When a packet has 2 stores, either both commit or neither commit.
At the beginning of gen_commit_packet, we check for multiple stores.
If there are multiple stores, call a helper that will probe each of
them before proceeding with the commit.
Note that we don't call the probe helper for packets with only one
store. Therefore, we call process_store_log before anything else
involved in committing the packet.
Test case added in tests/tcg/hexagon/hex_sigsegv.c
*** Changes in v2 ***
Reduce the overhead of probe_pkt_stores - pass a bit mask instead of
multiple booleans
Signed-off-by: Taylor Simpson <tsimp...@quicinc.com>
---
target/hexagon/helper.h | 2 +
target/hexagon/op_helper.c | 33 ++++++++++++
target/hexagon/translate.c | 33 +++++++++++-
tests/tcg/hexagon/hex_sigsegv.c | 106 ++++++++++++++++++++++++++++++++++++++
tests/tcg/hexagon/Makefile.target | 1 +
5 files changed, 174 insertions(+), 1 deletion(-)
create mode 100644 tests/tcg/hexagon/hex_sigsegv.c
diff --git a/target/hexagon/helper.h b/target/hexagon/helper.h
index ca201fb..412aaf9 100644
--- a/target/hexagon/helper.h
+++ b/target/hexagon/helper.h
@@ -89,3 +89,5 @@ DEF_HELPER_4(sffms_lib, f32, env, f32, f32, f32)
DEF_HELPER_3(dfmpyfix, f64, env, f64, f64)
DEF_HELPER_4(dfmpyhh, f64, env, f64, f64, f64)
+
+DEF_HELPER_3(probe_pkt_stores, void, env, int, int)
diff --git a/target/hexagon/op_helper.c b/target/hexagon/op_helper.c
index 61d5cde..fa65980 100644
--- a/target/hexagon/op_helper.c
+++ b/target/hexagon/op_helper.c
@@ -377,6 +377,39 @@ int32_t HELPER(vacsh_pred)(CPUHexagonState *env,
return PeV;
}
+static void probe_store(CPUHexagonState *env, int slot, int mmu_idx)
+{
+ if (!(env->slot_cancelled & (1 << slot))) {
+ size1u_t width = env->mem_log_stores[slot].width;
+ target_ulong va = env->mem_log_stores[slot].va;
+ uintptr_t ra = GETPC();
+ probe_write(env, va, width, mmu_idx, ra);
+ }
+}
+
+void HELPER(probe_pkt_stores)(CPUHexagonState *env, int mask, int mmu_idx)
+{
+ bool has_st0 = (mask >> 0) & 1;
+ bool has_st1 = (mask >> 1) & 1;
+ bool has_dczeroa = (mask >> 2) & 1;
+
+ if (has_st0 && !has_dczeroa) {
+ probe_store(env, 0, mmu_idx);
+ }
+ if (has_st1 && !has_dczeroa) {
+ probe_store(env, 1, mmu_idx);
+ }
+ if (has_dczeroa) {
+ /* Probe 32 bytes starting at (dczero_addr & ~0x1f) */
+ target_ulong va = env->dczero_addr & ~0x1f;
+ uintptr_t ra = GETPC();
+ probe_write(env, va + 0, 8, mmu_idx, ra);
+ probe_write(env, va + 8, 8, mmu_idx, ra);
+ probe_write(env, va + 16, 8, mmu_idx, ra);
+ probe_write(env, va + 24, 8, mmu_idx, ra);
+ }
+}
+
/*
* mem_noshuf
* Section 5.5 of the Hexagon V67 Programmer's Reference Manual
diff --git a/target/hexagon/translate.c b/target/hexagon/translate.c
index 6fb4e68..9e8d27a 100644
--- a/target/hexagon/translate.c
+++ b/target/hexagon/translate.c
@@ -471,9 +471,40 @@ static void update_exec_counters(DisasContext *ctx, Packet
*pkt)
static void gen_commit_packet(DisasContext *ctx, Packet *pkt)
{
+ /*
+ * If there is more than one store in a packet, make sure they are all OK
+ * before proceeding with the rest of the packet commit.
+ *
+ * Note that we don't call the probe helper for packets with only one
+ * store. Therefore, we call process_store_log before anything else
+ * involved in committing the packet.
