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2025-01-01Update copyright dates with scripts/update-copyrightsPaul Eggert1-1/+1
2024-12-24stdio-common: Tweak comment in MakefileSam James1-3/+3
Followup to 5a96da210c15e18c3c5298dc23a9e2e57691b6c6.
2024-12-24stdio-common: Use clang with bugfix for bug28Dmitry Chestnykh1-4/+4
The issue that was the cause of hang was fixed in upstream. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2024-12-23stdio-common: Suppress Clang warnings on scanf13.cH.J. Lu1-0/+2
Suppress Clang warnings on stdio-common/scanf13.c: 1. Before this commit: scanf13.c:43:17: error: invalid conversion specifier 'l' [-Werror,-Wformat-invalid-specifier] 43 | "A%mS%10mls%4ml[bcd]%4mCB", &lsp1, &lsp2, &lsp3, &lsp4) != 4) | ~~~~^ scanf13.c:43:22: error: invalid conversion specifier 'l' [-Werror,-Wformat-invalid-specifier] 43 | "A%mS%10mls%4ml[bcd]%4mCB", &lsp1, &lsp2, &lsp3, &lsp4) != 4) | ~~~~^ scanf13.c:43:50: error: data argument not used by format string [-Werror,-Wformat-extra-args] 43 | "A%mS%10mls%4ml[bcd]%4mCB", &lsp1, &lsp2, &lsp3, &lsp4) != 4) | ~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ scanf13.c:145:27: error: invalid conversion specifier 'l' [-Werror,-Wformat-invalid-specifier] 145 | if (sscanf (buf, "%2048mls%mlc", &lsp3, &lsp4) != 2) | ~~~~~~^ scanf13.c:145:31: error: invalid conversion specifier 'l' [-Werror,-Wformat-invalid-specifier] 145 | if (sscanf (buf, "%2048mls%mlc", &lsp3, &lsp4) != 2) | ~~~^ scanf13.c:145:43: error: data argument not used by format string [-Werror,-Wformat-extra-args] 145 | if (sscanf (buf, "%2048mls%mlc", &lsp3, &lsp4) != 2) | ~~~~~~~~~~~~~~ ^ scanf13.c:161:31: error: invalid conversion specifier 'l' [-Werror,-Wformat-invalid-specifier] 161 | if (sscanf (buf, "%4mC%1500ml[dr/]%548ml[abc/d]%3mlc", | ~~~~~~^ scanf13.c:161:42: error: invalid conversion specifier 'l' [-Werror,-Wformat-invalid-specifier] 161 | if (sscanf (buf, "%4mC%1500ml[dr/]%548ml[abc/d]%3mlc", | ~~~~~~~~~~^ scanf13.c:161:53: error: invalid conversion specifier 'l' [-Werror,-Wformat-invalid-specifier] 161 | if (sscanf (buf, "%4mC%1500ml[dr/]%548ml[abc/d]%3mlc", | ~~~~~~~~~~^ scanf13.c:162:15: error: data argument not used by format string [-Werror,-Wformat-extra-args] 161 | if (sscanf (buf, "%4mC%1500ml[dr/]%548ml[abc/d]%3mlc", | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 162 | &lsp1, &lsp2, &lsp3, &lsp4) != 4) | ^ 10 errors generated. 2. With DIAG_IGNORE_NEEDS_COMMENT_CLANG changes in stdio-common/scanf13.c: scanf13.c:28:40: error: 'sscanf' may overflow; destination buffer in argument 4 has size 8, but the corresponding specifier may require size 11 [-Werror,-Wfortify-source] 28 | "A%ms%10ms%4m[bcd]%4mcB", &sp1, &sp2, &sp3, &sp4) != 4) | ^ scanf13.c:94:34: error: 'sscanf' may overflow; destination buffer in argument 3 has size 8, but the corresponding specifier may require size 2049 [-Werror,-Wfortify-source] 94 | if (sscanf (buf, "%2048ms%mc", &sp3, &sp4) != 2) | ^ scanf13.c:110:61: error: 'sscanf' may overflow; destination buffer in argument 4 has size 8, but the corresponding specifier may require size 1501 [-Werror,-Wfortify-source] 110 | if (sscanf (buf, "%4mc%1500m[dr/]%548m[abc/d]%3mc", &sp1, &sp2, &sp3, &sp4) | ^ scanf13.c:110:67: error: 'sscanf' may overflow; destination buffer in argument 5 has size 8, but the corresponding specifier may require size 549 [-Werror,-Wfortify-source] 110 | if (sscanf (buf, "%4mc%1500m[dr/]%548m[abc/d]%3mc", &sp1, &sp2, &sp3, &sp4) | ^ 4 errors generated. Co-Authored-By: Adhemerval Zanella <adhemerval.zanella@linaro.org> Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Reviewed-by: Sam James <sam@gentoo.org>
2024-12-21stdio-common: Exclude bug28 when clang is usedH.J. Lu1-1/+10
Clang 19 takes a very long time, it ran more than 27 minutes on Intel Core i7-1195G7 before the process was killed, to compile bug28.c: https://github.com/llvm/llvm-project/issues/120462 Exclude it when Clang is used for testing. Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Reviewed-by: Sam James <sam@gentoo.org>
2024-12-17ungetc: Guarantee single char pushbackSiddhesh Poyarekar1-0/+2
The C standard requires that ungetc guarantees at least one pushback, but the malloc call to allocate the pushback buffer could fail, thus violating that requirement. Fix this by adding a single byte pushback buffer in the FILE struct that the pushback can fall back to if malloc fails. The side-effect is that if the initial malloc fails and the 1-byte fallback buffer is used, future resizing (if it succeeds) will be 2-bytes, 4-bytes and so on, which is suboptimal but it's after a malloc failure, so maybe even desirable. A future optimization here could be to have the pushback code use the single byte buffer first and only fall back to malloc for subsequent calls. Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Reviewed-by: Maciej W. Rozycki <macro@redhat.com>
