From patchwork Fri Oct 8 11:15:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 12545019 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A41F9C433EF for ; Fri, 8 Oct 2021 11:17:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 845BC61029 for ; Fri, 8 Oct 2021 11:17:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240211AbhJHLTL (ORCPT ); Fri, 8 Oct 2021 07:19:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240117AbhJHLTK (ORCPT ); Fri, 8 Oct 2021 07:19:10 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B14FFC061762; 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Fri, 8 Oct 2021 13:17:08 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id EC8112DB84A6B; Fri, 8 Oct 2021 13:17:07 +0200 (CEST) Message-ID: <20211008111626.392918519@infradead.org> User-Agent: quilt/0.66 Date: Fri, 08 Oct 2021 13:15:33 +0200 From: Peter Zijlstra To: keescook@chromium.org, jannh@google.com Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, vcaputo@pengaru.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, akpm@linux-foundation.org, christian.brauner@ubuntu.com, amistry@google.com, Kenta.Tada@sony.com, legion@kernel.org, michael.weiss@aisec.fraunhofer.de, mhocko@suse.com, deller@gmx.de, zhengqi.arch@bytedance.com, me@tobin.cc, tycho@tycho.pizza, tglx@linutronix.de, bp@alien8.de, hpa@zytor.com, mark.rutland@arm.com, axboe@kernel.dk, metze@samba.org, laijs@linux.alibaba.com, luto@kernel.org, dave.hansen@linux.intel.com, ebiederm@xmission.com, ohoono.kwon@samsung.com, kaleshsingh@google.com, yifeifz2@illinois.edu, jpoimboe@redhat.com, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, vgupta@kernel.org, linux@armlinux.org.uk, will@kernel.org, guoren@kernel.org, bcain@codeaurora.org, monstr@monstr.eu, tsbogend@alpha.franken.de, nickhu@andestech.com, jonas@southpole.se, mpe@ellerman.id.au, paul.walmsley@sifive.com, hca@linux.ibm.com, ysato@users.sourceforge.jp, davem@davemloft.net, chris@zankel.net Subject: [PATCH 6/7] arch: __get_wchan || STACKTRACE_SUPPORT References: <20211008111527.438276127@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org It's trivial to implement __get_wchan() with CONFIG_STACKTRACE Signed-off-by: Peter Zijlstra (Intel) --- arch/arc/include/asm/processor.h | 2 - arch/arc/kernel/stacktrace.c | 17 -------------- arch/arm/include/asm/processor.h | 2 - arch/arm/kernel/process.c | 22 ------------------- arch/arm64/include/asm/processor.h | 2 - arch/arm64/kernel/process.c | 26 ---------------------- arch/csky/include/asm/processor.h | 2 - arch/csky/kernel/stacktrace.c | 18 --------------- arch/hexagon/include/asm/processor.h | 3 -- arch/hexagon/kernel/process.c | 26 ---------------------- arch/ia64/include/asm/processor.h | 3 -- arch/ia64/kernel/process.c | 28 ------------------------ arch/microblaze/include/asm/processor.h | 2 - arch/microblaze/kernel/process.c | 6 ----- arch/mips/include/asm/processor.h | 2 - arch/mips/kernel/process.c | 27 ----------------------- arch/nds32/include/asm/processor.h | 2 - arch/nds32/kernel/process.c | 23 ------------------- arch/openrisc/include/asm/processor.h | 1 arch/openrisc/kernel/process.c | 6 ----- arch/parisc/include/asm/processor.h | 2 - arch/parisc/kernel/process.c | 24 -------------------- arch/powerpc/include/asm/processor.h | 2 - arch/powerpc/kernel/process.c | 37 -------------------------------- arch/riscv/include/asm/processor.h | 3 -- arch/riscv/kernel/stacktrace.c | 21 ------------------ arch/s390/include/asm/processor.h | 1 arch/s390/kernel/process.c | 29 ------------------------- arch/sh/include/asm/processor_32.h | 2 - arch/sh/kernel/process_32.c | 19 ---------------- arch/sparc/include/asm/processor_64.h | 2 - arch/sparc/kernel/process_64.c | 28 ------------------------ arch/um/include/asm/processor-generic.h | 1 arch/um/kernel/process.c | 32 --------------------------- arch/x86/include/asm/processor.h | 2 - arch/x86/kernel/process.c | 14 ------------ arch/xtensa/include/asm/processor.h | 2 - arch/xtensa/kernel/process.c | 29 ------------------------- kernel/sched/core.c | 15 ++++++++++++ lib/Kconfig.debug | 7 ------ 40 files changed, 16 insertions(+), 476 deletions(-) --- a/arch/arc/include/asm/processor.h +++ b/arch/arc/include/asm/processor.h @@ -70,8 +70,6 @@ struct task_struct; extern void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long usp); -extern unsigned int __get_wchan(struct task_struct *p); - #endif /* !__ASSEMBLY__ */ /* --- a/arch/arc/kernel/stacktrace.c +++ b/arch/arc/kernel/stacktrace.c @@ -217,14 +217,6 @@ static int __collect_all_but_sched(unsig #endif -static int __get_first_nonsched(unsigned int address, void *unused) -{ - if (in_sched_functions(address)) - return 0; - - return -1; -} - /*------------------------------------------------------------------------- * APIs expected by various kernel sub-systems *------------------------------------------------------------------------- @@ -244,15 +236,6 @@ void show_stack(struct task_struct *tsk, show_stacktrace(tsk, NULL, loglvl); } -/* Another API expected by schedular, shows up in "ps" as Wait Channel - * Of course just returning schedule( ) would be pointless so unwind until - * the function is not in schedular code - */ -unsigned int __get_wchan(struct task_struct *tsk) -{ - return arc_unwind_core(tsk, NULL, __get_first_nonsched, NULL); -} - #ifdef CONFIG_STACKTRACE /* --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -84,8 +84,6 @@ struct task_struct; /* Free all resources held by a thread. */ extern void release_thread(struct task_struct *); -unsigned long __get_wchan(struct task_struct *p); - #define task_pt_regs(p) \ ((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1) --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -276,28 +276,6 @@ int copy_thread(unsigned long clone_flag return 0; } -unsigned long __get_wchan(struct task_struct *p) -{ - struct stackframe frame; - unsigned long stack_page; - int count = 0; - - frame.fp = thread_saved_fp(p); - frame.sp = thread_saved_sp(p); - frame.lr = 0; /* recovered from the stack */ - frame.pc = thread_saved_pc(p); - stack_page = (unsigned long)task_stack_page(p); - do { - if (frame.sp < stack_page || - frame.sp >= stack_page + THREAD_SIZE || - unwind_frame(&frame) < 0) - return 0; - if (!in_sched_functions(frame.pc)) - return frame.pc; - } while (count ++ < 16); - return 0; -} - #ifdef CONFIG_MMU #ifdef CONFIG_KUSER_HELPERS /* --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -257,8 +257,6 @@ struct task_struct; /* Free all resources held by a thread. */ extern void release_thread(struct task_struct *); -unsigned long __get_wchan(struct task_struct *p); - void update_sctlr_el1(u64 sctlr); /* Thread switching */ --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -528,32 +528,6 @@ __notrace_funcgraph struct task_struct * return last; } -unsigned long __get_wchan(struct task_struct *p) -{ - struct stackframe frame; - unsigned long stack_page, ret = 0; - int count = 0; - - stack_page = (unsigned long)try_get_task_stack(p); - if (!stack_page) - return 0; - - start_backtrace(&frame, thread_saved_fp(p), thread_saved_pc(p)); - - do { - if (unwind_frame(p, &frame)) - goto out; - if (!in_sched_functions(frame.pc)) { - ret = frame.pc; - goto out; - } - } while (count++ < 16); - -out: - put_task_stack(p); - return ret; -} - unsigned long arch_align_stack(unsigned long sp) { if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) --- a/arch/csky/include/asm/processor.h +++ b/arch/csky/include/asm/processor.h @@ -81,8 +81,6 @@ static inline void release_thread(struct extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); -unsigned long __get_wchan(struct task_struct *p); - #define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc) #define KSTK_ESP(tsk) (task_pt_regs(tsk)->usp) --- a/arch/csky/kernel/stacktrace.c +++ b/arch/csky/kernel/stacktrace.c @@ -101,24 +101,6 @@ void show_stack(struct task_struct *task walk_stackframe(task, NULL, print_trace_address, (void *)loglvl); } -static bool save_wchan(unsigned long pc, void *arg) -{ - if (!in_sched_functions(pc)) { - unsigned long *p = arg; - *p = pc; - return true; - } - return false; -} - -unsigned long __get_wchan(struct task_struct *task) -{ - unsigned long pc = 0; - - walk_stackframe(task, NULL, save_wchan, &pc); - return pc; -} - #ifdef CONFIG_STACKTRACE static bool __save_trace(unsigned long pc, void *arg, bool nosched) { --- a/arch/hexagon/include/asm/processor.h +++ b/arch/hexagon/include/asm/processor.h @@ -63,9 +63,6 @@ struct thread_struct { /* Free all resources held by a thread; defined in process.c */ extern void release_thread(struct task_struct *dead_task); -/* Get wait channel for task P. */ -extern unsigned long __get_wchan(struct task_struct *p); - /* The following stuff is pretty HEXAGON specific. */ /* This is really just here for __switch_to. --- a/arch/hexagon/kernel/process.c +++ b/arch/hexagon/kernel/process.c @@ -126,32 +126,6 @@ void flush_thread(void) } /* - * The "wait channel" terminology is archaic, but what we want - * is an identification of the point at which the scheduler - * was invoked by a blocked thread. - */ -unsigned long __get_wchan(struct task_struct *p) -{ - unsigned long fp, pc; - unsigned long stack_page; - int count = 0; - - stack_page = (unsigned long)task_stack_page(p); - fp = ((struct hexagon_switch_stack *)p->thread.switch_sp)->fp; - do { - if (fp < (stack_page + sizeof(struct thread_info)) || - fp >= (THREAD_SIZE - 8 + stack_page)) - return 0; - pc = ((unsigned long *)fp)[1]; - if (!in_sched_functions(pc)) - return pc; - fp = *(unsigned long *) fp; - } while (count++ < 16); - - return 0; -} - -/* * Called on the exit path of event entry; see vm_entry.S * * Interrupts will already be disabled. --- a/arch/ia64/include/asm/processor.h +++ b/arch/ia64/include/asm/processor.h @@ -329,9 +329,6 @@ struct task_struct; */ #define release_thread(dead_task) -/* Get wait channel for task P. */ -extern unsigned long __get_wchan (struct task_struct *p); - /* Return instruction pointer of blocked task TSK. */ #define KSTK_EIP(tsk) \ ({ \ --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -522,34 +522,6 @@ exit_thread (struct task_struct *tsk) ia64_drop_fpu(tsk); } -unsigned long -__get_wchan (struct task_struct *p) -{ - struct unw_frame_info info; - unsigned long ip; - int count = 0; - - /* - * Note: p may not be a blocked task (it could be current or - * another process running on some other CPU. Rather than - * trying to determine if p is really blocked, we just assume - * it's blocked and rely on the unwind routines to fail - * gracefully if the process wasn't really blocked after all. - * --davidm 99/12/15 - */ - unw_init_from_blocked_task(&info, p); - do { - if (task_is_running(p)) - return 0; - if (unw_unwind(&info) < 0) - return 0; - unw_get_ip(&info, &ip); - if (!in_sched_functions(ip)) - return ip; - } while (count++ < 16); - return 0; -} - void cpu_halt (void) { --- a/arch/microblaze/include/asm/processor.h +++ b/arch/microblaze/include/asm/processor.h @@ -68,8 +68,6 @@ static inline void release_thread(struct { } -unsigned long __get_wchan(struct task_struct *p); - /* The size allocated for kernel stacks. This _must_ be a power of two! */ # define KERNEL_STACK_SIZE 0x2000 --- a/arch/microblaze/kernel/process.c +++ b/arch/microblaze/kernel/process.c @@ -112,12 +112,6 @@ int copy_thread(unsigned long clone_flag return 0; } -unsigned long __get_wchan(struct task_struct *p) -{ -/* TBD (used by procfs) */ - return 0; -} - /* Set up a thread for executing a new program */ void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp) { --- a/arch/mips/include/asm/processor.h +++ b/arch/mips/include/asm/processor.h @@ -369,8 +369,6 @@ static inline void flush_thread(void) { } -unsigned long __get_wchan(struct task_struct *p); - #define __KSTK_TOS(tsk) ((unsigned long)task_stack_page(tsk) + \ THREAD_SIZE - 32 - sizeof(struct pt_regs)) #define task_pt_regs(tsk) ((struct pt_regs *)__KSTK_TOS(tsk)) --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -651,33 +651,6 @@ unsigned long unwind_stack(struct task_s } #endif -/* - * __get_wchan - a maintenance nightmare^W^Wpain in the ass ... - */ -unsigned long __get_wchan(struct task_struct *task) -{ - unsigned long pc = 0; -#ifdef CONFIG_KALLSYMS - unsigned long sp; - unsigned long ra = 0; -#endif - - if (!task_stack_page(task)) - goto out; - - pc = thread_saved_pc(task); - -#ifdef CONFIG_KALLSYMS - sp = task->thread.reg29 + schedule_mfi.frame_size; - - while (in_sched_functions(pc)) - pc = unwind_stack(task, &sp, pc, &ra); -#endif - -out: - return pc; -} - unsigned long mips_stack_top(void) { unsigned long top = TASK_SIZE & PAGE_MASK; --- a/arch/nds32/include/asm/processor.h +++ b/arch/nds32/include/asm/processor.h @@ -83,8 +83,6 @@ extern struct task_struct *last_task_use /* Prepare to copy thread state - unlazy all lazy status */ #define prepare_to_copy(tsk) do { } while (0) -unsigned long __get_wchan(struct task_struct *p); - #define cpu_relax() barrier() #define task_pt_regs(task) \ --- a/arch/nds32/kernel/process.c +++ b/arch/nds32/kernel/process.c @@ -232,26 +232,3 @@ int dump_fpu(struct pt_regs *regs, elf_f } EXPORT_SYMBOL(dump_fpu); - -unsigned long __get_wchan(struct task_struct *p) -{ - unsigned long fp, lr; - unsigned long stack_start, stack_end; - int count = 0; - - if (IS_ENABLED(CONFIG_FRAME_POINTER)) { - stack_start = (unsigned long)end_of_stack(p); - stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE; - - fp = thread_saved_fp(p); - do { - if (fp < stack_start || fp > stack_end) - return 0; - lr = ((unsigned long *)fp)[0]; - if (!in_sched_functions(lr)) - return lr; - fp = *(unsigned long *)(fp + 4); - } while (count++ < 16); - } - return 0; -} --- a/arch/openrisc/include/asm/processor.h +++ b/arch/openrisc/include/asm/processor.h @@ -73,7 +73,6 @@ struct thread_struct { void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp); void release_thread(struct task_struct *); -unsigned long __get_wchan(struct task_struct *p); #define cpu_relax() barrier() --- a/arch/openrisc/kernel/process.c +++ b/arch/openrisc/kernel/process.c @@ -263,9 +263,3 @@ void dump_elf_thread(elf_greg_t *dest, s dest[35] = 0; } -unsigned long __get_wchan(struct