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1b29f8bdf7
commit6ae0806993upstream. pipe_write() would return 0 if it failed to merge the beginning of the data to write with the last, partially filled pipe buffer. It should return an error code instead. Userspace programs could be confused by write() returning 0 when called with a nonzero 'count'. The EFAULT error case was a regression fromf0d1bec9d5("new helper: copy_page_from_iter()"), while the ops->confirm() error case was a much older bug. Test program: #include <assert.h> #include <errno.h> #include <unistd.h> int main(void) { int fd[2]; char data[1] = {0}; assert(0 == pipe(fd)); assert(1 == write(fd[1], data, 1)); /* prior to this patch, write() returned 0 here */ assert(-1 == write(fd[1], NULL, 1)); assert(errno == EFAULT); } Signed-off-by: Eric Biggers <ebiggers3@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
1127 lines
25 KiB
1127 lines
25 KiB