From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rYVsX2095zDqmF for ; Tue, 21 Jun 2016 11:45:04 +1000 (AEST) Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u5L1hXXO108666 for ; Mon, 20 Jun 2016 21:45:02 -0400 Received: from e24smtp03.br.ibm.com (e24smtp03.br.ibm.com [32.104.18.24]) by mx0a-001b2d01.pphosted.com with ESMTP id 23n2cqrxfv-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 20 Jun 2016 21:45:02 -0400 Received: from localhost by e24smtp03.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 20 Jun 2016 22:44:59 -0300 Received: from d24relay02.br.ibm.com (d24relay02.br.ibm.com [9.13.184.26]) by d24dlp02.br.ibm.com (Postfix) with ESMTP id AC3EF1DC006E for ; Mon, 20 Jun 2016 21:44:50 -0400 (EDT) Received: from d24av02.br.ibm.com (d24av02.br.ibm.com [9.8.31.93]) by d24relay02.br.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u5L1iveV22348280 for ; Mon, 20 Jun 2016 22:44:57 -0300 Received: from d24av02.br.ibm.com (localhost [127.0.0.1]) by d24av02.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u5L1ivQS030021 for ; Mon, 20 Jun 2016 22:44:57 -0300 From: Thiago Jung Bauermann To: linuxppc-dev@lists.ozlabs.org Cc: kexec@lists.infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org, Eric Biederman , Dave Young , Michael Ellerman , Mimi Zohar , Eric Richter , Thiago Jung Bauermann Subject: [PATCH 4/6] kexec_file: Add mechanism to update kexec segments. Date: Mon, 20 Jun 2016 22:44:34 -0300 In-Reply-To: <1466473476-10104-1-git-send-email-bauerman@linux.vnet.ibm.com> References: <1466473476-10104-1-git-send-email-bauerman@linux.vnet.ibm.com> Message-Id: <1466473476-10104-5-git-send-email-bauerman@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , kexec_update_segment allows a given segment in kexec_image to have its contents updated. This is useful if the current kernel wants to send information to the next kernel that is up-to-date at the time of reboot. Signed-off-by: Thiago Jung Bauermann --- include/linux/kexec.h | 2 ++ kernel/kexec_core.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/kexec_file.c | 1 + 3 files changed, 91 insertions(+) diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 131b1fc7820e..14d4ac070a8c 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -222,6 +222,8 @@ extern int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long buf_align, unsigned long buf_min, unsigned long buf_max, bool top_down, bool checksum, unsigned long *load_addr); +int kexec_update_segment(const char *buffer, unsigned long bufsz, + unsigned long load_addr, unsigned long memsz); extern struct page *kimage_alloc_control_pages(struct kimage *image, unsigned int order); extern int kexec_load_purgatory(struct kimage *image, unsigned long min, diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 56b3ed0927b0..8781d3e4479d 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -700,6 +700,94 @@ static struct page *kimage_alloc_page(struct kimage *image, return page; } +/** + * kexec_update_segment - update the contents of a kimage segment + * @buffer: New contents of the segment. + * @bufsz: @buffer size. + * @load_addr: Segment's physical address in the next kernel. + * @memsz: Segment size. + * + * This function assumes kexec_mutex is held. + * + * Return: 0 on success, negative errno on error. + */ +int kexec_update_segment(const char *buffer, unsigned long bufsz, + unsigned long load_addr, unsigned long memsz) +{ + int i; + unsigned long entry; + unsigned long *ptr = NULL; + void *dest = NULL; + + for (i = 0; i < kexec_image->nr_segments; i++) + /* We only support updating whole segments. */ + if (load_addr == kexec_image->segment[i].mem && + memsz == kexec_image->segment[i].memsz) { + if (kexec_image->segment[i].do_checksum) { + pr_err("Trying to update non-modifiable segment.\n"); + return -EINVAL; + } + + break; + } + if (i == kexec_image->nr_segments) { + pr_err("Couldn't find segment to update: 0x%lx, size 0x%lx\n", + load_addr, memsz); + return -EINVAL; + } + + for (entry = kexec_image->head; !(entry & IND_DONE) && memsz; + entry = *ptr++) { + void *addr = (void *) (entry & PAGE_MASK); + + switch (entry & IND_FLAGS) { + case IND_DESTINATION: + dest = addr; + break; + case IND_INDIRECTION: + ptr = __va(addr); + break; + case IND_SOURCE: + /* Shouldn't happen, but verify just to be safe. */ + if (dest == NULL) { + pr_err("Invalid kexec entries list."); + return -EINVAL; + } + + if (dest == (void *) load_addr) { + struct page *page; + char *ptr; + size_t uchunk, mchunk; + + page = kmap_to_page(addr); + + ptr = kmap(page); + ptr += load_addr & ~PAGE_MASK; + mchunk = min_t(size_t, memsz, + PAGE_SIZE - (load_addr & ~PAGE_MASK)); + uchunk = min(bufsz, mchunk); + memcpy(ptr, buffer, uchunk); + + kunmap(page); + + bufsz -= uchunk; + load_addr += mchunk; + buffer += mchunk; + memsz -= mchunk; + } + dest += PAGE_SIZE; + } + + /* Shouldn't happen, but verify just to be safe. */ + if (ptr == NULL) { + pr_err("Invalid kexec entries list."); + return -EINVAL; + } + } + + return 0; +} + static int kimage_load_normal_segment(struct kimage *image, struct kexec_segment *segment) { diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 3aa829a78f50..79d09a7784d8 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include -- 1.9.1