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authorLinus Torvalds <torvalds@linux-foundation.org>2024-03-31 11:15:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2024-03-31 11:15:32 -0700
commit18737353cca01db58bb62256338cbb820c310bd7 (patch)
treef5a972de403ed3b94a4629dd5994ea5b568e0dd4
parent5dad26235c4adde4199c7750c696fd729e5020ae (diff)
parenta6b227d70d2ad9eb08adc3fe532ebb7ec88ac897 (diff)
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()
-rw-r--r--drivers/ras/amd/fmpm.c57
-rw-r--r--drivers/ras/debugfs.h4
2 files changed, 43 insertions, 18 deletions
diff --git a/drivers/ras/amd/fmpm.c b/drivers/ras/amd/fmpm.c
index 2f4ac9591c8f..271dfad05d68 100644
--- a/drivers/ras/amd/fmpm.c
+++ b/drivers/ras/amd/fmpm.c
@@ -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);
diff --git a/drivers/ras/debugfs.h b/drivers/ras/debugfs.h
index 4749ccdeeba1..5a2f48439258 100644
--- a/drivers/ras/debugfs.h
+++ b/drivers/ras/debugfs.h
@@ -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__ */