* [ammarfaizi2-block:bp/bp/rc0+ 6/11] arch/x86/kernel/cpu/common.c:1415:10: error: 'x86_cap_flags' undeclared; did you mean 'x86_cap_flag'? @ 2022-03-29 14:23 kernel test robot 2022-03-30 10:23 ` Borislav Petkov 0 siblings, 1 reply; 3+ messages in thread From: kernel test robot @ 2022-03-29 14:23 UTC (permalink / raw) To: Borislav Petkov Cc: kbuild-all, GNU/Weeb Mailing List, linux-kernel, Kees Cook tree: https://github.com/ammarfaizi2/linux-block bp/bp/rc0+ head: 2d784fc7295963360594f3de64446aa32841c694 commit: c3b9dcd01973935375ca9d0c67044bea7333d4ef [6/11] x86/cpu: Allow feature bit names from /proc/cpuinfo in clearcpuid= config: i386-tinyconfig (https://download.01.org/0day-ci/archive/20220329/202203292206.ICsY2RKX-lkp@intel.com/config) compiler: gcc-9 (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0 reproduce (this is a W=1 build): # https://github.com/ammarfaizi2/linux-block/commit/c3b9dcd01973935375ca9d0c67044bea7333d4ef git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block git fetch --no-tags ammarfaizi2-block bp/bp/rc0+ git checkout c3b9dcd01973935375ca9d0c67044bea7333d4ef # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/kernel/cpu/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@intel.com> All errors (new ones prefixed by >>): arch/x86/kernel/cpu/common.c: In function 'cpu_parse_early_param': >> arch/x86/kernel/cpu/common.c:1415:10: error: 'x86_cap_flags' undeclared (first use in this function); did you mean 'x86_cap_flag'? 1415 | if (!x86_cap_flags[bit]) | ^~~~~~~~~~~~~ | x86_cap_flag arch/x86/kernel/cpu/common.c:1415:10: note: each undeclared identifier is reported only once for each function it appears in vim +1415 arch/x86/kernel/cpu/common.c 1385 1386 if (cmdline_find_option_bool(boot_command_line, "noxsave")) 1387 setup_clear_cpu_cap(X86_FEATURE_XSAVE); 1388 1389 if (cmdline_find_option_bool(boot_command_line, "noxsaveopt")) 1390 setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); 1391 1392 if (cmdline_find_option_bool(boot_command_line, "noxsaves")) 1393 setup_clear_cpu_cap(X86_FEATURE_XSAVES); 1394 1395 arglen = cmdline_find_option(boot_command_line, "clearcpuid", arg, sizeof(arg)); 1396 if (arglen <= 0) 1397 return; 1398 1399 pr_info("Clearing CPUID bits:"); 1400 1401 while (argptr) { 1402 bool found __maybe_unused = false; 1403 unsigned int bit; 1404 1405 opt = strsep(&argptr, ","); 1406 1407 /* 1408 * Handle naked numbers first for feature flags which don't 1409 * have names. 1410 */ 1411 if (!kstrtouint(opt, 10, &bit)) { 1412 if (bit < NCAPINTS * 32) { 1413 1414 /* empty-string, i.e., ""-defined feature flags */ > 1415 if (!x86_cap_flags[bit]) 1416 pr_cont(" " X86_CAP_FMT_NUM, x86_cap_flag_num(bit)); 1417 else 1418 pr_cont(" " X86_CAP_FMT, x86_cap_flag(bit)); 1419 1420 setup_clear_cpu_cap(bit); 1421 taint++; 1422 } 1423 /* 1424 * The assumption is that there are no feature names with only 1425 * numbers in the name thus go to the next argument. 1426 */ 1427 continue; 1428 } 1429 -- 0-DAY CI Kernel Test Service https://01.org/lkp ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [ammarfaizi2-block:bp/bp/rc0+ 6/11] arch/x86/kernel/cpu/common.c:1415:10: error: 'x86_cap_flags' undeclared; did you mean 'x86_cap_flag'? 2022-03-29 14:23 [ammarfaizi2-block:bp/bp/rc0+ 6/11] arch/x86/kernel/cpu/common.c:1415:10: error: 'x86_cap_flags' undeclared; did you mean 'x86_cap_flag'? kernel test robot @ 2022-03-30 10:23 ` Borislav Petkov 0 siblings, 0 replies; 3+ messages in thread From: Borislav Petkov @ 2022-03-30 10:23 UTC (permalink / raw) To: kernel test robot Cc: kbuild-all, GNU/Weeb Mailing List, linux-kernel, Kees Cook On Tue, Mar 29, 2022 at 10:23:07PM +0800, kernel test robot wrote: > tree: https://github.com/ammarfaizi2/linux-block bp/bp/rc0+ > head: 2d784fc7295963360594f3de64446aa32841c694 > commit: c3b9dcd01973935375ca9d0c67044bea7333d4ef [6/11] x86/cpu: Allow feature bit names from /proc/cpuinfo in clearcpuid= > config: i386-tinyconfig (https://download.01.org/0day-ci/archive/20220329/202203292206.ICsY2RKX-lkp@intel.com/config) > compiler: gcc-9 (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0 > reproduce (this is a W=1 build): > # https://github.com/ammarfaizi2/linux-block/commit/c3b9dcd01973935375ca9d0c67044bea7333d4ef > git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block > git fetch --no-tags ammarfaizi2-block bp/bp/rc0+ > git checkout c3b9dcd01973935375ca9d0c67044bea7333d4ef > # save the config file to linux build tree > mkdir build_dir > make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/kernel/cpu/ > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@intel.com> Thanks for reporting, fixed: --- From: Borislav Petkov <bp@suse.de> Date: Thu, 27 Jan 2022 12:56:21 +0100 Subject: [PATCH] x86/cpu: Allow feature bit names from /proc/cpuinfo in clearcpuid= Having to give the X86_FEATURE array indices in order to disable a feature bit for testing is not really user-friendly. So accept the feature bit names too. Some feature bits don't have names so there the array indices are still accepted, of course. Clearing CPUID flags is not something which should be done in production so taint the kernel too. An exemplary cmdline would then be something like: clearcpuid=de,440,smca,succory,bmi1,3dnow ("succory" is wrong on purpose). And it says: [ ... ] Clearing CPUID bits: de 13:24 smca (unknown: succory) bmi1 3dnow [ Fix CONFIG_X86_FEATURE_NAMES=n build error as reported by the 0day robot: https://lore.kernel.org/r/202203292206.ICsY2RKX-lkp@intel.com ] Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220127115626.14179-2-bp@alien8.de --- .../admin-guide/kernel-parameters.txt | 11 +++- arch/x86/include/asm/cpufeature.h | 7 +- arch/x86/kernel/cpu/common.c | 64 +++++++++++++++---- 3 files changed, 65 insertions(+), 17 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b7ccaa2ea867..bdad3dfd6a37 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -631,12 +631,17 @@ Defaults to zero when built as a module and to 10 seconds when built into the kernel. - clearcpuid=BITNUM[,BITNUM...] [X86] + clearcpuid=X[,X...] [X86] Disable CPUID feature X for the kernel. See arch/x86/include/asm/cpufeatures.h for the valid bit - numbers. Note the Linux specific bits are not necessarily - stable over kernel options, but the vendor specific + numbers X. Note the Linux-specific bits are not necessarily + stable over kernel options, but the vendor-specific ones should be. + X can also be a string as appearing in the flags: line + in /proc/cpuinfo which does not have the above + instability issue. However, not all features have names + in /proc/cpuinfo. + Note that using this option will taint your kernel. Also note that user programs calling CPUID directly or using the feature without checking anything will still see it. This just prevents it from diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 1261842d006c..66d3e3b1d24d 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -34,14 +34,17 @@ enum cpuid_leafs CPUID_8000_001F_EAX, }; +#define X86_CAP_FMT_NUM "%d:%d" +#define x86_cap_flag_num(flag) ((flag) >> 5), ((flag) & 31) + #ifdef CONFIG_X86_FEATURE_NAMES extern const char * const x86_cap_flags[NCAPINTS*32]; extern const char * const x86_power_flags[32]; #define X86_CAP_FMT "%s" #define x86_cap_flag(flag) x86_cap_flags[flag] #else -#define X86_CAP_FMT "%d:%d" -#define x86_cap_flag(flag) ((flag) >> 5), ((flag) & 31) +#define X86_CAP_FMT X86_CAP_FMT_NUM +#define x86_cap_flag x86_cap_flag_num #endif /* diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index ed4417500700..69c7ea84b005 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1368,8 +1368,8 @@ static void detect_nopl(void) static void __init cpu_parse_early_param(void) { char arg[128]; - char *argptr = arg; - int arglen, res, bit; + char *argptr = arg, *opt; + int arglen, taint = 0; #ifdef CONFIG_X86_32 if (cmdline_find_option_bool(boot_command_line, "no387")) @@ -1397,21 +1397,61 @@ static void __init cpu_parse_early_param(void) return; pr_info("Clearing CPUID bits:"); - do { - res = get_option(&argptr, &bit); - if (res == 0 || res == 3) - break; - /* If the argument was too