1// SPDX-License-Identifier: GPL-2.0-only OR MIT
  2/*
  3 * Apple RTKit IPC library
  4 * Copyright (C) The Asahi Linux Contributors
  5 */
  6#include "rtkit-internal.h"
  7
  8#define FOURCC(a, b, c, d) \
  9	(((u32)(a) << 24) | ((u32)(b) << 16) | ((u32)(c) << 8) | ((u32)(d)))
 10
 11#define APPLE_RTKIT_CRASHLOG_HEADER FOURCC('C', 'L', 'H', 'E')
 12#define APPLE_RTKIT_CRASHLOG_STR FOURCC('C', 's', 't', 'r')
 13#define APPLE_RTKIT_CRASHLOG_VERSION FOURCC('C', 'v', 'e', 'r')
 14#define APPLE_RTKIT_CRASHLOG_MBOX FOURCC('C', 'm', 'b', 'x')
 15#define APPLE_RTKIT_CRASHLOG_TIME FOURCC('C', 't', 'i', 'm')
 16
 17struct apple_rtkit_crashlog_header {
 18	u32 fourcc;
 19	u32 version;
 20	u32 size;
 21	u32 flags;
 22	u8 _unk[16];
 23};
 24static_assert(sizeof(struct apple_rtkit_crashlog_header) == 0x20);
 25
 26struct apple_rtkit_crashlog_mbox_entry {
 27	u64 msg0;
 28	u64 msg1;
 29	u32 timestamp;
 30	u8 _unk[4];
 31};
 32static_assert(sizeof(struct apple_rtkit_crashlog_mbox_entry) == 0x18);
 33
 34static void apple_rtkit_crashlog_dump_str(struct apple_rtkit *rtk, u8 *bfr,
 35					  size_t size)
 36{
 37	u32 idx;
 38	u8 *ptr, *end;
 39
 40	memcpy(&idx, bfr, 4);
 41
 42	ptr = bfr + 4;
 43	end = bfr + size;
 44	while (ptr < end) {
 45		u8 *newline = memchr(ptr, '\n', end - ptr);
 46
 47		if (newline) {
 48			u8 tmp = *newline;
 49			*newline = '\0';
 50			dev_warn(rtk->dev, "RTKit: Message (id=%x): %s\n", idx,
 51				 ptr);
 52			*newline = tmp;
 53			ptr = newline + 1;
 54		} else {
 55			dev_warn(rtk->dev, "RTKit: Message (id=%x): %s", idx,
 56				 ptr);
 57			break;
 58		}
 59	}
 60}
 61
 62static void apple_rtkit_crashlog_dump_version(struct apple_rtkit *rtk, u8 *bfr,
 63					      size_t size)
 64{
 65	dev_warn(rtk->dev, "RTKit: Version: %s", bfr + 16);
 66}
 67
 68static void apple_rtkit_crashlog_dump_time(struct apple_rtkit *rtk, u8 *bfr,
 69					   size_t size)
 70{
 71	u64 crash_time;
 72
 73	memcpy(&crash_time, bfr, 8);
 74	dev_warn(rtk->dev, "RTKit: Crash time: %lld", crash_time);
 75}
 76
 77static void apple_rtkit_crashlog_dump_mailbox(struct apple_rtkit *rtk, u8 *bfr,
 78					      size_t size)
 79{
 80	u32 type, index, i;
 81	size_t n_messages;
 82	struct apple_rtkit_crashlog_mbox_entry entry;
 83
 84	memcpy(&type, bfr + 16, 4);
 85	memcpy(&index, bfr + 24, 4);
 86	n_messages = (size - 28) / sizeof(entry);
 87
 88	dev_warn(rtk->dev, "RTKit: Mailbox history (type = %d, index = %d)",
 89		 type, index);
 90	for (i = 0; i < n_messages; ++i) {
 91		memcpy(&entry, bfr + 28 + i * sizeof(entry), sizeof(entry));
 92		dev_warn(rtk->dev, "RTKit:  #%03d@%08x: %016llx %016llx", i,
 93			 entry.timestamp, entry.msg0, entry.msg1);
 94	}
 95}
 96
 97void apple_rtkit_crashlog_dump(struct apple_rtkit *rtk, u8 *bfr, size_t size)
 98{
 99	size_t offset;
100	u32 section_fourcc, section_size;
101	struct apple_rtkit_crashlog_header header;
102
103	memcpy(&header, bfr, sizeof(header));
104	if (header.fourcc != APPLE_RTKIT_CRASHLOG_HEADER) {
105		dev_warn(rtk->dev, "RTKit: Expected crashlog header but got %x",
106			 header.fourcc);
107		return;
108	}
109
110	if (header.size > size) {
111		dev_warn(rtk->dev, "RTKit: Crashlog size (%x) is too large",
112			 header.size);
113		return;
114	}
115
116	size = header.size;
117	offset = sizeof(header);
118
119	while (offset < size) {
120		memcpy(&section_fourcc, bfr + offset, 4);
121		memcpy(&section_size, bfr + offset + 12, 4);
122
123		switch (section_fourcc) {
124		case APPLE_RTKIT_CRASHLOG_HEADER:
125			dev_dbg(rtk->dev, "RTKit: End of crashlog reached");
126			return;
127		case APPLE_RTKIT_CRASHLOG_STR:
128			apple_rtkit_crashlog_dump_str(rtk, bfr + offset + 16,
129						      section_size);
130			break;
131		case APPLE_RTKIT_CRASHLOG_VERSION:
132			apple_rtkit_crashlog_dump_version(
133				rtk, bfr + offset + 16, section_size);
134			break;
135		case APPLE_RTKIT_CRASHLOG_MBOX:
136			apple_rtkit_crashlog_dump_mailbox(
137				rtk, bfr + offset + 16, section_size);
138			break;
139		case APPLE_RTKIT_CRASHLOG_TIME:
140			apple_rtkit_crashlog_dump_time(rtk, bfr + offset + 16,
141						       section_size);
142			break;
143		default:
144			dev_warn(rtk->dev,
145				 "RTKit: Unknown crashlog section: %x",
146				 section_fourcc);
147		}
148
149		offset += section_size;
150	}
151
152	dev_warn(rtk->dev,
153		 "RTKit: End of crashlog reached but no footer present");
154}