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/limits.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/limits.h') diff --git a/include/linux/limits.h b/include/linux/limits.h index b568b9c30bbf..f6bcc9369010 100644 --- a/include/linux/limits.h +++ b/include/linux/limits.h @@ -7,6 +7,7 @@ #include #define SIZE_MAX (~(size_t)0) +#define SSIZE_MAX ((ssize_t)(SIZE_MAX >> 1)) #define PHYS_ADDR_MAX (~(phys_addr_t)0) #define U8_MAX ((u8)~0U) -- cgit v1.2.3-59-g8ed1b