Re: [PATCH v2] x86/vm86: Remove deprecated VM86 support
From: kernel test robot
Date: Thu May 28 2026 - 06:00:31 EST
Hi Ashwin,
kernel test robot noticed the following build errors:
[auto build test ERROR on v7.1-rc5]
[also build test ERROR on linus/master next-20260527]
[cannot apply to tip/x86/core]
[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/Ashwin-Gundarapu/x86-vm86-Remove-deprecated-VM86-support/20260527-153401
base: v7.1-rc5
patch link: https://lore.kernel.org/r/19e6858d9db.3a90532342003.5043853571553507480%40zohomail.in
patch subject: [PATCH v2] x86/vm86: Remove deprecated VM86 support
config: x86_64-allnoconfig (https://download.01.org/0day-ci/archive/20260528/202605281705.9gRlhp1Y-lkp@xxxxxxxxx/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260528/202605281705.9gRlhp1Y-lkp@xxxxxxxxx/reproduce)
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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202605281705.9gRlhp1Y-lkp@xxxxxxxxx/
All errors (new ones prefixed by >>):
>> arch/x86/kernel/signal.c:261:3: error: call to undeclared function 'save_v86_state'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
261 | save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL);
| ^
1 error generated.
--
>> arch/x86/kernel/traps.c:289:9: error: call to undeclared function 'handle_vm86_trap'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
289 | if (!handle_vm86_trap((struct kernel_vm86_regs *) regs,
| ^
>> arch/x86/kernel/traps.c:927:3: error: call to undeclared function 'handle_vm86_fault'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
927 | handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
| ^
arch/x86/kernel/traps.c:927:3: note: did you mean 'handle_mm_fault'?
include/linux/mm.h:3144:19: note: 'handle_mm_fault' declared here
3144 | extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
| ^
arch/x86/kernel/traps.c:1347:3: error: call to undeclared function 'handle_vm86_trap'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
1347 | handle_vm86_trap((struct kernel_vm86_regs *)regs, 0, X86_TRAP_DB);
| ^
3 errors generated.
vim +/save_v86_state +261 arch/x86/kernel/signal.c
1d13024e624d0e2 arch/x86/kernel/signal_32.c Hiroshi Shimamoto 2008-09-05 253
a610d6e672d6d37 arch/x86/kernel/signal.c Al Viro 2012-05-21 254 static void
235b80226b986da arch/x86/kernel/signal.c Al Viro 2012-11-09 255 handle_signal(struct ksignal *ksig, struct pt_regs *regs)
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 256 {
fd0f86b66425bd8 arch/x86/kernel/signal.c Oleg Nesterov 2015-04-16 257 bool stepping, failed;
e3bfa3859936da3 arch/x86/kernel/signal.c Ingo Molnar 2025-04-09 258 struct fpu *fpu = x86_task_fpu(current);
fd0f86b66425bd8 arch/x86/kernel/signal.c Oleg Nesterov 2015-04-16 259
5ed92a8ab71f886 arch/x86/kernel/signal.c Brian Gerst 2015-07-29 260 if (v8086_mode(regs))
5ed92a8ab71f886 arch/x86/kernel/signal.c Brian Gerst 2015-07-29 @261 save_v86_state((struct kernel_vm86_regs *) regs, VM86_SIGNAL);
5ed92a8ab71f886 arch/x86/kernel/signal.c Brian Gerst 2015-07-29 262
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 263 /* Are we from a system call? */
9ddcb87b9218dec arch/x86/kernel/signal.c H. Peter Anvin 2021-05-10 264 if (syscall_get_nr(current, regs) != -1) {
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 265 /* If so, check system call restarting.. */
bb57925f5057837 arch/x86/kernel/signal_32.c Hiroshi Shimamoto 2008-09-05 266 switch (syscall_get_error(current, regs)) {
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 267 case -ERESTART_RESTARTBLOCK:
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 268 case -ERESTARTNOHAND:
65ea5b034990358 arch/x86/kernel/signal_32.c H. Peter Anvin 2008-01-30 269 regs->ax = -EINTR;
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 270 break;
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 271
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 272 case -ERESTARTSYS:
235b80226b986da arch/x86/kernel/signal.c Al Viro 2012-11-09 273 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
65ea5b034990358 arch/x86/kernel/signal_32.c H. Peter Anvin 2008-01-30 274 regs->ax = -EINTR;
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 275 break;
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 276 }
df561f6688fef77 arch/x86/kernel/signal.c Gustavo A. R. Silva 2020-08-23 277 fallthrough;
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 278 case -ERESTARTNOINTR:
65ea5b034990358 arch/x86/kernel/signal_32.c H. Peter Anvin 2008-01-30 279 regs->ax = regs->orig_ax;
65ea5b034990358 arch/x86/kernel/signal_32.c H. Peter Anvin 2008-01-30 280 regs->ip -= 2;
ac66f3fd89ee20b arch/x86/kernel/signal_32.c Harvey Harrison 2008-02-08 281 break;
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 282 }
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 283 }
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 284
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 285 /*
fd0f86b66425bd8 arch/x86/kernel/signal.c Oleg Nesterov 2015-04-16 286 * If TF is set due to a debugger (TIF_FORCED_TF), clear TF now
fd0f86b66425bd8 arch/x86/kernel/signal.c Oleg Nesterov 2015-04-16 287 * so that register information in the sigcontext is correct and
fd0f86b66425bd8 arch/x86/kernel/signal.c Oleg Nesterov 2015-04-16 288 * then notify the tracer before entering the signal handler.
