[PATCH] insane.bbclass: introduce SIGILL finder

[Benjamin Bara <bbara93@gmail.com>]

From: Benjamin Bara <benjamin.bara@skidata.com>

This commit should look for unsupported instructions depending on the
active tune features. For now, it checks for vfpv3d16 and other non-neon
machines, but it can be easily extended for other architectures/checks.

Reason for this check is that a couple of packages assume neon support
for armv7, but it is actually optional.

Signed-off-by: Benjamin Bara <benjamin.bara@skidata.com>
---
Hi,

as I lately played a little bit around with a vfpv3d16 machine and some
multimedia packages, I stumbled across a couple of illegal instructions
during runtime. Therefore I decided to hack a QA job which should find
these during package time. Not sure if this is the correct location to
do such a check and if this is something needed at all...

Regards,
Benjamin
---
 meta/classes-global/insane.bbclass | 78 +++++++++++++++++++++++++++++-
 meta/lib/oe/qa.py                  | 34 +++++++++++++
 2 files changed, 111 insertions(+), 1 deletion(-)

diff --git a/meta/classes-global/insane.bbclass b/meta/classes-global/insane.bbclass
index 2e53778934..5b9112d05c 100644
--- a/meta/classes-global/insane.bbclass
+++ b/meta/classes-global/insane.bbclass
@@ -44,7 +44,7 @@ ERROR_QA ?= "dev-so debug-deps dev-deps debug-files arch pkgconfig la \
             configure-gettext perllocalpod shebang-size \
             already-stripped installed-vs-shipped ldflags compile-host-path \
             install-host-path pn-overrides unknown-configure-option \
-            useless-rpaths rpaths staticdev empty-dirs \
+            useless-rpaths rpaths staticdev empty-dirs sigill \
             patch-fuzz \
             "
 # Add usrmerge QA check based on distro feature
@@ -635,6 +635,82 @@ def check_32bit_symbols(path, packagename, d, elf, messages):
                     'Suppress with INSANE_SKIP = "32bit-time"'
                 )
 
