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authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-16 09:26:42 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-16 09:26:42 -0800
commitde399813b521ea7e38bbfb5e5b620b5e202e5783 (patch)
treeceb8302f9d6a7a4f2e25b64c5dc42c1fb80b435b /arch/powerpc/kernel/machine_kexec_file_64.c
parent57ca04ab440168e101da746ef9edd1ec583b7214 (diff)
parentc6f6634721c871bfab4235e1cbcad208d3063798 (diff)
Merge tag 'powerpc-4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman: "Highlights include: - Support for the kexec_file_load() syscall, which is a prereq for secure and trusted boot. - Prevent kernel execution of userspace on P9 Radix (similar to SMEP/PXN). - Sort the exception tables at build time, to save time at boot, and store them as relative offsets to save space in the kernel image & memory. - Allow building the kernel with thin archives, which should allow us to build an allyesconfig once some other fixes land. - Build fixes to allow us to correctly rebuild when changing the kernel endian from big to little or vice versa. - Plumbing so that we can avoid doing a full mm TLB flush on P9 Radix. - Initial stack protector support (-fstack-protector). - Support for dumping the radix (aka. Linux) and hash page tables via debugfs. - Fix an oops in cxl coredump generation when cxl_get_fd() is used. - Freescale updates from Scott: "Highlights include 8xx hugepage support, qbman fixes/cleanup, device tree updates, and some misc cleanup." - Many and varied fixes and minor enhancements as always. Thanks to: Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anshuman Khandual, Anton Blanchard, Balbir Singh, Bartlomiej Zolnierkiewicz, Christophe Jaillet, Christophe Leroy, Denis Kirjanov, Elimar Riesebieter, Frederic Barrat, Gautham R. Shenoy, Geliang Tang, Geoff Levand, Jack Miller, Johan Hovold, Lars-Peter Clausen, Libin, Madhavan Srinivasan, Michael Neuling, Nathan Fontenot, Naveen N. Rao, Nicholas Piggin, Pan Xinhui, Peter Senna Tschudin, Rashmica Gupta, Rui Teng, Russell Currey, Scott Wood, Simon Guo, Suraj Jitindar Singh, Thiago Jung Bauermann, Tobias Klauser, Vaibhav Jain" [ And thanks to Michael, who took time off from a new baby to get this pull request done. - Linus ] * tag 'powerpc-4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (174 commits) powerpc/fsl/dts: add FMan node for t1042d4rdb powerpc/fsl/dts: add sg_2500_aqr105_phy4 alias on t1024rdb powerpc/fsl/dts: add QMan and BMan nodes on t1024 powerpc/fsl/dts: add QMan and BMan nodes on t1023 soc/fsl/qman: test: use DEFINE_SPINLOCK() powerpc/fsl-lbc: use DEFINE_SPINLOCK() powerpc/8xx: Implement support of hugepages powerpc: get hugetlbpage handling more generic powerpc: port 64 bits pgtable_cache to 32 bits powerpc/boot: Request no dynamic linker for boot wrapper soc/fsl/bman: Use resource_size instead of computation soc/fsl/qe: use builtin_platform_driver powerpc/fsl_pmc: use builtin_platform_driver powerpc/83xx/suspend: use builtin_platform_driver powerpc/ftrace: Fix the comments for ftrace_modify_code powerpc/perf: macros for power9 format encoding powerpc/perf: power9 raw event format encoding powerpc/perf: update attribute_group data structure powerpc/perf: factor out the event format field powerpc/mm/iommu, vfio/spapr: Put pages on VFIO container shutdown ...
Diffstat (limited to 'arch/powerpc/kernel/machine_kexec_file_64.c')
-rw-r--r--arch/powerpc/kernel/machine_kexec_file_64.c338
1 files changed, 338 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/machine_kexec_file_64.c b/arch/powerpc/kernel/machine_kexec_file_64.c
new file mode 100644
index 000000000000..7abc8a75ee48
--- /dev/null
+++ b/arch/powerpc/kernel/machine_kexec_file_64.c
@@ -0,0 +1,338 @@
+/*
+ * ppc64 code to implement the kexec_file_load syscall
+ *
+ * Copyright (C) 2004 Adam Litke (agl@us.ibm.com)
+ * Copyright (C) 2004 IBM Corp.
+ * Copyright (C) 2004,2005 Milton D Miller II, IBM Corporation
+ * Copyright (C) 2005 R Sharada (sharada@in.ibm.com)
+ * Copyright (C) 2006 Mohan Kumar M (mohan@in.ibm.com)
+ * Copyright (C) 2016 IBM Corporation
+ *
+ * Based on kexec-tools' kexec-elf-ppc64.c, fs2dt.c.
