[PATCH v2 00/10] kselftest/arm64: EXTRA_CONTEXT related fixes

[PATCH v2 00/10] kselftest/arm64: EXTRA_CONTEXT related fixes

[Mark Brown]

The arm64 architecture originally made the signal context a fixed size
structure containing a linked list of records with the various kinds of
register and other state which may be present. When SVE was implemented
it was realised that it supported implementations with more state than
could fit in that structure so a new record type EXTRA_CONTEXT was
introduced allowing the signal context to be extended beyond the
original size. Unfortunately the signal handling tests can not cope with
these EXTRA_CONTEXT records at all - some support was implemented but it
simply never worked.

v2:
 - Rebase onto v6.0-rc3

Mark Brown (10):
  kselftest/arm64: Enumerate SME rather than SVE vector lengths for
    za_regs
  kselftest/arm64: Validate signal ucontext in place
  kselftest/arm64: Fix validatation termination record after
    EXTRA_CONTEXT
  kselftest/arm64: Fix validation of EXTRA_CONTEXT signal context
    location
  kselftest/arm64: Remove unneeded protype for validate_extra_context()
  kselftest/arm64: Only validate each signal context once
  kselftest/arm64: Validate contents of EXTRA_CONTEXT blocks
  kselftest/arm64: Preserve any EXTRA_CONTEXT in handle_signal_copyctx()
  kselftest/arm64: Allow larger buffers in get_signal_context()
  kselftest/arm64: Include larger SVE and SME VLs in signal tests

 .../arm64/signal/test_signals_utils.c         | 59 +++++++++++++++++--
 .../arm64/signal/test_signals_utils.h         |  5 +-
 .../testcases/fake_sigreturn_bad_magic.c      |  2 +-
 .../testcases/fake_sigreturn_bad_size.c       |  2 +-
 .../fake_sigreturn_bad_size_for_magic0.c      |  2 +-
 .../fake_sigreturn_duplicated_fpsimd.c        |  2 +-
 .../testcases/fake_sigreturn_misaligned_sp.c  |  2 +-
 .../testcases/fake_sigreturn_missing_fpsimd.c |  2 +-
 .../testcases/fake_sigreturn_sme_change_vl.c  |  2 +-
 .../testcases/fake_sigreturn_sve_change_vl.c  |  2 +-
 .../selftests/arm64/signal/testcases/sme_vl.c |  2 +-
 .../arm64/signal/testcases/ssve_regs.c        | 25 +++-----
 .../arm64/signal/testcases/sve_regs.c         | 23 +++-----
 .../selftests/arm64/signal/testcases/sve_vl.c |  2 +-
 .../arm64/signal/testcases/testcases.c        | 48 +++++++++++----
 .../arm64/signal/testcases/testcases.h        |  9 ++-
 .../arm64/signal/testcases/za_regs.c          | 28 ++++-----
 17 files changed, 137 insertions(+), 80 deletions(-)


base-commit: b90cb1053190353cc30f0fef0ef1f378ccc063c5
-- 
2.30.2


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[PATCH v2 01/10] kselftest/arm64: Enumerate SME rather than SVE vector lengths for za_regs

[Mark Brown]

The za_regs signal test was enumerating the SVE vector lengths rather than
the SME vector lengths through cut'n'paste error when determining what to
test. Enumerate the SME vector lengths instead.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/signal/testcases/za_regs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/arm64/signal/testcases/za_regs.c b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
index b94e4f99fcac..9f1dd70289be 100644
--- a/tools/testing/selftests/arm64/signal/testcases/za_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
@@ -22,10 +22,10 @@ static bool sme_get_vls(struct tdescr *td)
 	int vq, vl;
 
 	/*
-	 * Enumerate up to SVE_VQ_MAX vector lengths
+	 * Enumerate up to SME_VQ_MAX vector lengths
 	 */
 	for (vq = SVE_VQ_MAX; vq > 0; --vq) {
-		vl = prctl(PR_SVE_SET_VL, vq * 16);
+		vl = prctl(PR_SME_SET_VL, vq * 16);
 		if (vl == -1)
 			return false;
 
-- 
2.30.2


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[PATCH v2 02/10] kselftest/arm64: Validate signal ucontext in place

[Mark Brown]

In handle_input_signal_copyctx() we use ASSERT_GOOD_CONTEXT() to validate
that the context we are saving meets expectations however we do this on
the saved copy rather than on the actual signal context passed in. This
breaks validation of EXTRA_CONTEXT since we attempt to validate the ABI
requirement that the additional space supplied is immediately after the
termination record in the standard context which will not be the case
after it has been copied to another location.

