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-rw-r--r--arch/x86/kernel/mmiotrace/mmio-mod.c527
1 files changed, 527 insertions, 0 deletions
diff --git a/arch/x86/kernel/mmiotrace/mmio-mod.c b/arch/x86/kernel/mmiotrace/mmio-mod.c
new file mode 100644
index 0000000..73561fe
--- /dev/null
+++ b/arch/x86/kernel/mmiotrace/mmio-mod.c
@@ -0,0 +1,527 @@
+/*
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) IBM Corporation, 2005
+ * Jeff Muizelaar, 2006, 2007
+ * Pekka Paalanen, 2008 <pq@iki.fi>
+ *
+ * Derived from the read-mod example from relay-examples by Tom Zanussi.
+ */
+#include <linux/module.h>
+#include <linux/relay.h>
+#include <linux/debugfs.h>
+#include <linux/proc_fs.h>
+#include <asm/io.h>
+#include <linux/version.h>
+#include <linux/kallsyms.h>
+#include <asm/pgtable.h>
+#include <linux/mmiotrace.h>
+#include <asm/e820.h> /* for ISA_START_ADDRESS */
+
+#include "kmmio.h"
+#include "pf_in.h"
+
+/* This app's relay channel files will appear in /debug/mmio-trace */
+#define APP_DIR "mmio-trace"
+/* the marker injection file in /proc */
+#define MARKER_FILE "mmio-marker"
+
+#define MODULE_NAME "mmiotrace"
+
+struct trap_reason {
+ unsigned long addr;
+ unsigned long ip;
+ enum reason_type type;
+ int active_traces;
+};
+
+static struct trap_reason pf_reason[NR_CPUS];
+static struct mm_io_header_rw cpu_trace[NR_CPUS];
+
+static struct file_operations mmio_fops = {
+ .owner = THIS_MODULE,
+};
+
+static const size_t subbuf_size = 256*1024;
+static struct rchan *chan;
+static struct dentry *dir;
+static int suspended; /* XXX should this be per cpu? */
+static struct proc_dir_entry *proc_marker_file;
+
+/* module parameters */
+static unsigned int n_subbufs = 32*4;
+static unsigned long filter_offset;
+static int nommiotrace;
+static int ISA_trace;
+static int trace_pc;
+
+module_param(n_subbufs, uint, 0);
+module_param(filter_offset, ulong, 0);
+module_param(nommiotrace, bool, 0);
+module_param(ISA_trace, bool, 0);
+module_param(trace_pc, bool, 0);
+
+MODULE_PARM_DESC(n_subbufs, "Number of 256kB buffers, default 128.");
+MODULE_PARM_DESC(filter_offset, "Start address of traced mappings.");
+MODULE_PARM_DESC(nommiotrace, "Disable actual MMIO tracing.");
+MODULE_PARM_DESC(ISA_trace, "Do not exclude the low ISA range.");
+MODULE_PARM_DESC(trace_pc, "Record address of faulting instructions.");
+
+static void record_timestamp(struct mm_io_header *header)
+{
+ struct timespec now;
+
+ getnstimeofday(&now);
+ header->sec = now.tv_sec;
+ header->nsec = now.tv_nsec;
+}
+
+/*
+ * Write callback for the /proc entry:
+ * Read a marker and write it to the mmio trace log
+ */
+static int write_marker(struct file *file, const char __user *buffer,
+ unsigned long count, void *data)
+{
+ char *event = NULL;
+ struct mm_io_header *headp;
+ int len = (count > 65535) ? 65535 : count;
+
+ event = kzalloc(sizeof(*headp) + len, GFP_KERNEL);
+ if (!event)
+ return -ENOMEM;
+
+ headp = (struct mm_io_header *)event;
+ headp->type = MMIO_MAGIC | (MMIO_MARKER << MMIO_OPCODE_SHIFT);
+ headp->data_len = len;
+ record_timestamp(headp);
+
+ if (copy_from_user(event + sizeof(*headp), buffer, len)) {
+ kfree(event);
+ return -EFAULT;
+ }
+
+ relay_write(chan, event, sizeof(*headp) + len);
+ kfree(event);
+ return len;
+}
+
+static void print_pte(unsigned long address)
+{
+ pgd_t *pgd = pgd_offset_k(address);
+ pud_t *pud = pud_offset(pgd, address);
+ pmd_t *pmd = pmd_offset(pud, address);
+ if (pmd_large(*pmd)) {
+ printk(KERN_EMERG MODULE_NAME ": 4MB pages are not "
+ "currently supported: %lx\n",
+ address);
+ BUG();
+ }
+ printk(KERN_DEBUG MODULE_NAME ": pte for 0x%lx: 0x%lx 0x%lx\n",
+ address,
+ pte_val(*pte_offset_kernel(pmd, address)),
+ pte_val(*pte_offset_kernel(pmd, address)) & _PAGE_PRESENT);
+}
+
+/*
+ * For some reason the pre/post pairs have been called in an
+ * unmatched order. Report and die.
