From 375906f8765e131a4a159b1ffebf78c15db7b3bf Mon Sep 17 00:00:00 2001 From: Stephen Wilson Date: Sun, 13 Mar 2011 15:49:14 -0400 Subject: [PATCH] x86: mark associated mm when running a task in 32 bit compatibility mode This patch simply follows the same practice as for setting the TIF_IA32 flag. In particular, an mm is marked as holding 32-bit tasks when a 32-bit binary is exec'ed. Both ELF and a.out formats are updated. Signed-off-by: Stephen Wilson Reviewed-by: Michel Lespinasse Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Signed-off-by: Al Viro --- arch/x86/ia32/ia32_aout.c | 1 + arch/x86/kernel/process_64.c | 8 ++++++++ 2 files changed, 9 insertions(+) diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c index 2d93bdbc9ac0..fd843877e841 100644 --- a/arch/x86/ia32/ia32_aout.c +++ b/arch/x86/ia32/ia32_aout.c @@ -298,6 +298,7 @@ static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs) /* OK, This is the point of no return */ set_personality(PER_LINUX); set_thread_flag(TIF_IA32); + current->mm->context.ia32_compat = 1; setup_new_exec(bprm); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index bd387e8f73b4..6c9dd922ac0d 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -501,6 +501,10 @@ void set_personality_64bit(void) /* Make sure to be in 64bit mode */ clear_thread_flag(TIF_IA32); + /* Ensure the corresponding mm is not marked. */ + if (current->mm) + current->mm->context.ia32_compat = 0; + /* TBD: overwrites user setup. Should have two bits. But 64bit processes have always behaved this way, so it's not too bad. The main problem is just that @@ -516,6 +520,10 @@ void set_personality_ia32(void) set_thread_flag(TIF_IA32); current->personality |= force_personality32; + /* Mark the associated mm as containing 32-bit tasks. */ + if (current->mm) + current->mm->context.ia32_compat = 1; + /* Prepare the first "return" to user space */ current_thread_info()->status |= TS_COMPAT; } -- 2.20.1