[src/trunk]: src/sys/arch/aarch64 SCTLR_EnIA should be enabled in the caller(...

[ryo <ryo%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3cabd4782e96
branches:  trunk
changeset: 932749:3cabd4782e96
user:      ryo <ryo%NetBSD.org@localhost>
date:      Fri May 15 04:55:40 2020 +0000

description:
SCTLR_EnIA should be enabled in the caller(locore).

For some reason, gcc make aarch64_pac_init() function non-leaf, and it uses paciasp/autiasp.

diffstat:

 sys/arch/aarch64/aarch64/cpufunc.c   |  24 ++++++++++++------------
 sys/arch/aarch64/aarch64/genassym.cf |   3 ++-
 sys/arch/aarch64/aarch64/locore.S    |  14 ++++++++++++--
 sys/arch/aarch64/include/cpufunc.h   |   4 ++--
 4 files changed, 28 insertions(+), 17 deletions(-)

diffs (136 lines):

diff -r fc5bc3abea48 -r 3cabd4782e96 sys/arch/aarch64/aarch64/cpufunc.c
--- a/sys/arch/aarch64/aarch64/cpufunc.c        Fri May 15 01:43:47 2020 +0000
+++ b/sys/arch/aarch64/aarch64/cpufunc.c        Fri May 15 04:55:40 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cpufunc.c,v 1.17 2020/04/12 07:49:58 maxv Exp $        */
+/*     $NetBSD: cpufunc.c,v 1.18 2020/05/15 04:55:40 ryo Exp $ */
 
 /*
  * Copyright (c) 2017 Ryo Shimizu <ryo%nerv.org@localhost>
@@ -30,7 +30,7 @@
 #include "opt_multiprocessor.h"
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: cpufunc.c,v 1.17 2020/04/12 07:49:58 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: cpufunc.c,v 1.18 2020/05/15 04:55:40 ryo Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -443,14 +443,15 @@
 }
 
 /*
- * TODO: this function should have a "no-pac" attribute. Right now it
- * doesn't use PAC so that's fine.
+ * In order to avoid inconsistencies with pointer authentication
+ * in this function itself, the caller must enable PAC according
+ * to the return value.
  */
-void
+int
 aarch64_pac_init(int primary)
 {
 #ifdef ARMV83_PAC
-       uint64_t reg, sctlr;
+       uint64_t reg;
 
        /* CPU0 does the detection. */
        if (primary) {
@@ -470,15 +471,14 @@
        }
 
        if (!aarch64_pac_enabled)
-               return;
-
-       /* Enable PAC on the CPU. */
-       sctlr = reg_sctlr_el1_read();
-       sctlr |= SCTLR_EnIA;
-       reg_sctlr_el1_write(sctlr);
+               return -1;
 
        /* Set the key. Curlwp here is the CPU's idlelwp. */
        reg_APIAKeyLo_EL1_write(curlwp->l_md.md_ia_kern_lo);
        reg_APIAKeyHi_EL1_write(curlwp->l_md.md_ia_kern_hi);
+
+       return 0;
+#else
+       return -1;
 #endif
 }
diff -r fc5bc3abea48 -r 3cabd4782e96 sys/arch/aarch64/aarch64/genassym.cf
--- a/sys/arch/aarch64/aarch64/genassym.cf      Fri May 15 01:43:47 2020 +0000
+++ b/sys/arch/aarch64/aarch64/genassym.cf      Fri May 15 04:55:40 2020 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: genassym.cf,v 1.23 2020/04/12 07:49:58 maxv Exp $
+# $NetBSD: genassym.cf,v 1.24 2020/05/15 04:55:40 ryo Exp $
 #-
 # Copyright (c) 2014 The NetBSD Foundation, Inc.
 # All rights reserved.
@@ -363,6 +363,7 @@
 define SCTLR_UCI               SCTLR_UCI
 define SCTLR_nTLSMD            SCTLR_nTLSMD
 define SCTLR_LSMAOE            SCTLR_LSMAOE
+define SCTLR_EnIA              SCTLR_EnIA
 
 define ICC_SRE_EL2_EN          ICC_SRE_EL2_EN
 define ICC_SRE_EL2_SRE         ICC_SRE_EL2_SRE
diff -r fc5bc3abea48 -r 3cabd4782e96 sys/arch/aarch64/aarch64/locore.S
--- a/sys/arch/aarch64/aarch64/locore.S Fri May 15 01:43:47 2020 +0000
+++ b/sys/arch/aarch64/aarch64/locore.S Fri May 15 04:55:40 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: locore.S,v 1.59 2020/04/12 07:49:58 maxv Exp $ */
+/*     $NetBSD: locore.S,v 1.60 2020/05/15 04:55:40 ryo Exp $  */
 
 /*
  * Copyright (c) 2017 Ryo Shimizu <ryo%nerv.org@localhost>
@@ -38,7 +38,7 @@
 #include <aarch64/hypervisor.h>
 #include "assym.h"
 
-RCSID("$NetBSD: locore.S,v 1.59 2020/04/12 07:49:58 maxv Exp $")
+RCSID("$NetBSD: locore.S,v 1.60 2020/05/15 04:55:40 ryo Exp $")
 
 #ifdef AARCH64_DEVICE_MEM_STRONGLY_ORDERED
 #define        MAIR_DEVICE_MEM         MAIR_DEVICE_nGnRnE
@@ -181,6 +181,11 @@
        /* init PAC if supported */
        mov     x0, #1
        bl      aarch64_pac_init
+       cbnz    w0, 1f                  /* if (aarch64_pac_init() == 0) */
+       mrs     x0, sctlr_el1
+       orr     x0, x0, #SCTLR_EnIA     /*  enable PAC */
+       msr     sctlr_el1, x0
+1:
 
        /* set topology information */
        mrs     x0, tpidr_el1           /* curcpu */
@@ -509,6 +514,11 @@
        /* init PAC if supported */
        mov     x0, #0
        bl      aarch64_pac_init
+       cbnz    w0, 1f                  /* if (aarch64_pac_init() == 0) */
+       mrs     x0, sctlr_el1
+       orr     x0, x0, #SCTLR_EnIA     /*  enable PAC */
+       msr     sctlr_el1, x0
+1:
 
        mov     fp, xzr                 /* trace back starts here */
        mrs     x0, tpidr_el1           /* curcpu() */
diff -r fc5bc3abea48 -r 3cabd4782e96 sys/arch/aarch64/include/cpufunc.h
--- a/sys/arch/aarch64/include/cpufunc.h        Fri May 15 01:43:47 2020 +0000
+++ b/sys/arch/aarch64/include/cpufunc.h        Fri May 15 04:55:40 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cpufunc.h,v 1.13 2020/05/13 06:08:51 ryo Exp $ */
+/*     $NetBSD: cpufunc.h,v 1.14 2020/05/15 04:55:40 ryo Exp $ */
 
 /*
  * Copyright (c) 2017 Ryo Shimizu <ryo%nerv.org@localhost>
@@ -70,7 +70,7 @@
 
 extern int aarch64_pac_enabled;
 
-void aarch64_pac_init(int);
+int aarch64_pac_init(int);
 
 int set_cpufuncs(void);
 void aarch64_getcacheinfo(int);