Implement specific usage of verify_pre_usermode_state for user-mode returns for x86. --- Based on next-20170308 --- arch/x86/Kconfig | 1 + arch/x86/entry/common.c | 3 +++ arch/x86/entry/entry_64.S | 6 ++++++ 3 files changed, 10 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 005df7c825f5..6d48e18e6f09 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -63,6 +63,7 @@ config X86 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI select ARCH_MIGHT_HAVE_PC_PARPORT select ARCH_MIGHT_HAVE_PC_SERIO + select ARCH_NO_SYSCALL_VERIFY_PRE_USERMODE_STATE select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 370c42c7f046..525edbb77f03 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -22,6 +22,7 @@ #include <linux/context_tracking.h> #include <linux/user-return-notifier.h> #include <linux/uprobes.h> +#include <linux/syscalls.h> #include <asm/desc.h> #include <asm/traps.h> @@ -180,6 +181,8 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs) struct thread_info *ti = current_thread_info(); u32 cached_flags; + verify_pre_usermode_state(); + if (IS_ENABLED(CONFIG_PROVE_LOCKING) && WARN_ON(!irqs_disabled())) local_irq_disable(); diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index d2b2a2948ffe..795c31eebd09 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -201,6 +201,7 @@ entry_SYSCALL_64_fastpath: * It might end up jumping to the slow path. If it jumps, RAX * and all argument registers are clobbered. */ + call *sys_call_table(, %rax, 8) .Lentry_SYSCALL_64_after_fastpath_call: @@ -218,6 +219,11 @@ entry_SYSCALL_64_fastpath: testl $_TIF_ALLWORK_MASK, TASK_TI_flags(%r11) jnz 1f + /* + * Check user-mode state on fast path return, the same check is done + * under the slow path through syscall_return_slowpath. + */ + call verify_pre_usermode_state LOCKDEP_SYS_EXIT TRACE_IRQS_ON /* user mode is traced as IRQs on */ movq RIP(%rsp), %rcx -- 2.12.0.246.ga2ecc84866-goog -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
