From patchwork Thu Jul 19 23:28:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laura Abbott X-Patchwork-Id: 10535681 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E9E35603B5 for ; Thu, 19 Jul 2018 23:28:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E355D29AC6 for ; Thu, 19 Jul 2018 23:28:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D72F129B04; Thu, 19 Jul 2018 23:28:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id A586629AC6 for ; Thu, 19 Jul 2018 23:28:45 +0000 (UTC) Received: (qmail 31949 invoked by uid 550); 19 Jul 2018 23:28:28 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 31866 invoked from network); 19 Jul 2018 23:28:27 -0000 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=fBabB29QkCUWDmAYSjnnQuwE5ckz2qn5sPmx5AWbtm4=; b=ofN0u9E/LUhYsthsd54v/uyB1neH9uRf+xOMe4dK5wNRidmnWRO6eVqfGrk6gawvkE FXh3lNeEaCXJ4Hu1kRGIVeX+wyEXP54j9LmhskAYU/S1wTJDKPSwewOixgxdJ3c1bc2e lRIyZ+mkSFVAtyTAbxxTCb70NhXPSrshrG3QfEfFjGo4qUNNInod2302h5Y3Fo4QXl1q HijQ8ncjIdb40BF+iVoQiFyY+/v13mWH0zVw094NypD+uq9oMqVl1aO6QXD51gkxXKXI 8SCIi05+x/aTvUrjxqOnR8YtHELcxeXcrO5O7x/lhXnIlSxN8ONzE75jDr9tkGasF7wy Yv4w== X-Gm-Message-State: AOUpUlGKIrB+yXrZ8D/Qf6DSr10gi2MvOzDw4Nrp+oL3a3nqxQSGqyQq fSAcIK+x7KvfJCF1LqzYDpo76Q== X-Google-Smtp-Source: AAOMgpdxa/BwXlDIumg3TZKP5MNGclW7kVZDJqUwH9GnT2MC+ZS9CNzuybuiiPsMliXd4zKEuO/Xtg== X-Received: by 2002:a37:1999:: with SMTP id 25-v6mr10825309qkz.405.1532042895544; Thu, 19 Jul 2018 16:28:15 -0700 (PDT) From: Laura Abbott To: Alexander Popov , Kees Cook , Mark Rutland , Ard Biesheuvel Cc: Laura Abbott , kernel-hardening@lists.openwall.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Will Deacon , Catalin Marinas Subject: [PATCHv2 1/2] arm64: Add stack information to on_accessible_stack Date: Thu, 19 Jul 2018 16:28:05 -0700 Message-Id: <20180719232806.3397-2-labbott@redhat.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180719232806.3397-1-labbott@redhat.com> References: <20180719232806.3397-1-labbott@redhat.com> X-Virus-Scanned: ClamAV using ClamSMTP In preparation for enabling the stackleak plugin on arm64, we need a way to get the bounds of the current stack. Extend on_accessible_stack to get this information. Signed-off-by: Laura Abbott Reviewed-by: Mark Rutland --- v2: Switched to using struct stack_info for argument passing. on_accessible_stack is now the primary API. Split STACK_TYPE_SDEI into STACK_TYPE_SDEI_NORMAL and STACK_TYPE_SDEI_CRITICAL. --- arch/arm64/include/asm/sdei.h | 9 ++-- arch/arm64/include/asm/stacktrace.h | 73 ++++++++++++++++++++++++----- arch/arm64/kernel/ptrace.c | 2 +- arch/arm64/kernel/sdei.c | 51 ++++++++++++++++---- arch/arm64/kernel/stacktrace.c | 2 +- 5 files changed, 112 insertions(+), 25 deletions(-) diff --git a/arch/arm64/include/asm/sdei.h b/arch/arm64/include/asm/sdei.h index e073e6886685..ffe47d766c25 100644 --- a/arch/arm64/include/asm/sdei.h +++ b/arch/arm64/include/asm/sdei.h @@ -40,15 +40,18 @@ asmlinkage unsigned long __sdei_handler(struct pt_regs *regs, unsigned long sdei_arch_get_entry_point(int conduit); #define sdei_arch_get_entry_point(x) sdei_arch_get_entry_point(x) -bool _on_sdei_stack(unsigned long sp); -static inline bool on_sdei_stack(unsigned long sp) +struct stack_info; + +bool _on_sdei_stack(unsigned long sp, struct stack_info *info); +static inline bool on_sdei_stack(unsigned long sp, + struct stack_info *info) { if (!IS_ENABLED(CONFIG_VMAP_STACK)) return false; if (!IS_ENABLED(CONFIG_ARM_SDE_INTERFACE)) return false; if (in_nmi()) - return _on_sdei_stack(sp); + return _on_sdei_stack(sp, info); return false; } diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h index 902f9edacbea..e86737b7c924 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h @@ -32,6 +32,21 @@ struct stackframe { #endif }; +enum stack_type { + STACK_TYPE_UNKNOWN, + STACK_TYPE_TASK, + STACK_TYPE_IRQ, + STACK_TYPE_OVERFLOW, + STACK_TYPE_SDEI_NORMAL, + STACK_TYPE_SDEI_CRITICAL, +}; + +struct stack_info { + unsigned long low; + unsigned long high; + enum stack_type type; +}; + extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame); extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame, int (*fn)(struct stackframe *, void *), void *data); @@ -39,7 +54,8 @@ extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk); DECLARE_PER_CPU(unsigned long *, irq_stack_ptr); -static inline bool on_irq_stack(unsigned long sp) +static inline bool on_irq_stack(unsigned long sp, + struct stack_info *info) { unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr); unsigned