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Message-ID: <20231206172844.1756871-1-jannh@google.com>
Date: Wed, 6 Dec 2023 18:28:44 +0100
From: Jann Horn <jannh@...gle.com>
To: Borislav Petkov <bp@...en8.de>
Cc: Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org
Subject: [PATCH] x86/microcode: Be more verbose, especially about loading errors
The AMD ucode loader contains several checks for corrupted ucode blobs that
only log with pr_debug(); make them pr_err(), corrupted ucode blobs are
bad.
Also make both microcode loaders a bit more verbose about whether they
found ucode blobs at all and whether they found ucode for the specific CPU.
Signed-off-by: Jann Horn <jannh@...gle.com>
---
compile-tested only since I don't have an easy setup for booting test
kernels on bare metal
arch/x86/kernel/cpu/microcode/amd.c | 34 +++++++++++++++++----------
arch/x86/kernel/cpu/microcode/intel.c | 24 ++++++++++++++++---
2 files changed, 42 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 13b45b9c806d..2312ddb031b5 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -136,13 +136,13 @@ static bool verify_container(const u8 *buf, size_t buf_size)
u32 cont_magic;
if (buf_size <= CONTAINER_HDR_SZ) {
- pr_debug("Truncated microcode container header.\n");
+ pr_err("Truncated microcode container header.\n");
return false;
}
cont_magic = *(const u32 *)buf;
if (cont_magic != UCODE_MAGIC) {
- pr_debug("Invalid magic value (0x%08x).\n", cont_magic);
+ pr_err("Invalid magic value (0x%08x).\n", cont_magic);
return false;
}
@@ -163,7 +163,7 @@ static bool verify_equivalence_table(const u8 *buf, size_t buf_size)
cont_type = hdr[1];
if (cont_type != UCODE_EQUIV_CPU_TABLE_TYPE) {
- pr_debug("Wrong microcode container equivalence table type: %u.\n",
+ pr_err("Wrong microcode container equivalence table type: %u.\n",
cont_type);
return false;
}
@@ -173,7 +173,7 @@ static bool verify_equivalence_table(const u8 *buf, size_t buf_size)
equiv_tbl_len = hdr[2];
if (equiv_tbl_len < sizeof(struct equiv_cpu_entry) ||
buf_size < equiv_tbl_len) {
- pr_debug("Truncated equivalence table.\n");
+ pr_err("Truncated equivalence table.\n");
return false;
}
@@ -194,7 +194,7 @@ __verify_patch_section(const u8 *buf, size_t buf_size, u32 *sh_psize)
const u32 *hdr;
if (buf_size < SECTION_HDR_SIZE) {
- pr_debug("Truncated patch section.\n");
+ pr_err("Truncated patch section.\n");
return false;
}
@@ -203,13 +203,13 @@ __verify_patch_section(const u8 *buf, size_t buf_size, u32 *sh_psize)
p_size = hdr[1];
if (p_type != UCODE_UCODE_TYPE) {
- pr_debug("Invalid type field (0x%x) in container file section header.\n",
+ pr_err("Invalid type field (0x%x) in container file section header.\n",
p_type);
return false;
}
if (p_size < sizeof(struct microcode_header_amd)) {
- pr_debug("Patch of size %u too short.\n", p_size);
+ pr_err("Patch of size %u too short.\n", p_size);
return false;
}
@@ -284,13 +284,13 @@ verify_patch(u8 family, const u8 *buf, size_t buf_size, u32 *patch_size)
* size sh_psize, as the section claims.
*/
if (buf_size < sh_psize) {
- pr_debug("Patch of size %u truncated.\n", sh_psize);
+ pr_err("Patch of size %u truncated.\n", sh_psize);
return -1;
}
ret = __verify_patch_size(family, sh_psize, buf_size);
if (!ret) {
- pr_debug("Per-family patch size mismatch.\n");
+ pr_err("Per-family patch size mismatch.\n");
return -1;
}
@@ -423,8 +423,10 @@ static int __apply_microcode_amd(struct microcode_amd *mc)
/* verify patch application was successful */
native_rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
- if (rev != mc->hdr.patch_id)
+ if (rev != mc->hdr.patch_id) {
+ pr_err("CPU did not accept microcode update!\n");
return -1;
+ }
return 0;
}
@@ -451,14 +453,18 @@ static bool early_apply_microcode(u32 cpuid_1_eax, u32 old_rev, void *ucode, siz
scan_containers(ucode, size, &desc);
mc = desc.mc;
- if (!mc)
+ if (!mc) {
+ pr_info("Found no patches for this CPU model in the microcode file\n");
return ret;
+ }
/*
* Allow application of the same revision to pick up SMT-specific
* changes even if the revision of the other SMT thread is already
* up-to-date.