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 289 */
fd0f86b66425bd8 arch/x86/kernel/signal.c Oleg Nesterov 2015-04-16 290 stepping = test_thread_flag(TIF_SINGLESTEP);
fd0f86b66425bd8 arch/x86/kernel/signal.c Oleg Nesterov 2015-04-16 291 if (stepping)
fd0f86b66425bd8 arch/x86/kernel/signal.c Oleg Nesterov 2015-04-16 292 user_disable_single_step(current);
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 293
235b80226b986da arch/x86/kernel/signal.c Al Viro 2012-11-09 294 failed = (setup_rt_frame(ksig, regs) < 0);
235b80226b986da arch/x86/kernel/signal.c Al Viro 2012-11-09 295 if (!failed) {
8b9c5ff380aa4f1 arch/x86/kernel/signal_32.c Roland McGrath 2008-04-19 296 /*
8b9c5ff380aa4f1 arch/x86/kernel/signal_32.c Roland McGrath 2008-04-19 297 * Clear the direction flag as per the ABI for function entry.
ddd40da4ccbabdd arch/x86/kernel/signal.c Jiri Olsa 2013-05-01 298 *
24cda10996f5420 arch/x86/kernel/signal.c Jiri Olsa 2013-05-01 299 * Clear RF when entering the signal handler, because
24cda10996f5420 arch/x86/kernel/signal.c Jiri Olsa 2013-05-01 300 * it might disable possible debug exception from the
24cda10996f5420 arch/x86/kernel/signal.c Jiri Olsa 2013-05-01 301 * signal handler.
ddd40da4ccbabdd arch/x86/kernel/signal.c Jiri Olsa 2013-05-01 302 *
fd0f86b66425bd8 arch/x86/kernel/signal.c Oleg Nesterov 2015-04-16 303 * Clear TF for the case when it wasn't set by debugger to
fd0f86b66425bd8 arch/x86/kernel/signal.c Oleg Nesterov 2015-04-16 304 * avoid the recursive send_sigtrap() in SIGTRAP handler.
8b9c5ff380aa4f1 arch/x86/kernel/signal_32.c Roland McGrath 2008-04-19 305 */
ddd40da4ccbabdd arch/x86/kernel/signal.c Jiri Olsa 2013-05-01 306 regs->flags &= ~(X86_EFLAGS_DF|X86_EFLAGS_RF|X86_EFLAGS_TF);
66463db4fc5605d arch/x86/kernel/signal.c Oleg Nesterov 2014-09-02 307 /*
66463db4fc5605d arch/x86/kernel/signal.c Oleg Nesterov 2014-09-02 308 * Ensure the signal handler starts with the new fpu state.
66463db4fc5605d arch/x86/kernel/signal.c Oleg Nesterov 2014-09-02 309 */
b860eb8dce5906b arch/x86/kernel/signal.c Fenghua Yu 2020-05-12 310 fpu__clear_user_states(fpu);
235b80226b986da arch/x86/kernel/signal.c Al Viro 2012-11-09 311 }
fd0f86b66425bd8 arch/x86/kernel/signal.c Oleg Nesterov 2015-04-16 312 signal_setup_done(failed, ksig, stepping);
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 313 }
^1da177e4c3f415 arch/i386/kernel/signal.c Linus Torvalds 2005-04-16 314
--
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