task_struct *p) -{ - /* TODO */ - - return 0; -} --- a/arch/parisc/include/asm/processor.h +++ b/arch/parisc/include/asm/processor.h @@ -273,8 +273,6 @@ struct mm_struct; /* Free all resources held by a thread. */ extern void release_thread(struct task_struct *); -extern unsigned long __get_wchan(struct task_struct *p); - #define KSTK_EIP(tsk) ((tsk)->thread.regs.iaoq[0]) #define KSTK_ESP(tsk) ((tsk)->thread.regs.gr[30]) --- a/arch/parisc/kernel/process.c +++ b/arch/parisc/kernel/process.c @@ -239,30 +239,6 @@ copy_thread(unsigned long clone_flags, u return 0; } -unsigned long -__get_wchan(struct task_struct *p) -{ - struct unwind_frame_info info; - unsigned long ip; - int count = 0; - - /* - * These bracket the sleeping functions.. - */ - - unwind_frame_init_from_blocked_task(&info, p); - do { - if (unwind_once(&info) < 0) - return 0; - if (task_is_running(p)) - return 0; - ip = info.ip; - if (!in_sched_functions(ip)) - return ip; - } while (count++ < MAX_UNWIND_ENTRIES); - return 0; -} - #ifdef CONFIG_64BIT void *dereference_function_descriptor(void *ptr) { --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -300,8 +300,6 @@ struct thread_struct { #define task_pt_regs(tsk) ((tsk)->thread.regs) -unsigned long __get_wchan(struct task_struct *p); - #define KSTK_EIP(tsk) ((tsk)->thread.regs? (tsk)->thread.regs->nip: 0) #define KSTK_ESP(tsk) ((tsk)->thread.regs? (tsk)->thread.regs->gpr[1]: 0) --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -2111,43 +2111,6 @@ int validate_sp(unsigned long sp, struct EXPORT_SYMBOL(validate_sp); -static unsigned long ___get_wchan(struct task_struct *p) -{ - unsigned long ip, sp; - int count = 0; - - sp = p->thread.ksp; - if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) - return 0; - - do { - sp = *(unsigned long *)sp; - if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) || - task_is_running(p)) - return 0; - if (count > 0) { - ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE]; - if (!in_sched_functions(ip)) - return ip; - } - } while (count++ < 16); - return 0; -} - -unsigned long __get_wchan(struct task_struct *p) -{ - unsigned long ret; - - if (!try_get_task_stack(p)) - return 0; - - ret = ___get_wchan(p); - - put_task_stack(p); - - return ret; -} - static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH; void __no_sanitize_address show_stack(struct task_struct *tsk, --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -66,9 +66,6 @@ static inline void release_thread(struct { } -extern unsigned long __get_wchan(struct task_struct *p); - - static inline void wait_for_interrupt(void) { __asm__ __volatile__ ("wfi"); --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -118,27 +118,6 @@ void show_stack(struct task_struct *task dump_backtrace(NULL, task, loglvl); } -static bool save_wchan(void *arg, unsigned long pc) -{ - if (!in_sched_functions(pc)) { - unsigned long *p = arg; - *p = pc; - return false; - } - return true; -} - -unsigned long __get_wchan(struct task_struct *task) -{ - unsigned long pc = 0; - - if (!try_get_task_stack(task)) - return 0; - walk_stackframe(task, NULL, save_wchan, &pc); - put_task_stack(task); - return pc; -} - #ifdef CONFIG_STACKTRACE noinline void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -192,7 +192,6 @@ static inline void release_thread(struct void guarded_storage_release(struct task_struct *tsk); void gs_load_bc_cb(struct pt_regs *regs); -unsigned long __get_wchan(struct task_struct *p); #define task_pt_regs(tsk) ((struct pt_regs *) \ (task_stack_page(tsk) + THREAD_SIZE) - 