+ */
+ if ((pkt->pkt_has_store_s0 &&
+ (pkt->pkt_has_store_s1 && !ctx->s1_store_processed)) ||
+ pkt->pkt_has_dczeroa) {
+ TCGv mem_idx = tcg_const_tl(ctx->mem_idx);
+ int mask = 0;
+ TCGv mask_tcgv;
+
+ if (pkt->pkt_has_store_s0) {
+ mask |= (1 << 0);
+ }
+ if (pkt->pkt_has_store_s1 && !ctx->s1_store_processed) {
+ mask |= (1 << 1);
+ }
+ if (pkt->pkt_has_dczeroa) {
+ mask |= (1 << 2);
+ }
+ mask_tcgv = tcg_const_tl(mask);
+ gen_helper_probe_pkt_stores(cpu_env, mask_tcgv, mem_idx);
+ tcg_temp_free(mem_idx);
+ tcg_temp_free(mask_tcgv);
+ }
+
+ process_store_log(ctx, pkt);
+
gen_reg_writes(ctx);
gen_pred_writes(ctx, pkt);
- process_store_log(ctx, pkt);
process_dczeroa(ctx, pkt);
update_exec_counters(ctx, pkt);
if (HEX_DEBUG) {
diff --git a/tests/tcg/hexagon/hex_sigsegv.c b/tests/tcg/hexagon/hex_sigsegv.c
new file mode 100644
index 0000000..dc2b349
--- /dev/null
+++ b/tests/tcg/hexagon/hex_sigsegv.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright(c) 2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * Test the VLIW semantics of two stores in a packet
+ *
+ * When a packet has 2 stores, either both commit or neither commit.
+ * We test this with a packet that does stores to both NULL and a global
+ * variable, "should_not_change". After the SIGSEGV is caught, we check
+ * that the "should_not_change" value is the same.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <setjmp.h>
+#include <signal.h>
+
+typedef unsigned char uint8_t;
+
+int err;
+int segv_caught;
+
+#define SHOULD_NOT_CHANGE_VAL 5
+int should_not_change = SHOULD_NOT_CHANGE_VAL;
+
+#define BUF_SIZE 300
+unsigned char buf[BUF_SIZE];
+
+
+static void __check(const char *filename, int line, int x, int expect)
+{
+ if (x != expect) {
+ printf("ERROR %s:%d - %d != %d\n",
+ filename, line, x, expect);
+ err++;
+ }
+}
+
+#define check(x, expect) __check(__FILE__, __LINE__, (x), (expect))
+
+static void __chk_error(const char *filename, int line, int ret)
+{
+ if (ret < 0) {
+ printf("ERROR %s:%d - %d\n", filename, line, ret);
+ err++;
+ }
+}
+
+#define chk_error(ret) __chk_error(__FILE__, __LINE__, (ret))
+
+jmp_buf jmp_env;
+
+static void sig_segv(int sig, siginfo_t *info, void *puc)
+{
+ check(sig, SIGSEGV);
+ segv_caught = 1;
+ longjmp(jmp_env, 1);
+}
+
+int main()
+{
+ struct sigaction act;
+
+ /* SIGSEGV test */
+ act.sa_sigaction = sig_segv;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = SA_SIGINFO;
+ chk_error(sigaction(SIGSEGV, &act, NULL));
+ if (setjmp(jmp_env) == 0) {
+ asm volatile("r18 = ##should_not_change\n\t"
+ "r19 = #0\n\t"
+ "{\n\t"
+ " memw(r18) = #7\n\t"
+ " memw(r19) = #0\n\t"
+ "}\n\t"
+ : : : "r18", "r19", "memory");
+ }
+
+ act.sa_handler = SIG_DFL;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = 0;
+ chk_error(sigaction(SIGSEGV, &act, NULL));
+
+ check(segv_caught, 1);
+ check(should_not_change, SHOULD_NOT_CHANGE_VAL);
+
+ puts(err ? "FAIL" : "PASS");
+ return err ? EXIT_FAILURE : EXIT_SUCCESS;
+}
diff --git a/tests/tcg/hexagon/Makefile.target
b/tests/tcg/hexagon/Makefile.target
index 050cd61..c1e1650 100644
--- a/tests/tcg/hexagon/Makefile.target
+++ b/tests/tcg/hexagon/Makefile.target
@@ -28,6 +28,7 @@ first: $(HEX_SRC)/first.S
$(CC) -static -mv67 -nostdlib $^ -o $@
HEX_TESTS = first
+HEX_TESTS += hex_sigsegv
HEX_TESTS += misc
HEX_TESTS += preg_alias
HEX_TESTS += dual_stores
--
2.7.4
