Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757892Ab3HAXqE (ORCPT ); Thu, 1 Aug 2013 19:46:04 -0400 Received: from mail-yh0-f54.google.com ([209.85.213.54]:52785 "EHLO mail-yh0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757713Ab3HAXqA (ORCPT ); Thu, 1 Aug 2013 19:46:00 -0400 From: David Long To: linux-arm-kernel@lists.infradead.org Cc: Rabin Vincent , "Jon Medhurst (Tixy)" , linux-kernel@vger.kernel.org Subject: [PATCH 3/9] uprobes: allow arch access to xol slot Date: Thu, 1 Aug 2013 19:45:47 -0400 Message-Id: <1375400753-3454-4-git-send-email-dave.long@linaro.org> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1375400753-3454-1-git-send-email-dave.long@linaro.org> References: <1375400753-3454-1-git-send-email-dave.long@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2556 Lines: 69 From: Rabin Vincent Allow arches to customize how the instruction is filled into the xol slot. ARM will use this to insert an undefined instruction after the real instruction in order to simulate a single step of the instruction without hardware support. Signed-off-by: Rabin Vincent Signed-off-by: David A. Long --- include/linux/uprobes.h | 1 + kernel/events/uprobes.c | 10 +++++++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index 7a7c035..f6287f0 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -134,6 +134,7 @@ extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk); extern int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data); extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs); extern bool __weak arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs); +extern void __weak arch_uprobe_xol_copy(struct arch_uprobe *auprobe, void *vaddr); #else /* !CONFIG_UPROBES */ struct uprobes_state { }; diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 2f3a4cb..64471bd 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1238,6 +1238,11 @@ static unsigned long xol_take_insn_slot(struct xol_area *area) return slot_addr; } +void __weak arch_uprobe_xol_copy(struct arch_uprobe *auprobe, void *vaddr) +{ + memcpy(vaddr, auprobe->insn, MAX_UINSN_BYTES); +} + /* * xol_get_insn_slot - allocate a slot for xol. * Returns the allocated slot address or 0. @@ -1246,6 +1251,7 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe) { struct xol_area *area; unsigned long xol_vaddr; + void *kaddr; area = get_xol_area(); if (!area) @@ -1256,7 +1262,9 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe) return 0; /* Initialize the slot */ - copy_to_page(area->page, xol_vaddr, uprobe->arch.insn, MAX_UINSN_BYTES); + kaddr = kmap_atomic(area->page); + arch_uprobe_xol_copy(&uprobe->arch, kaddr + (xol_vaddr & ~PAGE_MASK)); + kunmap_atomic(kaddr); /* * We probably need flush_icache_user_range() but it needs vma. * This should work on supported architectures too. -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/