Hi Juergen,
kernel test robot noticed the following build errors:
[auto build test ERROR on tip/master] [also build test ERROR on tip/x86/core linus/master v6.15 next-20250528] [cannot apply to tip/x86/mm tip/auto-latest] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Juergen-Gross/x86-execmem-don... base: tip/master patch link: https://lore.kernel.org/r/20250528123557.12847-4-jgross%40suse.com patch subject: [PATCH 3/3] x86/alternative: make kernel ITS thunks read-only config: x86_64-buildonly-randconfig-002-20250529 (https://download.01.org/0day-ci/archive/20250529/202505291124.eAZ7fgbG-lkp@i...) compiler: clang version 20.1.2 (https://github.com/llvm/llvm-project 58df0ef89dd64126512e4ee27b4ac3fd8ddf6247) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250529/202505291124.eAZ7fgbG-lkp@i...)
If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot lkp@intel.com | Closes: https://lore.kernel.org/oe-kbuild-all/202505291124.eAZ7fgbG-lkp@intel.com/
All errors (new ones prefixed by >>):
arch/x86/kernel/alternative.c:2353:6: error: use of undeclared identifier 'its_page'
2353 | if (its_page) | ^
arch/x86/kernel/alternative.c:2354:3: error: call to undeclared function 'its_set_kernel_ro'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
2354 | its_set_kernel_ro(its_page); | ^ arch/x86/kernel/alternative.c:2354:21: error: use of undeclared identifier 'its_page' 2354 | its_set_kernel_ro(its_page); | ^ arch/x86/kernel/alternative.c:2355:2: error: use of undeclared identifier 'its_page' 2355 | its_page = NULL; | ^ 4 errors generated.
vim +/its_page +2353 arch/x86/kernel/alternative.c
2308 2309 void __init alternative_instructions(void) 2310 { 2311 u64 ibt; 2312 2313 int3_selftest(); 2314 2315 /* 2316 * The patching is not fully atomic, so try to avoid local 2317 * interruptions that might execute the to be patched code. 2318 * Other CPUs are not running. 2319 */ 2320 stop_nmi(); 2321 2322 /* 2323 * Don't stop machine check exceptions while patching. 2324 * MCEs only happen when something got corrupted and in this 2325 * case we must do something about the corruption. 2326 * Ignoring it is worse than an unlikely patching race. 2327 * Also machine checks tend to be broadcast and if one CPU 2328 * goes into machine check the others follow quickly, so we don't 2329 * expect a machine check to cause undue problems during to code 2330 * patching. 2331 */ 2332 2333 /* 2334 * Make sure to set (artificial) features depending on used paravirt 2335 * functions which can later influence alternative patching. 2336 */ 2337 paravirt_set_cap(); 2338 2339 /* Keep CET-IBT disabled until caller/callee are patched */ 2340 ibt = ibt_save(/*disable*/ true); 2341 2342 __apply_fineibt(__retpoline_sites, __retpoline_sites_end, 2343 __cfi_sites, __cfi_sites_end, true); 2344 2345 /* 2346 * Rewrite the retpolines, must be done before alternatives since 2347 * those can rewrite the retpoline thunks. 2348 */ 2349 apply_retpolines(__retpoline_sites, __retpoline_sites_end); 2350 apply_returns(__return_sites, __return_sites_end); 2351 2352 /* Make potential last thunk page read-only. */
2353 if (its_page) 2354 its_set_kernel_ro(its_page);
2355 its_page = NULL; 2356 2357 /* 2358 * Adjust all CALL instructions to point to func()-10, including 2359 * those in .altinstr_replacement. 2360 */ 2361 callthunks_patch_builtin_calls(); 2362 2363 apply_alternatives(__alt_instructions, __alt_instructions_end); 2364 2365 /* 2366 * Seal all functions that do not have their address taken. 2367 */ 2368 apply_seal_endbr(__ibt_endbr_seal, __ibt_endbr_seal_end); 2369 2370 ibt_restore(ibt); 2371