#include <linux/sched.h>
#include <linux/highmem.h>
#include <linux/perf_event.h>
+#include <linux/preempt.h>
+#include <asm/bug.h>
+#include <asm/cpufeature.h>
#include <asm/exception.h>
#include <asm/debug-monitors.h>
#include <asm/esr.h>
+#include <asm/sysreg.h>
#include <asm/system_misc.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
printk("\n");
}
+#ifdef CONFIG_ARM64_HW_AFDBM
+/*
+ * This function sets the access flags (dirty, accessed), as well as write
+ * permission, and only to a more permissive setting.
+ *
+ * It needs to cope with hardware update of the accessed/dirty state by other
+ * agents in the system and can safely skip the __sync_icache_dcache() call as,
+ * like set_pte_at(), the PTE is never changed from no-exec to exec here.
+ *
+ * Returns whether or not the PTE actually changed.
+ */
+int ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep,
+ pte_t entry, int dirty)
+{
+ pteval_t old_pteval;
+ unsigned int tmp;
+
+ if (pte_same(*ptep, entry))
+ return 0;
+
+ /* only preserve the access flags and write permission */
+ pte_val(entry) &= PTE_AF | PTE_WRITE | PTE_DIRTY;
+
+ /*
+ * PTE_RDONLY is cleared by default in the asm below, so set it in
+ * back if necessary (read-only or clean PTE).
+ */
+ if (!pte_write(entry) || !pte_sw_dirty(entry))
+ pte_val(entry) |= PTE_RDONLY;
+
+ /*
+ * Setting the flags must be done atomically to avoid racing with the
+ * hardware update of the access/dirty state.
+ */
+ asm volatile("// ptep_set_access_flags\n"
+ " prfm pstl1strm, %2\n"
+ "1: ldxr %0, %2\n"
+ " and %0, %0, %3 // clear PTE_RDONLY\n"
+ " orr %0, %0, %4 // set flags\n"
+ " stxr %w1, %0, %2\n"
+ " cbnz %w1, 1b\n"
+ : "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep))
+ : "L" (~PTE_RDONLY), "r" (pte_val(entry)));
+
+ flush_tlb_fix_spurious_fault(vma, address);
+ return 1;
+}
+#endif
+
/*
* The kernel tried to access some page that wasn't present.
*/
{
struct siginfo si;
- if (show_unhandled_signals && unhandled_signal(tsk, sig) &&
- printk_ratelimit()) {
+ if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) {
pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n",
tsk->comm, task_pid_nr(tsk), fault_name(esr), sig,
addr, esr);
mm_flags |= FAULT_FLAG_WRITE;
}
+ /*
+ * PAN bit set implies the fault happened in kernel space, but not
+ * in the arch's user access functions.
+ */
+ if (IS_ENABLED(CONFIG_ARM64_PAN) && (regs->pstate & PSR_PAN_BIT))
+ goto no_context;
+
/*
* As per x86, we may deadlock here. However, since the kernel only
* validly references user space from well defined areas of the code,
* starvation.
