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Subject[tip:x86/fpu] x86: Make is_64bit_mm() widely available
Commit-ID:  b0e9b09b3bd64e67bba862e238d3757b2482b6de
Gitweb: http://git.kernel.org/tip/b0e9b09b3bd64e67bba862e238d3757b2482b6de
Author: Dave Hansen <dave.hansen@linux.intel.com>
AuthorDate: Sun, 7 Jun 2015 11:37:04 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 9 Jun 2015 12:24:32 +0200

x86: Make is_64bit_mm() widely available

The uprobes code has a nice helper, is_64bit_mm(), that consults
both the runtime and compile-time flags for 32-bit support.
Instead of reinventing the wheel, pull it in to an x86 header so
we can use it for MPX.

I prefer passing the 'mm' around to test_thread_flag(TIF_IA32)
because it makes it explicit where the context is coming from.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150607183704.F0209999@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/mmu_context.h | 13 +++++++++++++
arch/x86/kernel/uprobes.c | 10 +---------
2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 883f6b9..5e8daee 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -142,6 +142,19 @@ static inline void arch_exit_mmap(struct mm_struct *mm)
paravirt_arch_exit_mmap(mm);
}

+#ifdef CONFIG_X86_64
+static inline bool is_64bit_mm(struct mm_struct *mm)
+{
+ return !config_enabled(CONFIG_IA32_EMULATION) ||
+ !(mm->context.ia32_compat == TIF_IA32);
+}
+#else
+static inline bool is_64bit_mm(struct mm_struct *mm)
+{
+ return false;
+}
+#endif
+
static inline void arch_bprm_mm_init(struct mm_struct *mm,
struct vm_area_struct *vma)
{
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 0b81ad6..6647624 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -29,6 +29,7 @@
#include <linux/kdebug.h>
#include <asm/processor.h>
#include <asm/insn.h>
+#include <asm/mmu_context.h>

/* Post-execution fixups. */

@@ -312,11 +313,6 @@ static int uprobe_init_insn(struct arch_uprobe *auprobe, struct insn *insn, bool
}

#ifdef CONFIG_X86_64
-static inline bool is_64bit_mm(struct mm_struct *mm)
-{
- return !config_enabled(CONFIG_IA32_EMULATION) ||
- !(mm->context.ia32_compat == TIF_IA32);
-}
/*
* If arch_uprobe->insn doesn't use rip-relative addressing, return
* immediately. Otherwise, rewrite the instruction so that it accesses
@@ -497,10 +493,6 @@ static void riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
}
}
#else /* 32-bit: */
-static inline bool is_64bit_mm(struct mm_struct *mm)
-{
- return false;
-}
/*
* No RIP-relative addressing on 32-bit
*/

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