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Tsirkin" , Pekka Enberg , Peter Zijlstra , Petr Mladek , Steven Rostedt , Thomas Gleixner , Vasily Gorbik , Vegard Nossum , Vlastimil Babka , Linux Memory Management List , Linux-Arch , LKML Content-Type: text/plain; charset="UTF-8" X-Rspam-User: Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="rp/qQxgc"; spf=pass (imf17.hostedemail.com: domain of glider@google.com designates 209.85.219.176 as permitted sender) smtp.mailfrom=glider@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 7FDF740024 X-Stat-Signature: zizzocqx5s68spn58abb3dr3ps1jf69i X-HE-Tag: 1649083209-174849 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: > +depot_stack_handle_t kmsan_save_stack_with_flags(gfp_t flags, > + unsigned int extra) > +{ > + unsigned long entries[KMSAN_STACK_DEPTH]; > + unsigned int nr_entries; > + > + nr_entries = stack_trace_save(entries, KMSAN_STACK_DEPTH, 0); > + nr_entries = filter_irq_stacks(entries, nr_entries); This is redundant, __stack_depot_save() below already calls filter_irq_stacks(). > + > + if (depth >= MAX_CHAIN_DEPTH) { > + static atomic_long_t kmsan_skipped_origins; > + long skipped = atomic_long_inc_return(&kmsan_skipped_origins); > + > + if (skipped % NUM_SKIPPED_TO_WARN == 0) { > + pr_warn("not chained %ld origins\n", skipped); > + dump_stack(); > + kmsan_print_origin(id); > + } > + return id; > + } > + depth++; > + extra_bits = kmsan_extra_bits(depth, uaf); > + > + entries[0] = KMSAN_CHAIN_MAGIC_ORIGIN; > + entries[1] = kmsan_save_stack_with_flags(GFP_ATOMIC, 0); > + entries[2] = id; > + return __stack_depot_save(entries, ARRAY_SIZE(entries), extra_bits, > + GFP_ATOMIC, true); @entries is initialized in non-instrumented code, so passing it to filter_irq_stacks() etc. will result in false positives, unless we explicitly unpoison it. (right now KMSAN does not instrument kernel/stacktrace.c, but it probably should)