From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A660DC49ED7 for ; Fri, 13 Sep 2019 13:31:09 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EC18A205ED for ; Fri, 13 Sep 2019 13:31:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC18A205ED Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46VGk15qgnzF4pk for ; Fri, 13 Sep 2019 23:31:05 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=suse.de (client-ip=195.135.220.15; helo=mx1.suse.de; envelope-from=msuchanek@suse.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=suse.de Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46VG0B3rgRzF5VT for ; Fri, 13 Sep 2019 22:58:18 +1000 (AEST) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 86A65B601; Fri, 13 Sep 2019 12:58:15 +0000 (UTC) From: Michal Suchanek To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v9 8/8] powerpc/perf: split callchain.c by bitness Date: Fri, 13 Sep 2019 14:58:02 +0200 Message-Id: X-Mailer: git-send-email 2.23.0 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Madhavan Srinivasan , David Hildenbrand , Heiko Carstens , Paul Mackerras , Breno Leitao , Michael Neuling , Diana Craciun , Firoz Khan , Hari Bathini , Michal Suchanek , Joel Stanley , Arnd Bergmann , Nicholas Piggin , Alexander Viro , Thomas Gleixner , Allison Randal , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, "Eric W. Biederman" , Andrew Donnellan , linux-fsdevel@vger.kernel.org, Andrew Morton Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Building callchain.c with !COMPAT proved quite ugly with all the defines. Splitting out the 32bit and 64bit parts looks better. No code change intended. Signed-off-by: Michal Suchanek --- v6: - move current_is_64bit consolidetaion to earlier patch - move defines to the top of callchain_32.c - Makefile cleanup v8: - fix valid_user_sp --- arch/powerpc/perf/Makefile | 5 +- arch/powerpc/perf/callchain.c | 367 +------------------------------ arch/powerpc/perf/callchain.h | 25 +++ arch/powerpc/perf/callchain_32.c | 197 +++++++++++++++++ arch/powerpc/perf/callchain_64.c | 178 +++++++++++++++ 5 files changed, 405 insertions(+), 367 deletions(-) create mode 100644 arch/powerpc/perf/callchain.h create mode 100644 arch/powerpc/perf/callchain_32.c create mode 100644 arch/powerpc/perf/callchain_64.c diff --git a/arch/powerpc/perf/Makefile b/arch/powerpc/perf/Makefile index c155dcbb8691..53d614e98537 100644 --- a/arch/powerpc/perf/Makefile +++ b/arch/powerpc/perf/Makefile @@ -1,6 +1,9 @@ # SPDX-License-Identifier: GPL-2.0 -obj-$(CONFIG_PERF_EVENTS) += callchain.o perf_regs.o +obj-$(CONFIG_PERF_EVENTS) += callchain.o callchain_$(BITS).o perf_regs.o +ifdef CONFIG_COMPAT +obj-$(CONFIG_PERF_EVENTS) += callchain_32.o +endif obj-$(CONFIG_PPC_PERF_CTRS) += core-book3s.o bhrb.o obj64-$(CONFIG_PPC_PERF_CTRS) += ppc970-pmu.o power5-pmu.o \ diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c index d6ab1a734a6a..dd5051015008 100644 --- a/arch/powerpc/perf/callchain.c +++ b/arch/powerpc/perf/callchain.c @@ -15,11 +15,9 @@ #include #include #include -#ifdef CONFIG_COMPAT -#include "../kernel/ppc32.h" -#endif #include +#include "callchain.h" /* * Is sp valid as the address of the next kernel stack frame after prev_sp? @@ -102,369 +100,6 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re } } -static inline int valid_user_sp(unsigned long sp, int is_64) -{ - unsigned long stack_top; - - if (IS_ENABLED(CONFIG_PPC32)) - stack_top = STACK_TOP; - else /* STACK_TOP uses is_32bit_task() but we want is_64 */ - stack_top = is_64 ? STACK_TOP_USER64 : STACK_TOP_USER32; - - if (!sp || (sp & (is_64 ? 