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Fri, 26 Jun 2020 19:05:19 +0000 Received: from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 05QJ5GnV56295610 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 26 Jun 2020 19:05:16 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5C02C42045; Fri, 26 Jun 2020 19:05:16 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 17C274203F; Fri, 26 Jun 2020 19:05:13 +0000 (GMT) Received: from hbathini.in.ibm.com (unknown [9.102.0.159]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 26 Jun 2020 19:05:12 +0000 (GMT) Subject: [PATCH 04/11] ppc64/kexec_file: avoid stomping memory used by special regions From: Hari Bathini To: Michael Ellerman , Andrew Morton Date: Sat, 27 Jun 2020 00:35:11 +0530 Message-ID: <159319831192.16351.17443438699302756548.stgit@hbathini.in.ibm.com> In-Reply-To: <159319825403.16351.7253978047621755765.stgit@hbathini.in.ibm.com> References: <159319825403.16351.7253978047621755765.stgit@hbathini.in.ibm.com> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216, 18.0.687 definitions=2020-06-26_10:2020-06-26, 2020-06-26 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 mlxlogscore=999 impostorscore=0 clxscore=1015 bulkscore=0 phishscore=0 priorityscore=1501 adultscore=0 spamscore=0 lowpriorityscore=0 suspectscore=0 cotscore=-2147483648 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006260130 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Pingfan Liu , Kexec-ml , Petr Tesarik , Mahesh J Salgaonkar , Sourabh Jain , lkml , linuxppc-dev , Mimi Zohar , Vivek Goyal , Dave Young , Thiago Jung Bauermann , Eric Biederman Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" crashkernel region could have an overlap with special memory regions like opal, rtas, tce-table & such. These regions are referred to as exclude memory ranges. Setup this ranges during image probe in order to avoid them while finding the buffer for different kdump segments. Implement kexec_locate_mem_hole_ppc64() that locates a memory hole accounting for these ranges. Also, override arch_kexec_add_buffer() to locate a memory hole & later call __kexec_add_buffer() function with kbuf->mem set to skip the generic locate memory hole lookup. Signed-off-by: Hari Bathini --- arch/powerpc/include/asm/crashdump-ppc64.h | 10 + arch/powerpc/include/asm/kexec.h | 7 - arch/powerpc/kexec/elf_64.c | 7 + arch/powerpc/kexec/file_load_64.c | 292 ++++++++++++++++++++++++++++ 4 files changed, 312 insertions(+), 4 deletions(-) create mode 100644 arch/powerpc/include/asm/crashdump-ppc64.h diff --git a/arch/powerpc/include/asm/crashdump-ppc64.h b/arch/powerpc/include/asm/crashdump-ppc64.h new file mode 100644 index 0000000..3596c25 --- /dev/null +++ b/arch/powerpc/include/asm/crashdump-ppc64.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _ARCH_POWERPC_KEXEC_CRASHDUMP_PPC64_H +#define _ARCH_POWERPC_KEXEC_CRASHDUMP_PPC64_H + +/* min & max addresses for kdump load segments */ +#define KDUMP_BUF_MIN (crashk_res.start) +#define KDUMP_BUF_MAX ((crashk_res.end < ppc64_rma_size) ? \ + crashk_res.end : (ppc64_rma_size - 1)) + +#endif /* __ARCH_POWERPC_KEXEC_CRASHDUMP_PPC64_H */ diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index 7008ea1..bf47a01 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h @@ -100,14 +100,16 @@ void relocate_new_kernel(unsigned long indirection_page, unsigned long reboot_co #ifdef CONFIG_KEXEC_FILE extern const struct kexec_file_ops kexec_elf64_ops; -#ifdef CONFIG_IMA_KEXEC #define ARCH_HAS_KIMAGE_ARCH struct kimage_arch { + struct crash_mem *exclude_ranges; + +#ifdef CONFIG_IMA_KEXEC phys_addr_t ima_buffer_addr; size_t ima_buffer_size; -}; #endif +}; int setup_purgatory(struct kimage *image, const void *slave_code, const void *fdt, unsigned long kernel_load_addr, @@ -125,6 +127,7 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, unsigned long initrd_load_addr, unsigned long initrd_len, const char *cmdline); #endif /* CONFIG_PPC64 */ + #endif /* CONFIG_KEXEC_FILE */ #else /* !CONFIG_KEXEC_CORE */ diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c index 23ad04c..c695f94 100644 --- a/arch/powerpc/kexec/elf_64.c +++ b/arch/powerpc/kexec/elf_64.c @@ -22,6 +22,7 @@ #include #include #include +#include static void *elf64_load(struct kimage *image, char *kernel_buf, unsigned long