From: Cristian Marussi <cristian.marussi@arm.com>
To: linux-kselftest@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, shuah@kernel.org
Cc: andreyknvl@google.com, dave.martin@arm.com
Subject: [PATCH v3 06/11] kselftest: arm64: fake_sigreturn_bad_magic
Date: Fri, 2 Aug 2019 18:02:55 +0100 [thread overview]
Message-ID: <20190802170300.20662-7-cristian.marussi@arm.com> (raw)
In-Reply-To: <20190802170300.20662-1-cristian.marussi@arm.com>
Added a simple fake_sigreturn testcase which builds a ucontext_t
with a bad magic header and place it onto the stack.
Expects a SIGSEGV on test PASS.
This commit also introduces a common utility assembly function to
invoke a sigreturn using a fake provided sigframe.
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
tools/testing/selftests/arm64/signal/Makefile | 2 +-
.../testing/selftests/arm64/signal/signals.S | 64 +++++++++++++++++++
.../arm64/signal/test_signals_utils.h | 1 +
.../arm64/signal/testcases/.gitignore | 1 +
.../testcases/fake_sigreturn_bad_magic.c | 63 ++++++++++++++++++
5 files changed, 130 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/arm64/signal/signals.S
create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c
diff --git a/tools/testing/selftests/arm64/signal/Makefile b/tools/testing/selftests/arm64/signal/Makefile
index 8c8d08be4b0d..b3dcf315b5a4 100644
--- a/tools/testing/selftests/arm64/signal/Makefile
+++ b/tools/testing/selftests/arm64/signal/Makefile
@@ -80,7 +80,7 @@ endif
# Common test-unit targets to build common-layout test-cases executables
# Needs secondary expansion to properly include the testcase c-file in pre-reqs
.SECONDEXPANSION:
-$(PROGS): test_signals.c test_signals_utils.c testcases/testcases.c $$@.c test_signals.h test_signals_utils.h testcases/testcases.h
+$(PROGS): test_signals.c test_signals_utils.c testcases/testcases.c signals.S $$@.c test_signals.h test_signals_utils.h testcases/testcases.h
@if [ ! -d $(khdr_dir) ]; then \
echo -n "\n!!! WARNING: $(khdr_dir) NOT FOUND."; \
echo "===> Are you sure Kernel Headers have been installed properly ?\n"; \
diff --git a/tools/testing/selftests/arm64/signal/signals.S b/tools/testing/selftests/arm64/signal/signals.S
new file mode 100644
index 000000000000..6262b877400b
--- /dev/null
+++ b/tools/testing/selftests/arm64/signal/signals.S
@@ -0,0 +1,64 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0
+ * Copyright (C) 2019 ARM Limited
+ */
+
+#include <asm/unistd.h>
+
+.section ".rodata", "a"
+call_fmt:
+ .asciz "Calling sigreturn with fake sigframe sized:%zd at calculated SP @%08lX\n"
+
+.text
+
+.globl fake_sigreturn
+
+/* fake_sigreturn x0:&sigframe, x1:sigframe_size, x2:alignment_SP */
+fake_sigreturn:
+ mov x20, x0
+ mov x21, x1
+ mov x22, x2
+ mov x23, sp
+
+ /* create space on the stack for fake sigframe..."x22"-aligned */
+ mov x0, #0
+ add x0, x21, x22
+ sub x22, x22, #1
+ bic x0, x0, x22
+ sub x23, x23, x0
+
+ ldr x0, =call_fmt
+ mov x1, x21
+ mov x2, x23
+ bl printf
+
+ mov sp, x23
+
+ /* now fill it with the provided content... */
+ mov x0, sp
+ mov x1, x20
+ mov x2, x21
+ bl memcpy
+
+ /*
+ * Here saving a last minute SP to current->token acts as a marker:
+ * if we got here, we are successfully faking a sigreturn; in other
+ * words we are sure no bad fatal signal has been raised till now
+ * for unrelated reasons, so we should consider the possibl observed
+ * fatal signal like SEGV coming from Kernel restore_sigframe() and
+ * triggered as expected from our test-case.