7 : 3)) || sp > stack_top - (is_64 ? 32 : 16)) - return 0; - return 1; -} - -#ifdef CONFIG_PPC64 -/* - * On 64-bit we don't want to invoke hash_page on user addresses from - * interrupt context, so if the access faults, we read the page tables - * to find which page (if any) is mapped and access it directly. - */ -static int read_user_stack_slow(void __user *ptr, void *buf, int nb) -{ - int ret = -EFAULT; - pgd_t *pgdir; - pte_t *ptep, pte; - unsigned shift; - unsigned long addr = (unsigned long) ptr; - unsigned long offset; - unsigned long pfn, flags; - void *kaddr; - - pgdir = current->mm->pgd; - if (!pgdir) - return -EFAULT; - - local_irq_save(flags); - ptep = find_current_mm_pte(pgdir, addr, NULL, &shift); - if (!ptep) - goto err_out; - if (!shift) - shift = PAGE_SHIFT; - - /* align address to page boundary */ - offset = addr & ((1UL << shift) - 1); - - pte = READ_ONCE(*ptep); - if (!pte_present(pte) || !pte_user(pte)) - goto err_out; - pfn = pte_pfn(pte); - if (!page_is_ram(pfn)) - goto err_out; - - /* no highmem to worry about here */ - kaddr = pfn_to_kaddr(pfn); - memcpy(buf, kaddr + offset, nb); - ret = 0; -err_out: - local_irq_restore(flags); - return ret; -} - -static int read_user_stack_64(unsigned long __user *ptr, unsigned long *ret) -{ - if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned long) || - ((unsigned long)ptr & 7)) - return -EFAULT; - - pagefault_disable(); - if (!__get_user_inatomic(*ret, ptr)) { - pagefault_enable(); - return 0; - } - pagefault_enable(); - - return read_user_stack_slow(ptr, ret, 8); -} - -/* - * 64-bit user processes use the same stack frame for RT and non-RT signals. - */ -struct signal_frame_64 { - char dummy[__SIGNAL_FRAMESIZE]; - struct ucontext uc; - unsigned long unused[2]; - unsigned int tramp[6]; - struct siginfo *pinfo; - void *puc; - struct siginfo info; - char abigap[288]; -}; - -static int is_sigreturn_64_address(unsigned long nip, unsigned long fp) -{ - if (nip == fp + offsetof(struct signal_frame_64, tramp)) - return 1; - if (vdso64_rt_sigtramp && current->mm->context.vdso_base && - nip == current->mm->context.vdso_base + vdso64_rt_sigtramp) - return 1; - return 0; -} - -/* - * Do some sanity checking on the signal frame pointed to by sp. - * We check the pinfo and puc pointers in the frame. - */ -static int sane_signal_64_frame(unsigned long sp) -{ - struct signal_frame_64 __user *sf; - unsigned long pinfo, puc; - - sf = (struct signal_frame_64 __user *) sp; - if (read_user_stack_64((unsigned long __user *) &sf->pinfo, &pinfo) || - read_user_stack_64((unsigned long __user *) &sf->puc, &puc)) - return 0; - return pinfo == (unsigned long) &sf->info && - puc == (unsigned long) &sf->uc; -} - -static void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry, - struct pt_regs *regs) -{ - unsigned long sp, next_sp; - unsigned long next_ip; - unsigned long lr; - long level = 0; - struct signal_frame_64 __user *sigframe; - unsigned long __user *fp, *uregs; - - next_ip = perf_instruction_pointer(regs); - lr = regs->link; - sp = regs->gpr[1]; - perf_callchain_store(entry, next_ip); - - while (entry->nr < entry->max_stack) { - fp = (unsigned long __user *) sp; - if (!valid_user_sp(sp, 1) || read_user_stack_64(fp, &next_sp)) - return; - if (level > 0 && read_user_stack_64(&fp[2], &next_ip)) - return; - - /* - * Note: the next_sp - sp >= signal frame size check - * is true when next_sp < sp, which can happen when - * transitioning from an alternate signal stack to the - * normal stack. - */ - if (next_sp - sp >= sizeof(struct signal_frame_64) && - (is_sigreturn_64_address(next_ip, sp) || - (level <= 1 && is_sigreturn_64_address(lr, sp))) && - sane_signal_64_frame(sp)) { - /* - * This looks like an signal frame - */ - sigframe = (struct signal_frame_64 __user *) sp; - uregs = sigframe->uc.uc_mcontext.gp_regs; - if (read_user_stack_64(&uregs[PT_NIP], &next_ip) || - read_user_stack_64(&uregs[PT_LNK], &lr) || - read_user_stack_64(&uregs[PT_R1], &sp)) - return; - level = 0; - perf_callchain_store_context(entry, PERF_CONTEXT_USER); - perf_callchain_store(entry, next_ip); - continue; - } - - if (level == 0) - next_ip = lr; - perf_callchain_store(entry, next_ip); - ++level; - sp = next_sp; - } -} - -#else /* CONFIG_PPC64 */ -static int read_user_stack_slow(void __user *ptr, void *buf, int nb) -{ - return 0; -} - -static inline void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry, - struct pt_regs *regs) -{ -} - -#define __SIGNAL_FRAMESIZE32 __SIGNAL_FRAMESIZE -#define sigcontext32 sigcontext -#define mcontext32 mcontext -#define ucontext32 ucontext -#define compat_siginfo_t struct siginfo - -#endif /* CONFIG_PPC64 */ - -#if defined(CONFIG_PPC32) || defined(CONFIG_COMPAT) -/* - * On 32-bit we just access the address and let hash_page create a - * HPTE if necessary, so there is no need to fall back to reading - * the page tables. Since this is called at interrupt level, - * do_page_fault() won't treat a DSI as a page fault. - */ -static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret) -{ - int rc; - - if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) || - ((unsigned long)ptr & 3)) - return -EFAULT; - - pagefault_disable(); - rc = __get_user_inatomic(*ret, ptr); - pagefault_enable(); - - if (IS_ENABLED(CONFIG_PPC64) && rc) - return read_user_stack_slow(ptr, ret, 4); - return rc; -} - -/* - * Layout for non-RT signal frames - */ -struct signal_frame_32 { - char dummy[__SIGNAL_FRAMESIZE32]; - struct sigcontext32 sctx; - struct mcontext32 mctx; - int abigap[56]; -}; - -/* - * Layout for RT signal frames - */ -struct rt_signal_frame_32 { - char dummy[__SIGNAL_FRAMESIZE32 + 16]; - compat_siginfo_t info; - struct ucontext32 uc; - int abigap[56]; -}; - -static int is_sigreturn_32_address(unsigned int nip, unsigned int fp) -{ - if (nip == fp + offsetof(struct signal_frame_32, mctx.mc_pad)) - return 1; - if (vdso32_sigtramp && current->mm->context.vdso_base && - nip == current->mm->context.vdso_base + vdso32_sigtramp) - return 1; - return 0; -} - -static int is_rt_sigreturn_32_address(unsigned int nip, unsigned int fp) -{ - if (nip == fp + offsetof(struct rt_signal_frame_32, - uc.uc_mcontext.mc_pad)) - return 1; - if (vdso32_rt_sigtramp && current->mm->context.vdso_base && - nip == current->mm->context.vdso_base + vdso32_rt_sigtramp) - return 1; - return 0; -} - -static int sane_signal_32_frame(unsigned int sp) -{ - struct signal_frame_32 __user *sf; - unsigned int regs; - - sf = (struct signal_frame_32 __user *) (unsigned long) sp; - if (read_user_stack_32((unsigned int __user *) &sf->sctx.regs, ®s)) - return 0; - return regs == (unsigned long) &sf->mctx; -} - -static int sane_rt_signal_32_frame(unsigned int sp) -{ - struct rt_signal_frame_32 __user *sf; - unsigned int regs; - - sf = (struct rt_signal_frame_32 __user *) (unsigned long) sp; - if (read_user_stack_32((unsigned int __user *) &sf->uc.uc_regs, ®s)) - return 0; - return regs == (unsigned long) &sf->uc.uc_mcontext; -} - -static unsigned int __user *signal_frame_32_regs(unsigned int sp, - unsigned int next_sp, unsigned int next_ip) -{ - struct mcontext32 __user *mctx = NULL; - struct signal_frame_32 __user *sf; - struct rt_signal_frame_32 __user *rt_sf; - - /* - * Note: the next_sp - sp >= signal frame size check - * is true when next_sp < sp, for example, when - * transitioning from an alternate signal stack to the - * normal stack. - */ - if (next_sp - sp >= sizeof(struct signal_frame_32) && - is_sigreturn_32_address(next_ip, sp) && - sane_signal_32_frame(sp)) { - sf = (struct signal_frame_32 __user *) (unsigned long) sp; - mctx = &sf->mctx; - } - - if (!mctx && next_sp - sp >= sizeof(struct rt_signal_frame_32) && - is_rt_sigreturn_32_address(next_ip, sp) && - sane_rt_signal_32_frame(sp)) { - rt_sf = (struct rt_signal_frame_32 __user *) (unsigned long) sp; - mctx = &rt_sf->uc.uc_mcontext; - } - - if (!mctx) - return NULL; - return mctx->mc_gregs; -} - -static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry, - struct pt_regs *regs) -{ - unsigned int sp, next_sp; - unsigned int next_ip; - unsigned int lr; - long level = 0; - unsigned int __user *fp, *uregs; - - next_ip = perf_instruction_pointer(regs); - lr = regs->link; - sp = regs->gpr[1]; - perf_callchain_store(entry, next_ip); - - while (entry->nr < entry->max_stack) { - fp = (unsigned int __user *) (unsigned long) sp; - if (!valid_user_sp(sp, 0) || read_user_stack_32(fp, &next_sp)) - return; - if (level > 0 && read_user_stack_32(&fp[1], &next_ip)) - return; - - uregs = signal_frame_32_regs(sp, next_sp, next_ip); - if (!uregs && level <= 1) - uregs = signal_frame_32_regs(sp, next_sp, lr); - if (uregs) { - /* - * This looks like an signal frame, so restart - * the stack trace with the values in it. - */ - if (read_user_stack_32(&uregs[PT_NIP], &next_ip) || - read_user_stack_32(&uregs[PT_LNK], &lr) || - read_user_stack_32(&uregs[PT_R1], &sp)) - return; - level = 0; - perf_callchain_store_context(entry, PERF_CONTEXT_USER); - perf_callchain_store(entry, next_ip); - continue; - } - - if (level == 0) - next_ip = lr; - perf_callchain_store(entry, next_ip); - ++level; - sp = next_sp; - } -} -#else /* 32bit */ -static void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry, - struct pt_regs *regs) -{} -#endif /* 32bit */ - void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { diff --git a/arch/powerpc/perf/callchain.h b/arch/powerpc/perf/callchain.h new file mode 100644 index 000000000000..76905c195497 --- /dev/null +++ b/arch/powerpc/perf/callchain.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _POWERPC_PERF_CALLCHAIN_H +#define _POWERPC_PERF_CALLCHAIN_H + +int read_user_stack_slow(void __user *ptr, void *buf, int nb); +void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry, + struct pt_regs *regs); +void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry, + struct pt_regs *regs); + +static inline int valid_user_sp(unsigned long sp, int is_64) +{ + unsigned long stack_top; + + if (IS_ENABLED(CONFIG_PPC32)) + stack_top = STACK_TOP; + else /* STACK_TOP uses is_32bit_task() but we want is_64 */ + stack_top = is_64 ? STACK_TOP_USER64 : STACK_TOP_USER32; + + if (!sp || (sp & (is_64 ? 