Fix this by doing the validation before we copy. Note that nothing actually
looks inside the EXTRA_CONTEXT at present.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 .../testing/selftests/arm64/signal/test_signals_utils.c  | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.c b/tools/testing/selftests/arm64/signal/test_signals_utils.c
index b588d10afd5b..a54dc1b6f35c 100644
--- a/tools/testing/selftests/arm64/signal/test_signals_utils.c
+++ b/tools/testing/selftests/arm64/signal/test_signals_utils.c
@@ -165,12 +165,15 @@ static bool handle_signal_ok(struct tdescr *td,
 }
 
 static bool handle_signal_copyctx(struct tdescr *td,
-				  siginfo_t *si, void *uc)
+				  siginfo_t *si, void *uc_in)
 {
+	ucontext_t *uc = uc_in;
+
+	ASSERT_GOOD_CONTEXT(uc);
+
 	/* Mangling PC to avoid loops on original BRK instr */
-	((ucontext_t *)uc)->uc_mcontext.pc += 4;
+	uc->uc_mcontext.pc += 4;
 	memcpy(td->live_uc, uc, td->live_sz);
-	ASSERT_GOOD_CONTEXT(td->live_uc);
 	td->live_uc_valid = 1;
 	fprintf(stderr,
 		"GOOD CONTEXT grabbed from sig_copyctx handler\n");
-- 
2.30.2


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[PATCH v2 03/10] kselftest/arm64: Fix validatation termination record after EXTRA_CONTEXT

[Mark Brown]

When arm64 signal context data overflows the base struct sigcontext it gets
placed in an extra buffer pointed to by a record of type EXTRA_CONTEXT in
the base struct sigcontext which is required to be the last record in the
base struct sigframe. The current validation code attempts to check this
by using GET_RESV_NEXT_HEAD() to step forward from the current record to
the next but that is a macro which assumes it is being provided with a
struct _aarch64_ctx and uses the size there to skip forward to the next
record. Instead validate_extra_context() passes it a struct extra_context
which has a separate size field. This compiles but results in us trying
to validate a termination record in completely the wrong place, at best
failing validation and at worst just segfaulting. Fix this by passing
the struct _aarch64_ctx we meant to into the macro.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/signal/testcases/testcases.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.c b/tools/testing/selftests/arm64/signal/testcases/testcases.c
index 84c36bee4d82..d98828cb542b 100644
--- a/tools/testing/selftests/arm64/signal/testcases/testcases.c
+++ b/tools/testing/selftests/arm64/signal/testcases/testcases.c
@@ -33,7 +33,7 @@ bool validate_extra_context(struct extra_context *extra, char **err)
 		return false;
 
 	fprintf(stderr, "Validating EXTRA...\n");
-	term = GET_RESV_NEXT_HEAD(extra);
+	term = GET_RESV_NEXT_HEAD(&extra->head);
 	if (!term || term->magic || term->size) {
 		*err = "Missing terminator after EXTRA context";
 		return false;
-- 
2.30.2


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[PATCH v2 04/10] kselftest/arm64: Fix validation of EXTRA_CONTEXT signal context location

[Mark Brown]

Currently in validate_extra_context() we assert both that the extra data
pointed to by the EXTRA_CONTEXT is 16 byte aligned and that it immediately
follows the struct _aarch64_ctx providing the terminator for the linked
list of contexts in the signal frame. Since struct _aarch64_ctx is an 8
byte structure which must be 16 byte aligned these cannot both be true. As
documented in sigcontext.h and implemented by the kernel the extra data
should be at the next 16 byte aligned address after the terminator so fix
the validation to match.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/signal/testcases/testcases.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.c b/tools/testing/selftests/arm64/signal/testcases/testcases.c
index d98828cb542b..16dc916939f9 100644
--- a/tools/testing/selftests/arm64/signal/testcases/testcases.c
+++ b/tools/testing/selftests/arm64/signal/testcases/testcases.c
@@ -42,7 +42,7 @@ bool validate_extra_context(struct extra_context *extra, char **err)
 		*err = "Extra DATAP misaligned";
 	else if (extra->size & 0x0fUL)
 		*err = "Extra SIZE misaligned";
-	else if (extra->datap != (uint64_t)term + sizeof(*term))
+	else if (extra->datap != (uint64_t)term + 0x10UL)
 		*err = "Extra DATAP misplaced (not contiguous)";
 	if (*err)
 		return false;
-- 
2.30.2


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[PATCH v2 05/10] kselftest/arm64: Remove unneeded protype for validate_extra_context()

[Mark Brown]

Nothing outside testcases.c should need to use validate_extra_context(),
remove the prototype to ensure nothing does.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/signal/testcases/testcases.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.h b/tools/testing/selftests/arm64/signal/testcases/testcases.h
index 49f1d5de7b5b..b39f538c7be1 100644
--- a/tools/testing/selftests/arm64/signal/testcases/testcases.h
+++ b/tools/testing/selftests/arm64/signal/testcases/testcases.h
@@ -79,8 +79,6 @@ struct fake_sigframe {
 
 bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err);
 
