qemu/util
Eric Blake cf923b783e utils: Improve qemu_strtosz() to have 64 bits of precision
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>
2021-03-08 13:36:12 -06:00
..
aio-posix.c qmp: Move dispatcher to a coroutine 2020-10-09 07:08:20 +02:00
aio-posix.h
aio-wait.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
aio-win32.c qmp: fix aio_poll() assertion failure on Windows 2020-11-03 16:24:56 +01:00
aiocb.c
async.c util/async: Add aio_co_reschedule_self() 2020-10-09 07:08:20 +02:00
atomic64.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
base64.c nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
bitmap.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
bitops.c
block-helpers.c block: move logical block size check function to a common utility function 2020-10-23 13:42:16 +01:00
block-helpers.h block: move logical block size check function to a common utility function 2020-10-23 13:42:16 +01:00
buffer.c nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
bufferiszero.c
cacheflush.c util/cacheflush: Fix error generated by clang 2021-01-21 13:00:41 +01:00
cacheinfo.c util: Enhance flush_icache_range with separate data pointer 2021-01-07 05:09:41 -10:00
compatfd.c util/compatfd.c: Only include <sys/syscall.h> if CONFIG_SIGNALFD 2020-07-13 14:36:10 +01:00
coroutine-sigaltstack.c coroutine-sigaltstack: Add SIGUSR2 mutex 2021-01-26 14:36:37 +01:00
coroutine-ucontext.c Remove the CONFIG_PRAGMA_DIAGNOSTIC_AVAILABLE switch 2020-07-13 11:40:52 +02:00
coroutine-win32.c
crc32c.c
crc-ccitt.c util: Add CRC16 (CCITT) calculation routines 2021-01-24 20:10:54 +01:00
cutils.c utils: Improve qemu_strtosz() to have 64 bits of precision 2021-03-08 13:36:12 -06:00
dbus.c
drm.c util/drm: make portable by avoiding struct dirent d_type 2020-07-13 14:36:10 +01:00
envlist.c
error.c
event_notifier-posix.c event_notifier: Set ->initialized earlier in event_notifier_init() 2021-02-16 17:15:39 +01:00
event_notifier-win32.c
fdmon-epoll.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
fdmon-io_uring.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
fdmon-poll.c fdmon-poll: reset npfd when upgrading to fdmon-epoll 2020-09-23 13:45:52 +01:00
fifo8.c utils/fifo8: change fatal errors from abort() to assert() 2021-02-07 20:38:20 +00:00
filemonitor-inotify.c nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
filemonitor-stub.c nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
getauxval.c
guest-random.c
hbitmap.c
hexdump.c util/hexdump: introduce qemu_hexdump_line() 2020-09-29 02:14:30 -04:00
host-utils.c
id.c
iov.c util/iov: make qemu_iovec_init_extended() honest 2021-02-03 08:00:33 -06:00
iova-tree.c
keyval.c keyval: Use GString to accumulate value strings 2020-12-19 10:39:23 +01:00
lockcnt.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
log.c nomaintainer: Fix Lesser GPL version number 2020-11-15 17:04:40 +01:00
main-loop.c cfi: Initial support for cfi-icall in QEMU 2021-01-02 21:03:35 +01:00
memfd.c
meson.build migration: introduce UFFD-WP low-level interface helpers 2021-02-08 11:19:51 +00:00
mmap-alloc.c memory: alloc RAM from file at offset 2021-02-09 20:53:56 +00:00
module.c modules: turn off lazy binding 2020-10-29 06:37:24 +01:00
notify.c
nvdimm-utils.c Clean up includes 2020-12-10 17:16:44 +01:00
osdep.c Pull request trivial patches 20200919 2020-09-22 15:42:23 +01:00
oslib-posix.c memory: alloc RAM from file at offset 2021-02-09 20:53:56 +00:00
oslib-win32.c util/oslib-win32: Fix _aligned_malloc() arguments order 2021-01-11 14:59:21 +01:00
pagesize.c
path.c
qdist.c
qemu-co-shared-resource.c
qemu-config.c qemu-config: add error propagation to qemu_config_parse 2021-03-06 11:41:54 +01:00
qemu-coroutine-io.c
qemu-coroutine-lock.c coroutine: let CoQueue wake up outside a coroutine 2020-11-04 08:02:24 +01:00
qemu-coroutine-sleep.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
qemu-coroutine.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
qemu-error.c error: rename error_with_timestamp to message_with_timestamp 2021-02-01 10:50:55 +00:00
qemu-openpty.c util/qemu-openpty.c: Don't assume pty.h is glibc-only 2020-07-13 14:36:09 +01:00
qemu-option.c qemu-option: do not suggest using the delay option 2021-03-06 11:42:57 +01:00
qemu-print.c monitor: Use getter/setter functions for cur_mon 2020-10-09 07:08:19 +02:00
qemu-progress.c util/: fix some comment spelling errors 2020-09-17 20:38:42 +02:00
qemu-sockets.c sockets: Make abstract UnixSocketAddress depend on CONFIG_LINUX 2020-11-03 13:17:25 +00:00
qemu-thread-common.h
qemu-thread-posix.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
qemu-thread-win32.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
qemu-timer-common.c semihosting: Implement SYS_ELAPSED and SYS_TICKFREQ 2021-01-18 10:05:06 +00:00
qemu-timer.c cpus: prepare new CpusAccel cpu accelerator interface 2020-10-05 16:41:22 +02:00
qht.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
qsp.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
range.c
rcu.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
readline.c readline: Fix possible array index out of bounds in readline_hist_add() 2021-01-04 11:13:39 +00:00
selfmap.c
stats64.c qemu/atomic.h: rename atomic_ to qatomic_ 2020-09-23 16:07:44 +01:00
sys_membarrier.c
systemd.c
thread-pool.c
throttle.c Remove superfluous timer_del() calls 2021-01-08 15:13:38 +00:00
timed-average.c
trace-events migration: introduce UFFD-WP low-level interface helpers 2021-02-08 11:19:51 +00:00
trace.h trace: switch position of headers to what Meson requires 2020-08-21 06:18:24 -04:00
unicode.c
uri.c
userfaultfd.c migration: introduce UFFD-WP low-level interface helpers 2021-02-08 11:19:51 +00:00
uuid.c
vfio-helpers.c Pull request for 5.2 2020-11-23 13:03:13 +00:00
vhost-user-server.c util/vhost-user-server: move header to include/ 2020-10-23 13:42:16 +01:00
yank.c Introduce yank feature 2021-01-13 10:21:17 +01:00