Commit-ID: d430a305b7f8127d992e79e90b6fac00f99d23b3 Gitweb: https://git.kernel.org/tip/d430a305b7f8127d992e79e90b6fac00f99d23b3 Author: Borislav Petkov <b...@suse.de> AuthorDate: Fri, 19 Oct 2018 14:27:24 +0200 Committer: Borislav Petkov <b...@suse.de> CommitDate: Mon, 19 Nov 2018 10:51:06 +0100
x86/microcode/AMD: Change verify_patch()'s return value Have it return 0 on success, positive value when the current patch should be skipped and negative on error. Signed-off-by: Borislav Petkov <b...@suse.de> Cc: x...@kernel.org Link: https://lkml.kernel.org/r/20181107170218.7596-11...@alien8.de --- arch/x86/kernel/cpu/microcode/amd.c | 91 +++++++++++++++++++++---------------- 1 file changed, 52 insertions(+), 39 deletions(-) diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index ebac82357639..79216cfb9f72 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -210,24 +210,32 @@ __verify_patch_size(u8 family, u32 sh_psize, unsigned int buf_size) break; } - if (sh_psize > min_t(u32, buf_size, max_size)) { - pr_err("patch size mismatch\n"); + if (sh_psize > min_t(u32, buf_size, max_size)) return 0; - } return sh_psize; } -static unsigned int -verify_patch(u8 family, const u8 *buf, unsigned int buf_size, bool early) +/* + * Verify the patch in @buf. + * + * Returns: + * negative: on error + * positive: patch is not for this family, skip it + * 0: success + */ +static int +verify_patch(u8 family, const u8 *buf, size_t buf_size, u32 *patch_size, bool early) { struct microcode_header_amd *mc_hdr; + unsigned int ret; u32 sh_psize; u16 proc_id; u8 patch_fam; if (!__verify_patch_section(buf, buf_size, &sh_psize, early)) - return 0; + return -1; + /* * The section header length is not included in this indicated size * but is present in the leftover file length so we need to subtract @@ -243,23 +251,31 @@ verify_patch(u8 family, const u8 *buf, unsigned int buf_size, bool early) if (!early) pr_debug("Patch of size %u truncated.\n", sh_psize); - return 0; + return -1; } - mc_hdr = (struct microcode_header_amd *)(buf + SECTION_HDR_SIZE); - proc_id = mc_hdr->processor_rev_id; + ret = __verify_patch_size(family, sh_psize, buf_size); + if (!ret) { + if (!early) + pr_debug("Per-family patch size mismatch.\n"); + return -1; + } + + *patch_size = sh_psize; + mc_hdr = (struct microcode_header_amd *)(buf + SECTION_HDR_SIZE); if (mc_hdr->nb_dev_id || mc_hdr->sb_dev_id) { if (!early) pr_err("Patch-ID 0x%08x: chipset-specific code unsupported.\n", mc_hdr->patch_id); - return 0; + return -1; } + proc_id = mc_hdr->processor_rev_id; patch_fam = 0xf + (proc_id >> 12); if (patch_fam != family) - return 0; + return 1; - return __verify_patch_size(family, sh_psize, buf_size); + return 0; } /* @@ -729,23 +745,17 @@ static void cleanup(void) * driver cannot continue functioning normally. In such cases, we tear * down everything we've used up so far and exit. */ -static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover) +static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover, + unsigned int *patch_size) { struct microcode_header_amd *mc_hdr; - unsigned int patch_size, crnt_size; struct ucode_patch *patch; u16 proc_id; + int ret; - patch_size = verify_patch(family, fw, leftover, false); - if (!patch_size) { - pr_debug("Patch size mismatch.\n"); - return 1; - } - - /* If initial rough pokes pass, we can start looking at the header. */ - crnt_size = patch_size + SECTION_HDR_SIZE; - mc_hdr = (struct microcode_header_amd *)(fw + SECTION_HDR_SIZE); - proc_id = mc_hdr->processor_rev_id; + ret = verify_patch(family, fw, leftover, patch_size, false); + if (ret) + return ret; patch = kzalloc(sizeof(*patch), GFP_KERNEL); if (!patch) { @@ -753,13 +763,16 @@ 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, *patch_size, GFP_KERNEL); if (!patch->data) { pr_err("Patch data allocation failure.\n"); kfree(patch); return -EINVAL; } + mc_hdr = (struct microcode_header_amd *)(fw + SECTION_HDR_SIZE); + proc_id = mc_hdr->processor_rev_id; + INIT_LIST_HEAD(&patch->plist); patch->patch_id = mc_hdr->patch_id; patch->equiv_cpu = proc_id; @@ -770,39 +783,39 @@ static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover) /* ... and add to cache. */ update_cache(patch); - return crnt_size; + return 0; } static enum ucode_state __load_microcode_amd(u8 family, const u8 *data, size_t size) { - enum ucode_state ret = UCODE_ERROR; - unsigned int leftover; u8 *fw = (u8 *)data; - int crnt_size = 0; int offset; offset = install_equiv_cpu_table(data); if (offset < 0) { pr_err("failed to create equivalent cpu table\n"); - return ret; + return UCODE_ERROR; } - fw += offset; - leftover = size - offset; + fw += offset; + size -= offset; if (*(u32 *)fw != UCODE_UCODE_TYPE) { pr_err("invalid type field in container file section header\n"); free_equiv_cpu_table(); - return ret; + return UCODE_ERROR; } - while (leftover) { - crnt_size = verify_and_add_patch(family, fw, leftover); - if (crnt_size < 0) - return ret; + while (size > 0) { + unsigned int crnt_size = 0; + int ret; + + ret = verify_and_add_patch(family, fw, size, &crnt_size); + if (ret < 0) + return UCODE_ERROR; - fw += crnt_size; - leftover -= crnt_size; + fw += crnt_size + SECTION_HDR_SIZE; + size -= (crnt_size + SECTION_HDR_SIZE); } return UCODE_OK;