+ * For simplicity this assumes that current field 'token' is laid out
+ * as first in struct tdescr
+ */
+ ldr x0, current
+ str x23, [x0]
+ /* SP is already pointing back to the just built fake sigframe here */
+ mov x8, #__NR_rt_sigreturn
+ svc #0
+
+ /*
+ * Above sigreturn should not return...looping here leads to a timeout
+ * and ensure proper and clean test failure, instead of jumping around
+ * on a potentially corrupted stack.
+ */
+ b .
diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.h b/tools/testing/selftests/arm64/signal/test_signals_utils.h
index ce35be8ebc8e..2a71da7e6695 100644
--- a/tools/testing/selftests/arm64/signal/test_signals_utils.h
+++ b/tools/testing/selftests/arm64/signal/test_signals_utils.h
@@ -12,4 +12,5 @@ int test_run(struct tdescr *td);
void test_result(struct tdescr *td);
bool get_current_context(struct tdescr *td, ucontext_t *dest_uc);
+int fake_sigreturn(void *sigframe, size_t sz, int alignment);
#endif
diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore
index a48a118b1a1a..0ea6fdc3765c 100644
--- a/tools/testing/selftests/arm64/signal/testcases/.gitignore
+++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore
@@ -4,3 +4,4 @@ mangle_pstate_invalid_mode_el1
mangle_pstate_invalid_mode_el2
mangle_pstate_invalid_mode_el3
mangle_pstate_ssbs_regs
+fake_sigreturn_bad_magic
diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c
new file mode 100644
index 000000000000..b4c063e02a7a
--- /dev/null
+++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2019 ARM Limited */
+
+#include <stdio.h>
+#include <ucontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+struct fake_sigframe sf;
+
+static int fake_sigreturn_bad_magic_run(struct tdescr *td,
+ siginfo_t *si, ucontext_t *uc)
+{
+ size_t resv_sz, offset;
+ struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head;
+
+ /* just to fill the ucontext_t with something real */
+ if (!get_current_context(td, &sf.uc))
+ return 1;
+
+ resv_sz = GET_SF_RESV_SIZE(sf);
+ /*
+ * find the terminator, preserving existing headers
+ * and verify amount of spare room in __reserved area.
+ */
+ head = get_terminator(shead, resv_sz, &offset);
+ /*
+ * try stripping extra_context header when low on space:
+ * we need at least 2*HDR_SZ space ... one for the KSFT_BAD_MAGIC
+ * and the other for the usual terminator.
+ */
+ if (head && resv_sz - offset < HDR_SZ * 2) {
+ fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n",
+ resv_sz - offset);
+ head = get_header(shead, EXTRA_MAGIC, resv_sz, &offset);
+ }
+ /* just give up and timeout if still not enough space */
+ if (head && resv_sz - offset >= HDR_SZ) {
+ fprintf(stderr, "Mangling template header. Spare space:%zd\n",
+ resv_sz - offset);
+ /*
+ * use a well known NON existent bad magic...something
+ * we should pretty sure won't be ever defined in Kernel
+ */
+ head->magic = KSFT_BAD_MAGIC;
+ head->size = HDR_SZ;
+ write_terminator_record(GET_RESV_NEXT_HEAD(head));
+
+ ASSERT_BAD_CONTEXT(&sf.uc);
+ fake_sigreturn(&sf, sizeof(sf), 16);
+ }
+
+ return 1;
+}
+
+struct tdescr tde = {
+ .name = "FAKE_SIGRETURN_BAD_MAGIC",
