aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorRichard Henderson <richard.henderson@linaro.org>2021-04-06 10:40:20 -0700
committerPeter Maydell <peter.maydell@linaro.org>2021-04-12 11:06:24 +0100
commiteb42297a59e103500bdd2c352c5b52f54b1c33cd (patch)
treeaf7603fdfa104013fc2ef405f69533c996c55df5
parent017a913af4dff47ac5e62be613b9f8b88fc8fa96 (diff)
downloadqemu-arm-eb42297a59e103500bdd2c352c5b52f54b1c33cd.tar.gz
accel/tcg: Preserve PAGE_ANON when changing page permissions
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>
-rw-r--r--accel/tcg/translate-all.c9
-rw-r--r--tests/tcg/aarch64/Makefile.target2
-rw-r--r--tests/tcg/aarch64/mte-6.c43
-rw-r--r--tests/tcg/aarch64/mte.h3
4 files changed, 53 insertions, 4 deletions
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index f32df8b240..ba6ab09790 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/Makefile.target b/tests/tcg/aarch64/Makefile.target
index 56e48f4b34..05b2622bfc 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
diff --git a/tests/tcg/aarch64/mte-6.c b/tests/tcg/aarch64/mte-6.c
new file mode 100644
index 0000000000..60d51d18be
--- /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/mte.h b/tests/tcg/aarch64/mte.h
index 141cef522c..0805676b11 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);