petkov
2017-04-27 1:31 ` Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 12/21] x86/insn: Support both signed 32-bit and 64-bit effective addresses Ricardo Neri
2017-04-25 13:51 ` Borislav Petkov
2017-04-27 3:33 ` Ricardo Neri
2017-05-08 11:42 ` Borislav Petkov
2017-05-12 1:55 ` Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 13/21] x86/insn-eval: Add support to resolve 16-bit addressing encodings Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 14/21] x86/insn-eval: Add wrapper function for 16-bit and 32-bit address encodings Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 15/21] x86/mm: Relocate page fault error codes to traps.h Ricardo Neri
2017-03-08 16:08 ` Andy Lutomirski
2017-03-08 0:32 ` [v6 PATCH 16/21] x86/cpufeature: Add User-Mode Instruction Prevention definitions Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 17/21] x86: Add emulation code for UMIP instructions Ricardo Neri
2017-03-08 0:32 ` Ricardo Neri [this message]
2017-03-08 0:32 ` [v6 PATCH 19/21] x86/traps: Fixup general protection faults caused by UMIP Ricardo Neri
2017-03-08 15:54 ` Andy Lutomirski
2017-03-08 0:32 ` [v6 PATCH 20/21] x86: Enable User-Mode Instruction Prevention Ricardo Neri
2017-03-08 0:32 ` [v6 PATCH 21/21] selftests/x86: Add tests for " Ricardo Neri
2017-03-08 15:56 ` Andy Lutomirski
2017-03-10 23:38 ` Ricardo Neri
2017-03-08 14:08 ` [v6 PATCH 00/21] x86: Enable " Stas Sergeev
2017-03-08 16:06 ` Andy Lutomirski
2017-03-08 16:29 ` Stas Sergeev
2017-03-08 16:46 ` Andy Lutomirski
2017-03-08 16:53 ` Stas Sergeev
2017-03-09 1:11 ` Ricardo Neri
2017-03-09 22:05 ` Stas Sergeev
2017-03-10 2:41 ` Andy Lutomirski
2017-03-10 10:30 ` Stas Sergeev
2017-03-10 21:04 ` Andy Lutomirski
2017-03-10 21:37 ` Stas Sergeev
2017-03-09 1:15 ` Ricardo Neri
2017-03-09 22:10 ` Stas Sergeev
2017-03-10 2:39 ` Andy Lutomirski
2017-03-10 11:33 ` Stas Sergeev
2017-03-10 14:17 ` Andy Lutomirski
2017-03-11 1:22 ` Ricardo Neri
2017-03-10 23:59 ` Ricardo Neri
2017-03-13 21:25 ` Stas Sergeev
2017-03-27 23:46 ` Ricardo Neri
2017-03-28 9:38 ` Stas Sergeev
2017-03-29 4:38 ` Ricardo Neri
2017-03-29 20:55 ` Stas Sergeev
2017-03-30 5:14 ` Ricardo Neri
2017-03-30 10:10 ` Stas Sergeev
2017-03-31 1:33 ` Ricardo Neri
2017-03-31 14:11 ` Alexandre Julliard
2017-03-31 21:26 ` Stas Sergeev
2017-04-01 2:18 ` Andy Lutomirski
2017-04-04 2:02 ` Ricardo Neri
2017-04-04 6:08 ` Alexandre Julliard
2017-04-01 13:08 ` Stas Sergeev
2017-04-01 17:49 ` H. Peter Anvin
2017-04-02 15:52 ` Andy Lutomirski
2017-04-04 9:59 ` Stas Sergeev
2017-04-04 2:05 ` Ricardo Neri
2017-04-04 8:03 ` Stas Sergeev
2017-03-10 23:58 ` Ricardo Neri
2017-03-09 0:46 ` Ricardo Neri
2017-03-09 22:01 ` Stas Sergeev
2017-03-10 23:47 ` Ricardo Neri
2017-03-10 23:58 ` Stas Sergeev
2017-03-11 0:13 ` Ricardo Neri
2017-03-08 16:07 ` Andy Lutomirski
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