2024-11-07stdio-common: Add tests for formatted vsnprintf output specifiersMaciej W. Rozycki1-1/+1
Wire vsnprintf into test infrastructure for formatted printf output specifiers. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-11-07stdio-common: Add tests for formatted vsprintf output specifiersMaciej W. Rozycki1-1/+1
Wire vsprintf into test infrastructure for formatted printf output specifiers. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-11-07stdio-common: Add tests for formatted vfprintf output specifiersMaciej W. Rozycki1-1/+1
Wire vfprintf into test infrastructure for formatted printf output specifiers. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-11-07stdio-common: Add tests for formatted vdprintf output specifiersMaciej W. Rozycki1-1/+1
Wire vdprintf into test infrastructure for formatted printf output specifiers. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-11-07stdio-common: Add tests for formatted vasprintf output specifiersMaciej W. Rozycki1-1/+1
Wire vasprintf into test infrastructure for formatted printf output specifiers. Owing to mtrace logging these tests take amounts of time to complete similar to those of corresponding asprintf tests, so set timeouts for the tests accordingly, with a global default for all the vasprintf tests, and then individual higher settings for double and long double tests each. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-11-07stdio-common: Add tests for formatted vprintf output specifiersMaciej W. Rozycki1-1/+1
Wire vprintf into test infrastructure for formatted printf output specifiers. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-11-07stdio-common: Add tests for formatted snprintf output specifiersMaciej W. Rozycki1-1/+1
Wire snprintf into test infrastructure for formatted printf output specifiers. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-11-07stdio-common: Add tests for formatted sprintf output specifiersMaciej W. Rozycki1-1/+1
Wire sprintf into test infrastructure for formatted printf output specifiers. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-11-07stdio-common: Add tests for formatted fprintf output specifiersMaciej W. Rozycki1-1/+1
Wire fprintf into test infrastructure for formatted printf output specifiers. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-11-07stdio-common: Add tests for formatted dprintf output specifiersMaciej W. Rozycki1-1/+1
Wire dprintf into test infrastructure for formatted printf output specifiers. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-11-07stdio-common: Add tests for formatted asprintf output specifiersMaciej W. Rozycki1-1/+1
Wire asprintf into test infrastructure for formatted printf output specifiers. Owing to mtrace logging of lots of memory allocation calls these tests take a considerable amount of time to complete, except for the character conversion, taking from 00m20s for 'tst-printf-format-as-s --direct s', through 01m10s and 03m53s for 'tst-printf-format-as-char --direct i' and 'tst-printf-format-as-double --direct f' respectively, to 19m24s for 'tst-printf-format-as-ldouble --direct f', all in standalone execution from NFS on a RISC-V FU740@1.2GHz system and with output redirected over 100Mbps network via SSH. It is with the skeleton's stub implementation of dladdr(3); execution times with regular dladdr(3) are up to over twice longer. Set timeouts for the tests accordingly then, with a global default for all the asprintf tests, and then individual higher settings for double and long double tests each. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-11-07stdio-common: Add tests for formatted printf output specifiersMaciej W. Rozycki1-0/+52
This is a collection of tests for formatted printf output specifiers covering the d, i, o, u, x, and X integer conversions, the e, E, f, F, g, and G floating-point conversions, the c character conversion, and the s string conversion. Also the hh, h, l, and ll length modifiers are covered with the integer conversions as is the L length modifier with the floating-point conversions. The -, +, space, #, and 0 flags are iterated over, as permitted by the conversion handled, in tuples of 1..5, including tuples with repetitions of 2, and combined with field width and/or precision, again as permitted by the conversion. The resulting format string is then used to produce output from respective sets of input data corresponding to the specific conversion under test. POSIX extensions beyond ISO C are not used. Output is produced in the form of records which include both the format string (and width and/or precision where given in the form of separate arguments) and the conversion result, and is verified with GNU AWK using the format obtained from each such record against the reference value also supplied, relying on the fact that GNU AWK