long, the last bit may be cut off */ - if (res == 1 && arglen >= sizeof(arg)) - break; + while (argptr) { + bool found __maybe_unused = false; + unsigned int bit; + + opt = strsep(&argptr, ","); + + /* + * Handle naked numbers first for feature flags which don't + * have names. + */ + if (!kstrtouint(opt, 10, &bit)) { + if (bit < NCAPINTS * 32) { + +#ifdef CONFIG_X86_FEATURE_NAMES + /* empty-string, i.e., ""-defined feature flags */ + if (!x86_cap_flags[bit]) + pr_cont(" " X86_CAP_FMT_NUM, x86_cap_flag_num(bit)); + else +#endif + pr_cont(" " X86_CAP_FMT, x86_cap_flag(bit)); + + setup_clear_cpu_cap(bit); + taint++; + } + /* + * The assumption is that there are no feature names with only + * numbers in the name thus go to the next argument. + */ + continue; + } + +#ifdef CONFIG_X86_FEATURE_NAMES + for (bit = 0; bit < 32 * NCAPINTS; bit++) { + if (!x86_cap_flag(bit)) + continue; - if (bit >= 0 && bit < NCAPINTS * 32) { - pr_cont(" " X86_CAP_FMT, x86_cap_flag(bit)); + if (strcmp(x86_cap_flag(bit), opt)) + continue; + + pr_cont(" %s", opt); setup_clear_cpu_cap(bit); + taint++; + found = true; + break; } - } while (res == 2); + + if (!found) + pr_cont(" (unknown: %s)", opt); +#endif + } pr_cont("\n"); + + if (taint) + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); } /* -- 2.35.1 -- Regards/Gruss, Boris. SUSE Software Solutions Germany GmbH, GF: Ivo Totev, HRB 36809, AG Nürnberg ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [ammarfaizi2-block:bp/bp/rc0+ 6/11] arch/x86/kernel/cpu/common.c:1415:10: error: 'x86_cap_flags' undeclared; did you mean 'x86_cap_flag'? @ 2022-03-30 10:23 ` Borislav Petkov 0 siblings, 0 replies; 3+ messages in thread From: Borislav Petkov @ 2022-03-30 10:23 UTC (permalink / raw) To: kbuild-all [-- Attachment #1: Type: text/plain, Size: 6815 bytes --] On Tue, Mar 29, 2022 at 10:23:07PM +0800, kernel test robot wrote: > tree: https://github.com/ammarfaizi2/linux-block bp/bp/rc0+ > head: 2d784fc7295963360594f3de64446aa32841c694 > commit: c3b9dcd01973935375ca9d0c67044bea7333d4ef [6/11] x86/cpu: Allow feature bit names from /proc/cpuinfo in clearcpuid= > config: i386-tinyconfig (https://download.01.org/0day-ci/archive/20220329/202203292206.ICsY2RKX-lkp(a)intel.com/config) > compiler: gcc-9 (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0 > reproduce (this is a W=1 build): > # https://github.com/ammarfaizi2/linux-block/commit/c3b9dcd01973935375ca9d0c67044bea7333d4ef > git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block > git fetch --no-tags ammarfaizi2-block bp/bp/rc0+ > git checkout c3b9dcd01973935375ca9d0c67044bea7333d4ef > # save the config file to linux build tree > mkdir build_dir > make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/kernel/cpu/ > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@intel.com> Thanks for reporting, fixed: --- From: Borislav Petkov <bp@suse.de> Date: Thu, 27 Jan 2022 12:56:21 +0100 Subject: [PATCH] x86/cpu: Allow feature bit names from /proc/cpuinfo in clearcpuid= Having to give the X86_FEATURE array indices in order to disable a feature bit for testing is not really user-friendly. So accept the feature bit names too. Some feature bits don't have names so there the array indices are still accepted, of course. Clearing CPUID flags is not something which should be done in production so taint the kernel too. An exemplary cmdline would then be something like: clearcpuid=de,440,smca,succory,bmi1,3dnow ("succory" is wrong on purpose). And it says: [ ... ] Clearing CPUID bits: de 13:24 smca (unknown: succory) bmi1 3dnow [ Fix CONFIG_X86_FEATURE_NAMES=n build error as reported by the 0day robot: https://lore.kernel.org/r/202203292206.ICsY2RKX-lkp(a)intel.com ] Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220127115626.14179-2-bp(a)alien8.de --- .../admin-guide/kernel-parameters.txt | 11 +++- arch/x86/include/asm/cpufeature.h | 7 +- arch/x86/kernel/cpu/common.c | 64 +++++++++++++++---- 3 files changed, 65 insertions(+), 17 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b7ccaa2ea867..bdad3dfd6a37 