From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x226Hl3WOlHxavs+vgJF1JJzFJ5SWxLS5UnoUVdLuC5EpO5GZ3difNgnrtd5mB3pL3USbZaK/ ARC-Seal: i=1; a=rsa-sha256; t=1518709186; cv=none; d=google.com; s=arc-20160816; b=GgeQyZpoGrxKNije4tICo1FTYVYDNb2rHZtny2iPFFtMvDKHmQupeRWiWhsQOcvXlO nmIPoW3FfRCAwEV7IuNyCWUajLgdLegQ3ZWwsbXs3zY/SwgFy8Avp5QuZEWl/y6DpHwR sH7DQkFI9Too2FUwMcc1tIi1zYQYzpazDEgj4Z3D229mHCtiPlWVpJwiuLm9ZOrtqJI9 0pkaX8cPsgtdTAMKVUa1XoCeBpPOGIUwbIKz05LMPWA/SXmDJUSyYUYd5zLq/DP59V9+ fsQtphXQx1P1vdH7n0cPNXqZvAwJgMQ6ynQELdRllqlWR1oWbapk7Cw2fRVdBFWEncQu rKfQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=n/OtUdmAywOZ574eIQq3Aehza9bbgtLtI2gnGa7714k=; b=m4k9Ux6H6cMLGUu80VXSUYKsL/26w15f8INWKME65HKz7FUTGod29GcN70TMCtwWDO fZxcLEOUnRWBWW/L/fEqW4avygWmcORRkLugdcOdUKmNAJ8E5E2ELAqntOnMrHNY+Rs6 S6+AxxL3qfS2gyv3BC9rjKxHiy1dsHkodNVzL6iSznth9WaL9Mdxv5epKz22jPWsPQ9H lYxLV2YIwmZc/ohGUnLD0KkjIdWFaviIY/HG5MwDFx5a6xQ+rpXPQg1LX8HDheZ5PMq/ pWrPjU89aHJNR3fSFhrh9HVr8RqrZDnRRjMfcvkpci64Ye7y8DoRrkPztLVpxVbnu+Cd O4Kg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Rutland , Laura Abbott , Shanker Donthineni , Will Deacon Subject: [PATCH 4.15 027/202] [Variant 3/Meltdown] arm64: entry: Hook up entry trampoline to exception vectors Date: Thu, 15 Feb 2018 16:15:27 +0100 Message-Id: <20180215151714.347148508@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180215151712.768794354@linuxfoundation.org> References: <20180215151712.768794354@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1592481457484988866?= X-GMAIL-MSGID: =?utf-8?q?1592482004326905522?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon Commit 4bf3286d29f3 upstream. Hook up the entry trampoline to our exception vectors so that all exceptions from and returns to EL0 go via the trampoline, which swizzles the vector base register accordingly. Transitioning to and from the kernel clobbers x30, so we use tpidrro_el0 and far_el1 as scratch registers for native tasks. Reviewed-by: Mark Rutland Tested-by: Laura Abbott Tested-by: Shanker Donthineni Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/entry.S | 39 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 36 insertions(+), 3 deletions(-) --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -73,6 +73,17 @@ .macro kernel_ventry, el, label, regsize = 64 .align 7 +#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 + .if \el == 0 + .if \regsize == 64 + mrs x30, tpidrro_el0 + msr tpidrro_el0, xzr + .else + mov x30, xzr + .endif + .endif +#endif + sub sp, sp, #S_FRAME_SIZE #ifdef CONFIG_VMAP_STACK /* @@ -119,6 +130,11 @@ b el\()\el\()_\label .endm + .macro tramp_alias, dst, sym + mov_q \dst, TRAMP_VALIAS + add \dst, \dst, #(\sym - .entry.tramp.text) + .endm + .macro kernel_entry, el, regsize = 64 .if \regsize == 32 mov w0, w0 // zero upper 32 bits of x0 @@ -271,18 +287,20 @@ alternative_else_nop_endif .if \el == 0 ldr x23, [sp, #S_SP] // load return stack pointer msr sp_el0, x23 + tst x22, #PSR_MODE32_BIT // native task? + b.eq 3f + #ifdef CONFIG_ARM64_ERRATUM_845719 alternative_if ARM64_WORKAROUND_845719 - tbz x22, #4, 1f #ifdef CONFIG_PID_IN_CONTEXTIDR mrs x29, contextidr_el1 msr contextidr_el1, x29 #else msr contextidr_el1, xzr #endif -1: alternative_else_nop_endif #endif +3: .endif msr elr_el1, x21 // set up the return data @@ -304,7 +322,22 @@ alternative_else_nop_endif ldp x28, x29, [sp, #16 * 14] ldr lr, [sp, #S_LR] add sp, sp, #S_FRAME_SIZE // restore sp - eret // return to kernel + +#ifndef CONFIG_UNMAP_KERNEL_AT_EL0 + eret +#else + .if \el == 0 + bne 4f + msr far_el1, x30 + tramp_alias x30, tramp_exit_native + br x30 +4: + tramp_alias x30, tramp_exit_compat + br x30 + .else + eret + .endif +#endif .endm .macro irq_stack_entry