From dabba87229411a5e9d20ac03ffc36463c53ae672 Mon Sep 17 00:00:00 2001 From: Pasha Tatashin Date: Fri, 27 May 2022 02:55:34 +0000 Subject: fs/kernel_read_file: allow to read files up-to ssize_t Patch series "Allow to kexec with initramfs larger than 2G", v2. Currently, the largest initramfs that is supported by kexec_file_load() syscall is 2G. This is because kernel_read_file() returns int, and is limited to INT_MAX or 2G. On the other hand, there are kexec based boot loaders (i.e. u-root), that may need to boot netboot images that might be larger than 2G. The first patch changes the return type from int to ssize_t in kernel_read_file* functions. The second patch increases the maximum initramfs file size to 4G. Tested: verified that can kexec_file_load() works with 4G initramfs on x86_64. This patch (of 2): Currently, the maximum file size that is supported is 2G. This may be too small in some cases. For example, kexec_file_load() system call loads initramfs. In some netboot cases initramfs can be rather large. Allow to use up-to ssize_t bytes. The callers still can limit the maximum file size via buf_size. Link: https://lkml.kernel.org/r/20220527025535.3953665-1-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20220527025535.3953665-2-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Cc: Al Viro Cc: Baoquan He Cc: "Eric W. Biederman" Cc: Greg Thelen Cc: Sasha Levin Signed-off-by: Andrew Morton --- include/linux/kernel_read_file.h | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) (limited to 'include/linux/kernel_read_file.h') diff --git a/include/linux/kernel_read_file.h b/include/linux/kernel_read_file.h index 575ffa1031d3..90451e2e12bd 100644 --- a/include/linux/kernel_read_file.h +++ b/include/linux/kernel_read_file.h @@ -35,21 +35,21 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id) return kernel_read_file_str[id]; } -int kernel_read_file(struct file *file, loff_t offset, - void **buf, size_t buf_size, - size_t *file_size, - enum kernel_read_file_id id); -int kernel_read_file_from_path(const char *path, loff_t offset, - void **buf, size_t buf_size, - size_t *file_size, - enum kernel_read_file_id id); -int kernel_read_file_from_path_initns(const char *path, loff_t offset, - void **buf, size_t buf_size, - size_t *file_size, - enum kernel_read_file_id id); -int kernel_read_file_from_fd(int fd, loff_t offset, - void **buf, size_t buf_size, - size_t *file_size, - enum kernel_read_file_id id); +ssize_t kernel_read_file(struct file *file, loff_t offset, + void **buf, size_t buf_size, + size_t *file_size, + enum kernel_read_file_id id); +ssize_t kernel_read_file_from_path(const char *path, loff_t offset, + void **buf, size_t buf_size, + size_t *file_size, + enum kernel_read_file_id id); +ssize_t kernel_read_file_from_path_initns(const char *path, loff_t offset, + void **buf, size_t buf_size, + size_t *file_size, + enum kernel_read_file_id id); +ssize_t kernel_read_file_from_fd(int fd, loff_t offset, + void **buf, size_t buf_size, + size_t *file_size, + enum kernel_read_file_id id); #endif /* _LINUX_KERNEL_READ_FILE_H */ -- cgit