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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-06 16:37:43 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-06 16:37:43 -0700
commitfdafe5d1ffe8021704cb389e9823aef4235c88bc (patch)
treece7086715870aa49c8420669f340e2b612f1abba
parentMerge branch 'x86-topology-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (diff)
parentx86/microcode: Deprecate MICROCODE_OLD_INTERFACE (diff)
downloadlinux-dev-fdafe5d1ffe8021704cb389e9823aef4235c88bc.tar.xz
linux-dev-fdafe5d1ffe8021704cb389e9823aef4235c88bc.zip
Merge branch 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 microcode loading update from Borislav Petkov: "A nice Intel microcode blob loading cleanup which gets rid of the ugly memcpy wrappers and switches the driver to use the iov_iter API. By Jann Horn. In addition, the /dev/cpu/microcode interface is finally deprecated as it is inadequate for the same reasons the late microcode loading is" * 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode: Deprecate MICROCODE_OLD_INTERFACE x86/microcode: Fix the ancient deprecated microcode loading method x86/microcode/intel: Refactor Intel microcode blob loading
-rw-r--r--arch/x86/Kconfig10
-rw-r--r--arch/x86/kernel/cpu/microcode/core.c3
-rw-r--r--arch/x86/kernel/cpu/microcode/intel.c71
3 files changed, 47 insertions, 37 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 9fc73ca17844..0a3cc347143f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1317,8 +1317,16 @@ config MICROCODE_AMD
processors will be enabled.
config MICROCODE_OLD_INTERFACE
- def_bool y
+ bool "Ancient loading interface (DEPRECATED)"
+ default n
depends on MICROCODE
+ ---help---
+ DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
+ which was used by userspace tools like iucode_tool and microcode.ctl.
+ It is inadequate because it runs too late to be able to properly
+ load microcode on a machine and it needs special tools. Instead, you
+ should've switched to the early loading method with the initrd or
+ builtin microcode by now: Documentation/x86/microcode.txt
config X86_MSR
tristate "/dev/cpu/*/msr - Model-specific register support"
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index 5260185cbf7b..8a4a7823451a 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -418,8 +418,9 @@ static int do_microcode_update(const void __user *buf, size_t size)
if (ustate == UCODE_ERROR) {
error = -1;
break;
- } else if (ustate == UCODE_OK)
+ } else if (ustate == UCODE_NEW) {
apply_microcode_on_target(cpu);
+ }
}
return error;
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 16936a24795c..a44bdbe7c55e 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -31,6 +31,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/cpu.h>
+#include <linux/uio.h>
#include <linux/mm.h>
#include <asm/microcode_intel.h>
@@ -861,32 +862,33 @@ out:
return ret;
}
-static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
- int (*get_ucode_data)(void *, const void *, size_t))
+static enum ucode_state generic_load_microcode(int cpu, struct iov_iter *iter)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
- u8 *ucode_ptr = data, *new_mc = NULL, *mc = NULL;
- int new_rev = uci->cpu_sig.rev;
- unsigned int leftover = size;
unsigned int curr_mc_size = 0, new_mc_size = 0;
- unsigned int csig, cpf;
enum ucode_state ret = UCODE_OK;
+ int new_rev = uci->cpu_sig.rev;
+ u8 *new_mc = NULL, *mc = NULL;
+ unsigned int csig, cpf;
- while (leftover) {
+ while (iov_iter_count(iter)) {
struct microcode_header_intel mc_header;
- unsigned int mc_size;
+ unsigned int mc_size, data_size;
+ u8 *data;
- if (leftover < sizeof(mc_header)) {
- pr_err("error! Truncated header in microcode data file\n");
+ if (!copy_from_iter_full(&mc_header, sizeof(mc_header), iter)) {
+ pr_err("error! Truncated or inaccessible header in microcode data file\n");
break;
}
- if (get_ucode_data(&mc_header, ucode_ptr, sizeof(mc_header)))
- break;
-
mc_size = get_totalsize(&mc_header);
- if (!mc_size || mc_size > leftover) {
- pr_err("error! Bad data in microcode data file\n");
+ if (mc_size < sizeof(mc_header)) {
+ pr_err("error! Bad data in microcode data file (totalsize too small)\n");
+ break;
+ }
+ 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;
}
@@ -899,7 +901,9 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
curr_mc_size = mc_size;
}
- if (get_ucode_data(mc, ucode_ptr, mc_size) ||
+ memcpy(mc, &mc_header, sizeof(mc_header));
+ data = mc + sizeof(mc_header);
+ if (!copy_from_iter_full(data, data_size, iter) ||
microcode_sanity_check(mc, 1) < 0) {
break;
}
@@ -914,14 +918,11 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
mc = NULL; /* trigger new vmalloc */
ret = UCODE_NEW;
}
-
- ucode_ptr += mc_size;
- leftover -= mc_size;
}
vfree(mc);
- if (leftover) {
+ if (iov_iter_count(iter)) {
vfree(new_mc);
return UCODE_ERROR;
}
@@ -945,12 +946,6 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
return ret;
}
-static int get_ucode_fw(void *to, const void *from, size_t n)
-{
- memcpy(to, from, n);
- return 0;
-}
-
static bool is_blacklisted(unsigned int cpu)
{
struct cpuinfo_x86 *c = &cpu_data(cpu);
@@ -977,10 +972,12 @@ static bool is_blacklisted(unsigned int cpu)
static enum ucode_state request_microcode_fw(int cpu, struct device *device,
bool refresh_fw)
{
- char name[30];
struct cpuinfo_x86 *c = &cpu_data(cpu);
const struct firmware *firmware;
+ struct iov_iter iter;
enum ucode_state ret;
+ struct kvec kvec;
+ char name[30];
if (is_blacklisted(cpu))
return UCODE_NFOUND;
@@ -993,26 +990,30 @@ static enum ucode_state request_microcode_fw(int cpu, struct device *device,
return UCODE_NFOUND;
}
- ret = generic_load_microcode(cpu, (void *)firmware->data,
- firmware->size, &get_ucode_fw);
+ kvec.iov_base = (void *)firmware->data;
+ kvec.iov_len = firmware->size;
+ iov_iter_kvec(&iter, WRITE, &kvec, 1, firmware->size);
+ ret = generic_load_microcode(cpu, &iter);
release_firmware(firmware);
return ret;
}
-static int get_ucode_user(void *to, const void *from, size_t n)
-{
- return copy_from_user(to, from, n);
-}
-
static enum ucode_state
request_microcode_user(int cpu, const void __user *buf, size_t size)
{
+ struct iov_iter iter;
+ struct iovec iov;
+
if (is_blacklisted(cpu))
return UCODE_NFOUND;
- return generic_load_microcode(cpu, (void *)buf, size, &get_ucode_user);
+ iov.iov_base = (void __user *)buf;
+ iov.iov_len = size;
+ iov_iter_init(&iter, WRITE, &iov, 1, size);
+
+ return generic_load_microcode(cpu, &iter);
}
static struct microcode_ops microcode_intel_ops = {