tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 9f67672a817ec046f7554a885f0fe0d60e1bf99f
commit: f6780ce619f8daa285760302d56e95892087bd1f powerpc/watchpoint: Fix DAWR exception constraint
config: powerpc-randconfig-m031-20210501 (attached as .config)
compiler: powerpc-linux-gcc (GCC) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
New smatch warnings:
arch/powerpc/kernel/hw_breakpoint.c:715 hw_breakpoint_handler() error: uninitialized symbol 'ea'.
vim +/ea +715 arch/powerpc/kernel/hw_breakpoint.c
03465f899bdac7 Nicholas Piggin 2016-09-16 677 int hw_breakpoint_handler(struct die_args *args)
5aae8a53708025 K.Prasad 2010-06-15 678 {
74c6881019b7d5 Ravi Bangoria 2020-05-14 679 bool err = false;
5aae8a53708025 K.Prasad 2010-06-15 680 int rc = NOTIFY_STOP;
74c6881019b7d5 Ravi Bangoria 2020-05-14 681 struct perf_event *bp[HBP_NUM_MAX] = { NULL };
5aae8a53708025 K.Prasad 2010-06-15 682 struct pt_regs *regs = args->regs;
74c6881019b7d5 Ravi Bangoria 2020-05-14 683 struct arch_hw_breakpoint *info[HBP_NUM_MAX] = { NULL };
74c6881019b7d5 Ravi Bangoria 2020-05-14 684 int i;
74c6881019b7d5 Ravi Bangoria 2020-05-14 685 int hit[HBP_NUM_MAX] = {0};
74c6881019b7d5 Ravi Bangoria 2020-05-14 686 int nr_hit = 0;
74c6881019b7d5 Ravi Bangoria 2020-05-14 687 bool ptrace_bp = false;
74c6881019b7d5 Ravi Bangoria 2020-05-14 688 struct ppc_inst instr = ppc_inst(0);
74c6881019b7d5 Ravi Bangoria 2020-05-14 689 int type = 0;
74c6881019b7d5 Ravi Bangoria 2020-05-14 690 int size = 0;
f6780ce619f8da Ravi Bangoria 2020-07-23 691 unsigned long ea;
5aae8a53708025 K.Prasad 2010-06-15 692
5aae8a53708025 K.Prasad 2010-06-15 693 /* Disable breakpoints during exception handling */
9422de3e953d0e Michael Neuling 2012-12-20 694 hw_breakpoint_disable();
574cb24899d35e Paul Mackerras 2010-06-23 695
5aae8a53708025 K.Prasad 2010-06-15 696 /*
5aae8a53708025 K.Prasad 2010-06-15 697 * The counter may be concurrently released but that can only
5aae8a53708025 K.Prasad 2010-06-15 698 * occur from a call_rcu() path. We can then safely fetch
5aae8a53708025 K.Prasad 2010-06-15 699 * the breakpoint, use its callback, touch its counter
5aae8a53708025 K.Prasad 2010-06-15 700 * while we are in an rcu_read_lock() path.
5aae8a53708025 K.Prasad 2010-06-15 701 */
5aae8a53708025 K.Prasad 2010-06-15 702 rcu_read_lock();
5aae8a53708025 K.Prasad 2010-06-15 703
74c6881019b7d5 Ravi Bangoria 2020-05-14 704 if (!IS_ENABLED(CONFIG_PPC_8xx))
f6780ce619f8da Ravi Bangoria 2020-07-23 705 get_instr_detail(regs, &instr, &type, &size, &ea);
No else path.
74c6881019b7d5 Ravi Bangoria 2020-05-14 706
74c6881019b7d5 Ravi Bangoria 2020-05-14 707 for (i = 0; i < nr_wp_slots(); i++) {
74c6881019b7d5 Ravi Bangoria 2020-05-14 708 bp[i] = __this_cpu_read(bp_per_reg[i]);
74c6881019b7d5 Ravi Bangoria 2020-05-14 709 if (!bp[i])
74c6881019b7d5 Ravi Bangoria 2020-05-14 710 continue;
74c6881019b7d5 Ravi Bangoria 2020-05-14 711
74c6881019b7d5 Ravi Bangoria 2020-05-14 712 info[i] = counter_arch_bp(bp[i]);
74c6881019b7d5 Ravi Bangoria 2020-05-14 713 info[i]->type &= ~HW_BRK_TYPE_EXTRANEOUS_IRQ;
74c6881019b7d5 Ravi Bangoria 2020-05-14 714
f6780ce619f8da Ravi Bangoria 2020-07-23 @715 if (check_constraints(regs, instr, ea, type, size, info[i])) {
^^
Passing uninitialized data to a function will trigger a KUBSan warning
at runtime regardless of whether or not the parameter is used. (Unless
the compiler inlines the function then it would be fine).
74c6881019b7d5 Ravi Bangoria 2020-05-14 716 if (!IS_ENABLED(CONFIG_PPC_8xx) &&
74c6881019b7d5 Ravi Bangoria 2020-05-14 717 ppc_inst_equal(instr, ppc_inst(0))) {
74c6881019b7d5 Ravi Bangoria 2020-05-14 718 handler_error(bp[i], info[i]);
74c6881019b7d5 Ravi Bangoria 2020-05-14 719 info[i] = NULL;
74c6881019b7d5 Ravi Bangoria 2020-05-14 720 err = 1;
74c6881019b7d5 Ravi Bangoria 2020-05-14 721 continue;
74c6881019b7d5 Ravi Bangoria 2020-05-14 722 }
74c6881019b7d5 Ravi Bangoria 2020-05-14 723
74c6881019b7d5 Ravi Bangoria 2020-05-14 724 if (is_ptrace_bp(bp[i]))
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]