7 : 3)) || sp > stack_top - (is_64 ? 32 : 16)) + return 0; + return 1; +} + +#endif /* _POWERPC_PERF_CALLCHAIN_H */ diff --git a/arch/powerpc/perf/callchain_32.c b/arch/powerpc/perf/callchain_32.c new file mode 100644 index 000000000000..ae69d60953b8 --- /dev/null +++ b/arch/powerpc/perf/callchain_32.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Performance counter callchain support - powerpc architecture code + * + * Copyright © 2009 Paul Mackerras, IBM Corporation. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "callchain.h" + +#ifdef CONFIG_PPC64 +#include "../kernel/ppc32.h" +#else /* CONFIG_PPC64 */ + +#define __SIGNAL_FRAMESIZE32 __SIGNAL_FRAMESIZE +#define sigcontext32 sigcontext +#define mcontext32 mcontext +#define ucontext32 ucontext +#define compat_siginfo_t struct siginfo + +#endif /* CONFIG_PPC64 */ + +/* + * On 32-bit we just access the address and let hash_page create a + * HPTE if necessary, so there is no need to fall back to reading + * the page tables. Since this is called at interrupt level, + * do_page_fault() won't treat a DSI as a page fault. + */ +static int read_user_stack_32(unsigned int __user *ptr, unsigned int *ret) +{ + int rc; + + if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned int) || + ((unsigned long)ptr & 3)) + return -EFAULT; + + pagefault_disable(); + rc = __get_user_inatomic(*ret, ptr); + pagefault_enable(); + + if (IS_ENABLED(CONFIG_PPC64) && rc) + return read_user_stack_slow(ptr, ret, 4); + return rc; +} + +/* + * Layout for non-RT signal frames + */ +struct signal_frame_32 { + char dummy[__SIGNAL_FRAMESIZE32]; + struct sigcontext32 sctx; + struct mcontext32 mctx; + int abigap[56]; +}; + +/* + * Layout for RT signal frames + */ +struct rt_signal_frame_32 { + char dummy[__SIGNAL_FRAMESIZE32 + 16]; + compat_siginfo_t info; + struct ucontext32 uc; + int abigap[56]; +}; + +static int is_sigreturn_32_address(unsigned int nip, unsigned int fp) +{ + if (nip == fp + offsetof(struct signal_frame_32, mctx.mc_pad)) + return 1; + if (vdso32_sigtramp && current->mm->context.vdso_base && + nip == current->mm->context.vdso_base + vdso32_sigtramp) + return 1; + return 0; +} + +static int is_rt_sigreturn_32_address(unsigned int nip, unsigned int fp) +{ + if (nip == fp + offsetof(struct rt_signal_frame_32, + uc.uc_mcontext.mc_pad)) + return 1; + if (vdso32_rt_sigtramp && current->mm->context.vdso_base && + nip == current->mm->context.vdso_base + vdso32_rt_sigtramp) + return 1; + return 0; +} + +static int sane_signal_32_frame(unsigned int sp) +{ + struct signal_frame_32 __user *sf; + unsigned int regs; + + sf = (struct signal_frame_32 __user *) (unsigned long) sp; + if (read_user_stack_32((unsigned int __user *) &sf->sctx.regs, ®s)) + return 0; + return regs == (unsigned long) &sf->mctx; +} + +static int sane_rt_signal_32_frame(unsigned int sp) +{ + struct rt_signal_frame_32 __user *sf; + unsigned int regs; + + sf = (struct rt_signal_frame_32 __user *) (unsigned long) sp; + if (read_user_stack_32((unsigned int __user *) &sf->uc.uc_regs, ®s)) + return 0; + return regs == (unsigned long) &sf->uc.uc_mcontext; +} + +static