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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 | // SPDX-License-Identifier: GPL-2.0 #include <linux/init.h> #include <linux/seq_file.h> #include <linux/fs.h> #include <linux/mm.h> #include <linux/proc_fs.h> #include <linux/slab.h> #include <xen/interface/platform.h> #include <asm/xen/hypercall.h> #include <xen/xen-ops.h> #include "xenfs.h" #define XEN_KSYM_NAME_LEN 127 /* Hypervisor may have different name length */ struct xensyms { struct xen_platform_op op; char *name; uint32_t namelen; }; /* Grab next output page from the hypervisor */ static int xensyms_next_sym(struct xensyms *xs) { int ret; struct xenpf_symdata *symdata = &xs->op.u.symdata; uint64_t symnum; memset(xs->name, 0, xs->namelen); symdata->namelen = xs->namelen; symnum = symdata->symnum; ret = HYPERVISOR_platform_op(&xs->op); if (ret < 0) return ret; /* * If hypervisor's symbol didn't fit into the buffer then allocate * a larger buffer and try again. */ if (unlikely(symdata->namelen > xs->namelen)) { kfree(xs->name); xs->namelen = symdata->namelen; xs->name = kzalloc(xs->namelen, GFP_KERNEL); if (!xs->name) return -ENOMEM; set_xen_guest_handle(symdata->name, xs->name); symdata->symnum--; /* Rewind */ ret = HYPERVISOR_platform_op(&xs->op); if (ret < 0) return ret; } if (symdata->symnum == symnum) /* End of symbols */ return 1; return 0; } static void *xensyms_start(struct seq_file *m, loff_t *pos) { struct xensyms *xs = m->private; xs->op.u.symdata.symnum = *pos; if (xensyms_next_sym(xs)) return NULL; return m->private; } static void *xensyms_next(struct seq_file *m, void *p, loff_t *pos) { struct xensyms *xs = m->private; xs->op.u.symdata.symnum = ++(*pos); if (xensyms_next_sym(xs)) return NULL; return p; } static int xensyms_show(struct seq_file *m, void *p) { struct xensyms *xs = m->private; struct xenpf_symdata *symdata = &xs->op.u.symdata; seq_printf(m, "%016llx %c %s\n", symdata->address, symdata->type, xs->name); return 0; } static void xensyms_stop(struct seq_file *m, void *p) { } static const struct seq_operations xensyms_seq_ops = { .start = xensyms_start, .next = xensyms_next, .show = xensyms_show, .stop = xensyms_stop, }; static int xensyms_open(struct inode *inode, struct file *file) { struct seq_file *m; struct xensyms *xs; int ret; ret = seq_open_private(file, &xensyms_seq_ops, sizeof(struct xensyms)); if (ret) return ret; m = file->private_data; xs = m->private; xs->namelen = XEN_KSYM_NAME_LEN + 1; xs->name = kzalloc(xs->namelen, GFP_KERNEL); if (!xs->name) { seq_release_private(inode, file); return -ENOMEM; } set_xen_guest_handle(xs->op.u.symdata.name, xs->name); xs->op.cmd = XENPF_get_symbol; xs->op.u.symdata.namelen = xs->namelen; return 0; } static int xensyms_release(struct inode *inode, struct file *file) { struct seq_file *m = file->private_data; struct xensyms *xs = m->private; kfree(xs->name); return seq_release_private(inode, file); } const struct file_operations xensyms_ops = { .open = xensyms_open, .read = seq_read, .llseek = seq_lseek, .release = xensyms_release }; |