From 955426ef79ae635b74ff917c2b9ebc1a24c6a3ef Mon Sep 17 00:00:00 2001 From: Elliott Hughes Date: Tue, 26 Jan 2016 18:25:52 -0800 Subject: Fix a sign extension bug in stdio. This also lets us test the EOVERFLOW behavior, which pointed out that the fgetpos/fsetpos return on failure has always been wrong... Bug: http://b/24807045 Change-Id: I35273eb07c8c9155af858adb27569983397580b6 --- libc/stdio/stdio.cpp | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'libc/stdio/stdio.cpp') diff --git a/libc/stdio/stdio.cpp b/libc/stdio/stdio.cpp index 2139621cc..16cbd555c 100644 --- a/libc/stdio/stdio.cpp +++ b/libc/stdio/stdio.cpp @@ -426,7 +426,12 @@ static off64_t __seek_unlocked(FILE* fp, off64_t offset, int whence) { if (_EXT(fp)->_seek64 != nullptr) { return (*_EXT(fp)->_seek64)(fp->_cookie, offset, whence); } else if (fp->_seek != nullptr) { - return (*fp->_seek)(fp->_cookie, offset, whence); + off64_t result = (*fp->_seek)(fp->_cookie, offset, whence); +#if !defined(__LP64__) + // Avoid sign extension if off64_t is larger than off_t. + if (result != -1) result &= 0xffffffff; +#endif + return result; } else { errno = ESPIPE; return -1; @@ -531,12 +536,12 @@ off64_t ftello64(FILE* fp) { int fgetpos(FILE* fp, fpos_t* pos) { *pos = ftello(fp); - return (*pos == -1); + return (*pos == -1) ? -1 : 0; } int fgetpos64(FILE* fp, fpos64_t* pos) { *pos = ftello64(fp); - return (*pos == -1); + return (*pos == -1) ? -1 : 0; } static FILE* __funopen(const void* cookie, -- cgit v1.2.3