has its own independent implementation of format processing, striving to be ISO C compatible. In the course of implementation I have determined that in the non-bignum mode GNU AWK uses system sprintf(3) for the floating-point conversions, defeating the objective of doing the verification against an independent implementation. Additionally the bignum mode (using MPFR) is required to correctly output wider integer and floating-point data. Therefore for the conversions affected the relevant shell scripts sanity-check AWK and terminate with unsupported status if the bignum mode is unavailable for floating-point data or where data is output incorrectly. The f and F floating-point conversions are build-time options for GNU AWK, depending on the environment, so they are probed for before being used. Similarly the a and A floating-point conversions, however they are currently not used, see below. Also GNU AWK does not handle the b or B integer conversions at all at the moment, as at 5.3.0. Support for the a, A, b, and B conversions can however be easily added following the approach taken for the f and F conversions. Output produced by gawk for the a and A floating-point conversions does not match one produced by us: insufficient precision is used where one hasn't been explicitly given, e.g. for the negated maximum finite IEEE 754 64-bit value of -1.79769313486231570814527423731704357e+308 and "%a" format we produce -0x1.fffffffffffffp+1023 vs gawk's -0x1.000000p+1024 and a different exponent is chosen otherwise, such as with "%.a" where we output -0x2p+1023 vs gawk's -0x1p+1024 for the same value, or "%.20a" where -0x1.fffffffffffff0000000p+1023 is our output, but gawk produces -0xf.ffffffffffff80000000p+1020 instead. Consequently I chose not to include a and A conversions in testing at this time. And last but not least there are numerous corner cases that GNU AWK does not handle correctly, which are worked around by explicit handling in the AWK script. These are in particular: - extraneous leading 0 produced for the alternative form with the o conversion, e.g. { printf "%#.2o", 1 } produces "001" rather than "01", - unexpected 0 produced where no characters are expected for the input of 0 and the alternative form with the precision of 0 and the integer hexadecimal conversions, e.g. { printf "%#.x", 0 } produces "0" rather than "", - missing + character in the non-bignum mode only for the input of 0 with the + flag, precision of 0 and the signed integer conversions, e.g. { printf "%+.i", 0 } produces "" rather than "+", - missing space character in the non-bignum mode only for the input of 0 with the space flag, precision of 0 and the signed integer conversions, e.g. { printf "% .i", 0 } produces "" rather than " ", - for released gawk versions of up to 4.2.1 missing - character for the input of -NaN with the floating-point conversions, e.g. { printf "%e", "-nan" }' produces "nan" rather than "-nan", - for released gawk versions from 5.0.0 onwards + character output for the input of -NaN with the floating-point conversions, e.g. { printf "%e", "-nan" }' produces "+nan" rather than "-nan", - for released gawk versions from 5.0.0 onwards + character output for the input of Inf or NaN in the absence of the + or space flags with the floating-point conversions, e.g. { printf "%e", "inf" }' produces "+inf" rather than "inf", - for released gawk versions of up to 4.2.1 missing + character for the input of Inf or NaN with the + flag and the floating-point conversions, e.g. { printf "%+e", "inf" }' produces "inf" rather than "+inf", - for released gawk versions of up to 4.2.1 missing space character for the input of Inf or NaN with the space flag and the floating-point conversions, e.g. { printf "% e", "nan" }' produces "nan" rather than " nan", - for released gawk versions from 5.0.0 onwards + character output for the input of Inf or NaN with the space flag and the floating-point conversions, e.g. { printf "% e", "inf" }' produces "+inf" rather than " inf", - for released gawk versions from 5.0.0 onwards the field width is ignored for the input of Inf or NaN and the floating-point conversions, e.g. { printf "%20e", "-inf" }' produces "-inf" rather than " -inf", NB for released gawk versions of up to 4.2.1 floating-point conversion issues apply to the bignum mode only, as in the non-bignum mode system sprintf(3) is used. As from version 5.0.0 specialized handling has been added for [-]Inf and [-]NaN inputs and the issues listed apply to both modes. The '--posix' flag makes gawk versions from 5.0.0 onwards avoid the issue with field width and the + character unconditionally output for the input of Inf or NaN, however not the remaining issues and then the 'gensub' function is not supported in the POSIX mode, so to go this path I deemed not worth it. Each test completes within single seconds