+QAPATHTEST[sigill] = "package_qa_check_sigill"
+def package_qa_check_sigill(path, name, d, elf, messages):
+    """
+    Check that the package doesn't contain unsupported instructions.
+    """
+    import re
+
+    if not elf:
+        return
+
+    if os.path.islink(path):
+        return
+
+    def test_skeleton(grep, test):
+        dump = elf.run_filtered_objdump_unstripped("-d", grep, d, name)
+        if dump == 'stripped':
+            # stripped binaries might give false positives
+            return
+
+        # get all instructions and registers from the disassembled binary
+        instr_list = []
+        regs_list = []
+        for line in dump.split("\\n"):
+            splitted = dump.split("\\t")
+            if len(splitted) < 3:
+                continue
+            # 0 is just empty, as line starts with \t
+            instr_list.append(splitted[1])
+            regs_list.append(splitted[2])
+
+        # loop through instr+regs list and apply the given test function
+        uniques = set()
+        for index, regs in enumerate(regs_list):
+            instr = instr_list[index]
+            affected = test(instr, regs)
+            if affected:
+                uniques.add(f"{instr} {regs}")
+
+        for instr_regs in uniques:
+            oe.qa.add_message(messages, "sigill", "%s contains %s" % (path, instr_regs))
+
+    features = d.getVar('TUNE_FEATURES')
+    if "vfpv3d16" in features:
+        # grep for d16-d31, d0-d15 are valid for f64 instructions
+        vfpv3d16_grep = "f64\s+(d1|d2|d3)"
+
+        def vfpv3d16_test(instr, regs):
+            for reg in re.findall(r'd(\d+)', regs):
+                return int(reg) >= 16
+
+        test_skeleton(vfpv3d16_grep, vfpv3d16_test)
+
+    if "armv7a" in features and "neon" not in features:
+        # https://developer.arm.com/documentation/den0018/a/NEON-and-VFP-Instruction-Summary/List-of-all-NEON-and-VFP-instructions
+        neon_instrs = ["vq?r?shl", "vq?abs", "vq?add", "vq?movn", "vq?sub",
+                       "vr?addhn", "vr?hadd", "vr?shrn?", "vr?sra", "vr?subhn",
+                       "vabal?", "vabdl?", "vacge", "vacgt", "vacle", "vaclt",
+                       "vaddl", "vaddw", "vand", "vbic", "vbif", "vbit", "vceq",
+                       "vcge", "vcgt", "vcle", "vcls", "vclt", "vclz", "vcnt",
+                       "vdup", "veor", "vext", "vhsub", "vmax", "vmin", "vmlal",
+                       "vmlsl", "vmov2", "vmovl", "vmull", "vmvn", "vqneg",
+                       "vorn", "vorr", "vpadal", "vpaddl?", "vpmax", "vpmin",
+                       "vqr?dmulh", "vqr?shru?n", "vqdmlal", "vqdmlsl",
+                       "vqdmull", "vqmovun", "vqshl", "vqshlu", "vcrecpe",
+                       "vcrecps", "vrev", "vrsqrte", "vrsqrts", "vshl", "vshll",
+                       "vsli", "vsri", "vsubl", "vsubw", "vswp", "vtbl", "vtbx",
+                       "vtrn", "vtst", "vuzp", "vzip"]
+        # most of them are only NEON when the used data type isn't floating-point
+        neon_grep = "\s(" + "|".join(neon_instrs) + ")\.(s|u|p)"
+
+        def neon_test(instr, regs):
+            # if something is found by the grep, the package is affected
+            return True
+
+        test_skeleton(neon_grep, neon_test)
+
 # Check license variables
 do_populate_lic[postfuncs] += "populate_lic_qa_checksum"
 python populate_lic_qa_checksum() {
diff --git a/meta/lib/oe/qa.py b/meta/lib/oe/qa.py
index de980638c4..075622c98f 100644
--- a/meta/lib/oe/qa.py
+++ b/meta/lib/oe/qa.py
@@ -157,6 +157,40 @@ class ELFFile:
             bb.note("%s %s %s failed: %s" % (objdump, cmd, self.name, e))
             return ""
 
+    def run_filtered_objdump_unstripped(self, cmd, filter, d, pn):
+        import bb.process
+        import sys
+
+        objdump = d.getVar('OBJDUMP')
+
+        # we require the unstripped binary here, as objdump might have problems
+        # detecting the correct instruction format, which leads to false positives
+        name = self.name.replace(d.getVar('PKGDEST') + '/' + pn, d.getVar('D'))
+
+        env = os.environ.copy()
+        env["LC_ALL"] = "C"
+        env["PATH"] = d.getVar('PATH')
+
+        # ensure that binary is unstripped
+        try:
+            bb.note("file %s" % (name))
+            output = bb.process.run(["file", name], env=env, shell=False)[0]
+            if ", stripped" in output:
+                return "stripped"
+        except Exception as e:
+            bb.note("file %s failed: %s" % (name, e))
+            return ""
+
+        try:
+            bb.note("%s %s %s | grep -E %s" % (objdump, cmd, name, filter))
+            objdump_proc = bb.process.Popen([objdump, cmd, "--no-addresses", "--no-show-raw-insn", name], env=env, shell=False)
+            grep_proc = bb.process.Popen(["grep", "-E", filter], env=env, shell=False, stdin=objdump_proc.stdout)
+            objdump_proc.stdout.close()
+            return str(grep_proc.communicate()[0])
+        except Exception as e:
+            bb.note("%s %s %s failed: %s" % (objdump, cmd, name, e))
+            return ""
+
 def elf_machine_to_string(machine):
     """
     Return the name of a given ELF e_machine field or the hex value as a string
-- 
2.34.1