unsigned int __user *signal_frame_32_regs(unsigned int sp, + unsigned int next_sp, unsigned int next_ip) +{ + struct mcontext32 __user *mctx = NULL; + struct signal_frame_32 __user *sf; + struct rt_signal_frame_32 __user *rt_sf; + + /* + * Note: the next_sp - sp >= signal frame size check + * is true when next_sp < sp, for example, when + * transitioning from an alternate signal stack to the + * normal stack. + */ + if (next_sp - sp >= sizeof(struct signal_frame_32) && + is_sigreturn_32_address(next_ip, sp) && + sane_signal_32_frame(sp)) { + sf = (struct signal_frame_32 __user *) (unsigned long) sp; + mctx = &sf->mctx; + } + + if (!mctx && next_sp - sp >= sizeof(struct rt_signal_frame_32) && + is_rt_sigreturn_32_address(next_ip, sp) && + sane_rt_signal_32_frame(sp)) { + rt_sf = (struct rt_signal_frame_32 __user *) (unsigned long) sp; + mctx = &rt_sf->uc.uc_mcontext; + } + + if (!mctx) + return NULL; + return mctx->mc_gregs; +} + +void perf_callchain_user_32(struct perf_callchain_entry_ctx *entry, + struct pt_regs *regs) +{ + unsigned int sp, next_sp; + unsigned int next_ip; + unsigned int lr; + long level = 0; + unsigned int __user *fp, *uregs; + + next_ip = perf_instruction_pointer(regs); + lr = regs->link; + sp = regs->gpr[1]; + perf_callchain_store(entry, next_ip); + + while (entry->nr < entry->max_stack) { + fp = (unsigned int __user *) (unsigned long) sp; + if (!valid_user_sp(sp, 0) || read_user_stack_32(fp, &next_sp)) + return; + if (level > 0 && read_user_stack_32(&fp[1], &next_ip)) + return; + + uregs = signal_frame_32_regs(sp, next_sp, next_ip); + if (!uregs && level <= 1) + uregs = signal_frame_32_regs(sp, next_sp, lr); + if (uregs) { + /* + * This looks like an signal frame, so restart + * the stack trace with the values in it. + */ + if (read_user_stack_32(&uregs[PT_NIP], &next_ip) || + read_user_stack_32(&uregs[PT_LNK], &lr) || + read_user_stack_32(&uregs[PT_R1], &sp)) + return; + level = 0; + perf_callchain_store_context(entry, PERF_CONTEXT_USER); + perf_callchain_store(entry, next_ip); + continue; + } + + if (level == 0) + next_ip = lr; + perf_callchain_store(entry, next_ip); + ++level; + sp = next_sp; + } +} diff --git a/arch/powerpc/perf/callchain_64.c b/arch/powerpc/perf/callchain_64.c new file mode 100644 index 000000000000..0a32e0bc4f03 --- /dev/null +++ b/arch/powerpc/perf/callchain_64.c @@ -0,0 +1,178 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Performance counter callchain support - powerpc architecture code + * + * Copyright © 2009 Paul Mackerras, IBM Corporation. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "callchain.h" + +/* + * On 64-bit we don't want to invoke hash_page on user addresses from + * interrupt context, so if the access faults, we read the page tables + * to find which page (if any) is mapped and access it directly. + */ +int read_user_stack_slow(void __user *ptr, void *buf, int nb) +{ + int ret = -EFAULT; + pgd_t *pgdir; + pte_t *ptep, pte; + unsigned int shift; + unsigned long addr = (unsigned long) ptr; + unsigned long offset; + unsigned long pfn, flags; + void *kaddr; + + pgdir = current->mm->pgd; + if (!pgdir) + return -EFAULT; + + local_irq_save(flags); + ptep = find_current_mm_pte(pgdir, addr, NULL, &shift); + if (!ptep) + goto err_out; + if (!shift) + shift = PAGE_SHIFT; + + /* align address to page boundary */ + offset = addr & ((1UL << shift) - 1); + + pte = READ_ONCE(*ptep); + if (!pte_present(pte) || !pte_user(pte)) + goto err_out; + pfn = pte_pfn(pte); + if (!page_is_ram(pfn)) + goto err_out; + + /* no highmem to worry about here */ + kaddr = pfn_to_kaddr(pfn); + memcpy(buf, kaddr + offset, nb); + ret = 0; +err_out: + local_irq_restore(flags); + return ret; +} + +static int read_user_stack_64(unsigned long __user *ptr, unsigned long *ret) +{ + if ((unsigned long)ptr > TASK_SIZE - sizeof(unsigned long) || + ((unsigned long)ptr & 7)) + return -EFAULT; + + pagefault_disable(); + if (!__get_user_inatomic(*ret, ptr)) { + pagefault_enable(); + return 0; + } + pagefault_enable(); + + return read_user_stack_slow(ptr, ret, 8); +} + +/* + * 64-bit user processes use the same stack frame for RT and non-RT signals. + */ +struct signal_frame_64 { + char dummy[__SIGNAL_FRAMESIZE]; + struct ucontext uc; + unsigned long unused[2]; + unsigned int tramp[6]; + struct siginfo *pinfo; + void *puc; + struct siginfo info; + char abigap[288]; +}; + +static int is_sigreturn_64_address(unsigned long nip, unsigned long fp) +{ + if (nip == fp + offsetof(struct signal_frame_64, tramp)) + return 1; + if (vdso64_rt_sigtramp && current->mm->context.vdso_base && + nip == current->mm->context.vdso_base + vdso64_rt_sigtramp) + return 1; + return 0; +} + +/* + * Do some sanity checking on the signal frame pointed to by sp. + * We check the pinfo and puc pointers in the frame. + */ +static int sane_signal_64_frame(unsigned long sp) +{ + struct signal_frame_64 __user *sf; + unsigned long pinfo, puc; + + sf = (struct signal_frame_64 __user *) sp; + if (read_user_stack_64((unsigned long __user *) &sf->pinfo, &pinfo) || + read_user_stack_64((unsigned long __user *) &sf->puc, &puc)) + return 0; + return pinfo == (unsigned long) &sf->info && + puc == (unsigned long) &sf->uc; +} + +void perf_callchain_user_64(struct perf_callchain_entry_ctx *entry, + struct pt_regs *regs) +{ + unsigned long sp, next_sp; + unsigned long next_ip; + unsigned long lr; + long level = 0; + struct signal_frame_64 __user *sigframe; + unsigned long __user *fp, *uregs; + + next_ip = perf_instruction_pointer(regs); + lr = regs->link; + sp = regs->gpr[1]; + perf_callchain_store(entry, next_ip); + + while (entry->nr < entry->max_stack) { + fp = (unsigned long __user *) sp; + if (!valid_user_sp(sp, 1) || read_user_stack_64(fp, &next_sp)) + return; + if (level > 0 && read_user_stack_64(&fp[2], &next_ip)) + return; + + /* + * Note: the next_sp - sp >= signal frame size check + * is true when next_sp < sp, which can happen when + * transitioning from an alternate signal stack to the + * normal stack. + */ + if (next_sp - sp >= sizeof(struct signal_frame_64) && + (is_sigreturn_64_address(next_ip, sp) || + (level <= 1 && is_sigreturn_64_address(lr, sp))) && + sane_signal_64_frame(sp)) { + /* + * This looks like an signal frame + */ + sigframe = (struct signal_frame_64 __user *) sp; + uregs = sigframe->uc.uc_mcontext.gp_regs; + if (read_user_stack_64(&uregs[PT_NIP], &next_ip) || + read_user_stack_64(&uregs[PT_LNK], &lr) || + read_user_stack_64(&uregs[PT_R1], &sp)) + return; + level = 0; + perf_callchain_store_context(entry, PERF_CONTEXT_USER); + perf_callchain_store(entry, next_ip); + continue; + } + + if (level == 0) + next_ip = lr; + perf_callchain_store(entry, next_ip); + ++level; + sp = next_sp; + } +} -- 2.23.0