except for the long double one. There the F/f formats produce a large number of digits, which appears to be computationally intensive and CPU-bound. Standalone execution time for 'tst-printf-format-p-ldouble --direct f' is in the range of 00m36s for POWER9@2.166GHz and 09m52s for FU740@1.2GHz and output redirected locally to /dev/null, and 10m11s for FU740 and output redirected over 100Mbps network via SSH to /dev/null, so the throughput of the network adds very little (~3.2% in this case) to the processing time. This is with IEEE 754 quad. So I have scaled the timeout for 'tst-printf-format-skeleton-ldouble' accordingly. Regardless, following recent practice the test has been added to the standard rather than extended set. However, unlike most of the remaining tests it has been split by the conversion specifier, so as to allow better parallelization of this long-running test. As a side effect this lets the test report the unsupported status for the F/f conversions where applicable, so 'tst-printf-format-p-double' has been split for consistency as well. Only printf itself is handled at the moment, but the infrastructure provides for all the printf family functions to be verified, changes for which to be supplied separately. The complication around having some tests iterating over all the relevant conversion specifiers and other verifying conversion specifiers individually combined with iterating over printf family functions has hit a peculiarity in GNU make where the use of multiple targets with a pattern rule is handled differently from such use with an ordinary rule. Consequently it seems impossible to bulk-define a pattern rule using '$(foreach ...)', where each target would simply trigger the recipe according to the pattern and matching dependencies individually (such a rule does work, but implies all targets to be updated with a single recipe execution). Therefore as a compromise a single single-target pattern rule has been defined that has listed all the conversion-specific scripts and all the test executables as dependencies. Consequently tests will be rerun in the absence of changes to their actual sources or scripts whenever an unrelated file has changed that has been listed. Also all the formatted printf output tests will always be built whenever any single one is to be run. This only affects test development and not test runs in the field, though it does change the order of execution of the individual steps and also acts as a Makefile barrier in parallel runs. As the execution time dominates the compilation time for these tests it is not seen as a serious shortcoming. As pointed out by Florian Weimer <fweimer@redhat.com> the malloc tracing facility can take a substantial amount of time in calling dladdr(3) to determine the caller's location. This is not needed by the verification made with these tests, so I chose to interpose the symbol with a stub implementation that always fails in the shared skeleton. We have total control over the test environment, so I think it is a safe and minimal impact approach. If there's ever anything else added to the tests that would actually rely on dladdr(3) returning usable results, only then we can think of a different approach. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-10-25stdio-common: Fix scanf parsing for NaN types [BZ #30647]Avinal Kumar1-0/+1
The scanf family of functions like sscanf and fscanf currently ignore nan() and nan(n-char-sequence). This happens because __vfscanf_internal only checks for 'nan'. This commit adds support for all valid nan types i.e. nan, nan() and nan(n-char-sequence), where n-char-sequence can be [a-zA-Z0-9_]+, thus fixing the bug 30647. Any other representation of NaN should result in conversion error. New tests are also added to verify the correct parsing of NaN types for float, double and long double formats. Signed-off-by: Avinal Kumar <avinal.xlvii@gmail.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2024-10-08stdio-common/Makefile: Fix FAIL: lint-makefilesH.J. Lu1-1/+1
Fix stdio-common/Makefile: @@ -224,12 +224,12 @@ tst-freopen4 \ tst-freopen5 \ tst-freopen6 \ + tst-freopen7 \ tst-freopen64-2 \ tst-freopen64-3 \ tst-freopen64-4 \ tst-freopen64-6 \ tst-freopen64-7 \ - tst-freopen7 \ tst-fseek \ tst-fwrite \ tst-fwrite-memstrm \ Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
2024-10-07Add freopen special-case tests: thread cancellationJoseph Myers1-0/+5
Add tests of freopen adding or removing "c" (non-cancelling I/O) from the mode string (so completing my planned tests of freopen with different features used in the mode strings). Note that it's in the nature of the uncertain time at which cancellation might act (possibly during freopen, possibly during subsequent reads) that these can leak memory or file descriptors, so these do not include leak tests. Tested for x86_64.