+ * Heavily modified for the kernel by
+ * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/slab.h>
+#include <linux/kexec.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+
+#define SLAVE_CODE_SIZE 256
+
+static struct kexec_file_ops *kexec_file_loaders[] = {
+ &kexec_elf64_ops,
+};
+
+int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
+ unsigned long buf_len)
+{
+ int i, ret = -ENOEXEC;
+ struct kexec_file_ops *fops;
+
+ /* We don't support crash kernels yet. */
+ if (image->type == KEXEC_TYPE_CRASH)
+ return -ENOTSUPP;
+
+ for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
+ fops = kexec_file_loaders[i];
+ if (!fops || !fops->probe)
+ continue;
+
+ ret = fops->probe(buf, buf_len);
+ if (!ret) {
+ image->fops = fops;
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
+void *arch_kexec_kernel_image_load(struct kimage *image)
+{
+ if (!image->fops || !image->fops->load)
+ return ERR_PTR(-ENOEXEC);
+
+ return image->fops->load(image, image->kernel_buf,
+ image->kernel_buf_len, image->initrd_buf,
+ image->initrd_buf_len, image->cmdline_buf,
+ image->cmdline_buf_len);
+}
+
+int arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+ if (!image->fops || !image->fops->cleanup)
+ return 0;
+
+ return image->fops->cleanup(image->image_loader_data);
+}
+
+/**
+ * arch_kexec_walk_mem - call func(data) for each unreserved memory block
+ * @kbuf: Context info for the search. Also passed to @func.
+ * @func: Function to call for each memory block.
+ *
+ * This function is used by kexec_add_buffer and kexec_locate_mem_hole
+ * to find unreserved memory to load kexec segments into.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *))
+{
+ int ret = 0;
+ u64 i;
+ phys_addr_t mstart, mend;
+
+ if (kbuf->top_down) {
+ for_each_free_mem_range_reverse(i, NUMA_NO_NODE, 0,
+ &mstart, &mend, NULL) {
+ /*
+ * In memblock, end points to the first byte after the
+ * range while in kexec, end points to the last byte
+ * in the range.
+ */
+ ret = func(mstart, mend - 1, kbuf);
+ if (ret)
+ break;
+ }
+ } else {
+ for_each_free_mem_range(i, NUMA_NO_NODE, 0, &mstart, &mend,
+ NULL) {
+ /*
+ * In memblock, end points to the first byte after the
+ * range while in kexec, end points to the last byte
+ * in the range.
+ */
+ ret = func(mstart, mend - 1, kbuf);
+ if (ret)
+ break;
+ }
+ }
+
+ return ret;
+}
+
+/**
+ * setup_purgatory - initialize the purgatory's global variables
+ * @image: kexec image.
+ * @slave_code: Slave code for the purgatory.
+ * @fdt: Flattened device tree for the next kernel.
+ * @kernel_load_addr: Address where the kernel is loaded.
+ * @fdt_load_addr: Address where the flattened device tree is loaded.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int setup_purgatory(struct kimage *image, const void *slave_code,
+ const void *fdt, unsigned long kernel_load_addr,
+ unsigned long fdt_load_addr)
+{
+ unsigned int *slave_code_buf, master_entry;
+ int ret;
+
+ slave_code_buf = kmalloc(SLAVE_CODE_SIZE, GFP_KERNEL);
+ if (!slave_code_buf)
+ return -ENOMEM;
+
+ /* Get the slave code from the new kernel and put it in purgatory. */
+ ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+ slave_code_buf, SLAVE_CODE_SIZE,
+ true);
+ if (ret) {
+ kfree(slave_code_buf);
+ return ret;
+ }
+
+ master_entry = slave_code_buf[0];
+ memcpy(slave_code_buf, slave_code, SLAVE_CODE_SIZE);
+ slave_code_buf[0] = master_entry;
+ ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+ slave_code_buf, SLAVE_CODE_SIZE,
+ false);
+ kfree(slave_code_buf);
+
+ ret = kexec_purgatory_get_set_symbol(image, "kernel", &kernel_load_addr,
+ sizeof(kernel_load_addr), false);
+ if (ret)
+ return ret;
+ ret = kexec_purgatory_get_set_symbol(image, "dt_offset", &fdt_load_addr,
+ sizeof(fdt_load_addr), false);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+/**
+ * delete_fdt_mem_rsv - delete memory reservation with given address and size
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
+{
+ int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
+
+ for (i = 0; i < num_rsvs; i++) {
+ uint64_t rsv_start, rsv_size;
+
+ ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+ if (ret) {
+ pr_err("Malformed device tree.\n");
+ return -EINVAL;
+ }
+
+ if (rsv_start == start && rsv_size == size) {
+ ret = fdt_del_mem_rsv(fdt, i);
+ if (ret) {
+ pr_err("Error deleting device tree reservation.\n");
+ return -EINVAL;
+ }
+
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
+
+/*
+ * setup_new_fdt - modify /chosen and memory reservation for the next kernel
+ * @fdt: Flattened device tree for the next kernel.
