From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kunihiko Hayashi , James Morse , Will Deacon , Catalin Marinas Subject: [PATCH 4.19 080/118] arm64: hibernate: Avoid sending cross-calling with interrupts disabled Date: Tue, 11 Dec 2018 16:41:39 +0100 Message-Id: <20181211151647.498633571@linuxfoundation.org> In-Reply-To: <20181211151644.216668863@linuxfoundation.org> References: <20181211151644.216668863@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon commit b4aecf78083d8c6424657c1746c7c3de6e61669f upstream. Since commit 3b8c9f1cdfc50 ("arm64: IPI each CPU after invalidating the I-cache for kernel mappings"), a call to flush_icache_range() will use an IPI to cross-call other online CPUs so that any stale instructions are flushed from their pipelines. This triggers a WARN during the hibernation resume path, where flush_icache_range() is called with interrupts disabled and is therefore prone to deadlock: | Disabling non-boot CPUs ... | CPU1: shutdown | psci: CPU1 killed. | CPU2: shutdown | psci: CPU2 killed. | CPU3: shutdown | psci: CPU3 killed. | WARNING: CPU: 0 PID: 1 at ../kernel/smp.c:416 smp_call_function_many+0xd4/0x350 | Modules linked in: | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.20.0-rc4 #1 Since all secondary CPUs have been taken offline prior to invalidating the I-cache, there's actually no need for an IPI and we can simply call __flush_icache_range() instead. Cc: Fixes: 3b8c9f1cdfc50 ("arm64: IPI each CPU after invalidating the I-cache for kernel mappings") Reported-by: Kunihiko Hayashi Tested-by: Kunihiko Hayashi Tested-by: James Morse Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/hibernate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm64/kernel/hibernate.c +++ b/arch/arm64/kernel/hibernate.c @@ -214,7 +214,7 @@ static int create_safe_exec_page(void *s } memcpy((void *)dst, src_start, length); - flush_icache_range(dst, dst + length); + __flush_icache_range(dst, dst + length); pgdp = pgd_offset_raw(allocator(mask), dst_addr); if (pgd_none(READ_ONCE(*pgdp))) {