2024-10-01Do not use -Wp to disable fortify (BZ 31928)Adhemerval Zanella1-1/+1
The -Wp does not work properly if the compiler is configured to enable fortify by default, since it bypasses the compiler driver (which defines the fortify flags in this case). This patch is similar to the one used on Ubuntu [1]. I checked with a build for x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, s390x-linux-gnu, and riscv64-linux-gnu with gcc-13 that enables the fortify by default. Co-authored-by: Matthias Klose <matthias.klose@canonical.com> [1] https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/glibc/tree/debian/patches/ubuntu/fix-fortify-source.patch Reviewed-by: DJ Delorie <dj@redhat.com>
2024-09-30Add a new fwrite test that exercises buffer overflowTulio Magno Quites Machado Filho1-0/+1
Exercises fwrite's internal buffer when doing a file operation. The new test, exercises 2 overflow behaviors: 1. Call fwrite multiple times making usage of fwrite's internal buffer. The total number of bytes written is larger than fwrite's internal buffer, forcing an automatic flush. 2. Call fwrite a single time with an amount of data that is larger than fwrite's internal buffer. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-09-26stdio-common: Add new test for fdopenSergey Kolosov1-0/+1
This commit adds fdopen test with all modes. Reviewed-by: DJ Delorie <dj@redhat.com>
2024-09-24Add tests of freadJoseph Myers1-0/+1
There seem to be no glibc tests specifically for the fread function. Add basic tests of that function. Tested for x86_64.
2024-09-20Add freopen special-case tests: chroot, EFBIG, stdin/stdout/stderrJoseph Myers1-0/+35
Add tests of special cases for freopen that were omitted from the more general tests of different modes and similar issues. The special cases in the three tests here are logically unconnected, it was simply convenient to put these tests in one patch. * Test freopen with a NULL path to the new file, in a chroot. Rather than asserting that this fails (logically, failure in this case is an implementation detail; it's not required for freopen to rely on /proc), verify that either it fails (without memory leaks) or that it succeeds and behaves as expected on success. There is no check for file descriptor leaks because the machinery for that also depends on /proc, so can't be used in a chroot. * Test that freopen and freopen64 are genuinely different in configurations with 32-bit off_t by checking for an EFBIG trying to write past 2GB in a file opened with freopen in such a configuration but no error with 64-bit off_t or when opening with freopen64. * Test freopen of stdin, stdout and stderr. Tested for x86_64 and x86.
