We add the necessary call to task_isolation_enter() in the prepare_exit_to_usermode() routine. We already unconditionally call into this routine if TIF_NOHZ is set, since that's where we do the user_enter() call.
We add calls to task_isolation_check_exception() in places where exceptions may not generate signals to the application. In addition, we add an overriding task_isolation_wait() call that runs a nap instruction while waiting for an interrupt, to make the task_isolation_enter() loop run in a lower-power state. Signed-off-by: Chris Metcalf <[email protected]> --- arch/tile/kernel/process.c | 6 +++++- arch/tile/kernel/ptrace.c | 6 +++++- arch/tile/kernel/single_step.c | 5 +++++ arch/tile/kernel/unaligned.c | 3 +++ arch/tile/mm/fault.c | 3 +++ arch/tile/mm/homecache.c | 5 ++++- 6 files changed, 25 insertions(+), 3 deletions(-) diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c index b5f30d376ce1..832febfd65df 100644 --- a/arch/tile/kernel/process.c +++ b/arch/tile/kernel/process.c @@ -29,6 +29,7 @@ #include <linux/signal.h> #include <linux/delay.h> #include <linux/context_tracking.h> +#include <linux/isolation.h> #include <asm/stack.h> #include <asm/switch_to.h> #include <asm/homecache.h> @@ -495,10 +496,13 @@ void prepare_exit_to_usermode(struct pt_regs *regs, u32 thread_info_flags) tracehook_notify_resume(regs); } + task_isolation_enter(); + local_irq_disable(); thread_info_flags = READ_ONCE(current_thread_info()->flags); - } while (thread_info_flags & _TIF_WORK_MASK); + } while ((thread_info_flags & _TIF_WORK_MASK) || + !task_isolation_ready()); if (thread_info_flags & _TIF_SINGLESTEP) { single_step_once(regs); diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c index bdc126faf741..63acf7b4655f 100644 --- a/arch/tile/kernel/ptrace.c +++ b/arch/tile/kernel/ptrace.c @@ -23,6 +23,7 @@ #include <linux/elf.h> #include <linux/tracehook.h> #include <linux/context_tracking.h> +#include <linux/isolation.h> #include <asm/traps.h> #include <arch/chip.h> @@ -259,8 +260,11 @@ int do_syscall_trace_enter(struct pt_regs *regs) * If TIF_NOHZ is set, we are required to call user_exit() before * doing anything that could touch RCU. */ - if (work & _TIF_NOHZ) + if (work & _TIF_NOHZ) { user_exit(); + if (task_isolation_check_syscall(regs->regs[TREG_SYSCALL_NR])) + return -1; + } if (secure_computing() == -1) return -1; diff --git a/arch/tile/kernel/single_step.c b/arch/tile/kernel/single_step.c index 53f7b9def07b..4cba9f4a1915 100644 --- a/arch/tile/kernel/single_step.c +++ b/arch/tile/kernel/single_step.c @@ -23,6 +23,7 @@ #include <linux/types.h> #include <linux/err.h> #include <linux/prctl.h> +#include <linux/isolation.h> #include <linux/context_tracking.h> #include <asm/cacheflush.h> #include <asm/traps.h> @@ -321,6 +322,8 @@ void single_step_once(struct pt_regs *regs) int size = 0, sign_ext = 0; /* happy compiler */ int align_ctl; + task_isolation_check_exception("single step at %#lx", regs->pc); + align_ctl = unaligned_fixup; switch (task_thread_info(current)->align_ctl) { case PR_UNALIGN_NOPRINT: @@ -770,6 +773,8 @@ void single_step_once(struct pt_regs *regs) unsigned long *ss_pc = this_cpu_ptr(&ss_saved_pc); unsigned long control = __insn_mfspr(SPR_SINGLE_STEP_CONTROL_K); + task_isolation_check_exception("single step at %#lx", regs->pc); + *ss_pc = regs->pc; control |= SPR_SINGLE_STEP_CONTROL_1__CANCELED_MASK; control |= SPR_SINGLE_STEP_CONTROL_1__INHIBIT_MASK; diff --git a/arch/tile/kernel/unaligned.c b/arch/tile/kernel/unaligned.c index d075f92ccee0..dbb9c1144236 100644 --- a/arch/tile/kernel/unaligned.c +++ b/arch/tile/kernel/unaligned.c @@ -26,6 +26,7 @@ #include <linux/compat.h> #include <linux/prctl.h> #include <linux/context_tracking.h> +#include <linux/isolation.h> #include <asm/cacheflush.h> #include <asm/traps.h> #include <asm/uaccess.h> @@ -1547,6 +1548,8 @@ void do_unaligned(struct pt_regs *regs, int vecnum) goto done; } + task_isolation_check_exception("unaligned JIT at %#lx", regs->pc); + if (!info->unalign_jit_base) { void __user *user_page; diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c index 13eac59bf16a..53514ca54143 100644 --- a/arch/tile/mm/fault.c +++ b/arch/tile/mm/fault.c @@ -36,6 +36,7 @@ #include <linux/uaccess.h> #include <linux/kdebug.h> #include <linux/context_tracking.h> +#include <linux/isolation.h> #include <asm/pgalloc.h> #include <asm/sections.h> @@ -846,6 +847,8 @@ void do_page_fault(struct pt_regs *regs, int fault_num, unsigned long address, unsigned long write) { enum ctx_state prev_state = exception_enter(); + task_isolation_check_exception("page fault interrupt %d at %#lx (%#lx)", + fault_num, regs->pc, address); __do_page_fault(regs, fault_num, address, write); exception_exit(prev_state); } diff --git a/arch/tile/mm/homecache.c b/arch/tile/mm/homecache.c index 40ca30a9fee3..a79325113105 100644 --- a/arch/tile/mm/homecache.c +++ b/arch/tile/mm/homecache.c @@ -31,6 +31,7 @@ #include <linux/smp.h> #include <linux/module.h> #include <linux/hugetlb.h> +#include <linux/isolation.h> #include <asm/page.h> #include <asm/sections.h> @@ -83,8 +84,10 @@ static void hv_flush_update(const struct cpumask *cache_cpumask, * Don't bother to update atomically; losing a count * here is not that critical. */ - for_each_cpu(cpu, &mask) + for_each_cpu(cpu, &mask) { ++per_cpu(irq_stat, cpu).irq_hv_flush_count; + task_isolation_debug(cpu); + } } /* -- 2.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
