[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH v4 20/23] linux-user/aarch64: Signal SEGV_MTEAERR for async tag c
From: |
Richard Henderson |
Subject: |
[PATCH v4 20/23] linux-user/aarch64: Signal SEGV_MTEAERR for async tag check error |
Date: |
Thu, 28 Jan 2021 12:41:38 -1000 |
The real kernel collects _TIF_MTE_ASYNC_FAULT into the current thread's
state on any kernel entry (interrupt, exception etc), and then delivers
the signal in advance of resuming the thread.
This means that while the signal won't be delivered immediately, it will
not be delayed forever -- at minimum it will be delivered after the next
clock interrupt.
We don't have a clock interrupt in linux-user, so we issue a cpu_kick
to signal a return to the main loop at the end of the current TB.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/aarch64/target_signal.h | 1 +
linux-user/aarch64/cpu_loop.c | 11 +++++++++++
target/arm/mte_helper.c | 10 ++++++++++
3 files changed, 22 insertions(+)
diff --git a/linux-user/aarch64/target_signal.h
b/linux-user/aarch64/target_signal.h
index 777fb667fe..18013e1b23 100644
--- a/linux-user/aarch64/target_signal.h
+++ b/linux-user/aarch64/target_signal.h
@@ -21,6 +21,7 @@ typedef struct target_sigaltstack {
#include "../generic/signal.h"
+#define TARGET_SEGV_MTEAERR 8 /* Asynchronous ARM MTE error */
#define TARGET_SEGV_MTESERR 9 /* Synchronous ARM MTE exception */
#define TARGET_ARCH_HAS_SETUP_FRAME
diff --git a/linux-user/aarch64/cpu_loop.c b/linux-user/aarch64/cpu_loop.c
index b6a2e65593..7c42f65706 100644
--- a/linux-user/aarch64/cpu_loop.c
+++ b/linux-user/aarch64/cpu_loop.c
@@ -164,6 +164,17 @@ void cpu_loop(CPUARMState *env)
EXCP_DUMP(env, "qemu: unhandled CPU exception 0x%x - aborting\n",
trapnr);
abort();
}
+
+ /* Check for MTE asynchronous faults */
+ if (unlikely(env->cp15.tfsr_el[0])) {
+ env->cp15.tfsr_el[0] = 0;
+ info.si_signo = TARGET_SIGSEGV;
+ info.si_errno = 0;
+ info._sifields._sigfault._addr = 0;
+ info.si_code = TARGET_SEGV_MTEAERR;
+ queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
+ }
+
process_pending_signals(env);
/* Exception return on AArch64 always clears the exclusive monitor,
* so any return to running guest code implies this.
diff --git a/target/arm/mte_helper.c b/target/arm/mte_helper.c
index 153bd1e9df..d55f8d1e1e 100644
--- a/target/arm/mte_helper.c
+++ b/target/arm/mte_helper.c
@@ -565,6 +565,16 @@ static void mte_check_fail(CPUARMState *env, uint32_t desc,
select = 0;
}
env->cp15.tfsr_el[el] |= 1 << select;
+#ifdef CONFIG_USER_ONLY
+ /*
+ * Stand in for a timer irq, setting _TIF_MTE_ASYNC_FAULT,
+ * which then sends a SIGSEGV when the thread is next scheduled.
+ * This cpu will return to the main loop at the end of the TB,
+ * which is rather sooner than "normal". But the alternative
+ * is waiting until the next syscall.
+ */
+ qemu_cpu_kick(env_cpu(env));
+#endif
break;
default:
--
2.25.1
- [PATCH v4 09/23] linux-user: Do not use guest_addr_valid for h2g_valid, (continued)
- [PATCH v4 09/23] linux-user: Do not use guest_addr_valid for h2g_valid, Richard Henderson, 2021/01/28
- [PATCH v4 06/23] linux-user: Check for overflow in access_ok, Richard Henderson, 2021/01/28
- [PATCH v4 11/23] exec: Add support for TARGET_TAGGED_ADDRESSES, Richard Henderson, 2021/01/28
- [PATCH v4 08/23] bsd-user: Tidy VERIFY_READ/VERIFY_WRITE, Richard Henderson, 2021/01/28
- [PATCH v4 13/23] target/arm: Improve gen_top_byte_ignore, Richard Henderson, 2021/01/28
- [PATCH v4 15/23] linux-user/aarch64: Implement PR_MTE_TCF and PR_MTE_TAG, Richard Henderson, 2021/01/28
- [PATCH v4 12/23] linux-user/aarch64: Implement PR_TAGGED_ADDR_ENABLE, Richard Henderson, 2021/01/28
- [PATCH v4 14/23] target/arm: Use the proper TBI settings for linux-user, Richard Henderson, 2021/01/28
- [PATCH v4 17/23] target/arm: Split out syndrome.h from internals.h, Richard Henderson, 2021/01/28
- [PATCH v4 16/23] linux-user/aarch64: Implement PROT_MTE, Richard Henderson, 2021/01/28
- [PATCH v4 20/23] linux-user/aarch64: Signal SEGV_MTEAERR for async tag check error,
Richard Henderson <=
- [PATCH v4 21/23] target/arm: Add allocation tag storage for user mode, Richard Henderson, 2021/01/28
- [PATCH v4 18/23] linux-user/aarch64: Pass syndrome to EXC_*_ABORT, Richard Henderson, 2021/01/28
- [PATCH v4 19/23] linux-user/aarch64: Signal SEGV_MTESERR for sync tag check fault, Richard Henderson, 2021/01/28
- [PATCH v4 23/23] tests/tcg/aarch64: Add mte smoke tests, Richard Henderson, 2021/01/28
- [PATCH v4 22/23] target/arm: Enable MTE for user-only, Richard Henderson, 2021/01/28
- Re: [PATCH v4 00/23] target-arm: Implement ARMv8.5-MemTag, user mode, no-reply, 2021/01/28