+ * @initrd_load_addr: Address where the next initrd will be loaded.
+ * @initrd_len: Size of the next initrd, or 0 if there will be none.
+ * @cmdline: Command line for the next kernel, or NULL if there will
+ * be none.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
+ unsigned long initrd_len, const char *cmdline)
+{
+ int ret, chosen_node;
+ const void *prop;
+
+ /* Remove memory reservation for the current device tree. */
+ ret = delete_fdt_mem_rsv(fdt, __pa(initial_boot_params),
+ fdt_totalsize(initial_boot_params));
+ if (ret == 0)
+ pr_debug("Removed old device tree reservation.\n");
+ else if (ret != -ENOENT)
+ return ret;
+
+ chosen_node = fdt_path_offset(fdt, "/chosen");
+ if (chosen_node == -FDT_ERR_NOTFOUND) {
+ chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
+ "chosen");
+ if (chosen_node < 0) {
+ pr_err("Error creating /chosen.\n");
+ return -EINVAL;
+ }
+ } else if (chosen_node < 0) {
+ pr_err("Malformed device tree: error reading /chosen.\n");
+ return -EINVAL;
+ }
+
+ /* Did we boot using an initrd? */
+ prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
+ if (prop) {
+ uint64_t tmp_start, tmp_end, tmp_size;
+
+ tmp_start = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+ prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", NULL);
+ if (!prop) {
+ pr_err("Malformed device tree.\n");
+ return -EINVAL;
+ }
+ tmp_end = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+ /*
+ * kexec reserves exact initrd size, while firmware may
+ * reserve a multiple of PAGE_SIZE, so check for both.
+ */
+ tmp_size = tmp_end - tmp_start;
+ ret = delete_fdt_mem_rsv(fdt, tmp_start, tmp_size);
+ if (ret == -ENOENT)
+ ret = delete_fdt_mem_rsv(fdt, tmp_start,
+ round_up(tmp_size, PAGE_SIZE));
+ if (ret == 0)
+ pr_debug("Removed old initrd reservation.\n");
+ else if (ret != -ENOENT)
+ return ret;
+
+ /* If there's no new initrd, delete the old initrd's info. */
+ if (initrd_len == 0) {
+ ret = fdt_delprop(fdt, chosen_node,
+ "linux,initrd-start");
+ if (ret) {
+ pr_err("Error deleting linux,initrd-start.\n");
+ return -EINVAL;
+ }
+
+ ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end");
+ if (ret) {
+ pr_err("Error deleting linux,initrd-end.\n");
+ return -EINVAL;
+ }
+ }
+ }
+
+ if (initrd_len) {
+ ret = fdt_setprop_u64(fdt, chosen_node,
+ "linux,initrd-start",
+ initrd_load_addr);
+ if (ret < 0) {
+ pr_err("Error setting up the new device tree.\n");
+ return -EINVAL;
+ }
+
+ /* initrd-end is the first address after the initrd image. */
+ ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end",
+ initrd_load_addr + initrd_len);
+ if (ret < 0) {
+ pr_err("Error setting up the new device tree.\n");
+ return -EINVAL;
+ }
+
+ ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
+ if (ret) {
+ pr_err("Error reserving initrd memory: %s\n",
+ fdt_strerror(ret));
+ return -EINVAL;
+ }
+ }
+
+ if (cmdline != NULL) {
+ ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);
+ if (ret < 0) {
+ pr_err("Error setting up the new device tree.\n");
+ return -EINVAL;
+ }
+ } else {
+ ret = fdt_delprop(fdt, chosen_node, "bootargs");
+ if (ret && ret != -FDT_ERR_NOTFOUND) {
+ pr_err("Error deleting bootargs.\n");
+ return -EINVAL;
+ }
+ }
+
+ ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
+ if (ret) {
+ pr_err("Error setting up the new device tree.\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}