From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>,
Sergey Fedorov <serge.fdrv@gmail.com>,
qemu-arm@nongnu.org, patches@linaro.org
Subject: [Qemu-devel] [PATCH 4/4] target-arm: UNDEF in the UNPREDICTABLE SRS-from-System case
Date: Thu, 11 Feb 2016 19:11:49 +0000 [thread overview]
Message-ID: <1455217909-28317-5-git-send-email-peter.maydell@linaro.org> (raw)
In-Reply-To: <1455217909-28317-1-git-send-email-peter.maydell@linaro.org>
Make get_r13_banked() raise an exception at runtime for the
corner case of SRS from System mode, so that we can UNDEF it;
this brings us in to line with the ARM ARM's set of permitted
CONSTRAINED UNPREDICTABLE choices.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
target-arm/op_helper.c | 8 ++++++++
target-arm/translate.c | 9 +++++----
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
index 05f97a7..8183108 100644
--- a/target-arm/op_helper.c
+++ b/target-arm/op_helper.c
@@ -474,6 +474,14 @@ uint32_t HELPER(get_r13_banked)(CPUARMState *env, uint32_t mode)
#if defined(CONFIG_USER_ONLY)
g_assert_not_reached();
#endif
+ if ((env->uncached_cpsr & CPSR_M) == ARM_CPU_MODE_SYS) {
+ /* SRS instruction is UNPREDICTABLE from System mode; we UNDEF.
+ * Other UNPREDICTABLE and UNDEF cases were caught at translate time.
+ */
+ raise_exception(env, EXCP_UDEF, syn_uncategorized(),
+ exception_target_el(env));
+ }
+
if ((env->uncached_cpsr & CPSR_M) == mode) {
return env->regs[13];
} else {
diff --git a/target-arm/translate.c b/target-arm/translate.c
index 7bceb05..e69145d 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -7590,10 +7590,7 @@ static void gen_srs(DisasContext *s,
* -- not a valid mode number
* -- a mode that's at a higher exception level
* -- Monitor, if we are Non-secure
- * For the UNPREDICTABLE cases we choose to UNDEF, except that for
- * "current mode is System" we will write a garbage SPSR.
- * (This is because we don't have access to our current mode here
- * and would have to do a runtime check to UNDEF for System.)
+ * For the UNPREDICTABLE cases we choose to UNDEF.
*/
if (s->current_el == 1 && !s->ns) {
gen_exception_insn(s, 4, EXCP_UDEF, syn_uncategorized(), 3);
@@ -7639,6 +7636,9 @@ static void gen_srs(DisasContext *s,
addr = tcg_temp_new_i32();
tmp = tcg_const_i32(mode);
+ /* get_r13_banked() will raise an exception if called from System mode */
+ gen_set_condexec(s);
+ gen_set_pc_im(s, s->pc - 4);
gen_helper_get_r13_banked(addr, cpu_env, tmp);
tcg_temp_free_i32(tmp);
switch (amode) {
@@ -7688,6 +7688,7 @@ static void gen_srs(DisasContext *s,
tcg_temp_free_i32(tmp);
}
tcg_temp_free_i32(addr);
+ s->is_jmp = DISAS_UPDATE;
}
static void disas_arm_insn(DisasContext *s, unsigned int insn)
--
1.9.1
next prev parent reply other threads:[~2016-02-11 19:23 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-11 19:11 [Qemu-devel] [PATCH 0/4] target-arm: Clean up trap/undef handling of SRS Peter Maydell
2016-02-11 19:11 ` [Qemu-devel] [PATCH 1/4] " Peter Maydell
2016-02-12 8:48 ` Sergey Fedorov
2016-02-12 14:56 ` Edgar E. Iglesias
2016-02-11 19:11 ` [Qemu-devel] [PATCH 2/4] target-arm: Move get/set_r13_banked() to op_helper.c Peter Maydell
2016-02-12 8:56 ` Sergey Fedorov
2016-02-12 15:05 ` Edgar E. Iglesias
2016-02-11 19:11 ` [Qemu-devel] [PATCH 3/4] target-arm: Combine user-only and softmmu get/set_r13_banked() Peter Maydell
2016-02-12 8:58 ` Sergey Fedorov
2016-02-12 15:12 ` Edgar E. Iglesias
2016-02-12 15:15 ` Peter Maydell
2016-02-12 15:16 ` Edgar E. Iglesias
2016-02-12 15:48 ` Sergey Fedorov
2016-02-12 15:49 ` Peter Maydell
2016-02-12 15:15 ` Edgar E. Iglesias
2016-02-11 19:11 ` Peter Maydell [this message]
2016-02-12 9:34 ` [Qemu-devel] [PATCH 4/4] target-arm: UNDEF in the UNPREDICTABLE SRS-from-System case Sergey Fedorov
2016-02-12 15:17 ` Edgar E. Iglesias
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1455217909-28317-5-git-send-email-peter.maydell@linaro.org \
--to=peter.maydell@linaro.org \
--cc=edgar.iglesias@gmail.com \
--cc=patches@linaro.org \
--cc=qemu-arm@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=serge.fdrv@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).