[tip: x86/microcode] x86/microcode/intel: Switch to kvmalloc()

From: tip-bot2 for Thomas Gleixner
Date: Mon Oct 09 2023 - 08:30:58 EST


The following commit has been merged into the x86/microcode branch of tip:

Commit-ID: 2ef5bac8c869ac24f51c94df1ae6d23c7679d905
Gitweb: https://git.kernel.org/tip/2ef5bac8c869ac24f51c94df1ae6d23c7679d905
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Mon, 02 Oct 2023 13:59:45 +02:00
Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Tue, 03 Oct 2023 15:59:30 +02:00

x86/microcode/intel: Switch to kvmalloc()

Microcode blobs are getting larger and might soon reach the kmalloc()
limit. Switch over kvmalloc().

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/r/20231002115902.564323243@xxxxxxxxxxxxx
---
arch/x86/kernel/cpu/microcode/intel.c | 48 +++++++++++++-------------
1 file changed, 25 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 2d88929..f06889e 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -14,7 +14,6 @@
#include <linux/earlycpio.h>
#include <linux/firmware.h>
#include <linux/uaccess.h>
-#include <linux/vmalloc.h>
#include <linux/initrd.h>
#include <linux/kernel.h>
#include <linux/slab.h>
@@ -243,7 +242,7 @@ EXPORT_SYMBOL_GPL(intel_microcode_sanity_check);

static void update_ucode_pointer(struct microcode_intel *mc)
{
- kfree(ucode_patch_va);
+ kvfree(ucode_patch_va);

/*
* Save the virtual address for early loading and for eventual free
@@ -254,11 +253,14 @@ static void update_ucode_pointer(struct microcode_intel *mc)

static void save_microcode_patch(struct microcode_intel *patch)
{
+ unsigned int size = get_totalsize(&patch->hdr);
struct microcode_intel *mc;

- mc = kmemdup(patch, get_totalsize(&patch->hdr), GFP_KERNEL);
+ mc = kvmemdup(patch, size, GFP_KERNEL);
if (mc)
update_ucode_pointer(mc);
+ else
+ pr_err("Unable to allocate microcode memory size: %u\n", size);
}

/* Scan blob for microcode matching the boot CPUs family, model, stepping */
@@ -530,36 +532,34 @@ static enum ucode_state parse_microcode_blobs(int cpu, struct iov_iter *iter)

if (!copy_from_iter_full(&mc_header, sizeof(mc_header), iter)) {
pr_err("error! Truncated or inaccessible header in microcode data file\n");
- break;
+ goto fail;
}

mc_size = get_totalsize(&mc_header);
if (mc_size < sizeof(mc_header)) {
pr_err("error! Bad data in microcode data file (totalsize too small)\n");
- break;
+ goto fail;
}
-
data_size = mc_size - sizeof(mc_header);
if (data_size > iov_iter_count(iter)) {
pr_err("error! Bad data in microcode data file (truncated file?)\n");
- break;
+ goto fail;
}

/* For performance reasons, reuse mc area when possible */
if (!mc || mc_size > curr_mc_size) {
- vfree(mc);
- mc = vmalloc(mc_size);
+ kvfree(mc);
+ mc = kvmalloc(mc_size, GFP_KERNEL);
if (!mc)
- break;
+ goto fail;
curr_mc_size = mc_size;
}

memcpy(mc, &mc_header, sizeof(mc_header));
data = mc + sizeof(mc_header);
if (!copy_from_iter_full(data, data_size, iter) ||
- intel_microcode_sanity_check(mc, true, MC_HEADER_TYPE_MICROCODE) < 0) {
- break;
- }
+ intel_microcode_sanity_check(mc, true, MC_HEADER_TYPE_MICROCODE) < 0)
+ goto fail;

if (cur_rev >= mc_header.rev)
continue;
@@ -567,24 +567,26 @@ static enum ucode_state parse_microcode_blobs(int cpu, struct iov_iter *iter)
if (!intel_find_matching_signature(mc, uci->cpu_sig.sig, uci->cpu_sig.pf))
continue;

- vfree(new_mc);
+ kvfree(new_mc);
cur_rev = mc_header.rev;
new_mc = mc;
mc = NULL;
}

- vfree(mc);
-
- if (iov_iter_count(iter)) {
- vfree(new_mc);
- return UCODE_ERROR;
- }
+ if (iov_iter_count(iter))
+ goto fail;

+ kvfree(mc);
if (!new_mc)
return UCODE_NFOUND;

ucode_patch_late = (struct microcode_intel *)new_mc;
return UCODE_NEW;
+
+fail:
+ kvfree(mc);
+ kvfree(new_mc);
+ return UCODE_ERROR;
}

static bool is_blacklisted(unsigned int cpu)
@@ -643,9 +645,9 @@ static enum ucode_state request_microcode_fw(int cpu, struct device *device)
static void finalize_late_load(int result)
{
if (!result)
- save_microcode_patch(ucode_patch_late);
-
- vfree(ucode_patch_late);
+ update_ucode_pointer(ucode_patch_late);
+ else
+ kvfree(ucode_patch_late);
ucode_patch_late = NULL;
}