1) #define KSTK_EIP(tsk) (task_pt_regs(tsk)->psw.addr) --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -181,35 +181,6 @@ void execve_tail(void) asm volatile("sfpc %0" : : "d" (0)); } -unsigned long __get_wchan(struct task_struct *p) -{ - struct unwind_state state; - unsigned long ip = 0; - - if (!task_stack_page(p)) - return 0; - - if (!try_get_task_stack(p)) - return 0; - - unwind_for_each_frame(&state, p, NULL, 0) { - if (state.stack_info.type != STACK_TYPE_TASK) { - ip = 0; - break; - } - - ip = unwind_get_return_address(&state); - if (!ip) - break; - - if (!in_sched_functions(ip)) - break; - } - - put_task_stack(p); - return ip; -} - unsigned long arch_align_stack(unsigned long sp) { if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) --- a/arch/sh/include/asm/processor_32.h +++ b/arch/sh/include/asm/processor_32.h @@ -180,8 +180,6 @@ static inline void show_code(struct pt_r } #endif -extern unsigned long __get_wchan(struct task_struct *p); - #define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc) #define KSTK_ESP(tsk) (task_pt_regs(tsk)->regs[15]) --- a/arch/sh/kernel/process_32.c +++ b/arch/sh/kernel/process_32.c @@ -181,22 +181,3 @@ __switch_to(struct task_struct *prev, st return prev; } - -unsigned long __get_wchan(struct task_struct *p) -{ - unsigned long pc; - - /* - * The same comment as on the Alpha applies here, too ... - */ - pc = thread_saved_pc(p); - -#ifdef CONFIG_FRAME_POINTER - if (in_sched_functions(pc)) { - unsigned long schedule_frame = (unsigned long)p->thread.sp; - return ((unsigned long *)schedule_frame)[21]; - } -#endif - - return pc; -} --- a/arch/sparc/include/asm/processor_64.h +++ b/arch/sparc/include/asm/processor_64.h @@ -183,8 +183,6 @@ do { \ /* Free all resources held by a thread. */ #define release_thread(tsk) do { } while (0) -unsigned long __get_wchan(struct task_struct *task); - #define task_pt_regs(tsk) (task_thread_info(tsk)->kregs) #define KSTK_EIP(tsk) (task_pt_regs(tsk)->tpc) #define KSTK_ESP(tsk) (task_pt_regs(tsk)->u_regs[UREG_FP]) --- a/arch/sparc/kernel/process_64.c +++ b/arch/sparc/kernel/process_64.c @@ -662,31 +662,3 @@ int arch_dup_task_struct(struct task_str *dst = *src; return 0; } - -unsigned long __get_wchan(struct task_struct *task) -{ - unsigned long pc, fp, bias = 0; - struct thread_info *tp; - struct reg_window *rw; - unsigned long ret = 0; - int count = 0; - - tp = task_thread_info(task); - bias = STACK_BIAS; - fp = task_thread_info(task)->ksp + bias; - - do { - if (!kstack_valid(tp, fp)) - break; - rw = (struct reg_window *) fp; - pc = rw->ins[7]; - if (!in_sched_functions(pc)) { - ret = pc; - goto out; - } - fp = rw->ins[6] + bias; - } while (++count < 16); - -out: - return ret; -} --- a/arch/um/include/asm/processor-generic.h +++ b/arch/um/include/asm/processor-generic.h @@ -106,6 +106,5 @@ extern struct cpuinfo_um boot_cpu_data; #define cache_line_size() (boot_cpu_data.cache_alignment) #define KSTK_REG(tsk, reg) get_thread_reg(reg, &tsk->thread.switch_buf) -extern unsigned long __get_wchan(struct task_struct *p); #endif --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -364,38 +364,6 @@ unsigned long arch_align_stack(unsigned } #endif -unsigned long __get_wchan(struct task_struct *p) -{ - unsigned long stack_page, sp, ip; - bool seen_sched = 0; - - stack_page = (unsigned long) task_stack_page(p); - /* Bail if the process has no kernel stack for some reason */ - if (stack_page == 0) - return 0; - - sp = p->thread.switch_buf->JB_SP; - /* - * Bail if the stack pointer is below the bottom of the kernel - * stack for some reason - */ - if (sp < stack_page) - return 0; - - while (sp < stack_page + THREAD_SIZE) { - ip = *((unsigned long *) sp); - if (in_sched_functions(ip)) - /* Ignore everything until we're above the scheduler */ - seen_sched = 1; - else if (kernel_text_address(ip) && seen_sched) - return ip; - - sp += sizeof(unsigned long); - } - - return 0; -} - int elf_core_copy_fpregs(struct task_struct *t, elf_fpregset_t *fpu) { int cpu = current_thread_info()->cpu; --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -590,8 +590,6 @@ static inline void load_sp0(unsigned lon /* Free all resources held by a thread. */ extern void release_thread(struct task_struct *); -unsigned long __get_wchan(struct task_struct *p); - /* * Generic CPUID function * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -937,20 +937,6 @@ unsigned long arch_randomize_brk(struct return randomize_page(mm->brk, 0x02000000); } -/* - * Called from fs/proc with a reference on @p to find the function - * which called into schedule(). This needs to be done carefully - * because the task might wake up and we might look at a stack - * changing under us. - */ -unsigned long __get_wchan(struct task_struct *p) -{ - unsigned long entry = 0; - - stack_trace_save_tsk(p, &entry, 1, 0); - return entry; -} - long do_arch_prctl_common(struct task_struct *task, int option, unsigned long cpuid_enabled) { --- a/arch/xtensa/include/asm/processor.h +++ b/arch/xtensa/include/asm/processor.h @@ -215,8 +215,6 @@ struct mm_struct; /* Free all resources held by a thread. */ #define release_thread(thread) do { } while(0) -extern unsigned long __get_wchan(struct task_struct *p); - #define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc) #define KSTK_ESP(tsk) (task_pt_regs(tsk)->areg[1]) --- a/arch/xtensa/kernel/process.c +++ b/arch/xtensa/kernel/process.c @@ -293,32 +293,3 @@ int copy_thread(unsigned long clone_flag return 0; } - -/* - * These bracket the sleeping functions.. - */ - -unsigned long __get_wchan(struct task_struct *p) -{ - unsigned long sp, pc; - unsigned long stack_page = (unsigned long) task_stack_page(p); - int count = 0; - - sp = p->thread.sp; - pc = MAKE_PC_FROM_RA(p->thread.ra, p->thread.sp); - - do { - if (sp < stack_page + sizeof(struct task_struct) || - sp >= (stack_page + THREAD_SIZE) || - pc == 0) - return 0; - if (!in_sched_functions(pc)) - return pc; - - /* Stack layout: sp-4: ra, sp-3: sp' */ - - pc = MAKE_PC_FROM_RA(SPILL_SLOT(sp, 0), sp); - sp = SPILL_SLOT(sp, 1); - } while (count++ < 16); - return 0; -} --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1966,6 +1966,21 @@ bool sched_task_on_rq(struct task_struct return task_on_rq_queued(p); } +#ifdef CONFIG_STACKTRACE +static unsigned long __get_wchan(struct task_struct *p) +{ + unsigned long entry = 0; + + stack_trace_save_tsk(p, &entry, 1, 0); + + return entry; +} +#endif + +/* + * Called from fs/proc with a reference on @p to find the function + * which called into schedule(). + */ unsigned long get_wchan(struct task_struct *p) { unsigned long ip = 0; --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1531,13 +1531,8 @@ config DEBUG_IRQFLAGS are enabled. config STACKTRACE - bool "Stack backtrace support" + def_bool y depends on STACKTRACE_SUPPORT - help - This option causes the kernel to create a /proc/pid/stack for - every process, showing its current stack trace. - It is also used by various kernel debugging features that require - stack trace generation. config WARN_ALL_UNSEEDED_RANDOM bool "Warn for all uses of unseeded randomness"