[PATCH 14/16] x86/microcode/AMD: Convert CPU equivalence table variable into a struct

From: Borislav Petkov
Date: Wed Nov 07 2018 - 12:02:46 EST


From: "Maciej S. Szmigiero" <mail@xxxxxxxxxxxxxxxxxxxxx>

Convert the CPU equivalence table into a proper struct in preparation
for tracking also the size of this table.

Signed-off-by: Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx>
[ Have functions deal with struct equiv_cpu_table pointers only. Rediff. ]
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
arch/x86/kernel/cpu/microcode/amd.c | 32 ++++++++++++++++-------------
1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 5d822ed295b5..99c9928ec240 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -38,7 +38,9 @@
#include <asm/cpu.h>
#include <asm/msr.h>

-static struct equiv_cpu_entry *equiv_cpu_table;
+static struct equiv_cpu_table {
+ struct equiv_cpu_entry *entry;
+} equiv_table;

/*
* This points to the current valid container of microcode patches which we will
@@ -63,11 +65,13 @@ static u8 amd_ucode_patch[PATCH_MAX_SIZE];
static const char
ucode_path[] __maybe_unused = "kernel/x86/microcode/AuthenticAMD.bin";

-static u16 find_equiv_id(struct equiv_cpu_entry *equiv_table, u32 sig)
+static u16 find_equiv_id(struct equiv_cpu_table *et, u32 sig)
{
- for (; equiv_table && equiv_table->installed_cpu; equiv_table++) {
- if (sig == equiv_table->installed_cpu)
- return equiv_table->equiv_cpu;
+ struct equiv_cpu_entry *entry = et->entry;
+
+ for (; entry && entry->installed_cpu; entry++) {
+ if (sig == entry->installed_cpu)
+ return entry->equiv_cpu;
}

return 0;
@@ -286,7 +290,7 @@ verify_patch(u8 family, const u8 *buf, size_t buf_size, u32 *patch_size, bool ea
*/
static size_t parse_container(u8 *ucode, size_t size, struct cont_desc *desc)
{
- struct equiv_cpu_entry *eq;
+ struct equiv_cpu_table table;
size_t orig_size = size;
u32 *hdr = (u32 *)ucode;
u16 eq_id;
@@ -297,14 +301,14 @@ static size_t parse_container(u8 *ucode, size_t size, struct cont_desc *desc)

buf = ucode;

- eq = (struct equiv_cpu_entry *)(buf + CONTAINER_HDR_SZ);
+ table.entry = (struct equiv_cpu_entry *)(buf + CONTAINER_HDR_SZ);

/*
* Find the equivalence ID of our CPU in this table. Even if this table
* doesn't contain a patch for the CPU, scan through the whole container
* so that it can be skipped in case there are other containers appended.
*/
- eq_id = find_equiv_id(eq, desc->cpuid_1_eax);
+ eq_id = find_equiv_id(&table, desc->cpuid_1_eax);

buf += hdr[2] + CONTAINER_HDR_SZ;
size -= hdr[2] + CONTAINER_HDR_SZ;
@@ -572,7 +576,7 @@ void reload_ucode_amd(void)
static u16 __find_equiv_id(unsigned int cpu)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
- return find_equiv_id(equiv_cpu_table, uci->cpu_sig.sig);
+ return find_equiv_id(&equiv_table, uci->cpu_sig.sig);
}

/*
@@ -716,13 +720,13 @@ static size_t install_equiv_cpu_table(const u8 *buf, size_t buf_size)
hdr = (const u32 *)buf;
equiv_tbl_len = hdr[2];

- equiv_cpu_table = vmalloc(equiv_tbl_len);
- if (!equiv_cpu_table) {
+ equiv_table.entry = vmalloc(equiv_tbl_len);
+ if (!equiv_table.entry) {
pr_err("failed to allocate equivalent CPU table\n");
return 0;
}

- memcpy(equiv_cpu_table, buf + CONTAINER_HDR_SZ, equiv_tbl_len);
+ memcpy(equiv_table.entry, buf + CONTAINER_HDR_SZ, equiv_tbl_len);

/* add header length */
return equiv_tbl_len + CONTAINER_HDR_SZ;
@@ -730,8 +734,8 @@ static size_t install_equiv_cpu_table(const u8 *buf, size_t buf_size)

static void free_equiv_cpu_table(void)
{
- vfree(equiv_cpu_table);
- equiv_cpu_table = NULL;
+ vfree(equiv_table.entry);
+ equiv_table.entry = NULL;
}

static void cleanup(void)
--
2.19.1