kernel_len, char *initrd, @@ -46,6 +47,12 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, if (ret) goto out; + if (image->type == KEXEC_TYPE_CRASH) { + /* min & max buffer values for kdump case */ + kbuf.buf_min = pbuf.buf_min = KDUMP_BUF_MIN; + kbuf.buf_max = pbuf.buf_max = KDUMP_BUF_MAX; + } + ret = kexec_elf_load(image, &ehdr, &elf_info, &kbuf, &kernel_load_addr); if (ret) goto out; diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c index e6bff960..f1d7160 100644 --- a/arch/powerpc/kexec/file_load_64.c +++ b/arch/powerpc/kexec/file_load_64.c @@ -17,6 +17,8 @@ #include #include #include +#include +#include const struct kexec_file_ops * const kexec_file_loaders[] = { &kexec_elf64_ops, @@ -24,6 +26,247 @@ const struct kexec_file_ops * const kexec_file_loaders[] = { }; /** + * get_exclude_memory_ranges - Get exclude memory ranges. This list includes + * regions like opal/rtas, tce-table, initrd, + * kernel, htab which should be avoided while + * setting up kexec load segments. + * @mem_ranges: Range list to add the memory ranges to. + * + * Returns 0 on success, negative errno on error. + */ +static int get_exclude_memory_ranges(struct crash_mem **mem_ranges) +{ + int ret; + + ret = add_tce_mem_ranges(mem_ranges); + if (ret) + goto out; + + ret = add_initrd_mem_range(mem_ranges); + if (ret) + goto out; + + ret = add_htab_mem_range(mem_ranges); + if (ret) + goto out; + + ret = add_kernel_mem_range(mem_ranges); + if (ret) + goto out; + + ret = add_rtas_mem_range(mem_ranges, false); + if (ret) + goto out; + + ret = add_opal_mem_range(mem_ranges, false); + if (ret) + goto out; + + ret = add_reserved_ranges(mem_ranges); + if (ret) + goto out; + + /* exclude memory ranges should be sorted for easy lookup */ + sort_memory_ranges(*mem_ranges); +out: + if (ret) + pr_err("Failed to setup exclude memory ranges\n"); + return ret; +} + +/** + * __locate_mem_hole_ppc64 - Tests if the memory hole between buf_min & buf_max + * is large enough for the buffer. If true, sets + * kbuf->mem to the buffer. + * @kbuf: Buffer contents and memory parameters. + * @buf_min: Minimum address for the buffer. + * @buf_max: Maximum address for the buffer. + * + * Returns 0 on success, negative errno on error. + */ +static int __locate_mem_hole_ppc64(struct kexec_buf *kbuf, + u64 buf_min, u64 buf_max) +{ + int ret = -EADDRNOTAVAIL; + + buf_min = ALIGN(buf_min, kbuf->buf_align); + + if (buf_min < buf_max && + (buf_max - buf_min + 1) >= kbuf->memsz) { + /* + * Suitable memory range found. Set kbuf->mem here to skip + * locate memory hole routine in __kexec_add_buffer() call. + */ + ret = 0; + if (kbuf->top_down) + kbuf->mem = ALIGN_DOWN(buf_max - kbuf->memsz + 1, + kbuf->buf_align); + else + kbuf->mem = buf_min; + } + + return ret; +} + +/** + * locate_mem_hole_top_down_ppc64 - Skip special memory regions to find a + * suitable buffer with top down approach. + * @kbuf: Buffer contents and memory parameters. + * @buf_min: Minimum address for the buffer. + * @buf_max: Maximum address for the buffer. + * @emem: Exclude memory ranges. + * + * Returns 0 on success, negative errno on error. + */ +static int locate_mem_hole_top_down_ppc64(struct kexec_buf *kbuf, + u64 buf_min, u64 buf_max, + const struct crash_mem *emem) +{ + int i, ret = 0, err = -EADDRNOTAVAIL; + u64 start, end, tmin, tmax; + + tmax = buf_max; + for (i = (emem->nr_ranges - 1); i >= 0; i--) { + start = emem->ranges[i].start; + end = emem->ranges[i].end; + + if (start > tmax) + continue; + + if (end < tmax) { + tmin = (end < buf_min ? buf_min : end + 1); + ret = __locate_mem_hole_ppc64(kbuf, tmin, tmax); + if (!ret) + return 0; + } + + tmax = start - 1; + + if (tmax < buf_min) { + ret = err; + break; + } + ret = 0; + } + + if (!ret) { + tmin = buf_min; + ret = __locate_mem_hole_ppc64(kbuf, tmin, tmax); + } + return ret; +} + +/** + * locate_mem_hole_bottom_up_ppc64 - Skip special memory regions to find a + * suitable buffer with bottom up approach. + * @kbuf: Buffer contents and memory parameters. + * @buf_min: Minimum address for the buffer. + * @buf_max: Maximum address for the buffer. + * @emem: Exclude memory ranges. + * + * Returns 0 on success, negative errno on error. + */ +static int locate_mem_hole_bottom_up_ppc64(struct kexec_buf *kbuf, + u64 buf_min, u64 buf_max, + const struct crash_mem *emem) +{ + int