evm_read_protected_xattrs(9)

✨ evm_read_protected_xattrs ✨

okay so bestie, welcome to the evm_read_protected_xattrs(9) page from the Kernel API Manual 💖 this one's a little function in the EVM (Extended Verification Module) corner of the kernel, and honestly? it's giving "quietly doing important work" energy. let's get into it 🫶

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🌸 SYNOPSIS 🌸

int evm_read_protected_xattrs (struct dentry *dentry , u8 *buffer , int
buffer_size , char type , bool canonical_fmt );

that's the whole vibe — it hands you back an int, which (spoiler) is either the total size of the stuff it copied or a negative value if things went sideways 😭

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🎀 ARGUMENTS 🎀

• dentry — the dentry of the xattrs being read, like "which file are we even talking about" energy 💅
• buffer — the buffer where the xattr names, lengths or values get copied to. this is the destination, the main character of the copy operation ✨
• buffer_size — the size of that buffer, obviously. gotta know how much room we're working with 🎀
• type — a char that picks what you want, and the options are iconic:
  • n → names
  • l → lengths
  • v → values
• canonical_fmt — the data format, as a bool: true means little endian, false means native format. choose wisely 🦋

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💜 DESCRIPTION 💜

so what does it actually do? it reads the protected xattr names (separated by | — yes, that's a pipe character, not me being dramatic), the lengths (as u32), or the values, for a given dentry, and then returns the total size of the data it copied 💖

and here's the cute part: if buffer is NULL, it just returns the total size. no copying, no nothing, just a little "here's how much room you'd need" heads up. lowkey iconic of it, honestly 🧚

returns the total size on success, a negative value on error. that's it, that's the contract. no cap 💀

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🦋 SEE ALSO 🦋

the kernel file lives at ./security/integrity/evm/evm_main.c, and if you're the kind of bestie who likes to go down the rabbit hole, here's the whole friend group 👑

• evm_verifyxattr(9)
• evm_inode_setxattr(9)
• evm_inode_removexattr(9)
• evm_inode_set_acl(9)
• evm_inode_remove_acl(9)
• evm_metadata_changed(9)
• evm_revalidate_status(9)
• evm_fix_hmac(9)
• evm_inode_post_setxattr(9)
• evm_inode_post_set_acl(9)
• evm_inode_post_removexattr(9)
• evm_inode_post_remove_acl(9)
• evm_inode_setattr(9)
• evm_inode_post_setattr(9)

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okay that's the whole page, bestie, you ate that 🫶 this beauty comes to you from ./security/integrity/evm, dated October 2026, straight out of the Kernel API Manual 💅✨ periodt.