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cf923b783e
We have multiple clients of qemu_strtosz (qemu-io, the opts visitor, the keyval visitor), and it gets annoying that edge-case testing is impacted by implicit rounding to 53 bits of precision due to parsing with strtod(). As an example posted by Rich Jones: $ nbdkit memory $(( 2**63 - 2**30 )) --run \ 'build/qemu-io -f raw "$uri" -c "w -P 3 $(( 2**63 - 2**30 - 512 )) 512" ' write failed: Input/output error because 9223372035781033472 got rounded to 0x7fffffffc0000000 which is out of bounds. It is also worth noting that our existing parser, by virtue of using strtod(), accepts decimal AND hex numbers, even though test-cutils previously lacked any coverage of the latter until the previous patch. We do have existing clients that expect a hex parse to work (for example, iotest 33 using qemu-io -c "write -P 0xa 0x200 0x400"), but strtod() parses "08" as 8 rather than as an invalid octal number, so we know there are no clients that depend on octal. Our use of strtod() also means that "0x1.8k" would actually parse as 1536 (the fraction is 8/16), rather than 1843 (if the fraction were 8/10); but as this was not covered in the testsuite, I have no qualms forbidding hex fractions as invalid, so this patch declares that the use of fractions is only supported with decimal input, and enhances the testsuite to document that. Our previous use of strtod() meant that -1 parsed as a negative; now that we parse with strtoull(), negative values can wrap around modulo 2^64, so we have to explicitly check whether the user passed in a '-'; and make it consistent to also reject '-0'. This has the minor effect of treating negative values as EINVAL (with no change to endptr) rather than ERANGE (with endptr advanced to what was parsed), visible in the updated iotest output. We also had no testsuite coverage of "1.1e0k", which happened to parse under strtod() but is unlikely to occur in practice; as long as we are making things more robust, it is easy enough to reject the use of exponents in a strtod parse. The fix is done by breaking the parse into an integer prefix (no loss in precision), rejecting negative values (since we can no longer rely on strtod() to do that), determining if a decimal or hexadecimal parse was intended (with the new restriction that a fractional hex parse is not allowed), and where appropriate, using a floating point fractional parse (where we also scan to reject use of exponents in the fraction). The bulk of the patch is then updates to the testsuite to match our new precision, as well as adding new cases we reject (whether they were rejected or inadvertently accepted before). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20210211204438.1184395-3-eblake@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> |
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.. | ||
acceptance | ||
data | ||
decode | ||
docker | ||
fp | ||
guest-debug | ||
image-fuzzer | ||
include | ||
keys | ||
migration | ||
multiboot | ||
perf/block/qcow2 | ||
plugin | ||
qapi-schema | ||
qemu-iotests | ||
qtest | ||
rocker | ||
tcg | ||
tsan | ||
uefi-test-tools | ||
vm | ||
vmstate-static-checker-data | ||
atomic64-bench.c | ||
atomic_add-bench.c | ||
benchmark-crypto-cipher.c | ||
benchmark-crypto-hash.c | ||
benchmark-crypto-hmac.c | ||
check-block-qdict.c | ||
check-block.sh | ||
check-qdict.c | ||
check-qjson.c | ||
check-qlist.c | ||
check-qlit.c | ||
check-qnull.c | ||
check-qnum.c | ||
check-qobject.c | ||
check-qom-interface.c | ||
check-qom-proplist.c | ||
check-qstring.c | ||
crypto-tls-psk-helpers.c | ||
crypto-tls-psk-helpers.h | ||
crypto-tls-x509-helpers.c | ||
crypto-tls-x509-helpers.h | ||
dbus-vmstate-daemon.sh | ||
io-channel-helpers.c | ||
io-channel-helpers.h | ||
iothread.c | ||
iothread.h | ||
Makefile.include | ||
meson.build | ||
pkix_asn1_tab.c | ||
ptimer-test-stubs.c | ||
ptimer-test.c | ||
ptimer-test.h | ||
qht-bench.c | ||
rcutorture.c | ||
requirements.txt | ||
socket-helpers.c | ||
socket-helpers.h | ||
test-aio-multithread.c | ||
test-aio.c | ||
test-authz-list.c | ||
test-authz-listfile.c | ||
test-authz-pam.c | ||
test-authz-simple.c | ||
test-base64.c | ||
test-bdrv-drain.c | ||
test-bdrv-graph-mod.c | ||
test-bitcnt.c | ||
test-bitmap.c | ||
test-bitops.c | ||
test-block-backend.c | ||
test-block-iothread.c | ||
test-blockjob-txn.c | ||
test-blockjob.c | ||
test-bufferiszero.c | ||
test-char.c | ||
test-clone-visitor.c | ||
test-coroutine.c | ||
test-crypto-afsplit.c | ||
test-crypto-block.c | ||
test-crypto-cipher.c | ||
test-crypto-hash.c | ||
test-crypto-hmac.c | ||
test-crypto-ivgen.c | ||
test-crypto-pbkdf.c | ||
test-crypto-secret.c | ||
test-crypto-tlscredsx509.c | ||
test-crypto-tlssession.c | ||
test-crypto-xts.c | ||
test-cutils.c | ||
test-fdmon-epoll.c | ||
test-hbitmap.c | ||
test-image-locking.c | ||
test-int128.c | ||
test-io-channel-buffer.c | ||
test-io-channel-command.c | ||
test-io-channel-file.c | ||
test-io-channel-socket.c | ||
test-io-channel-tls.c | ||
test-io-task.c | ||
test-iov.c | ||
test-keyval.c | ||
test-logging.c | ||
test-mul64.c | ||
test-opts-visitor.c | ||
test-qapi-util.c | ||
test-qdev-global-props.c | ||
test-qdist.c | ||
test-qemu-opts.c | ||
test-qga.c | ||
test-qgraph.c | ||
test-qht-par.c | ||
test-qht.c | ||
test-qmp-cmds.c | ||
test-qmp-event.c | ||
test-qobject-input-visitor.c | ||
test-qobject-output-visitor.c | ||
test-rcu-list.c | ||
test-rcu-simpleq.c | ||
test-rcu-slist.c | ||
test-rcu-tailq.c | ||
test-replication.c | ||
test-shift128.c | ||
test-string-input-visitor.c | ||
test-string-output-visitor.c | ||
test-thread-pool.c | ||
test-throttle.c | ||
test-timed-average.c | ||
test-util-filemonitor.c | ||
test-util-sockets.c | ||
test-uuid.c | ||
test-visitor-serialization.c | ||
test-vmstate.c | ||
test-write-threshold.c | ||
test-x86-cpuid.c | ||
test-xbzrle.c | ||
vhost-user-bridge.c |