Commit 18737353 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'edac_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras 

Pull EDAC fixes from Borislav Petkov:

 - Fix more issues in the AMD FMPM driver

* tag 'edac_urgent_for_v6.9_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  RAS: Avoid build errors when CONFIG_DEBUG_FS=n
  RAS/AMD/FMPM: Safely handle saved records of various sizes
  RAS/AMD/FMPM: Avoid NULL ptr deref in get_saved_records()
parents 5dad2623 a6b227d7

drivers/ras/amd/fmpm.c

+39 −18
Original line number Diff line number Diff line
@@ -150,6 +150,8 @@ static unsigned int max_nr_fru; 
/* Total length of record including headers and list of descriptor entries. */

static size_t max_rec_len;



#define FMPM_MAX_REC_LEN (sizeof(struct fru_rec) + (sizeof(struct cper_fru_poison_desc) * 255))



/* Total number of SPA entries across all FRUs. */

static unsigned int spa_nr_entries;
@@ -475,6 +477,16 @@ static void set_rec_fields(struct fru_rec *rec) 
	struct cper_section_descriptor	*sec_desc = &rec->sec_desc;

	struct cper_record_header	*hdr	  = &rec->hdr;



	/*

	 * This is a saved record created with fewer max_nr_entries.

	 * Update the record lengths and keep everything else as-is.

	 */

	if (hdr->record_length && hdr->record_length < max_rec_len) {

		pr_debug("Growing record 0x%016llx from %u to %zu bytes\n",

			 hdr->record_id, hdr->record_length, max_rec_len);

		goto update_lengths;

	}



	memcpy(hdr->signature, CPER_SIG_RECORD, CPER_SIG_SIZE);

	hdr->revision			= CPER_RECORD_REV;

	hdr->signature_end		= CPER_SIG_END;
@@ -489,19 +501,21 @@ static void set_rec_fields(struct fru_rec *rec) 
	hdr->error_severity		= CPER_SEV_RECOVERABLE;



	hdr->validation_bits		= 0;

	hdr->record_length		= max_rec_len;

	hdr->creator_id			= CPER_CREATOR_FMP;

	hdr->notification_type		= CPER_NOTIFY_MCE;

	hdr->record_id			= cper_next_record_id();

	hdr->flags			= CPER_HW_ERROR_FLAGS_PREVERR;



	sec_desc->section_offset	= sizeof(struct cper_record_header);

	sec_desc->section_length	= max_rec_len - sizeof(struct cper_record_header);

	sec_desc->revision		= CPER_SEC_REV;

	sec_desc->validation_bits	= 0;

	sec_desc->flags			= CPER_SEC_PRIMARY;

	sec_desc->section_type		= CPER_SECTION_TYPE_FMP;

	sec_desc->section_severity	= CPER_SEV_RECOVERABLE;



update_lengths:

	hdr->record_length		= max_rec_len;

	sec_desc->section_length	= max_rec_len - sizeof(struct cper_record_header);

}



static int save_new_records(void)
@@ -512,16 +526,18 @@ static int save_new_records(void) 
	int ret = 0;



	for_each_fru(i, rec) {

		if (rec->hdr.record_length)

		/* No need to update saved records that match the current record size. */

		if (rec->hdr.record_length == max_rec_len)

			continue;



		if (!rec->hdr.record_length)

			set_bit(i, new_records);



		set_rec_fields(rec);



		ret = update_record_on_storage(rec);

		if (ret)

			goto out_clear;



		set_bit(i, new_records);

	}



	return ret;
@@ -641,12 +657,7 @@ static int get_saved_records(void) 
	int ret, pos;

	ssize_t len;



	/*

	 * Assume saved records match current max size.

	 *

	 * However, this may not be true depending on module parameters.

	 */

	old = kmalloc(max_rec_len, GFP_KERNEL);

	old = kmalloc(FMPM_MAX_REC_LEN, GFP_KERNEL);

	if (!old) {

		ret = -ENOMEM;

		goto out;
@@ -663,21 +674,31 @@ static int get_saved_records(void) 
		 * Make sure to clear temporary buffer between reads to avoid

		 * leftover data from records of various sizes.

		 */

		memset(old, 0, max_rec_len);

		memset(old, 0, FMPM_MAX_REC_LEN);



		len = erst_read_record(record_id, &old->hdr, max_rec_len,

		len = erst_read_record(record_id, &old->hdr, FMPM_MAX_REC_LEN,

				       sizeof(struct fru_rec), &CPER_CREATOR_FMP);

		if (len < 0)

			continue;



		if (len > max_rec_len) {

			pr_debug("Found record larger than max_rec_len\n");

		new = get_valid_record(old);

		if (!new) {

			erst_clear(record_id);

			continue;

		}



		new = get_valid_record(old);

		if (!new)

			erst_clear(record_id);

		if (len > max_rec_len) {

			unsigned int saved_nr_entries;



			saved_nr_entries  = len - sizeof(struct fru_rec);

			saved_nr_entries /= sizeof(struct cper_fru_poison_desc);



			pr_warn("Saved record found with %u entries.\n", saved_nr_entries);

			pr_warn("Please increase max_nr_entries to %u.\n", saved_nr_entries);



			ret = -EINVAL;

			goto out_end;

		}



		/* Restore the record */

		memcpy(new, old, len);

drivers/ras/debugfs.h

+4 −0
Original line number Diff line number Diff line
@@ -4,6 +4,10 @@ 


#include <linux/debugfs.h>



#if IS_ENABLED(CONFIG_DEBUG_FS)

struct dentry *ras_get_debugfs_root(void);

#else

static inline struct dentry *ras_get_debugfs_root(void) { return NULL; }

#endif /* DEBUG_FS */



#endif /* __RAS_DEBUGFS_H__ */