#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/nospec.h>
+#include <linux/sched.h>
#include <linux/stddef.h>
#include <linux/sysctl.h>
#include <linux/unistd.h>
write_sysreg(val, cntkctl_el1);
}
-static void compat_thread_switch(struct task_struct *next)
-{
- if (!is_compat_thread(task_thread_info(next)))
- return;
-
- if (static_branch_unlikely(&arm64_mismatched_32bit_el0))
- set_tsk_thread_flag(next, TIF_NOTIFY_RESUME);
-}
-
/*
* __switch_to() checks current->thread.sctlr_user as an optimisation. Therefore
* this function must be called with preemption disabled and the update to
ssbs_thread_switch(next);
erratum_1418040_thread_switch(prev, next);
ptrauth_thread_switch_user(next);
- compat_thread_switch(next);
/*
* Complete any pending TLB or cache maintenance on this CPU in case
return sp & ~0xf;
}
+#ifdef CONFIG_COMPAT
+int compat_elf_check_arch(const struct elf32_hdr *hdr)
+{
+ if (!system_supports_32bit_el0())
+ return false;
+
+ if ((hdr)->e_machine != EM_ARM)
+ return false;
+
+ if (!((hdr)->e_flags & EF_ARM_EABI_MASK))
+ return false;
+
+ /*
+ * Prevent execve() of a 32-bit program from a deadline task
+ * if the restricted affinity mask would be inadmissible on an
+ * asymmetric system.
+ */
+ return !static_branch_unlikely(&arm64_mismatched_32bit_el0) ||
+ !dl_task_check_affinity(current, system_32bit_el0_cpumask());
+}
+#endif
+
/*
* Called from setup_new_exec() after (COMPAT_)SET_PERSONALITY.
*/
if (is_compat_task()) {
mmflags = MMCF_AARCH32;
+
+ /*
+ * Restrict the CPU affinity mask for a 32-bit task so that
+ * it contains only 32-bit-capable CPUs.
+ *
+ * From the perspective of the task, this looks similar to
+ * what would happen if the 64-bit-only CPUs were hot-unplugged
+ * at the point of execve(), although we try a bit harder to
+ * honour the cpuset hierarchy.
+ */
if (static_branch_unlikely(&arm64_mismatched_32bit_el0))
- set_tsk_thread_flag(current, TIF_NOTIFY_RESUME);
+ force_compatible_cpus_allowed_ptr(current);
+ } else if (static_branch_unlikely(&arm64_mismatched_32bit_el0)) {
+ relax_compatible_cpus_allowed_ptr(current);
}
current->mm->context.flags = mmflags;