-bool validate_extra_context(struct extra_context *extra, char **err);
-
 struct _aarch64_ctx *get_header(struct _aarch64_ctx *head, uint32_t magic,
 				size_t resv_sz, size_t *offset);
 
-- 
2.30.2


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[PATCH v2 06/10] kselftest/arm64: Only validate each signal context once

[Mark Brown]

Currently for the more complex signal context types we validate the context
specific details the end of the parsing loop validate_reserved() if we've
ever seen a context of that type. This is currently merely a bit inefficient
but will get a bit awkward when we start parsing extra_context, at which
point we will need to reset the head to advance into the extra space that
extra_context provides. Instead only do the more detailed checks on each
context type the first time we see that context type.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 .../arm64/signal/testcases/testcases.c        | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.c b/tools/testing/selftests/arm64/signal/testcases/testcases.c
index 16dc916939f9..0b3c9b4b1d39 100644
--- a/tools/testing/selftests/arm64/signal/testcases/testcases.c
+++ b/tools/testing/selftests/arm64/signal/testcases/testcases.c
@@ -105,6 +105,7 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 	bool terminated = false;
 	size_t offs = 0;
 	int flags = 0;
+	int new_flags;
 	struct extra_context *extra = NULL;
 	struct sve_context *sve = NULL;
 	struct za_context *za = NULL;
@@ -120,6 +121,8 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 			return false;
 		}
 
+		new_flags = 0;
+
 		switch (head->magic) {
 		case 0:
 			if (head->size)
@@ -133,7 +136,7 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 			else if (head->size !=
 				 sizeof(struct fpsimd_context))
 				*err = "Bad size for fpsimd_context";
-			flags |= FPSIMD_CTX;
+			new_flags |= FPSIMD_CTX;
 			break;
 		case ESR_MAGIC:
 			if (head->size != sizeof(struct esr_context))
@@ -144,14 +147,14 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 				*err = "Multiple SVE_MAGIC";
 			/* Size is validated in validate_sve_context() */
 			sve = (struct sve_context *)head;
-			flags |= SVE_CTX;
+			new_flags |= SVE_CTX;
 			break;
 		case ZA_MAGIC:
 			if (flags & ZA_CTX)
 				*err = "Multiple ZA_MAGIC";
 			/* Size is validated in validate_za_context() */
 			za = (struct za_context *)head;
-			flags |= ZA_CTX;
+			new_flags |= ZA_CTX;
 			break;
 		case EXTRA_MAGIC:
 			if (flags & EXTRA_CTX)
@@ -159,7 +162,7 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 			else if (head->size !=
 				 sizeof(struct extra_context))
 				*err = "Bad size for extra_context";
-			flags |= EXTRA_CTX;
+			new_flags |= EXTRA_CTX;
 			extra = (struct extra_context *)head;
 			break;
 		case KSFT_BAD_MAGIC:
@@ -192,16 +195,18 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 			return false;
 		}
 
-		if (flags & EXTRA_CTX)
+		if (new_flags & EXTRA_CTX)
 			if (!validate_extra_context(extra, err))
 				return false;
-		if (flags & SVE_CTX)
+		if (new_flags & SVE_CTX)
 			if (!validate_sve_context(sve, err))
 				return false;
-		if (flags & ZA_CTX)
+		if (new_flags & ZA_CTX)
 			if (!validate_za_context(za, err))
 				return false;
 
+		flags |= new_flags;
+
 		head = GET_RESV_NEXT_HEAD(head);
 	}
 
-- 
2.30.2


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[PATCH v2 07/10] kselftest/arm64: Validate contents of EXTRA_CONTEXT blocks

[Mark Brown]

Currently in validate_reserved() we check the basic form and contents of
an EXTRA_CONTEXT block but do not actually validate anything inside the
data block it provides. Extend the validation to do so, when we get to the
terminator for the main data block reset and start walking the extra data
block instead.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 .../arm64/signal/testcases/testcases.c        | 25 ++++++++++++++++---
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.c b/tools/testing/selftests/arm64/signal/testcases/testcases.c
index 0b3c9b4b1d39..e1c625b20ac4 100644
--- a/tools/testing/selftests/arm64/signal/testcases/testcases.c
+++ b/tools/testing/selftests/arm64/signal/testcases/testcases.c
@@ -25,7 +25,8 @@ struct _aarch64_ctx *get_header(struct _aarch64_ctx *head, uint32_t magic,
 	return found;
 }
 
-bool validate_extra_context(struct extra_context *extra, char **err)
+bool validate_extra_context(struct extra_context *extra, char **err,
+			    void **extra_data, size_t *extra_size)
 {
 	struct _aarch64_ctx *term;
 