+ */
+static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr)
+{
+ const unsigned long cpu = smp_processor_id();
+ printk(KERN_EMERG MODULE_NAME ": unexpected fault for address: %lx, "
+ "last fault for address: %lx\n",
+ addr, pf_reason[cpu].addr);
+ print_pte(addr);
+#ifdef __i386__
+ print_symbol(KERN_EMERG "faulting EIP is at %s\n", regs->ip);
+ print_symbol(KERN_EMERG "last faulting EIP was at %s\n",
+ pf_reason[cpu].ip);
+ printk(KERN_EMERG
+ "eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
+ regs->ax, regs->bx, regs->cx, regs->dx);
+ printk(KERN_EMERG
+ "esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n",
+ regs->si, regs->di, regs->bp, regs->sp);
+#else
+ print_symbol(KERN_EMERG "faulting RIP is at %s\n", regs->ip);
+ print_symbol(KERN_EMERG "last faulting RIP was at %s\n",
+ pf_reason[cpu].ip);
+ printk(KERN_EMERG "rax: %016lx rcx: %016lx rdx: %016lx\n",
+ regs->ax, regs->cx, regs->dx);
+ printk(KERN_EMERG "rsi: %016lx rdi: %016lx "
+ "rbp: %016lx rsp: %016lx\n",
+ regs->si, regs->di, regs->bp, regs->sp);
+#endif
+ BUG();
+}
+
+static void pre(struct kmmio_probe *p, struct pt_regs *regs,
+ unsigned long addr)
+{
+ const unsigned long cpu = smp_processor_id();
+ const unsigned long instptr = instruction_pointer(regs);
+ const enum reason_type type = get_ins_type(instptr);
+
+ /* it doesn't make sense to have more than one active trace per cpu */
+ if (pf_reason[cpu].active_traces)
+ die_kmmio_nesting_error(regs, addr);
+ else
+ pf_reason[cpu].active_traces++;
+
+ pf_reason[cpu].type = type;
+ pf_reason[cpu].addr = addr;
+ pf_reason[cpu].ip = instptr;
+
+ cpu_trace[cpu].header.type = MMIO_MAGIC;
+ cpu_trace[cpu].header.pid = 0;
+ cpu_trace[cpu].header.data_len = sizeof(struct mm_io_rw);
+ cpu_trace[cpu].rw.address = addr;
+
+ /*
+ * Only record the program counter when requested.
+ * It may taint clean-room reverse engineering.
