From: Dave Hansen <dave.hansen@linux.intel.com>
To: linux-kernel@vger.kernel.org
Cc: Dave Hansen <dave.hansen@linux.intel.com>,
sean.j.christopherson@intel.com, peterz@infradead.org,
tglx@linutronix.de, x86@kernel.org, luto@kernel.org,
jannh@google.com
Subject: [PATCH 6/8] x86/mm: add vsyscall address helper
Date: Fri, 28 Sep 2018 09:02:28 -0700 [thread overview]
Message-ID: <20180928160228.C593509B@viggo.jf.intel.com> (raw)
In-Reply-To: <20180928160219.3402F0AA@viggo.jf.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
We will shortly be using this check in two locations. Put it in
a helper before we do so.
Let's also insert PAGE_MASK instead of the open-coded ~0xfff.
It is easier to read and also more obviously correct considering
the implicit type conversion that has to happen when it is not
an implicit 'unsigned long'.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
---
b/arch/x86/mm/fault.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff -puN arch/x86/mm/fault.c~is-vsyscall-addr arch/x86/mm/fault.c
--- a/arch/x86/mm/fault.c~is-vsyscall-addr 2018-09-27 10:17:23.988343565 -0700
+++ b/arch/x86/mm/fault.c 2018-09-27 10:17:23.992343565 -0700
@@ -842,6 +842,15 @@ show_signal_msg(struct pt_regs *regs, un
show_opcodes(regs, loglvl);
}
+/*
+ * The (legacy) vsyscall page is the long page in the kernel portion
+ * of the address space that has user-accessible permissions.
+ */
+static bool is_vsyscall_vaddr(unsigned long vaddr)
+{
+ return (vaddr & PAGE_MASK) == VSYSCALL_ADDR;
+}
+
static void
__bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
unsigned long address, u32 *pkey, int si_code)
@@ -871,7 +880,7 @@ __bad_area_nosemaphore(struct pt_regs *r
* emulation.
*/
if (unlikely((error_code & X86_PF_INSTR) &&
- ((address & ~0xfff) == VSYSCALL_ADDR))) {
+ is_vsyscall_vaddr(address))) {
if (emulate_vsyscall(regs, address))
return;
}
_
next prev parent reply other threads:[~2018-09-28 16:06 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-28 16:02 [PATCH 0/8] [v2] x86/mm: page fault handling cleanups Dave Hansen
2018-09-28 16:02 ` [PATCH 1/8] x86/mm: clarify hardware vs. software "error_code" Dave Hansen
2018-10-09 15:02 ` [tip:x86/mm] x86/mm: Clarify " tip-bot for Dave Hansen
2018-09-28 16:02 ` [PATCH 2/8] x86/mm: break out kernel address space handling Dave Hansen
2018-10-09 15:02 ` [tip:x86/mm] x86/mm: Break " tip-bot for Dave Hansen
2018-09-28 16:02 ` [PATCH 3/8] x86/mm: break out user " Dave Hansen
2018-10-09 15:03 ` [tip:x86/mm] x86/mm: Break " tip-bot for Dave Hansen
2018-10-15 5:43 ` Eric W. Biederman
2018-10-19 5:58 ` Ingo Molnar
2018-09-28 16:02 ` [PATCH 4/8] x86/mm: add clarifying comments for user addr space Dave Hansen
2018-10-09 15:03 ` [tip:x86/mm] x86/mm: Add " tip-bot for Dave Hansen
2018-09-28 16:02 ` [PATCH 5/8] x86/mm: fix exception table comments Dave Hansen
2018-10-09 15:04 ` [tip:x86/mm] x86/mm: Fix " tip-bot for Dave Hansen
2018-09-28 16:02 ` Dave Hansen [this message]
2018-10-09 15:04 ` [tip:x86/mm] x86/mm: Add vsyscall address helper tip-bot for Dave Hansen
2018-09-28 16:02 ` [PATCH 7/8] x86/mm/vsyscall: consider vsyscall page part of user address space Dave Hansen
2018-10-09 15:05 ` [tip:x86/mm] x86/mm/vsyscall: Consider " tip-bot for Dave Hansen
2018-09-28 16:02 ` [PATCH 8/8] x86/mm: remove spurious fault pkey check Dave Hansen
2018-10-09 15:05 ` [tip:x86/mm] x86/mm: Remove " tip-bot for Dave Hansen
2018-10-02 9:54 ` [PATCH 0/8] [v2] x86/mm: page fault handling cleanups Peter Zijlstra
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