From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e2.ny.us.ibm.com (e2.ny.us.ibm.com [32.97.182.142]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e2.ny.us.ibm.com", Issuer "Equifax" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 6CCD9B7B5C for ; Thu, 20 Aug 2009 00:28:53 +1000 (EST) Received: from d01relay07.pok.ibm.com (d01relay07.pok.ibm.com [9.56.227.147]) by e2.ny.us.ibm.com (8.14.3/8.13.1) with ESMTP id n7JEMf5J007478 for ; Wed, 19 Aug 2009 10:22:41 -0400 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d01relay07.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n7JEST8m1052788 for ; Wed, 19 Aug 2009 10:28:30 -0400 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n7JESGa5025902 for ; Wed, 19 Aug 2009 08:28:17 -0600 Date: Wed, 19 Aug 2009 10:27:53 -0400 From: Josh Boyer To: benh@kernel.crashing.org Subject: [PATCH v2] powerpc: Fix __flush_icache_range on 44x Message-ID: <20090819142753.GD2530@zod.rchland.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , The ptrace POKETEXT interface allows a process to modify the text pages of a child process being ptraced, usually to insert breakpoints via trap instructions. The kernel eventually calls copy_to_user_page, which in turn calls __flush_icache_range to invalidate the icache lines for the child process. However, this function does not work on 44x due to the icache being virtually indexed. This was noticed by a breakpoint being triggered after it had been cleared by ltrace on a 440EPx board. The convenient solution is to do a flash invalidate of the icache in the __flush_icache_range function. Signed-off-by: Josh Boyer --- I tested this on powerpc-next this morning using the same testcase as before. diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index 15f28e0..da9c0c4 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -342,10 +342,17 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE) addi r3,r3,L1_CACHE_BYTES bdnz 1b sync /* wait for dcbst's to get to ram */ +#ifndef CONFIG_44x mtctr r4 2: icbi 0,r6 addi r6,r6,L1_CACHE_BYTES bdnz 2b +#else + /* Flash invalidate on 44x because we are passed kmapped addresses and + this doesn't work for userspace pages due to the virtually tagged + icache. Sigh. */ + iccci 0, r0 +#endif sync /* additional sync needed on g4 */ isync blr