Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64...

[linux-2.6-block.git] / arch / arm64 / kernel / entry.S

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index cccd2788e63195199b67bf1006d7f5ea9a056702..ec2ee720e33e4c59885ff9a8cccb685adffbaa9f 100644 (file)
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -167,10 +167,10 @@ alternative_else_nop_endif
        .else
        add     x21, sp, #S_FRAME_SIZE
        get_thread_info tsk
-       /* Save the task's original addr_limit and set USER_DS (TASK_SIZE_64) */
+       /* Save the task's original addr_limit and set USER_DS */
        ldr     x20, [tsk, #TSK_TI_ADDR_LIMIT]
        str     x20, [sp, #S_ORIG_ADDR_LIMIT]
-       mov     x20, #TASK_SIZE_64
+       mov     x20, #USER_DS
        str     x20, [tsk, #TSK_TI_ADDR_LIMIT]
        /* No need to reset PSTATE.UAO, hardware's already set it to 0 for us */
        .endif /* \el == 0 */
@@ -382,6 +382,7 @@ alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0
  * x7 is reserved for the system call number in 32-bit mode.
  */
 wsc_nr .req    w25             // number of system calls
+xsc_nr .req    x25             // number of system calls (zero-extended)
 wscno  .req    w26             // syscall number
 xscno  .req    x26             // syscall number (zero-extended)
 stbl   .req    x27             // syscall table pointer
@@ -770,7 +771,10 @@ el0_sp_pc:
         * Stack or PC alignment exception handling
         */
        mrs     x26, far_el1
-       enable_daif
+       enable_da_f
+#ifdef CONFIG_TRACE_IRQFLAGS
+       bl      trace_hardirqs_off
+#endif
        ct_user_exit
        mov     x0, x26
        mov     x1, x25
@@ -828,6 +832,11 @@ el0_irq_naked:
 #endif
 
        ct_user_exit
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+       tbz     x22, #55, 1f
+       bl      do_el0_irq_bp_hardening
+1:
+#endif
        irq_handler
 
 #ifdef CONFIG_TRACE_IRQFLAGS
@@ -939,6 +948,7 @@ el0_svc_naked:                                      // compat entry point
        b.ne    __sys_trace
        cmp     wscno, wsc_nr                   // check upper syscall limit
        b.hs    ni_sys
+       mask_nospec64 xscno, xsc_nr, x19        // enforce bounds for syscall number
        ldr     x16, [stbl, xscno, lsl #3]      // address in the syscall table
        blr     x16                             // call sys_* routine
        b       ret_fast_syscall
@@ -1017,16 +1027,9 @@ alternative_else_nop_endif
        orr     \tmp, \tmp, #USER_ASID_FLAG
        msr     ttbr1_el1, \tmp
        /*
-        * We avoid running the post_ttbr_update_workaround here because the
-        * user and kernel ASIDs don't have conflicting mappings, so any
-        * "blessing" as described in:
-        *
-        *   http://lkml.kernel.org/r/56BB848A.6060603@caviumnetworks.com
-        *
-        * will not hurt correctness. Whilst this may partially defeat the
-        * point of using split ASIDs in the first place, it avoids
-        * the hit of invalidating the entire I-cache on every return to
-        * userspace.
+        * We avoid running the post_ttbr_update_workaround here because
+        * it's only needed by Cavium ThunderX, which requires KPTI to be
+        * disabled.
         */
        .endm