+ .descr = "Triggers a fake sigreturn with a sigframe including a bad non-existent magic",
+ .sig_ok = SIGSEGV,
+ .timeout = 3,
+ .run = fake_sigreturn_bad_magic_run,
+};
--
2.17.1
next prev parent reply other threads:[~2019-08-02 17:03 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-02 17:02 [PATCH v3 00/11] Add arm64/signal initial kselftest support Cristian Marussi
2019-08-02 17:02 ` [PATCH v3 01/11] kselftest: arm64: introduce new boilerplate code Cristian Marussi
2019-08-13 16:23 ` Dave Martin
2019-08-27 12:14 ` Cristian Marussi
2019-08-02 17:02 ` [PATCH v3 02/11] kselftest: arm64: adds first test and common utils Cristian Marussi
2019-08-06 15:50 ` Cristian Marussi
2019-08-07 15:42 ` Cristian Marussi
2019-08-09 10:54 ` Cristian Marussi
2019-08-09 11:16 ` Dave Martin
2019-08-09 12:20 ` Cristian Marussi
2019-08-09 12:32 ` Dave Martin
2019-08-12 12:43 ` Amit Kachhap
2019-08-13 13:22 ` Cristian Marussi
2019-08-14 10:22 ` Amit Kachhap
2019-08-27 14:24 ` Cristian Marussi
2019-08-13 16:24 ` Dave Martin
2019-08-28 17:34 ` Cristian Marussi
2019-09-03 15:34 ` Dave Martin
2019-09-03 16:08 ` Cristian Marussi
2019-08-02 17:02 ` [PATCH v3 03/11] kselftest: arm64: mangle_pstate_invalid_daif_bits Cristian Marussi
2019-08-13 16:24 ` Dave Martin
2019-08-29 10:19 ` Cristian Marussi
2019-08-02 17:02 ` [PATCH v3 04/11] kselftest: arm64: mangle_pstate_invalid_mode_el Cristian Marussi
2019-08-13 16:24 ` Dave Martin
2019-08-29 11:50 ` Cristian Marussi
2019-08-02 17:02 ` [PATCH v3 05/11] kselftest: arm64: mangle_pstate_ssbs_regs Cristian Marussi
2019-08-13 16:25 ` Dave Martin
2019-08-29 15:35 ` Cristian Marussi
2019-08-02 17:02 ` Cristian Marussi [this message]
2019-08-13 16:25 ` [PATCH v3 06/11] kselftest: arm64: fake_sigreturn_bad_magic Dave Martin
2019-08-30 14:29 ` Cristian Marussi
2019-09-04 10:05 ` Dave Martin
2019-09-04 10:37 ` Cristian Marussi
2019-09-04 10:47 ` Dave Martin
2019-08-02 17:02 ` [PATCH v3 07/11] kselftest: arm64: fake_sigreturn_bad_size_for_magic0 Cristian Marussi
2019-08-13 16:25 ` Dave Martin
2019-08-30 14:49 ` Cristian Marussi
2019-08-02 17:02 ` [PATCH v3 08/11] kselftest: arm64: fake_sigreturn_missing_fpsimd Cristian Marussi
2019-08-13 16:26 ` Dave Martin
2019-08-30 14:55 ` Cristian Marussi
2019-08-02 17:02 ` [PATCH v3 09/11] kselftest: arm64: fake_sigreturn_duplicated_fpsimd Cristian Marussi
2019-08-13 16:26 ` Dave Martin
2019-08-30 15:11 ` Cristian Marussi
2019-08-02 17:02 ` [PATCH v3 10/11] kselftest: arm64: fake_sigreturn_bad_size Cristian Marussi
2019-08-13 16:26 ` Dave Martin
2019-08-30 15:21 ` Cristian Marussi
2019-08-02 17:03 ` [PATCH v3 11/11] kselftest: arm64: fake_sigreturn_misaligned_sp Cristian Marussi
2019-08-07 16:04 ` Cristian Marussi
2019-08-13 16:28 ` Dave Martin
2019-08-30 15:22 ` Cristian Marussi
2019-08-13 16:27 ` Dave Martin
2019-08-30 16:33 ` Cristian Marussi
2019-08-13 16:22 ` [PATCH v3 00/11] Add arm64/signal initial kselftest support Dave Martin
2019-08-30 16:40 ` Cristian Marussi
2019-09-02 10:53 ` Dave Martin
2019-09-02 11:30 ` Cristian Marussi
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