From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Subject: [PULL 3/5] accel/tcg: Preserve PAGE_ANON when changing page permissions
Date: Mon, 12 Apr 2021 11:31:50 +0100 [thread overview]
Message-ID: <20210412103152.28433-4-peter.maydell@linaro.org> (raw)
In-Reply-To: <20210412103152.28433-1-peter.maydell@linaro.org>
From: Richard Henderson <richard.henderson@linaro.org>
Using mprotect() to change PROT_* does not change the MAP_ANON
previously set with mmap(). Our linux-user version of MTE only
works with MAP_ANON pages, so losing PAGE_ANON caused MTE to
stop working.
Reported-by: Stephen Long <steplong@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
tests/tcg/aarch64/mte.h | 3 ++-
accel/tcg/translate-all.c | 9 +++++--
tests/tcg/aarch64/mte-6.c | 43 +++++++++++++++++++++++++++++++
tests/tcg/aarch64/Makefile.target | 2 +-
4 files changed, 53 insertions(+), 4 deletions(-)
create mode 100644 tests/tcg/aarch64/mte-6.c
diff --git a/tests/tcg/aarch64/mte.h b/tests/tcg/aarch64/mte.h
index 141cef522ce..0805676b116 100644
--- a/tests/tcg/aarch64/mte.h
+++ b/tests/tcg/aarch64/mte.h
@@ -48,7 +48,8 @@ static void enable_mte(int tcf)
}
}
-static void *alloc_mte_mem(size_t size)
+static void * alloc_mte_mem(size_t size) __attribute__((unused));
+static void * alloc_mte_mem(size_t size)
{
void *p = mmap(NULL, size, PROT_READ | PROT_WRITE | PROT_MTE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index f32df8b2404..ba6ab09790e 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -2714,6 +2714,8 @@ void page_set_flags(target_ulong start, target_ulong end, int flags)
a missing call to h2g_valid. */
assert(end - 1 <= GUEST_ADDR_MAX);
assert(start < end);
+ /* Only set PAGE_ANON with new mappings. */
+ assert(!(flags & PAGE_ANON) || (flags & PAGE_RESET));
assert_memory_lock();
start = start & TARGET_PAGE_MASK;
@@ -2737,11 +2739,14 @@ void page_set_flags(target_ulong start, target_ulong end, int flags)
p->first_tb) {
tb_invalidate_phys_page(addr, 0);
}
- if (reset_target_data && p->target_data) {
+ if (reset_target_data) {
g_free(p->target_data);
p->target_data = NULL;
+ p->flags = flags;
+ } else {
+ /* Using mprotect on a page does not change MAP_ANON. */
+ p->flags = (p->flags & PAGE_ANON) | flags;
}
- p->flags = flags;
}
}
diff --git a/tests/tcg/aarch64/mte-6.c b/tests/tcg/aarch64/mte-6.c
new file mode 100644
index 00000000000..60d51d18be5
--- /dev/null
+++ b/tests/tcg/aarch64/mte-6.c
@@ -0,0 +1,43 @@
+#include "mte.h"
+
+void pass(int sig, siginfo_t *info, void *uc)
+{
+ assert(info->si_code == SEGV_MTESERR);
+ exit(0);
+}
+
+int main(void)
+{
+ enable_mte(PR_MTE_TCF_SYNC);
+
+ void *brk = sbrk(16);
+ if (brk == (void *)-1) {
+ perror("sbrk");
+ return 2;
+ }
+
+ if (mprotect(brk, 16, PROT_READ | PROT_WRITE | PROT_MTE)) {
+ perror("mprotect");
+ return 2;
+ }
+
+ int *p1, *p2;
+ long excl = 1;
+
+ asm("irg %0,%1,%2" : "=r"(p1) : "r"(brk), "r"(excl));
+ asm("gmi %0,%1,%0" : "+r"(excl) : "r"(p1));
+ asm("irg %0,%1,%2" : "=r"(p2) : "r"(brk), "r"(excl));
+ asm("stg %0,[%0]" : : "r"(p1));
+
+ *p1 = 0;
+
+ struct sigaction sa;
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_sigaction = pass;
+ sa.sa_flags = SA_SIGINFO;
+ sigaction(SIGSEGV, &sa, NULL);
+
+ *p2 = 0;
+
+ abort();
+}
diff --git a/tests/tcg/aarch64/Makefile.target b/tests/tcg/aarch64/Makefile.target
index 56e48f4b34f..05b2622bfc9 100644
--- a/tests/tcg/aarch64/Makefile.target
+++ b/tests/tcg/aarch64/Makefile.target
@@ -37,7 +37,7 @@ AARCH64_TESTS += bti-2
# MTE Tests
ifneq ($(DOCKER_IMAGE)$(CROSS_CC_HAS_ARMV8_MTE),)
-AARCH64_TESTS += mte-1 mte-2 mte-3 mte-4
+AARCH64_TESTS += mte-1 mte-2 mte-3 mte-4 mte-6
mte-%: CFLAGS += -march=armv8.5-a+memtag
endif
--
2.20.1
next prev parent reply other threads:[~2021-04-12 10:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-12 10:31 [PULL 0/5] target-arm queue Peter Maydell
2021-04-12 10:31 ` [PULL 1/5] hw/arm/virt-acpi-build: Fix GSIV values of the {GERR, Sync} interrupts Peter Maydell
2021-04-12 10:31 ` [PULL 2/5] hw/arm/smmuv3: Emulate CFGI_STE_RANGE for an aligned range of StreamIDs Peter Maydell
2021-04-12 10:31 ` Peter Maydell [this message]
2021-04-12 10:31 ` [PULL 4/5] target/arm: Check PAGE_WRITE_ORG for MTE writeability Peter Maydell
2021-04-12 10:31 ` [PULL 5/5] exec: Fix overlap of PAGE_ANON and PAGE_TARGET_1 Peter Maydell
2021-04-12 10:42 ` [PULL 0/5] target-arm queue no-reply
2021-04-12 14:50 ` Peter Maydell
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=20210412103152.28433-4-peter.maydell@linaro.org \
--to=peter.maydell@linaro.org \
--cc=qemu-devel@nongnu.org \
/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).