From: Pasha Tatashin <pasha.tatashin@soleen.com>
To: kexec@lists.infradead.org
Subject: [PATCH v2 1/2] fs/kernel_read_file: Allow to read files up-to ssize_t
Date: Fri, 27 May 2022 02:55:34 +0000 [thread overview]
Message-ID: <20220527025535.3953665-2-pasha.tatashin@soleen.com> (raw)
In-Reply-To: <20220527025535.3953665-1-pasha.tatashin@soleen.com>
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.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
---
fs/kernel_read_file.c | 38 ++++++++++++++++----------------
include/linux/kernel_read_file.h | 32 +++++++++++++--------------
include/linux/limits.h | 1 +
3 files changed, 36 insertions(+), 35 deletions(-)
diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c
index 1b07550485b9..5d826274570c 100644
--- a/fs/kernel_read_file.c
+++ b/fs/kernel_read_file.c
@@ -29,15 +29,15 @@
* change between calls to kernel_read_file().
*
* Returns number of bytes read (no single read will be bigger
- * than INT_MAX), or negative on error.
+ * than SSIZE_MAX), or negative on error.
*
*/
-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)
+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)
{
loff_t i_size, pos;
- size_t copied;
+ ssize_t copied;
void *allocated = NULL;
bool whole_file;
int ret;
@@ -58,7 +58,7 @@ int kernel_read_file(struct file *file, loff_t offset, void **buf,
goto out;
}
/* The file is too big for sane activities. */
- if (i_size > INT_MAX) {
+ if (i_size > SSIZE_MAX) {
ret = -EFBIG;
goto out;
}
@@ -124,12 +124,12 @@ int kernel_read_file(struct file *file, loff_t offset, void **buf,
}
EXPORT_SYMBOL_GPL(kernel_read_file);
-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)
+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)
{
struct file *file;
- int ret;
+ ssize_t ret;
if (!path || !*path)
return -EINVAL;
@@ -144,14 +144,14 @@ int kernel_read_file_from_path(const char *path, loff_t offset, void **buf,
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
-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)
+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)
{
struct file *file;
struct path root;
- int ret;
+ ssize_t ret;
if (!path || !*path)
return -EINVAL;
@@ -171,12 +171,12 @@ int kernel_read_file_from_path_initns(const char *path, loff_t offset,
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);
-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_from_fd(int fd, loff_t offset, void **buf,
+ size_t buf_size, size_t *file_size,
+ enum kernel_read_file_id id)
{
struct fd f = fdget(fd);
- int ret = -EBADF;
+ ssize_t ret = -EBADF;
if (!f.file || !(f.file->f_mode & FMODE_READ))
goto out;
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 */
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 <vdso/limits.h>
#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)
--
2.36.1.124.g0e6072fb45-goog
next prev parent reply other threads:[~2022-05-27 2:55 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-27 2:55 [PATCH v2 0/2] Allow to kexec with initramfs larger than 2G Pasha Tatashin
2022-05-27 2:55 ` Pasha Tatashin [this message]
2022-06-06 2:45 ` [PATCH v2 1/2] fs/kernel_read_file: Allow to read files up-to ssize_t Baoquan He
2022-06-07 15:52 ` Pasha Tatashin
2022-06-08 0:57 ` Baoquan He
2022-06-08 0:58 ` Baoquan He
2022-05-27 2:55 ` [PATCH v2 2/2] kexec_file: Increase maximum file size to 4G Pasha Tatashin
2022-06-06 2:56 ` Baoquan He
2022-06-07 16:02 ` Pasha Tatashin
2022-06-08 0:28 ` Baoquan He
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