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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-07 01:37:43 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-07 01:37:43 +0200 |
commit | fdafe5d1ffe8021704cb389e9823aef4235c88bc (patch) | |
tree | ce7086715870aa49c8420669f340e2b612f1abba /arch | |
parent | Merge branch 'x86-topology-for-linus' of git://git.kernel.org/pub/scm/linux/k... (diff) | |
parent | x86/microcode: Deprecate MICROCODE_OLD_INTERFACE (diff) | |
download | linux-fdafe5d1ffe8021704cb389e9823aef4235c88bc.tar.xz linux-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
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/Kconfig | 10 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/microcode/core.c | 3 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/microcode/intel.c | 71 |
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 = { |