linux-kernel - [PATCH 12/19] x86: make is_64bit

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20150607183704.F0209999@viggo.jf.intel.com>
Date:	Sun, 07 Jun 2015 11:37:04 -0700
From:	Dave Hansen <dave@...1.net>
To:	linux-kernel@...r.kernel.org
Cc:	x86@...nel.org, tglx@...utronix.de, Dave Hansen <dave@...1.net>,
	dave.hansen@...ux.intel.com, oleg@...hat.com
Subject: [PATCH 12/19] x86: make is_64bit_mm() widely available


From: Dave Hansen <dave.hansen@...ux.intel.com>

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@...ux.intel.com>
Cc: Oleg Nesterov <oleg@...hat.com>
Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
---

 b/arch/x86/include/asm/mmu_context.h |   13 +++++++++++++
 b/arch/x86/kernel/uprobes.c          |   10 +---------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff -puN arch/x86/include/asm/mmu_context.h~x86-make-is_64bit_mm-available arch/x86/include/asm/mmu_context.h
--- a/arch/x86/include/asm/mmu_context.h~x86-make-is_64bit_mm-available	2015-06-01 10:24:07.787891484 -0700
+++ b/arch/x86/include/asm/mmu_context.h	2015-06-01 10:24:07.793891755 -0700
@@ -142,6 +142,19 @@ static inline void arch_exit_mmap(struct
 	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 -puN arch/x86/kernel/uprobes.c~x86-make-is_64bit_mm-available arch/x86/kernel/uprobes.c
--- a/arch/x86/kernel/uprobes.c~x86-make-is_64bit_mm-available	2015-06-01 10:24:07.789891574 -0700
+++ b/arch/x86/kernel/uprobes.c	2015-06-01 10:24:07.793891755 -0700
@@ -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_
 }
 
 #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_
 	}
 }
 #else /* 32-bit: */
-static inline bool is_64bit_mm(struct mm_struct *mm)
-{
-	return false;
-}
 /*
  * No RIP-relative addressing on 32-bit
  */
_
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/