commit 51977e25f77faae6949c7eb51c86f0319b82a77d
author Richard Henderson <richard.henderson@linaro.org> Tue Mar 12 19:22:20 2019 -0700
committer Richard Henderson <richard.henderson@linaro.org> Wed May 22 12:38:54 2019 -0400
tree 605108fe227d449c4367a6ec8c56f524102a64f4
parent c6a2377fb2e27970c584313ef32f04e5a56d0fdd

linux-user/aarch64: Use qemu_guest_getrandom for PAUTH keys

Use a better interface for random numbers than rand() * 3.

Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/syscall.c

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index f3ea9ca..72e43b5 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -108,6 +108,7 @@
 
 #include "qemu.h"
 #include "qemu/guest-random.h"
+#include "qapi/error.h"
 #include "fd-trans.h"
 
 #ifndef CLONE_IO
@@ -9765,25 +9766,45 @@
                     int all = (TARGET_PR_PAC_APIAKEY | TARGET_PR_PAC_APIBKEY |
                                TARGET_PR_PAC_APDAKEY | TARGET_PR_PAC_APDBKEY |
                                TARGET_PR_PAC_APGAKEY);
+                    int ret = 0;
+                    Error *err = NULL;
+
                     if (arg2 == 0) {
                         arg2 = all;
                     } else if (arg2 & ~all) {
                         return -TARGET_EINVAL;
                     }
                     if (arg2 & TARGET_PR_PAC_APIAKEY) {
-                        arm_init_pauth_key(&env->apia_key);
+                        ret |= qemu_guest_getrandom(&env->apia_key,
+                                                    sizeof(ARMPACKey), &err);
                     }
                     if (arg2 & TARGET_PR_PAC_APIBKEY) {
-                        arm_init_pauth_key(&env->apib_key);
+                        ret |= qemu_guest_getrandom(&env->apib_key,
+                                                    sizeof(ARMPACKey), &err);
                     }
                     if (arg2 & TARGET_PR_PAC_APDAKEY) {
-                        arm_init_pauth_key(&env->apda_key);
+                        ret |= qemu_guest_getrandom(&env->apda_key,
+                                                    sizeof(ARMPACKey), &err);
                     }
                     if (arg2 & TARGET_PR_PAC_APDBKEY) {
-                        arm_init_pauth_key(&env->apdb_key);
+                        ret |= qemu_guest_getrandom(&env->apdb_key,
+                                                    sizeof(ARMPACKey), &err);
                     }
                     if (arg2 & TARGET_PR_PAC_APGAKEY) {
-                        arm_init_pauth_key(&env->apga_key);
+                        ret |= qemu_guest_getrandom(&env->apga_key,
+                                                    sizeof(ARMPACKey), &err);
+                    }
+                    if (ret != 0) {
+                        /*
+                         * Some unknown failure in the crypto.  The best
+                         * we can do is log it and fail the syscall.
+                         * The real syscall cannot fail this way.
+                         */
+                        qemu_log_mask(LOG_UNIMP,
+                                      "PR_PAC_RESET_KEYS: Crypto failure: %s",
+                                      error_get_pretty(err));
+                        error_free(err);
+                        return -TARGET_EIO;
                     }
                     return 0;
                 }