process_buffer_measurement(9)

💅 process_buffer_measurement(9) 💅

okay so bestie, welcome to the Kernel API Manual — yes, that's the manual name, we're in the kernel API girlies now 🎀. This one's about process_buffer_measurement, and no cap, it's a whole vibe: it measures the buffer or the buffer data hash. Let me walk you through it 🫶

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✨ NAME ✨

process_buffer_measurement — literally measures the buffer or the buffer data hash. that's the whole job. iconic. 👑

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🌸 SYNOPSIS 🌸

int process_buffer_measurement (struct mnt_idmap *idmap , struct inode
*inode , const void *buf , int size , const char *eventname , enum
ima_hooks func , int pcr , const char *func_data , bool buf_hash , u8
*digest , size_t digest_len );

look at all those parameters. she's got range 💅

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🦋 ARGUMENTS 🦋

• idmap — the idmap of the mount the inode was found from. like, the mapping context, iykyk.
• inode — the inode associated with the object being measured. heads up: this is NULL for KEY_CHECK. not me warning you about the NULL case 😭
• buf — pointer to the buffer that needs to be added to the log. the actual data bestie.
• size — size of the buffer, in bytes. keep it in bytes fr fr.
• eventname — the event name to be used for the buffer entry. name her, she deserves it ✨
• func — the IMA hook. this is an enum ima_hooks, very official.
• pcr — the pcr to extend the measurement into.
• func_data — func-specific data. she may be NULL, that's totally fine, we don't judge 🫶
• buf_hash — measure the buffer data hash. your bool era.
• digest — the buffer digest will be written to here. destination unlocked 💖
• digest_len — buffer length. the length. of the buffer. 💀

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💜 DESCRIPTION 💜

so here's the tea: based on policy, either the buffer data or the buffer data hash is measured. that's it. policy decides, not you. main character energy belongs to the policy 🧚

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⭐ RETURN ⭐

• 0 — the buffer has been successfully measured. slay! 🎉
• 1 — the digest has been written to the passed location, but it was not added to a measurement entry. like, partial credit 💅
• negative value — something went wrong otherwise. we don't love that for us 🙈

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🌈 SEE ALSO 🌈

kernel file ./security/integrity/ima/ima_main.c, plus the whole friend group:

• ima_file_free(9)
• ima_file_mmap(9)
• ima_file_mprotect(9)
• ima_bprm_check(9)
• ima_creds_check(9)
• ima_bprm_creds_for_exec(9)
• ima_file_check(9)
• ima_file_hash(9)
• ima_inode_hash(9)
• ima_post_create_tmpfile(9)
• ima_post_path_mknod(9)
• ima_read_file(9)
• ima_post_read_file(9)
• ima_load_data(9)
• ima_post_load_data(9)
• ima_kexec_cmdline(9)
• ima_measure_critical_data(9)
• ima_measure_raw_policy(9)
• ima_kernel_module_request(9)

they all live at ./security/integrity/ima, a very exclusive address 🏠✨

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lowkey reminder: inode can be NULL for KEY_CHECK, and func_data may be NULL too — handle them with care bestie, no crash era allowed 💀

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and that's the page! brought to you by ./security/integrity/ima, dated October 2026 — mwah, love u, go measure some buffers 💋💖🦋