summaryrefslogtreecommitdiffstats
path: root/arch/s390/boot/ipl_report.c
blob: 9b14045065b6e1e4bfbfcfa6c714a1d5d1e08a6e (plain)
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
153
154
155
156
157
158
159
160
161
162
163
164
165
// SPDX-License-Identifier: GPL-2.0
#include <linux/init.h>
#include <linux/ctype.h>
#include <asm/ebcdic.h>
#include <asm/sclp.h>
#include <asm/sections.h>
#include <asm/boot_data.h>
#include <uapi/asm/ipl.h>
#include "boot.h"

int __bootdata_preserved(ipl_secure_flag);

unsigned long __bootdata_preserved(ipl_cert_list_addr);
unsigned long __bootdata_preserved(ipl_cert_list_size);

unsigned long __bootdata(early_ipl_comp_list_addr);
unsigned long __bootdata(early_ipl_comp_list_size);

#define for_each_rb_entry(entry, rb) \
	for (entry = rb->entries; \
	     (void *) entry + sizeof(*entry) <= (void *) rb + rb->len; \
	     entry++)

static inline bool intersects(unsigned long addr0, unsigned long size0,
			      unsigned long addr1, unsigned long size1)
{
	return addr0 + size0 > addr1 && addr1 + size1 > addr0;
}

static unsigned long find_bootdata_space(struct ipl_rb_components *comps,
					 struct ipl_rb_certificates *certs,
					 unsigned long safe_addr)
{
	struct ipl_rb_certificate_entry *cert;
	struct ipl_rb_component_entry *comp;
	size_t size;

	/*
	 * Find the length for the IPL report boot data
	 */
	early_ipl_comp_list_size = 0;
	for_each_rb_entry(comp, comps)
		early_ipl_comp_list_size += sizeof(*comp);
	ipl_cert_list_size = 0;
	for_each_rb_entry(cert, certs)
		ipl_cert_list_size += sizeof(unsigned int) + cert->len;
	size = ipl_cert_list_size + early_ipl_comp_list_size;

	/*
	 * Start from safe_addr to find a free memory area large
	 * enough for the IPL report boot data. This area is used
	 * for ipl_cert_list_addr/ipl_cert_list_size and
	 * early_ipl_comp_list_addr/early_ipl_comp_list_size. It must
	 * not overlap with any component or any certificate.
	 */
repeat:
	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && initrd_data.start && initrd_data.size &&
	    intersects(initrd_data.start, initrd_data.size, safe_addr, size))
		safe_addr = initrd_data.start + initrd_data.size;
	for_each_rb_entry(comp, comps)
		if (intersects(safe_addr, size, comp->addr, comp->len)) {
			safe_addr = comp->addr + comp->len;
			goto repeat;
		}
	for_each_rb_entry(cert, certs)
		if (intersects(safe_addr, size, cert->addr, cert->len)) {
			safe_addr = cert->addr + cert->len;
			goto repeat;
		}
	early_ipl_comp_list_addr = safe_addr;
	ipl_cert_list_addr = safe_addr + early_ipl_comp_list_size;

	return safe_addr + size;
}

static void copy_components_bootdata(struct ipl_rb_components *comps)
{
	struct ipl_rb_component_entry *comp, *ptr;

	ptr = (struct ipl_rb_component_entry *) early_ipl_comp_list_addr;
	for_each_rb_entry(comp, comps)
		memcpy(ptr++, comp, sizeof(*ptr));
}

static void copy_certificates_bootdata(struct ipl_rb_certificates *certs)
{
	struct ipl_rb_certificate_entry *cert;
	void *ptr;

	ptr = (void *) ipl_cert_list_addr;
	for_each_rb_entry(cert, certs) {
		*(unsigned int *) ptr = cert->len;
		ptr += sizeof(unsigned int);
		memcpy(ptr, (void *) cert->addr, cert->len);
		ptr += cert->len;
	}
}

unsigned long read_ipl_report(unsigned long safe_addr)
{
	struct ipl_rb_certificates *certs;
	struct ipl_rb_components *comps;
	struct ipl_pl_hdr *pl_hdr;
	struct ipl_rl_hdr *rl_hdr;
	struct ipl_rb_hdr *rb_hdr;
	unsigned long tmp;
	void *rl_end;

	/*
	 * Check if there is a IPL report by looking at the copy
	 * of the IPL parameter information block.
	 */
	if (!ipl_block_valid ||
	    !(ipl_block.hdr.flags & IPL_PL_FLAG_IPLSR))
		return safe_addr;
	ipl_secure_flag = !!(ipl_block.hdr.flags & IPL_PL_FLAG_SIPL);
	/*
	 * There is an IPL report, to find it load the pointer to the
	 * IPL parameter information block from lowcore and skip past
	 * the IPL parameter list, then align the address to a double
	 * word boundary.
	 */
	tmp = (unsigned long) S390_lowcore.ipl_parmblock_ptr;
	pl_hdr = (struct ipl_pl_hdr *) tmp;
	tmp = (tmp + pl_hdr->len + 7) & -8UL;
	rl_hdr = (struct ipl_rl_hdr *) tmp;
	/* Walk through the IPL report blocks in the IPL Report list */
	certs = NULL;
	comps = NULL;
	rl_end = (void *) rl_hdr + rl_hdr->len;
	rb_hdr = (void *) rl_hdr + sizeof(*rl_hdr);
	while ((void *) rb_hdr + sizeof(*rb_hdr) < rl_end &&
	       (void *) rb_hdr + rb_hdr->len <= rl_end) {

		switch (rb_hdr->rbt) {
		case IPL_RBT_CERTIFICATES:
			certs = (struct ipl_rb_certificates *) rb_hdr;
			break;
		case IPL_RBT_COMPONENTS:
			comps = (struct ipl_rb_components *) rb_hdr;
			break;
		default:
			break;
		}

		rb_hdr = (void *) rb_hdr + rb_hdr->len;
	}

	/*
	 * With either the component list or the certificate list
	 * missing the kernel will stay ignorant of secure IPL.
	 */
	if (!comps || !certs)
		return safe_addr;

	/*
	 * Copy component and certificate list to a safe area
	 * where the decompressed kernel can find them.
	 */
	safe_addr = find_bootdata_space(comps, certs, safe_addr);
	copy_components_bootdata(comps);
	copy_certificates_bootdata(certs);

	return safe_addr;
}