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authorRichard Henderson <richard.henderson@linaro.org>2019-03-12 19:22:20 -0700
committerRichard Henderson <richard.henderson@linaro.org>2019-05-22 12:38:54 -0400
commit51977e25f77faae6949c7eb51c86f0319b82a77d (patch)
tree605108fe227d449c4367a6ec8c56f524102a64f4
parentc6a2377fb2e27970c584313ef32f04e5a56d0fdd (diff)
downloadqemu-arm-51977e25f77faae6949c7eb51c86f0319b82a77d.tar.gz
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>
-rw-r--r--linux-user/aarch64/cpu_loop.c29
-rw-r--r--linux-user/aarch64/target_syscall.h2
-rw-r--r--linux-user/syscall.c31
3 files changed, 32 insertions, 30 deletions
diff --git a/linux-user/aarch64/cpu_loop.c b/linux-user/aarch64/cpu_loop.c
index d75fd9d3e2..cedad39ca0 100644
--- a/linux-user/aarch64/cpu_loop.c
+++ b/linux-user/aarch64/cpu_loop.c
@@ -20,6 +20,7 @@
#include "qemu/osdep.h"
#include "qemu.h"
#include "cpu_loop-common.h"
+#include "qemu/guest-random.h"
#define get_user_code_u32(x, gaddr, env) \
({ abi_long __r = get_user_u32((x), (gaddr)); \
@@ -147,24 +148,6 @@ void cpu_loop(CPUARMState *env)
}
}
-static uint64_t arm_rand64(void)
-{
- int shift = 64 - clz64(RAND_MAX);
- int i, n = 64 / shift + (64 % shift != 0);
- uint64_t ret = 0;
-
- for (i = 0; i < n; i++) {
- ret = (ret << shift) | rand();
- }
- return ret;
-}
-
-void arm_init_pauth_key(ARMPACKey *key)
-{
- key->lo = arm_rand64();
- key->hi = arm_rand64();
-}
-
void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
{
ARMCPU *cpu = arm_env_get_cpu(env);
@@ -192,11 +175,11 @@ void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
#endif
if (cpu_isar_feature(aa64_pauth, cpu)) {
- arm_init_pauth_key(&env->apia_key);
- arm_init_pauth_key(&env->apib_key);
- arm_init_pauth_key(&env->apda_key);
- arm_init_pauth_key(&env->apdb_key);
- arm_init_pauth_key(&env->apga_key);
+ qemu_guest_getrandom_nofail(&env->apia_key, sizeof(ARMPACKey));
+ qemu_guest_getrandom_nofail(&env->apib_key, sizeof(ARMPACKey));
+ qemu_guest_getrandom_nofail(&env->apda_key, sizeof(ARMPACKey));
+ qemu_guest_getrandom_nofail(&env->apdb_key, sizeof(ARMPACKey));
+ qemu_guest_getrandom_nofail(&env->apga_key, sizeof(ARMPACKey));
}
ts->stack_base = info->start_stack;
diff --git a/linux-user/aarch64/target_syscall.h b/linux-user/aarch64/target_syscall.h
index b595e5da82..995e475c73 100644
--- a/linux-user/aarch64/target_syscall.h
+++ b/linux-user/aarch64/target_syscall.h
@@ -29,6 +29,4 @@ struct target_pt_regs {
# define TARGET_PR_PAC_APDBKEY (1 << 3)
# define TARGET_PR_PAC_APGAKEY (1 << 4)
-void arm_init_pauth_key(ARMPACKey *key);
-
#endif /* AARCH64_TARGET_SYSCALL_H */
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index f3ea9cac21..72e43b517a 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 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,
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;
}