[PATCH] fdtable: Delete pointless code in dup_fd() (f3d19c90) · Commits · 戴 / test

The dup_fd() function creates a new files_struct and fdtable embedded inside that files_struct, and then possibly expands the fdtable using expand_files(). The out_release error path is invoked when expand_files() returns an error code. However, when this attempt to expand fails, the fdtable is left in its original embedded form, so it is pointless to try to free the associated fdarray and fdsets. Signed-off-by:

Vadim Lobanov <vlobanov@speakeasy.net> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

kernel/fork.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -711,8 +711,10 @@ static struct files_struct dup_fd(struct files_struct oldf, int *errorp)
		old_fds = old_fdt->fd;
		new_fds = new_fdt->fd;

		memcpy(new_fdt->open_fds->fds_bits, old_fdt->open_fds->fds_bits, open_files/8);
		memcpy(new_fdt->close_on_exec->fds_bits, old_fdt->close_on_exec->fds_bits, open_files/8);
		memcpy(new_fdt->open_fds->fds_bits,
		old_fdt->open_fds->fds_bits, open_files/8);
		memcpy(new_fdt->close_on_exec->fds_bits,
		old_fdt->close_on_exec->fds_bits, open_files/8);

		for (i = open_files; i != 0; i--) {
		struct file f = old_fds++;
		@@ -745,14 +747,11 @@ static struct files_struct dup_fd(struct files_struct oldf, int *errorp)
		memset(&new_fdt->close_on_exec->fds_bits[start], 0, left);
		}

		out:
		return newf;

		out_release:
		free_fdset (new_fdt->close_on_exec, new_fdt->max_fdset);
		free_fdset (new_fdt->open_fds, new_fdt->max_fdset);
		free_fd_array(new_fdt->fd, new_fdt->max_fds);
		kmem_cache_free(files_cachep, newf);
		out:
		return NULL;
		}

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