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -631,12 +631,17 @@ Defaults to zero when built as a module and to 10 seconds when built into the kernel. - clearcpuid=BITNUM[,BITNUM...] [X86] + clearcpuid=X[,X...] [X86] Disable CPUID feature X for the kernel. See arch/x86/include/asm/cpufeatures.h for the valid bit - numbers. Note the Linux specific bits are not necessarily - stable over kernel options, but the vendor specific + numbers X. Note the Linux-specific bits are not necessarily + stable over kernel options, but the vendor-specific ones should be. + X can also be a string as appearing in the flags: line + in /proc/cpuinfo which does not have the above + instability issue. However, not all features have names + in /proc/cpuinfo. + Note that using this option will taint your kernel. Also note that user programs calling CPUID directly or using the feature without checking anything will still see it. This just prevents it from diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 1261842d006c..66d3e3b1d24d 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -34,14 +34,17 @@ enum cpuid_leafs CPUID_8000_001F_EAX, }; +#define X86_CAP_FMT_NUM "%d:%d" +#define x86_cap_flag_num(flag) ((flag) >> 5), ((flag) & 31) + #ifdef CONFIG_X86_FEATURE_NAMES extern const char * const x86_cap_flags[NCAPINTS*32]; extern const char * const x86_power_flags[32]; #define X86_CAP_FMT "%s" #define x86_cap_flag(flag) x86_cap_flags[flag] #else -#define X86_CAP_FMT "%d:%d" -#define x86_cap_flag(flag) ((flag) >> 5), ((flag) & 31) +#define X86_CAP_FMT X86_CAP_FMT_NUM +#define x86_cap_flag x86_cap_flag_num #endif /* diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index ed4417500700..69c7ea84b005 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1368,8 +1368,8 @@ static void detect_nopl(void) static void __init cpu_parse_early_param(void) { char arg[128]; - char *argptr = arg; - int arglen, res, bit; + char *argptr = arg, *opt; + int arglen, taint = 0; #ifdef CONFIG_X86_32 if (cmdline_find_option_bool(boot_command_line, "no387")) @@ -1397,21 +1397,61 @@ static void __init cpu_parse_early_param(void) return; pr_info("Clearing CPUID bits:"); - do { - res = get_option(&argptr, &bit); - if (res == 0 || res == 3) - break; - /* If the argument was too long, the last bit may be cut off */ - if (res == 1 && arglen >= sizeof(arg)) - break; + while (argptr) { + bool found __maybe_unused = false; + unsigned int bit; + + opt = strsep(&argptr, ","); + + /* + * Handle naked numbers first for feature flags which don't + * have names. + */ + if (!kstrtouint(opt, 10, &bit)) { + if (bit < NCAPINTS * 32) { + +#ifdef CONFIG_X86_FEATURE_NAMES + /* empty-string, i.e., ""-defined feature flags */ + if (!x86_cap_flags[bit]) + pr_cont(" " X86_CAP_FMT_NUM, x86_cap_flag_num(bit)); + else +#endif + pr_cont(" " X86_CAP_FMT, x86_cap_flag(bit)); + + setup_clear_cpu_cap(bit); + taint++; + } + /* + * The assumption is that there are no feature names with only + * numbers in the name thus go to the next argument. + */ + continue; + } + +#ifdef CONFIG_X86_FEATURE_NAMES + for (bit = 0; bit < 32 * NCAPINTS; bit++) { + if (!x86_cap_flag(bit)) + continue; - if (bit >= 0 && bit < NCAPINTS * 32) { - pr_cont(" " X86_CAP_FMT, x86_cap_flag(bit)); + if (strcmp(x86_cap_flag(bit), opt)) + continue; + + pr_cont(" %s", opt); setup_clear_cpu_cap(bit); + taint++; + found = true; + break; } - } while (res == 2); + + if (!found) + pr_cont(" (unknown: %s)", opt); +#endif + } pr_cont("\n"); + + if (taint) + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); } /* -- 2.35.1 -- Regards/Gruss, Boris. SUSE Software Solutions Germany GmbH, GF: Ivo Totev, HRB 36809, AG Nürnberg ^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-03-30 10:23 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-03-29 14:23 [ammarfaizi2-block:bp/bp/rc0+ 6/11] arch/x86/kernel/cpu/common.c:1415:10: error: 'x86_cap_flags' undeclared; did you mean 'x86_cap_flag'? kernel test robot 2022-03-30 10:23 ` Borislav Petkov 2022-03-30 10:23 ` Borislav Petkov
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