2024-09-09Add a new fwrite test for memory streamsTulio Magno Quites Machado Filho1-0/+1
Ensure that fwrite() behaves correctly when using memory streams. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-09-09Add a new fwrite test for read-only streamsTulio Magno Quites Machado Filho1-0/+1
Ensure that fwrite() behaves correctly even when the stream is read-only. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-09-05Fix memory leak on freopen error return (bug 32140)Joseph Myers1-0/+12
As reported in bug 32140, freopen leaks the FILE object when it returns NULL: there is no valid use of the FILE * pointer (including passing to freopen again or to fclose) after such an error return, so the underlying object should be freed. Add code to free it. Note 1: while I think it's clear from the relevant standards that the object should be freed and the FILE * can't be used after the call in this case (the stream is closed, which ends the lifetime of the FILE), it's entirely possible that some existing code does in fact try to use the existing FILE * in some way and could be broken by this change. (Though the most common case for freopen may be stdin / stdout / stderr, which _IO_deallocate_file explicitly checks for and does not deallocate.) Note 2: the deallocation is only done in the _IO_IS_FILEBUF case. Other kinds of streams bypass all the freopen logic handling closing the file, meaning a call to _IO_deallocate_file would neither be safe (the FILE might still be linked into the list of all open FILEs) nor sufficient (other internal memory allocations associated with the file would not have been freed). I think the validity of freopen for any other kind of stream will need clarifying with the Austin Group, but if it is valid in any such case (where "valid" means "not undefined behavior so required to close the stream" rather than "required to successfully associate the stream with the new file in cases where fopen would work"), more significant changes would be needed to ensure the stream gets fully closed. Tested for x86_64.
2024-09-04fgets: more testsDJ Delorie1-0/+1
Add more tests for unusual situations fgets() might see: * zero size file * zero sized buffer * NULL buffer * NUL data * writable stream * closed stream Reviewed-by: Florian Weimer <fweimer@redhat.com>
2024-09-04Add more thorough tests of freopenJoseph Myers1-0/+16
freopen is rather minimally tested in libio/tst-freopen and libio/test-freopen. Add some more thorough tests, covering different cases for change of mode in particular. The tests are run for both freopen and freopen64 (given that those functions have two separate copies of much of the code, so any bug fix directly in the freopen code would probably need applying in both places). Note that there are two parts of the tests disabled because of bugs discovered through running the tests, with bug numbers given in comments. I expect to address those separately. The tests also don't cover changes to cancellation ("c" in mode); I think that will better be handled through a separate test. Also to handle separately: testing on stdin / stdout / stderr; documenting lack of support for streams opened with popen / fmemopen / open_memstream / fopencookie; maybe also a chroot test without /proc; maybe also more thorough tests for large file handling on 32-bit systems (freopen64). Tested for x86_64.
2024-08-21Add more tests of getlineJoseph Myers1-0/+14
There is very little test coverage for getline (only a minimal stdio-common/tstgetln.c which doesn't verify anything about the results of the getline calls). Add some more thorough tests (generally using fopencookie for convenience in testing various cases for what the input and possible errors / EOF in the file read might look like). Note the following regarding testing of error cases: * Nothing is said in the specifications about what if anything might be written into the buffer, and whether it might be reallocated, in error cases. The expectation of the tests (required to avoid memory leaks on error) is that at least on error cases, the invariant that lineptr points to at least n bytes is maintained. * The optional EOVERFLOW error case specified in POSIX, "The number of bytes to be written into the buffer, including the delimiter character (if encountered), would exceed {SSIZE_MAX}.", doesn't seem practically testable, as any case reading so many characters (half the address space) would also be liable to run into allocation failure along (ENOMEM) the way. * If a read error occurs part way through reading an input line, it seems unclear whether a partial line should be returned by getline (avoid input getting lost), which is what glibc does at least in the fopencookie case used in this test, or whether getline should return -1 (error) (so avoiding the program misbehaving by processing a truncated line as if it were complete). (There was a short, inconclusive discussion about this on the Austin Group list on 9-10 November 2014.) * The POSIX specification of getline inherits errors from fgetc. I didn't try to cover fgetc errors systematically, just one example of such an error. Tested for x86_64 and x86.
2024-08-15ungetc: Fix backup buffer leak on program exit [BZ #27821]Siddhesh Poyarekar1-0/+7
If a file descriptor is left unclosed and is cleaned up by _IO_cleanup on exit, its backup buffer remains unfreed, registering as a leak in valgrind. This is not strictly an issue since (1) the program should ideally be closing the stream once it's not in use and (2) the program is about to exit anyway, so keeping the backup buffer around a wee bit longer isn't a real problem. Free it anyway to keep valgrind happy when the streams in question are the standard ones, i.e. stdout, stdin or stderr. Also, the _IO_have_backup macro checks for _IO_save_base, which is a roundabout way to check for a backup buffer instead of directly looking for _IO_backup_base. The roundabout check breaks when the main get area has not been used and user pushes a char into the backup buffer with ungetc. Fix this to use the _IO_backup_base directly. Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2024-07-26stdio-common: Add test for v