Commit-ID: cc87324b3dbb9bdf6916c7f479230db24c4aa309 Gitweb: http://git.kernel.org/tip/cc87324b3dbb9bdf6916c7f479230db24c4aa309 Author: Dmitry Safonov <dsafo...@virtuozzo.com> AuthorDate: Mon, 5 Sep 2016 16:33:07 +0300 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Wed, 14 Sep 2016 21:28:11 +0200
x86/ptrace: Down with test_thread_flag(TIF_IA32) As the task isn't executing at the moment of {GET,SET}REGS, return regset that corresponds to code selector, rather than value of TIF_IA32 flag. I.e. if we ptrace i386 elf binary that has just changed it's code selector to __USER_CS, than GET_REGS will return full x86_64 register set. Note, that this will work only if application has changed it's CS. If the application does 32-bit syscall with __USER_CS, ptrace will still return 64-bit register set. Which might be still confusing for tools that expect TS_COMPACT to be exposed [1, 2]. So this this change should make PTRACE_GETREGSET more reliable and this will be another step to drop TIF_{IA32,X32} flags. [1]: https://sourceforge.net/p/strace/mailman/message/30471411/ [2]: https://lkml.org/lkml/2012/1/18/320 Signed-off-by: Dmitry Safonov <dsafo...@virtuozzo.com> Cc: 0x7f454...@gmail.com Cc: o...@redhat.com Cc: linux...@kvack.org Cc: l...@kernel.org Cc: Pedro Alves <pal...@redhat.com> Cc: gorcu...@openvz.org Cc: xe...@virtuozzo.com Link: http://lkml.kernel.org/r/20160905133308.28234-6-dsafo...@virtuozzo.com Signed-off-by: Thomas Gleixner <t...@linutronix.de> --- arch/x86/kernel/ptrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index f79576a..ad0bab8 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -1358,7 +1358,7 @@ void update_regset_xstate_info(unsigned int size, u64 xstate_mask) const struct user_regset_view *task_user_regset_view(struct task_struct *task) { #ifdef CONFIG_IA32_EMULATION - if (test_tsk_thread_flag(task, TIF_IA32)) + if (!user_64bit_mode(task_pt_regs(task))) #endif #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION return &user_x86_32_view;