Andy Lutomirski feed36cde0 x86/entry: Add enter_from_user_mode() and use it in syscalls ... Changing the x86 context tracking hooks is dangerous because there are no good checks that we track our context correctly. Add a helper to check that we're actually in CONTEXT_USER when we enter from user mode and wire it up for syscall entries. Subsequent patches will wire this up for all non-NMI entries as well. NMIs are their own special beast and cannot currently switch overall context tracking state. Instead, they have their own special RCU hooks. This is a tiny speedup if !CONFIG_CONTEXT_TRACKING (removes a branch) and a tiny slowdown if CONFIG_CONTEXT_TRACING (adds a layer of indirection). Eventually, we should fix up the core context tracking code to supply a function that does what we want (and can be much simpler than user_exit), which will enable us to get rid of the extra call. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Denys Vlasenko <vda.linux@googlemail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/853b42420066ec3fb856779cdc223a6dcb5d355b.1435952415.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>		2015-07-07 10:59:06 +02:00
..
syscalls
vdso	x86/compat: Don't build the 32-bit VDSO if not needed	2015-07-06 15:28:56 +02:00
vsyscall	x86/compat: Check for both 32-bit compat and x32 in get_gate_vma()	2015-07-06 15:28:57 +02:00
calling.h	x86/asm/entry/32: Replace RESTORE_RSI_RDI with open-coded 32-bit reads	2015-07-06 14:56:50 +02:00
common.c	x86/entry: Add enter_from_user_mode() and use it in syscalls	2015-07-07 10:59:06 +02:00
entry_32.S
entry_64_compat.S	x86/entry/64/compat: Fix bad fast syscall arg failure path	2015-07-07 10:58:30 +02:00
entry_64.S	x86/entry/64/compat: Fix bad fast syscall arg failure path	2015-07-07 10:58:30 +02:00
Makefile	x86/entry: Move C entry and exit code to arch/x86/entry/common.c	2015-07-07 10:59:05 +02:00
syscall_32.c
syscall_64.c
thunk_32.S
thunk_64.S