*/
+ pr_info("CPU had microcode revision 0x%x, latest available patch is 0x%x\n",
+ old_rev, mc->hdr.patch_id);
if (old_rev > mc->hdr.patch_id)
return ret;
@@ -507,8 +513,10 @@ void __init load_ucode_amd_bsp(struct early_load_data *ed, unsigned int cpuid_1_
ucode_cpu_info[0].cpu_sig.sig = cpuid_1_eax;
find_blobs_in_containers(cpuid_1_eax, &cp);
- if (!(cp.data && cp.size))
+ if (!(cp.data && cp.size)) {
+ pr_info("Unable to find any microcode blob for early loading\n");
return;
+ }
if (early_apply_microcode(cpuid_1_eax, ed->old_rev, cp.data, cp.size))
native_rdmsr(MSR_AMD64_PATCH_LEVEL, ed->new_rev, dummy);
@@ -883,7 +891,7 @@ static enum ucode_state request_microcode_amd(int cpu, struct device *device)
snprintf(fw_name, sizeof(fw_name), "amd-ucode/microcode_amd_fam%.2xh.bin", c->x86);
if (request_firmware_direct(&fw, (const char *)fw_name, device)) {
- pr_debug("failed to load file %s\n", fw_name);
+ pr_err("failed to load file %s\n", fw_name);
goto out;
}
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 070426b9895f..c56819dc6730 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -266,6 +266,7 @@ static __init struct microcode_intel *scan_microcode(void *data, size_t size,
struct microcode_intel *patch = NULL;
u32 cur_rev = uci->cpu_sig.rev;
unsigned int mc_size;
+ bool any_matches = false;
for (; size >= sizeof(struct microcode_header_intel); size -= mc_size, data += mc_size) {
mc_header = (struct microcode_header_intel *)data;
@@ -277,6 +278,7 @@ static __init struct microcode_intel *scan_microcode(void *data, size_t size,
if (!intel_find_matching_signature(data, &uci->cpu_sig))
continue;
+ any_matches = true;
/*
* For saving the early microcode, find the matching revision which
@@ -296,7 +298,21 @@ static __init struct microcode_intel *scan_microcode(void *data, size_t size,
cur_rev = mc_header->rev;
}
- return size ? NULL : patch;
+ if (size) {
+ pr_err("Unable to parse microcode blob!\n");
+ return NULL;
+ }
+
+ if (!save) {
+ if (patch)
+ pr_info("Found microcode update\n");
+ else if (any_matches)
+ pr_info("Found microcode update but it's not newer\n");
+ else
+ pr_info("Found no microcode update for this CPU\n");
+ }
+
+ return patch;
}
static enum ucode_state __apply_microcode(struct ucode_cpu_info *uci,
@@ -373,8 +389,10 @@ static __init struct microcode_intel *get_microcode_blob(struct ucode_cpu_info *
if (!load_builtin_intel_microcode(&cp))
cp = find_microcode_in_initrd(ucode_path);
- if (!(cp.data && cp.size))
+ if (!(cp.data && cp.size)) {
+ pr_info("Unable to find any microcode blob for early loading\n");
return NULL;
+ }
intel_collect_cpu_info(&uci->cpu_sig);
@@ -612,7 +630,7 @@ static enum ucode_state request_microcode_fw(int cpu, struct device *device)
c->x86, c->x86_model, c->x86_stepping);
if (request_firmware_direct(&firmware, name, device)) {
- pr_debug("data file %s load failed\n", name);
+ pr_info("data file %s load failed\n", name);
return UCODE_NFOUND;
}
base-commit: bee0e7762ad2c6025b9f5245c040fcc36ef2bde8
--
2.43.0.472.g3155946c3a-goog
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