Commit c1b530e7 authored by Baokun Li's avatar Baokun Li Committed by Yifan Qiao
Browse files

ext4: refactor out ext4_generic_attr_show() 

mainline inclusion
from mainline-v6.10-rc1
commit 57341fe3179c7694c92dcf99e7f836cee4c800dd
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAD018
CVE: CVE-2024-40955

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=57341fe3179c7694c92dcf99e7f836cee4c800dd



--------------------------------

Refactor out the function ext4_generic_attr_show() to handle the reading
of values of various common types, with no functional changes.

Signed-off-by: default avatarBaokun Li <libaokun1@huawei.com>
Reviewed-by: default avatarZhang Yi <yi.zhang@huawei.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240319113325.3110393-4-libaokun1@huawei.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Signed-off-by: default avatarYifan Qiao <qiaoyifan4@huawei.com>
parent 0660f2c7

fs/ext4/sysfs.c

+32 −42
Original line number Diff line number Diff line
@@ -366,13 +366,42 @@ static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi) 
#define print_tstamp(buf, es, tstamp) \

	__print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi)



static ssize_t ext4_generic_attr_show(struct ext4_attr *a,

				      struct ext4_sb_info *sbi, char *buf)

{

	void *ptr = calc_ptr(a, sbi);



	if (!ptr)

		return 0;



	switch (a->attr_id) {

	case attr_inode_readahead:

	case attr_pointer_ui:

		if (a->attr_ptr == ptr_ext4_super_block_offset)

			return sysfs_emit(buf, "%u\n", le32_to_cpup(ptr));

		return sysfs_emit(buf, "%u\n", *((unsigned int *) ptr));

	case attr_pointer_ul:

		return sysfs_emit(buf, "%lu\n", *((unsigned long *) ptr));

	case attr_pointer_u8:

		return sysfs_emit(buf, "%u\n", *((unsigned char *) ptr));

	case attr_pointer_u64:

		if (a->attr_ptr == ptr_ext4_super_block_offset)

			return sysfs_emit(buf, "%llu\n", le64_to_cpup(ptr));

		return sysfs_emit(buf, "%llu\n", *((unsigned long long *) ptr));

	case attr_pointer_string:

		return sysfs_emit(buf, "%.*s\n", a->attr_size, (char *) ptr);

	case attr_pointer_atomic:

		return sysfs_emit(buf, "%d\n", atomic_read((atomic_t *) ptr));

	}

	return 0;

}



static ssize_t ext4_attr_show(struct kobject *kobj,

			      struct attribute *attr, char *buf)

{

	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,

						s_kobj);

	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);

	void *ptr = calc_ptr(a, sbi);



	switch (a->attr_id) {

	case attr_delayed_allocation_blocks:
@@ -391,45 +420,6 @@ static ssize_t ext4_attr_show(struct kobject *kobj, 
		return sysfs_emit(buf, "%llu\n",

				(unsigned long long)

			percpu_counter_sum(&sbi->s_sra_exceeded_retry_limit));

	case attr_inode_readahead:

	case attr_pointer_ui:

		if (!ptr)

			return 0;

		if (a->attr_ptr == ptr_ext4_super_block_offset)

			return sysfs_emit(buf, "%u\n",

					le32_to_cpup(ptr));

		else

			return sysfs_emit(buf, "%u\n",

					*((unsigned int *) ptr));

	case attr_pointer_ul:

		if (!ptr)

			return 0;

		return sysfs_emit(buf, "%lu\n",

				*((unsigned long *) ptr));

	case attr_pointer_u8:

		if (!ptr)

			return 0;

		return sysfs_emit(buf, "%u\n",

				*((unsigned char *) ptr));

	case attr_pointer_u64:

		if (!ptr)

			return 0;

		if (a->attr_ptr == ptr_ext4_super_block_offset)

			return sysfs_emit(buf, "%llu\n",

					le64_to_cpup(ptr));

		else

			return sysfs_emit(buf, "%llu\n",

					*((unsigned long long *) ptr));

	case attr_pointer_string:

		if (!ptr)

			return 0;

		return sysfs_emit(buf, "%.*s\n", a->attr_size,

				(char *) ptr);

	case attr_pointer_atomic:

		if (!ptr)

			return 0;

		return sysfs_emit(buf, "%d\n",

				atomic_read((atomic_t *) ptr));

	case attr_feature:

		return sysfs_emit(buf, "supported\n");

	case attr_first_error_time:
@@ -438,9 +428,9 @@ static ssize_t ext4_attr_show(struct kobject *kobj, 
		return print_tstamp(buf, sbi->s_es, s_last_error_time);

	case attr_journal_task:

		return journal_task_show(sbi, buf);

	default:

		return ext4_generic_attr_show(a, sbi, buf);

	}



	return 0;

}



static ssize_t ext4_generic_attr_store(struct ext4_attr *a,