From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out1-smtp.messagingengine.com ([66.111.4.25]:52387 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934428AbdEWOdu (ORCPT ); Tue, 23 May 2017 10:33:50 -0400 Subject: FAILED: patch "[PATCH] arm64: hw_breakpoint: fix watchpoint matching for tagged" failed to apply to 3.18-stable tree To: kristina.martsenko@arm.com, catalin.marinas@arm.com, mark.rutland@arm.com, stable@vger.kernel.org, will.deacon@arm.com Cc: From: Date: Tue, 23 May 2017 16:33:37 +0200 Message-ID: <1495550017127250@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >>From 7dcd9dd8cebe9fa626af7e2358d03a37041a70fb Mon Sep 17 00:00:00 2001 From: Kristina Martsenko Date: Wed, 3 May 2017 16:37:46 +0100 Subject: [PATCH] arm64: hw_breakpoint: fix watchpoint matching for tagged pointers When we take a watchpoint exception, the address that triggered the watchpoint is found in FAR_EL1. We compare it to the address of each configured watchpoint to see which one was hit. The configured watchpoint addresses are untagged, while the address in FAR_EL1 will have an address tag if the data access was done using a tagged address. The tag needs to be removed to compare the address to the watchpoints. Currently we don't remove it, and as a result can report the wrong watchpoint as being hit (specifically, always either the highest TTBR0 watchpoint or lowest TTBR1 watchpoint). This patch removes the tag. Fixes: d50240a5f6ce ("arm64: mm: permit use of tagged pointers at EL0") Cc: # 3.12.x- Acked-by: Mark Rutland Acked-by: Will Deacon Signed-off-by: Kristina Martsenko Signed-off-by: Catalin Marinas diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 5308d696311b..0221029e27ff 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -106,9 +106,9 @@ static inline void set_fs(mm_segment_t fs) }) /* - * When dealing with data aborts or instruction traps we may end up with - * a tagged userland pointer. Clear the tag to get a sane pointer to pass - * on to access_ok(), for instance. + * When dealing with data aborts, watchpoints, or instruction traps we may end + * up with a tagged userland pointer. Clear the tag to get a sane pointer to + * pass on to access_ok(), for instance. */ #define untagged_addr(addr) sign_extend64(addr, 55) diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c index 0296e7924240..749f81779420 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -36,6 +36,7 @@ #include #include #include +#include /* Breakpoint currently in use for each BRP. */ static DEFINE_PER_CPU(struct perf_event *, bp_on_reg[ARM_MAX_BRP]); @@ -721,6 +722,8 @@ static u64 get_distance_from_watchpoint(unsigned long addr, u64 val, u64 wp_low, wp_high; u32 lens, lene; + addr = untagged_addr(addr); + lens = __ffs(ctrl->len); lene = __fls(ctrl->len);