| Message ID | fa1f6a475bd87ff4615ad71c5253257c21cc0816.1707491940.git.fweimer@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | Build getdomainname, gethostname, syslog with fortification | expand |
On 09/02/24 12:25, Florian Weimer wrote: > Making the written field signed allows subtraction of a prefix count > in case multiple writes happen to the same buffer. LGTM, thanks. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> > --- > include/printf_buffer.h | 8 +++++--- > stdio-common/tst-printf_buffer.c | 18 ++++++++++++++++++ > 2 files changed, 23 insertions(+), 3 deletions(-) > > diff --git a/include/printf_buffer.h b/include/printf_buffer.h > index a5483e8a97..2400371b94 100644 > --- a/include/printf_buffer.h > +++ b/include/printf_buffer.h > @@ -92,8 +92,10 @@ struct __printf_buffer > buffer). Potentially updated on flush. The actual number of > written bytes also includes the unflushed-but-written buffer > part, write_ptr - write_base. A 64-bit value is used to avoid > - the need for overflow checks. */ > - uint64_t written; > + the need for intermediate overflow checks. Negative values can > + be used to ignore leading parts of the buffer for %n computations > + (for repeated __printf_buffer calls to the same buffer). */ > + int64_t written; > > /* Identifies the flush callback. */ > enum __printf_buffer_mode mode; > @@ -225,7 +227,7 @@ struct __wprintf_buffer > wchar_t *write_base; > wchar_t *write_ptr; > wchar_t *write_end; > - uint64_t written; > + int64_t written; > enum __wprintf_buffer_mode mode; > }; > > diff --git a/stdio-common/tst-printf_buffer.c b/stdio-common/tst-printf_buffer.c > index d12da8c939..2a3ee511d0 100644 > --- a/stdio-common/tst-printf_buffer.c > +++ b/stdio-common/tst-printf_buffer.c > @@ -132,6 +132,24 @@ do_test (void) > TEST_VERIFY (!__printf_buffer_has_failed (&buf.base)); > TEST_COMPARE (__printf_buffer_asprintf_free (&buf), -1); > } > + > + /* Test %n with initial skip. */ > + { > + struct __printf_buffer_asprintf buf; > + __printf_buffer_asprintf_init (&buf); > + __printf_buffer (&buf.base, "abc"); > + buf.base.written = -2; > + int n = -1; > + __printf_buffer (&buf.base, "D%nEF", &n); > + TEST_COMPARE (n, 2); /* Two characters were skipped. */ > + TEST_VERIFY (buf.base.write_base == buf.direct); > + TEST_COMPARE_BLOB (buf.base.write_base, > + buf.base.write_ptr - buf.base.write_base, "abcDEF", 6); > + TEST_VERIFY (!__printf_buffer_has_failed (&buf.base)); > + TEST_COMPARE (__printf_buffer_done (&buf.base), 4); /* Two skipped. */ > + TEST_COMPARE (__printf_buffer_asprintf_free (&buf), -1); > + } > + > return 0; > } >
diff --git a/include/printf_buffer.h b/include/printf_buffer.h index a5483e8a97..2400371b94 100644 --- a/include/printf_buffer.h +++ b/include/printf_buffer.h @@ -92,8 +92,10 @@ struct __printf_buffer buffer). Potentially updated on flush. The actual number of written bytes also includes the unflushed-but-written buffer part, write_ptr - write_base. A 64-bit value is used to avoid - the need for overflow checks. */ - uint64_t written; + the need for intermediate overflow checks. Negative values can + be used to ignore leading parts of the buffer for %n computations + (for repeated __printf_buffer calls to the same buffer). */ + int64_t written; /* Identifies the flush callback. */ enum __printf_buffer_mode mode; @@ -225,7 +227,7 @@ struct __wprintf_buffer wchar_t *write_base; wchar_t *write_ptr; wchar_t *write_end; - uint64_t written; + int64_t written; enum __wprintf_buffer_mode mode; }; diff --git a/stdio-common/tst-printf_buffer.c b/stdio-common/tst-printf_buffer.c index d12da8c939..2a3ee511d0 100644 --- a/stdio-common/tst-printf_buffer.c +++ b/stdio-common/tst-printf_buffer.c @@ -132,6 +132,24 @@ do_test (void) TEST_VERIFY (!__printf_buffer_has_failed (&buf.base)); TEST_COMPARE (__printf_buffer_asprintf_free (&buf), -1); } + + /* Test %n with initial skip. */ + { + struct __printf_buffer_asprintf buf; + __printf_buffer_asprintf_init (&buf); + __printf_buffer (&buf.base, "abc"); + buf.base.written = -2; + int n = -1; + __printf_buffer (&buf.base, "D%nEF", &n); + TEST_COMPARE (n, 2); /* Two characters were skipped. */ + TEST_VERIFY (buf.base.write_base == buf.direct); + TEST_COMPARE_BLOB (buf.base.write_base, + buf.base.write_ptr - buf.base.write_base, "abcDEF", 6); + TEST_VERIFY (!__printf_buffer_has_failed (&buf.base)); + TEST_COMPARE (__printf_buffer_done (&buf.base), 4); /* Two skipped. */ + TEST_COMPARE (__printf_buffer_asprintf_free (&buf), -1); + } + return 0; }