@@ -47,6 +48,9 @@ bool validate_extra_context(struct extra_context *extra, char **err)
 	if (*err)
 		return false;
 
+	*extra_data = (void *)extra->datap;
+	*extra_size = extra->size;
+
 	return true;
 }
 
@@ -111,6 +115,8 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 	struct za_context *za = NULL;
 	struct _aarch64_ctx *head =
 		(struct _aarch64_ctx *)uc->uc_mcontext.__reserved;
+	void *extra_data = NULL;
+	size_t extra_sz = 0;
 
 	if (!err)
 		return false;
@@ -125,10 +131,20 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 
 		switch (head->magic) {
 		case 0:
-			if (head->size)
+			if (head->size) {
 				*err = "Bad size for terminator";
-			else
+			} else if (extra_data) {
+				/* End of main data, walking the extra data */
+				head = extra_data;
+				resv_sz = extra_sz;
+				offs = 0;
+
+				extra_data = NULL;
+				extra_sz = 0;
+				continue;
+			} else {
 				terminated = true;
+			}
 			break;
 		case FPSIMD_MAGIC:
 			if (flags & FPSIMD_CTX)
@@ -196,7 +212,8 @@ bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
 		}
 
 		if (new_flags & EXTRA_CTX)
-			if (!validate_extra_context(extra, err))
+			if (!validate_extra_context(extra, err,
+						    &extra_data, &extra_sz))
 				return false;
 		if (new_flags & SVE_CTX)
 			if (!validate_sve_context(sve, err))
-- 
2.30.2


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[PATCH v2 08/10] kselftest/arm64: Preserve any EXTRA_CONTEXT in handle_signal_copyctx()

[Mark Brown]

When preserving the signal context for later verification by testcases
check for and include any EXTRA_CONTEXT block if enough space has been
provided.

Since the EXTRA_CONTEXT block includes a pointer to the start of the
additional data block we need to do at least some fixup on the copied
data. For simplicity in users we do this by extending the length of
the EXTRA_CONTEXT to include the following termination record, this
will cause users to see the extra data as part of the linked list of
contexts without needing any special handling. Care will be needed if
any specific tests for EXTRA_CONTEXT are added beyond the validation
done in ASSERT_GOOD_CONTEXT.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 .../arm64/signal/test_signals_utils.c         | 50 ++++++++++++++++++-
 1 file changed, 48 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.c b/tools/testing/selftests/arm64/signal/test_signals_utils.c
index a54dc1b6f35c..308e229e58ab 100644
--- a/tools/testing/selftests/arm64/signal/test_signals_utils.c
+++ b/tools/testing/selftests/arm64/signal/test_signals_utils.c
@@ -168,15 +168,61 @@ static bool handle_signal_copyctx(struct tdescr *td,
 				  siginfo_t *si, void *uc_in)
 {
 	ucontext_t *uc = uc_in;
+	struct _aarch64_ctx *head;
+	struct extra_context *extra, *copied_extra;
+	size_t offset = 0;
+	size_t to_copy;
 
 	ASSERT_GOOD_CONTEXT(uc);
 
 	/* Mangling PC to avoid loops on original BRK instr */
 	uc->uc_mcontext.pc += 4;
-	memcpy(td->live_uc, uc, td->live_sz);
+
+	/*
+	 * Check for an preserve any extra data too with fixups.
+	 */
+	head = (struct _aarch64_ctx *)uc->uc_mcontext.__reserved;
+	head = get_header(head, EXTRA_MAGIC, td->live_sz, &offset);
+	if (head) {
+		extra = (struct extra_context *)head;
+
+		/*
+		 * The extra buffer must be immediately after the
+		 * extra_context and a 16 byte terminator. Include it
+		 * in the copy, this was previously validated in
+		 * ASSERT_GOOD_CONTEXT().
+		 */
+		to_copy = offset + sizeof(struct extra_context) + 16 +
+			extra->size;
+		copied_extra = (struct extra_context *)&(td->live_uc->uc_mcontext.__reserved[offset]);
+	} else {
+		copied_extra = NULL;
+		to_copy = sizeof(ucontext_t);
+	}
+
+	if (to_copy > td->live_sz) {
+		fprintf(stderr,
+			"Not enough space to grab context, %lu/%lu bytes\n",
+			td->live_sz, to_copy);
+		return false;
+	}
+
+	memcpy(td->live_uc, uc, to_copy);
+
+	/*
+	 * If there was any EXTRA_CONTEXT fix up the size to be the
+	 * struct extra_context and the following terminator record,
+	 * this means that the rest of the code does not need to have
+	 * special handling for the record and we don't need to fix up
+	 * datap for the new location.
+	 */
+	if (copied_extra)
+		copied_extra->head.size = sizeof(*copied_extra) + 16;
+
 	td->live_uc_valid = 1;
 	fprintf(stderr,
-		"GOOD CONTEXT grabbed from sig_copyctx handler\n");
+		"%lu byte GOOD CONTEXT grabbed from sig_copyctx handler\n",
+		to_copy);
 
 	return true;
 }
-- 
2.30.2


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[PATCH v2 09/10] kselftest/arm64: Allow larger buffers in get_signal_context()