i, ret = 0, err = -EADDRNOTAVAIL; + u64 start, end, tmin, tmax; + + tmin = buf_min; + for (i = 0; i < emem->nr_ranges; i++) { + start = emem->ranges[i].start; + end = emem->ranges[i].end; + + if (end < tmin) + continue; + + if (start > tmin) { + tmax = (start > buf_max ? buf_max : start - 1); + ret = __locate_mem_hole_ppc64(kbuf, tmin, tmax); + if (!ret) + return 0; + } + + tmin = end + 1; + + if (tmin > buf_max) { + ret = err; + break; + } + ret = 0; + } + + if (!ret) { + tmax = buf_max; + ret = __locate_mem_hole_ppc64(kbuf, tmin, tmax); + } + return ret; +} + +/** + * kexec_locate_mem_hole_ppc64 - Skip special memory regions like rtas, + * tce-table, opal, reserved-ranges & such + * (exclude memory ranges) as they can't be + * used for kexec segment buffer. Use buf_min + * & buf_max fields in kexec_buf structure to + * skip regions. Sets kbuf->mem when a + * suitable memory hole is found. + * @kbuf: Buffer contents and memory parameters. + * + * Returns 0 on success, negative errno on error. + */ +static int kexec_locate_mem_hole_ppc64(struct kexec_buf *kbuf) +{ + struct crash_mem **emem; + u64 buf_min, buf_max; + int ret; + + /* + * Use the locate_mem_hole logic in kexec_add_buffer() for regular + * kexec_file_load syscall + */ + if (kbuf->image->type != KEXEC_TYPE_CRASH) + return 0; + + /* Look up the exclude ranges list while locating the memory hole */ + emem = &(kbuf->image->arch.exclude_ranges); + if (!(*emem) || ((*emem)->nr_ranges == 0)) { + pr_warn("No exclude range list. Using the default locate mem hole method\n"); + return 0; + } + + /* Ensure minimum alignment needed for segments. */ + kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE); + kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE); + + /* Segments for kdump kernel should be within crashkernel region */ + buf_min = (kbuf->buf_min < crashk_res.start ? + crashk_res.start : kbuf->buf_min); + buf_max = (kbuf->buf_max > crashk_res.end ? + crashk_res.end : kbuf->buf_max); + + if (buf_min > buf_max) { + pr_err("Invalid buffer min and/or max values\n"); + return -EINVAL; + } + + if (kbuf->top_down) + ret = locate_mem_hole_top_down_ppc64(kbuf, buf_min, buf_max, + *emem); + else + ret = locate_mem_hole_bottom_up_ppc64(kbuf, buf_min, buf_max, + *emem); + + /* Add the buffer allocated to the exclude list for the next lookup */ + if (!ret) { + add_mem_range(emem, kbuf->mem, kbuf->memsz); + sort_memory_ranges(*emem); + } + return ret; +} + +/** * setup_purgatory_ppc64 - initialize PPC64 specific purgatory's global * variables and call setup_purgatory() to initialize * common global variable. @@ -89,6 +332,29 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, } /** + * arch_kexec_add_buffer - Locate memory hole before calling kexec_add_buffer(). + * All kexec_add_buffer() callers should use this + * function instead. + * @kbuf: Buffer contents and memory parameters. + * + * Returns 0 on success, negative errno on error. + */ +int arch_kexec_add_buffer(struct kexec_buf *kbuf) +{ + int ret; + + ret = kexec_locate_mem_hole_ppc64(kbuf); + if (ret) + goto out; + + ret = __kexec_add_buffer(kbuf); +out: + if (ret) + pr_err("Failed to add buffer of size %lu\n", kbuf->memsz); + return ret; +} + +/** * arch_kexec_kernel_image_probe - Does additional handling needed to setup * kexec segments. * @image: kexec image being loaded. @@ -100,9 +366,31 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len) { - /* We don't support crash kernels yet. */ - if (image->type == KEXEC_TYPE_CRASH) + if (image->type == KEXEC_TYPE_CRASH) { + int ret; + + /* Get exclude memory ranges needed for setting up kdump segments */ + ret = get_exclude_memory_ranges(&(image->arch.exclude_ranges)); + if (ret) + pr_err("Failed to setup exclude memory ranges for buffer lookup\n"); + /* Return this until all changes for panic kernel are in */ return -EOPNOTSUPP; + } return kexec_image_probe_default(image, buf, buf_len); } + +/** + * arch_kimage_file_post_load_cleanup - Frees up all the allocations done + * while loading the image. + * @image: kexec image being loaded. + * + * Returns 0 on success, negative errno on error. + */ +int arch_kimage_file_post_load_cleanup(struct kimage *image) +{ + kfree(image->arch.exclude_ranges); + image->arch.exclude_ranges = NULL; + + return kexec_image_post_load_cleanup_default(image); +}