long high = low + IRQ_STACK_SIZE; @@ -47,46 +63,79 @@ static inline bool on_irq_stack(unsigned long sp) if (!low) return false; - return (low <= sp && sp < high); + if (sp < low || sp >= high) + return false; + + if (info) { + info->low = low; + info->high = high; + info->type = STACK_TYPE_IRQ; + } + + return true; } -static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp) +static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp, + struct stack_info *info) { unsigned long low = (unsigned long)task_stack_page(tsk); unsigned long high = low + THREAD_SIZE; - return (low <= sp && sp < high); + if (sp < low || sp >= high) + return false; + + if (info) { + info->low = low; + info->high = high; + info->type = STACK_TYPE_TASK; + } + + return true; } #ifdef CONFIG_VMAP_STACK DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack); -static inline bool on_overflow_stack(unsigned long sp) +static inline bool on_overflow_stack(unsigned long sp, + struct stack_info *info) { unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack); unsigned long high = low + OVERFLOW_STACK_SIZE; - return (low <= sp && sp < high); + if (sp < low || sp >= high) + return false; + + if (info) { + info->low = low; + info->high = high; + info->type = STACK_TYPE_OVERFLOW; + } + + return true; } #else -static inline bool on_overflow_stack(unsigned long sp) { return false; } +static inline bool on_overflow_stack(unsigned long sp, + struct stack_info *info) { return false; } #endif + /* * We can only safely access per-cpu stacks from current in a non-preemptible * context. */ -static inline bool on_accessible_stack(struct task_struct *tsk, unsigned long sp) +static inline bool on_accessible_stack(struct task_struct *tsk, + unsigned long sp, + struct stack_info *info) { - if (on_task_stack(tsk, sp)) + if (on_task_stack(tsk, sp, info)) return true; if (tsk != current || preemptible()) return false; - if (on_irq_stack(sp)) + if (on_irq_stack(sp, info)) return true; - if (on_overflow_stack(sp)) + if (on_overflow_stack(sp, info)) return true; - if (on_sdei_stack(sp)) + if (on_sdei_stack(sp, info)) return true; return false; diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 5c338ce5a7fa..cf94e1498ba6 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -132,7 +132,7 @@ static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) { return ((addr & ~(THREAD_SIZE - 1)) == (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))) || - on_irq_stack(addr); + on_irq_stack(addr, NULL); } /** diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c index 6b8d90d5ceae..f0787610f82e 100644 --- a/arch/arm64/kernel/sdei.c +++ b/arch/arm64/kernel/sdei.c @@ -88,23 +88,58 @@ static int init_sdei_stacks(void) return err; } -bool _on_sdei_stack(unsigned long sp) +bool on_sdei_normal_stack(unsigned long sp, + struct stack_info *info) +{ + unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_normal_ptr); + unsigned long high = low + SDEI_STACK_SIZE; + + if (low <= sp && sp < high) { + if (info) { + info->low = low; + info->high = high; + info->type = STACK_TYPE_SDEI_NORMAL; + } + return true; + } + + return false; +} + +bool on_sdei_critical_stack(unsigned long sp, + struct stack_info *info) +{ + unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr); + unsigned long high = low + SDEI_STACK_SIZE; + + if (low <= sp && sp < high) { + if (info) { + info->low = low; + info->high = high; + info->type = STACK_TYPE_SDEI_CRITICAL; + } + return true; + } + + return false; +} + +bool _on_sdei_stack(unsigned long sp, + unsigned long *stack_low, + unsigned long *stack_high) { unsigned long low, high; if (!IS_ENABLED(CONFIG_VMAP_STACK)) return false; - low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr); - high = low + SDEI_STACK_SIZE; - - if (low <= sp && sp < high) + if (on_sdei_critical_stack(sp, info)) return true; - low = (unsigned long)raw_cpu_read(sdei_stack_normal_ptr); - high = low + SDEI_STACK_SIZE; + if (on_sdei_normal_stack(sp, info)) + return true; - return (low <= sp && sp < high); + return false; } unsigned long sdei_arch_get_entry_point(int conduit) diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index d5718a060672..4989f7ea1e59 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -50,7 +50,7 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) if (!tsk) tsk = current; - if (!on_accessible_stack(tsk, fp)) + if (!on_accessible_stack(tsk, fp, NULL)) return -EINVAL; frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));