[Mark Brown]

In order to allow testing of signal contexts that overflow the base signal
frame allow callers to pass the buffer size for the user context into
get_signal_context(). No functional change.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/signal/test_signals_utils.h    | 5 +++--
 .../arm64/signal/testcases/fake_sigreturn_bad_magic.c        | 2 +-
 .../arm64/signal/testcases/fake_sigreturn_bad_size.c         | 2 +-
 .../signal/testcases/fake_sigreturn_bad_size_for_magic0.c    | 2 +-
 .../signal/testcases/fake_sigreturn_duplicated_fpsimd.c      | 2 +-
 .../arm64/signal/testcases/fake_sigreturn_misaligned_sp.c    | 2 +-
 .../arm64/signal/testcases/fake_sigreturn_missing_fpsimd.c   | 2 +-
 .../arm64/signal/testcases/fake_sigreturn_sme_change_vl.c    | 2 +-
 .../arm64/signal/testcases/fake_sigreturn_sve_change_vl.c    | 2 +-
 tools/testing/selftests/arm64/signal/testcases/sme_vl.c      | 2 +-
 tools/testing/selftests/arm64/signal/testcases/ssve_regs.c   | 2 +-
 tools/testing/selftests/arm64/signal/testcases/sve_regs.c    | 2 +-
 tools/testing/selftests/arm64/signal/testcases/sve_vl.c      | 2 +-
 tools/testing/selftests/arm64/signal/testcases/za_regs.c     | 2 +-
 14 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.h b/tools/testing/selftests/arm64/signal/test_signals_utils.h
index f3aa99ba67bb..222093f51b67 100644
--- a/tools/testing/selftests/arm64/signal/test_signals_utils.h
+++ b/tools/testing/selftests/arm64/signal/test_signals_utils.h
@@ -56,7 +56,8 @@ static inline bool feats_ok(struct tdescr *td)
  * at sizeof(ucontext_t).
  */
 static __always_inline bool get_current_context(struct tdescr *td,
-						ucontext_t *dest_uc)
+						ucontext_t *dest_uc,
+						size_t dest_sz)
 {
 	static volatile bool seen_already;
 
@@ -64,7 +65,7 @@ static __always_inline bool get_current_context(struct tdescr *td,
 	/* it's a genuine invocation..reinit */
 	seen_already = 0;
 	td->live_uc_valid = 0;
-	td->live_sz = sizeof(*dest_uc);
+	td->live_sz = dest_sz;
 	memset(dest_uc, 0x00, td->live_sz);
 	td->live_uc = dest_uc;
 	/*
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
index 8dc600a7d4fd..8c7f00ea9823 100644
--- a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c
+++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c
@@ -21,7 +21,7 @@ static int fake_sigreturn_bad_magic_run(struct tdescr *td,
 	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))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	/* need at least 2*HDR_SZ space: KSFT_BAD_MAGIC + terminator. */
diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c
index b3c362100666..1c03f6b638e0 100644
--- a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c
+++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size.c
@@ -24,7 +24,7 @@ static int fake_sigreturn_bad_size_run(struct tdescr *td,
 	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))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	resv_sz = GET_SF_RESV_SIZE(sf);
diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
index a44b88bfc81a..bc22f64b544e 100644
--- a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
+++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
@@ -21,7 +21,7 @@ static int fake_sigreturn_bad_size_for_magic0_run(struct tdescr *td,
 	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))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	/* at least HDR_SZ for the badly sized terminator. */
diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_duplicated_fpsimd.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_duplicated_fpsimd.c
index afe8915f0998..63e3906b631c 100644
--- a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_duplicated_fpsimd.c
+++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_duplicated_fpsimd.c
@@ -21,7 +21,7 @@ static int fake_sigreturn_duplicated_fpsimd_run(struct tdescr *td,
 	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))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	head = get_starting_head(shead, sizeof(struct fpsimd_context) + HDR_SZ,
diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned_sp.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned_sp.c
index 1e089e66f9f3..d00625ff12c2 100644
--- a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned_sp.c
+++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_misaligned_sp.c
@@ -19,7 +19,7 @@ static int fake_sigreturn_misaligned_run(struct tdescr *td,
 					 siginfo_t *si, ucontext_t *uc)
 {
 	/* just to fill the ucontext_t with something real */
-	if (!get_current_context(td, &sf.uc))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	/* Forcing sigframe on misaligned SP (16 + 3) */
diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_missing_fpsimd.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_missing_fpsimd.c
index 08ecd8073a1a..f805138cb20d 100644
--- a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_missing_fpsimd.c
+++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_missing_fpsimd.c
@@ -23,7 +23,7 @@ static int fake_sigreturn_missing_fpsimd_run(struct tdescr *td,
 	struct _aarch64_ctx *head = GET_SF_RESV_HEAD(sf);
 
