Commit 70887cb2 authored by Borislav Petkov's avatar Borislav Petkov
Browse files

x86/microcode/AMD: Cleanup verify_patch_size() more 



Rename the variable which contains the patch size read out from the
section header to sh_psize for better differentiation of all the "sizes"
in that function.

Also, improve the comment above it.

No functional changes.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: x86@kernel.org
Link: https://lkml.kernel.org/r/20181107170218.7596-6-bp@alien8.de
parent cfffbfeb

arch/x86/kernel/cpu/microcode/amd.c

+14 −12
Original line number Diff line number Diff line
@@ -175,16 +175,18 @@ static bool verify_patch_section(const u8 *buf, size_t buf_size, bool early) 
}



/*

 * Check whether the passed remaining file @size is large enough to contain a

 * patch of the indicated @patch_size (and also whether this size does not

 * exceed the per-family maximum).

 * Check whether the passed remaining file @buf_size is large enough to contain

 * a patch of the indicated @sh_psize (and also whether this size does not

 * exceed the per-family maximum). @sh_psize is the size read from the section

 * header.

 */

static unsigned int verify_patch_size(u8 family, u32 patch_size, unsigned int size)

static unsigned int

verify_patch_size(u8 family, u32 sh_psize, unsigned int buf_size)

{

	u32 max_size;



	if (family >= 0x15)

		return min_t(u32, patch_size, size);

		return min_t(u32, sh_psize, buf_size);



#define F1XH_MPB_MAX_SIZE 2048

#define F14H_MPB_MAX_SIZE 1824
@@ -202,12 +204,12 @@ static unsigned int verify_patch_size(u8 family, u32 patch_size, unsigned int si 
		break;

	}



	if (patch_size > min_t(u32, size, max_size)) {

	if (sh_psize > min_t(u32, buf_size, max_size)) {

		pr_err("patch size mismatch\n");

		return 0;

	}



	return patch_size;

	return sh_psize;

}



/*
@@ -693,14 +695,14 @@ static void cleanup(void) 
 */

static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover)

{

	unsigned int sh_psize, crnt_size, ret;

	struct microcode_header_amd *mc_hdr;

	struct ucode_patch *patch;

	unsigned int patch_size, crnt_size, ret;

	u32 proc_fam;

	u16 proc_id;



	patch_size  = *(u32 *)(fw + 4);

	crnt_size   = patch_size + SECTION_HDR_SIZE;

	sh_psize    = *(u32 *)(fw + 4);

	crnt_size   = sh_psize + SECTION_HDR_SIZE;

	mc_hdr	    = (struct microcode_header_amd *)(fw + SECTION_HDR_SIZE);

	proc_id	    = mc_hdr->processor_rev_id;
@@ -726,7 +728,7 @@ static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover) 
	 * but is present in the leftover file length so we need to subtract

	 * it before passing this value to the function below.

	 */

	ret = verify_patch_size(family, patch_size, leftover - SECTION_HDR_SIZE);

	ret = verify_patch_size(family, sh_psize, leftover - SECTION_HDR_SIZE);

	if (!ret) {

		pr_err("Patch-ID 0x%08x: size mismatch.\n", mc_hdr->patch_id);

		return crnt_size;
@@ -738,7 +740,7 @@ static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover) 
		return -EINVAL;

	}



	patch->data = kmemdup(fw + SECTION_HDR_SIZE, patch_size, GFP_KERNEL);

	patch->data = kmemdup(fw + SECTION_HDR_SIZE, sh_psize, GFP_KERNEL);

	if (!patch->data) {

		pr_err("Patch data allocation failure.\n");

		kfree(patch);

CRA Git | Maintained and supported by SUSTech CRA and CCSE