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[PULL 08/13] semihosting: Check for errors on SET_ARG()
From: |
Alex Bennée |
Subject: |
[PULL 08/13] semihosting: Check for errors on SET_ARG() |
Date: |
Fri, 29 Jul 2022 10:19:38 +0100 |
From: Peter Maydell <peter.maydell@linaro.org>
The SET_ARG() macro returns an error indication; we check this in the
TARGET_SYS_GET_CMDLINE case but not when we use it in implementing
TARGET_SYS_ELAPSED. Check for and handle the errors via the do_fault
codepath, and update the comment documenting the SET_ARG() and
GET_ARG() macros to note how they handle memory access errors.
Resolves: Coverity CID 1490287
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220719121110.225657-4-peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220725140520.515340-9-alex.bennee@linaro.org>
diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c
index 1a1e2a6960..d12288fc80 100644
--- a/semihosting/arm-compat-semi.c
+++ b/semihosting/arm-compat-semi.c
@@ -171,6 +171,12 @@ static LayoutInfo common_semi_find_bases(CPUState *cs)
* Read the input value from the argument block; fail the semihosting
* call if the memory read fails. Eventually we could use a generic
* CPUState helper function here.
+ * Note that GET_ARG() handles memory access errors by jumping to
+ * do_fault, so must be used as the first thing done in handling a
+ * semihosting call, to avoid accidentally leaking allocated resources.
+ * SET_ARG(), since it unavoidably happens late, instead returns an
+ * error indication (0 on success, non-0 for error) which the caller
+ * should check.
*/
#define GET_ARG(n) do { \
@@ -739,10 +745,14 @@ void do_common_semihosting(CPUState *cs)
case TARGET_SYS_ELAPSED:
elapsed = get_clock() - clock_start;
if (sizeof(target_ulong) == 8) {
- SET_ARG(0, elapsed);
+ if (SET_ARG(0, elapsed)) {
+ goto do_fault;
+ }
} else {
- SET_ARG(0, (uint32_t) elapsed);
- SET_ARG(1, (uint32_t) (elapsed >> 32));
+ if (SET_ARG(0, (uint32_t) elapsed) ||
+ SET_ARG(1, (uint32_t) (elapsed >> 32))) {
+ goto do_fault;
+ }
}
common_semi_set_ret(cs, 0);
break;
--
2.30.2
- [PULL 00/13] testing, semihosting and doc fixes, Alex Bennée, 2022/07/29
- [PULL 04/13] .cirrus.yml: Change winsymlinks to 'native', Alex Bennée, 2022/07/29
- [PULL 05/13] .gitlab-ci.d/windows.yml: Enable native Windows symlink, Alex Bennée, 2022/07/29
- [PULL 06/13] semihosting: Don't return negative values on qemu_semihosting_console_write() failure, Alex Bennée, 2022/07/29
- [PULL 02/13] gitlab: show testlog.txt contents when cirrus/custom-runner jobs fail, Alex Bennée, 2022/07/29
- [PULL 03/13] gitlab: drop 'containers-layer2' stage, Alex Bennée, 2022/07/29
- [PULL 01/13] tests: refresh to latest libvirt-ci module, Alex Bennée, 2022/07/29
- [PULL 08/13] semihosting: Check for errors on SET_ARG(),
Alex Bennée <=
- [PULL 07/13] semihosting: Don't copy buffer after console_write(), Alex Bennée, 2022/07/29
- [PULL 12/13] docs/devel: fix description of OBJECT_DECLARE_SIMPLE_TYPE, Alex Bennée, 2022/07/29
- [PULL 10/13] qapi: Add exit-failure PanicAction, Alex Bennée, 2022/07/29
- [PULL 13/13] qemu-options: bring the kernel and image options together, Alex Bennée, 2022/07/29
- [PULL 11/13] tests/tcg/s390x: Test unaligned accesses to lowcore, Alex Bennée, 2022/07/29
- [PULL 09/13] semihosting: Fix handling of buffer in TARGET_SYS_TMPNAM, Alex Bennée, 2022/07/29
- Re: [PULL 00/13] testing, semihosting and doc fixes, Richard Henderson, 2022/07/29