 	/* just to fill the ucontext_t with something real */
-	if (!get_current_context(td, &sf.uc))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	resv_sz = GET_SF_RESV_SIZE(sf);
diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sme_change_vl.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sme_change_vl.c
index 7ed762b7202f..ebd5815b54bb 100644
--- a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sme_change_vl.c
+++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sme_change_vl.c
@@ -54,7 +54,7 @@ static int fake_sigreturn_ssve_change_vl(struct tdescr *td,
 	struct sve_context *sve;
 
 	/* Get a signal context with a SME ZA frame in it */
-	if (!get_current_context(td, &sf.uc))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	resv_sz = GET_SF_RESV_SIZE(sf);
diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sve_change_vl.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sve_change_vl.c
index 915821375b0a..e2a452190511 100644
--- a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sve_change_vl.c
+++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_sve_change_vl.c
@@ -56,7 +56,7 @@ static int fake_sigreturn_sve_change_vl(struct tdescr *td,
 	struct sve_context *sve;
 
 	/* Get a signal context with a SVE frame in it */
-	if (!get_current_context(td, &sf.uc))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	resv_sz = GET_SF_RESV_SIZE(sf);
diff --git a/tools/testing/selftests/arm64/signal/testcases/sme_vl.c b/tools/testing/selftests/arm64/signal/testcases/sme_vl.c
index 13ff3b35cbaf..75f387f2db81 100644
--- a/tools/testing/selftests/arm64/signal/testcases/sme_vl.c
+++ b/tools/testing/selftests/arm64/signal/testcases/sme_vl.c
@@ -34,7 +34,7 @@ static int sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
 	struct za_context *za;
 
 	/* Get a signal context which should have a ZA frame in it */
-	if (!get_current_context(td, &sf.uc))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	resv_sz = GET_SF_RESV_SIZE(sf);
diff --git a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
index 9022a6cab4b3..71f14632c524 100644
--- a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
@@ -73,7 +73,7 @@ static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 	 * in it.
 	 */
 	setup_ssve_regs();
-	if (!get_current_context(td, &sf.uc))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	resv_sz = GET_SF_RESV_SIZE(sf);
diff --git a/tools/testing/selftests/arm64/signal/testcases/sve_regs.c b/tools/testing/selftests/arm64/signal/testcases/sve_regs.c
index 4b2418aa08a9..4cdedb706786 100644
--- a/tools/testing/selftests/arm64/signal/testcases/sve_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/sve_regs.c
@@ -71,7 +71,7 @@ static int do_one_sve_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 	 * in it.
 	 */
 	setup_sve_regs();
-	if (!get_current_context(td, &sf.uc))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	resv_sz = GET_SF_RESV_SIZE(sf);
diff --git a/tools/testing/selftests/arm64/signal/testcases/sve_vl.c b/tools/testing/selftests/arm64/signal/testcases/sve_vl.c
index 92904653add1..aa835acec062 100644
--- a/tools/testing/selftests/arm64/signal/testcases/sve_vl.c
+++ b/tools/testing/selftests/arm64/signal/testcases/sve_vl.c
@@ -34,7 +34,7 @@ static int sve_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
 	struct sve_context *sve;
 
 	/* Get a signal context which should have a SVE frame in it */
-	if (!get_current_context(td, &sf.uc))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	resv_sz = GET_SF_RESV_SIZE(sf);
diff --git a/tools/testing/selftests/arm64/signal/testcases/za_regs.c b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
index 9f1dd70289be..1c008bca73a1 100644
--- a/tools/testing/selftests/arm64/signal/testcases/za_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
@@ -71,7 +71,7 @@ static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 	 * in it.
 	 */
 	setup_za_regs();
-	if (!get_current_context(td, &sf.uc))
+	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
 		return 1;
 
 	resv_sz = GET_SF_RESV_SIZE(sf);
-- 
2.30.2


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[PATCH v2 10/10] kselftest/arm64: Include larger SVE and SME VLs in signal tests

[Mark Brown]