*/
mm_flags &= ~FAULT_FLAG_ALLOW_RETRY;
+ mm_flags |= FAULT_FLAG_TRIED;
goto retry;
}
}
{ do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" },
{ do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" },
{ do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" },
- { do_bad, SIGBUS, 0, "reserved access flag fault" },
+ { do_bad, SIGBUS, 0, "unknown 8" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" },
- { do_bad, SIGBUS, 0, "reserved permission fault" },
+ { do_bad, SIGBUS, 0, "unknown 12" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
{ do_bad, SIGBUS, 0, "synchronous external abort" },
- { do_bad, SIGBUS, 0, "asynchronous external abort" },
+ { do_bad, SIGBUS, 0, "unknown 17" },
{ do_bad, SIGBUS, 0, "unknown 18" },
{ do_bad, SIGBUS, 0, "unknown 19" },
{ do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
{ do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
{ do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
{ do_bad, SIGBUS, 0, "synchronous parity error" },
- { do_bad, SIGBUS, 0, "asynchronous parity error" },
+ { do_bad, SIGBUS, 0, "unknown 25" },
{ do_bad, SIGBUS, 0, "unknown 26" },
{ do_bad, SIGBUS, 0, "unknown 27" },
- { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
- { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
- { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
- { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
+ { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" },
+ { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" },
+ { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" },
+ { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" },
{ do_bad, SIGBUS, 0, "unknown 32" },
{ do_bad, SIGBUS, BUS_ADRALN, "alignment fault" },
- { do_bad, SIGBUS, 0, "debug event" },
+ { do_bad, SIGBUS, 0, "unknown 34" },
{ do_bad, SIGBUS, 0, "unknown 35" },
{ do_bad, SIGBUS, 0, "unknown 36" },
{ do_bad, SIGBUS, 0, "unknown 37" },
{ do_bad, SIGBUS, 0, "unknown 45" },
{ do_bad, SIGBUS, 0, "unknown 46" },
{ do_bad, SIGBUS, 0, "unknown 47" },
- { do_bad, SIGBUS, 0, "unknown 48" },
+ { do_bad, SIGBUS, 0, "TLB conflict abort" },
{ do_bad, SIGBUS, 0, "unknown 49" },
{ do_bad, SIGBUS, 0, "unknown 50" },
{ do_bad, SIGBUS, 0, "unknown 51" },
{ do_bad, SIGBUS, 0, "implementation fault (lockdown abort)" },
- { do_bad, SIGBUS, 0, "unknown 53" },
+ { do_bad, SIGBUS, 0, "implementation fault (unsupported exclusive)" },
{ do_bad, SIGBUS, 0, "unknown 54" },
{ do_bad, SIGBUS, 0, "unknown 55" },
{ do_bad, SIGBUS, 0, "unknown 56" },
{ do_bad, SIGBUS, 0, "unknown 57" },
- { do_bad, SIGBUS, 0, "implementation fault (coprocessor abort)" },
+ { do_bad, SIGBUS, 0, "unknown 58" },
{ do_bad, SIGBUS, 0, "unknown 59" },
{ do_bad, SIGBUS, 0, "unknown 60" },
- { do_bad, SIGBUS, 0, "unknown 61" },
- { do_bad, SIGBUS, 0, "unknown 62" },
+ { do_bad, SIGBUS, 0, "section domain fault" },
+ { do_bad, SIGBUS, 0, "page domain fault" },
{ do_bad, SIGBUS, 0, "unknown 63" },
};
struct pt_regs *regs)
{
struct siginfo info;
+ struct task_struct *tsk = current;
+
+ if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS))
+ pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n",
+ tsk->comm, task_pid_nr(tsk),
+ esr_get_class_string(esr), (void *)regs->pc,
+ (void *)regs->sp);
info.si_signo = SIGBUS;
info.si_errno = 0;
info.si_code = BUS_ADRALN;
info.si_addr = (void __user *)addr;
- arm64_notify_die("", regs, &info, esr);
+ arm64_notify_die("Oops - SP/PC alignment exception", regs, &info, esr);
}
-static struct fault_info debug_fault_info[] = {
+int __init early_brk64(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs);
+
+/*
+ * __refdata because early_brk64 is __init, but the reference to it is
+ * clobbered at arch_initcall time.
+ * See traps.c and debug-monitors.c:debug_traps_init().
+ */
+static struct fault_info __refdata debug_fault_info[] = {
{ do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" },
{ do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" },
{ do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" },
{ do_bad, SIGBUS, 0, "unknown 3" },
{ do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" },
{ do_bad, SIGTRAP, 0, "aarch32 vector catch" },
- { do_bad, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" },
+ { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" },
{ do_bad, SIGBUS, 0, "unknown 7" },
};
return 0;
}
+
+#ifdef CONFIG_ARM64_PAN
+int cpu_enable_pan(void *__unused)
+{
+ /*
+ * We modify PSTATE. This won't work from irq context as the PSTATE
+ * is discarded once we return from the exception.
+ */
+ WARN_ON_ONCE(in_interrupt());
+
+ config_sctlr_el1(SCTLR_EL1_SPAN, 0);
+ asm(SET_PSTATE_PAN(1));
+ return 0;
+}
+#endif /* CONFIG_ARM64_PAN */