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[PULL,30/30] target-arm: Only trap SRS from S-EL1 if specified mode is MON

Message ID 1457091713-10138-31-git-send-email-peter.maydell@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Peter Maydell March 4, 2016, 11:41 a.m. UTC 
From: Ralf-Philipp Weinmann <ralf+devel@comsecuris.com>

Commit cbc0326b6fb9 caused SRS instructions executed from Secure
EL1 to trap to EL3 even if the specified mode was not monitor mode.

According to the ARMv8 Architecture reference manual [F6.1.203], ALL
of the following conditions need to be met for SRS to trap to EL3:
* It is executed at Secure PL1.
* The specified mode is monitor mode.
* EL3 is using AArch64.

Correct the condition governing the trap to EL3 to check the
specified mode.

Signed-off-by: Ralf-Philipp Weinmann <ralf+devel@comsecuris.com>
Message-id: 20160222224251.GA11654@beta.comsecuris.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: tweaked comment text to read 'specified mode'; edited
 commit message]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target-arm/translate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/target-arm/translate.c b/target-arm/translate.c
index 25db09e..025c7a5 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -7655,6 +7655,7 @@  static void gen_srs(DisasContext *s,
 
     /* SRS is:
      * - trapped to EL3 if EL3 is AArch64 and we are at Secure EL1
+     *   and specified mode is monitor mode
      * - UNDEFINED in Hyp mode
      * - UNPREDICTABLE in User or System mode
      * - UNPREDICTABLE if the specified mode is:
@@ -7664,7 +7665,7 @@  static void gen_srs(DisasContext *s,
      * -- Monitor, if we are Non-secure
      * For the UNPREDICTABLE cases we choose to UNDEF.
      */
-    if (s->current_el == 1 && !s->ns) {
+    if (s->current_el == 1 && !s->ns && mode == ARM_CPU_MODE_MON) {
         gen_exception_insn(s, 4, EXCP_UDEF, syn_uncategorized(), 3);
         return;
     }