Now that the core utilities for signal testing support handling data in
EXTRA_CONTEXT blocks we can test larger SVE and SME VLs which spill over
the limits in the base signal context. This is done by defining storage
for the context as a union with a ucontext_t and a buffer together with
some helpers for getting relevant sizes and offsets like we do for
fake_sigframe, this isn't the most lovely code ever but is fairly
straightforward to implement and much less invasive to the somewhat
unclear and indistinct layers of abstraction in the signal handling test
code.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 .../arm64/signal/testcases/ssve_regs.c        | 25 +++++++------------
 .../arm64/signal/testcases/sve_regs.c         | 23 +++++++----------
 .../arm64/signal/testcases/testcases.h        |  7 ++++++
 .../arm64/signal/testcases/za_regs.c          | 24 ++++++------------
 4 files changed, 33 insertions(+), 46 deletions(-)

diff --git a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
index 71f14632c524..d0a178945b1a 100644
--- a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
@@ -13,7 +13,10 @@
 #include "test_signals_utils.h"
 #include "testcases.h"
 
-struct fake_sigframe sf;
+static union {
+	ucontext_t uc;
+	char buf[1024 * 64];
+} context;
 static unsigned int vls[SVE_VQ_MAX];
 unsigned int nvls = 0;
 
@@ -55,8 +58,8 @@ static void setup_ssve_regs(void)
 static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 			 unsigned int vl)
 {
-	size_t resv_sz, offset;
-	struct _aarch64_ctx *head = GET_SF_RESV_HEAD(sf);
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
 	struct sve_context *ssve;
 	int ret;
 
@@ -73,11 +76,11 @@ static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 	 * in it.
 	 */
 	setup_ssve_regs();
-	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
+	if (!get_current_context(td, &context.uc, sizeof(context)))
 		return 1;
 
-	resv_sz = GET_SF_RESV_SIZE(sf);
-	head = get_header(head, SVE_MAGIC, resv_sz, &offset);
+	head = get_header(head, SVE_MAGIC, GET_BUF_RESV_SIZE(context),
+			  &offset);
 	if (!head) {
 		fprintf(stderr, "No SVE context\n");
 		return 1;
@@ -101,16 +104,6 @@ static int sme_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
 	int i;
 
 	for (i = 0; i < nvls; i++) {
-		/*
-		 * TODO: the signal test helpers can't currently cope
-		 * with signal frames bigger than struct sigcontext,
-		 * skip VLs that will trigger that.
-		 */
-		if (vls[i] > 64) {
-			printf("Skipping VL %u due to stack size\n", vls[i]);
-			continue;
-		}
-
 		if (do_one_sme_vl(td, si, uc, vls[i]))
 			return 1;
 	}
diff --git a/tools/testing/selftests/arm64/signal/testcases/sve_regs.c b/tools/testing/selftests/arm64/signal/testcases/sve_regs.c
index 4cdedb706786..8b16eabbb769 100644
--- a/tools/testing/selftests/arm64/signal/testcases/sve_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/sve_regs.c
@@ -13,7 +13,10 @@
 #include "test_signals_utils.h"
 #include "testcases.h"
 
-struct fake_sigframe sf;
+static union {
+	ucontext_t uc;
+	char buf[1024 * 64];
+} context;
 static unsigned int vls[SVE_VQ_MAX];
 unsigned int nvls = 0;
 
@@ -55,8 +58,8 @@ static void setup_sve_regs(void)
 static int do_one_sve_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 			 unsigned int vl)
 {
-	size_t resv_sz, offset;
-	struct _aarch64_ctx *head = GET_SF_RESV_HEAD(sf);
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
 	struct sve_context *sve;
 
 	fprintf(stderr, "Testing VL %d\n", vl);
@@ -71,11 +74,11 @@ static int do_one_sve_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 	 * in it.
 	 */
 	setup_sve_regs();
-	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
+	if (!get_current_context(td, &context.uc, sizeof(context)))
 		return 1;
 
-	resv_sz = GET_SF_RESV_SIZE(sf);
-	head = get_header(head, SVE_MAGIC, resv_sz, &offset);
+	head = get_header(head, SVE_MAGIC, GET_BUF_RESV_SIZE(context),
+			  &offset);
 	if (!head) {
 		fprintf(stderr, "No SVE context\n");
 		return 1;
@@ -99,14 +102,6 @@ static int sve_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
 	int i;
 
 	for (i = 0; i < nvls; i++) {
-		/*
-		 * TODO: the signal test helpers can't currently cope
-		 * with signal frames bigger than struct sigcontext,
-		 * skip VLs that will trigger that.
-		 */
-		if (vls[i] > 64)
-			continue;
-
 		if (do_one_sve_vl(td, si, uc, vls[i]))
 			return 1;
 	}
diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.h b/tools/testing/selftests/arm64/signal/testcases/testcases.h
index b39f538c7be1..040afded0b76 100644
--- a/tools/testing/selftests/arm64/signal/testcases/testcases.h
+++ b/tools/testing/selftests/arm64/signal/testcases/testcases.h
@@ -30,6 +30,13 @@
 #define GET_SF_RESV_SIZE(sf) \
 	sizeof((sf).uc.uc_mcontext.__reserved)
 
+#define GET_BUF_RESV_HEAD(buf) \
+	(struct _aarch64_ctx *)(&(buf).uc.uc_mcontext.__reserved)
+
+#define GET_BUF_RESV_SIZE(buf) \
+	(sizeof(buf) - sizeof(buf.uc) +	\
+	 sizeof((buf).uc.uc_mcontext.__reserved))
+
 #define GET_UCP_RESV_SIZE(ucp) \
 	sizeof((ucp)->uc_mcontext.__reserved)
 
diff --git a/tools/testing/selftests/arm64/signal/testcases/za_regs.c b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
index 1c008bca73a1..d334fe210595 100644
--- a/tools/testing/selftests/arm64/signal/testcases/za_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
@@ -13,7 +13,10 @@
 #include "test_signals_utils.h"
 #include "testcases.h"
 
-struct fake_sigframe sf;
+static union {
+	ucontext_t uc;
+	char buf[1024 * 128];
+} context;
 static unsigned int vls[SVE_VQ_MAX];
 unsigned int nvls = 0;
 
@@ -55,8 +58,8 @@ static void setup_za_regs(void)
 static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 			 unsigned int vl)
 {
-	size_t resv_sz, offset;
-	struct _aarch64_ctx *head = GET_SF_RESV_HEAD(sf);
+	size_t offset;
+	struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
 	struct za_context *za;
 
 	fprintf(stderr, "Testing VL %d\n", vl);
@@ -71,11 +74,10 @@ static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 	 * in it.
 	 */
 	setup_za_regs();
-	if (!get_current_context(td, &sf.uc, sizeof(sf.uc)))
+	if (!get_current_context(td, &context.uc, sizeof(context)))
 		return 1;
 
-	resv_sz = GET_SF_RESV_SIZE(sf);
-	head = get_header(head, ZA_MAGIC, resv_sz, &offset);
+	head = get_header(head, ZA_MAGIC, GET_BUF_RESV_SIZE(context), &offset);
 	if (!head) {
 		fprintf(stderr, "No ZA context\n");
 		return 1;
@@ -99,16 +101,6 @@ static int sme_regs(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
 	int i;
 
 	for (i = 0; i < nvls; i++) {
-		/*
-		 * TODO: the signal test helpers can't currently cope
-		 * with signal frames bigger than struct sigcontext,
-		 * skip VLs that will trigger that.
-		 */
-		if (vls[i] > 32) {
-			printf("Skipping VL %u due to stack size\n", vls[i]);
-			continue;
-		}
-
 		if (do_one_sme_vl(td, si, uc, vls[i]))
 			return 1;
 	}
-- 
2.30.2


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Re: [PATCH v2 00/10] kselftest/arm64: EXTRA_CONTEXT related fixes

[Catalin Marinas]

On Mon, 29 Aug 2022 17:06:53 +0100, Mark Brown wrote:
> The arm64 architecture originally made the signal context a fixed size
> structure containing a linked list of records with the various kinds of
> register and other state which may be present. When SVE was implemented
> it was realised that it supported implementations with more state than
> could fit in that structure so a new record type EXTRA_CONTEXT was
> introduced allowing the signal context to be extended beyond the
> original size. Unfortunately the signal handling tests can not cope with
> these EXTRA_CONTEXT records at all - some support was implemented but it
> simply never worked.
> 
> [...]

Applied to arm64 (for-next/kselftest), thanks!

[01/10] kselftest/arm64: Enumerate SME rather than SVE vector lengths for za_regs
        https://git.kernel.org/arm64/c/b3321fbd7fa2
[02/10] kselftest/arm64: Validate signal ucontext in place
        https://git.kernel.org/arm64/c/b97ff4f3ad95
[03/10] kselftest/arm64: Fix validatation termination record after EXTRA_CONTEXT
        https://git.kernel.org/arm64/c/909e2105c748
[04/10] kselftest/arm64: Fix validation of EXTRA_CONTEXT signal context location
        https://git.kernel.org/arm64/c/a934077a3f94
[05/10] kselftest/arm64: Remove unneeded protype for validate_extra_context()
        https://git.kernel.org/arm64/c/e374ab27e738
[06/10] kselftest/arm64: Only validate each signal context once
        https://git.kernel.org/arm64/c/b9731674ec9c
[07/10] kselftest/arm64: Validate contents of EXTRA_CONTEXT blocks
        https://git.kernel.org/arm64/c/3df95c1efeaf
[08/10] kselftest/arm64: Preserve any EXTRA_CONTEXT in handle_signal_copyctx()
        https://git.kernel.org/arm64/c/91f48fb9f82b
[09/10] kselftest/arm64: Allow larger buffers in get_signal_context()
        https://git.kernel.org/arm64/c/5f6539724421
[10/10] kselftest/arm64: Include larger SVE and SME VLs in signal tests
        https://git.kernel.org/arm64/c/7384bddbe246

-- 
Catalin


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