+ */
+ if (trace_pc)
+ cpu_trace[cpu].rw.pc = instptr;
+ else
+ cpu_trace[cpu].rw.pc = 0;
+
+ record_timestamp(&cpu_trace[cpu].header);
+
+ switch (type) {
+ case REG_READ:
+ cpu_trace[cpu].header.type |=
+ (MMIO_READ << MMIO_OPCODE_SHIFT) |
+ (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT);
+ break;
+ case REG_WRITE:
+ cpu_trace[cpu].header.type |=
+ (MMIO_WRITE << MMIO_OPCODE_SHIFT) |
+ (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT);
+ cpu_trace[cpu].rw.value = get_ins_reg_val(instptr, regs);
+ break;
+ case IMM_WRITE:
+ cpu_trace[cpu].header.type |=
+ (MMIO_WRITE << MMIO_OPCODE_SHIFT) |
+ (get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT);
+ cpu_trace[cpu].rw.value = get_ins_imm_val(instptr);
+ break;
+ default:
+ {
+ unsigned char *ip = (unsigned char *)instptr;
+ cpu_trace[cpu].header.type |=
+ (MMIO_UNKNOWN_OP << MMIO_OPCODE_SHIFT);
+ cpu_trace[cpu].rw.value = (*ip) << 16 |
+ *(ip + 1) << 8 |
+ *(ip + 2);
+ }
+ }
+}
+
+static void post(struct kmmio_probe *p, unsigned long condition,
+ struct pt_regs *regs)
+{
+ const unsigned long cpu = smp_processor_id();
+
+ /* this should always return the active_trace count to 0 */
+ pf_reason[cpu].active_traces--;
+ if (pf_reason[cpu].active_traces) {
+ printk(KERN_EMERG MODULE_NAME ": unexpected post handler");
+ BUG();
+ }
+
+ switch (pf_reason[cpu].type) {
+ case REG_READ:
+ cpu_trace[cpu].rw.value = get_ins_reg_val(pf_reason[cpu].ip,
+ regs);
+ break;
+ default:
+ break;
+ }
+ relay_write(chan, &cpu_trace[cpu], sizeof(struct mm_io_header_rw));
+}
+
+/*
+ * subbuf_start() relay callback.
+ *
+ * Defined so that we know when events are dropped due to the buffer-full
+ * condition.
+ */
+static int subbuf_start_handler(struct rchan_buf *buf, void *subbuf,
+ void *prev_subbuf, size_t prev_padding)
+{
+ if (relay_buf_full(buf)) {
+ if (!suspended) {
+ suspended = 1;
+ printk(KERN_ERR MODULE_NAME
+ ": cpu %d buffer full!!!\n",
+ smp_processor_id());
+ }
+ return 0;
+ } else if (suspended) {
+ suspended = 0;
+ printk(KERN_ERR MODULE_NAME
+ ": cpu %d buffer no longer full.\n",
+ smp_processor_id());
+ }
+
+ return 1;
+}
+
+/* file_create() callback. Creates relay file in debugfs. */
+static struct dentry *create_buf_file_handler(const char *filename,
+ struct dentry *parent,
+ int mode,
+ struct rchan_buf *buf,
+ int *is_global)
+{
+ struct dentry *buf_file;
+
+ mmio_fops.read = relay_file_operations.read;
+ mmio_fops.open = relay_file_operations.open;
+ mmio_fops.poll = relay_file_operations.poll;
+ mmio_fops.mmap = relay_file_operations.mmap;
+ mmio_fops.release = relay_file_operations.release;
+ mmio_fops.splice_read = relay_file_operations.splice_read;
+
+ buf_file = debugfs_create_file(filename, mode, parent, buf,
+ &mmio_fops);
+
+ return buf_file;
+}
+
+/* file_remove() default callback. Removes relay file in debugfs. */
+static int remove_buf_file_handler(struct dentry *dentry)
+{
+ debugfs_remove(dentry);
+ return 0;
+}
+
+static struct rchan_callbacks relay_callbacks = {
+ .subbuf_start = subbuf_start_handler,
+ .create_buf_file = create_buf_file_handler,
+ .remove_buf_file = remove_buf_file_handler,
+};
+
+/*
+ * create_channel - creates channel /debug/APP_DIR/cpuXXX
+ * Returns channel on success, NULL otherwise
+ */
+static struct rchan *create_channel(unsigned size, unsigned n)
+{
+ return relay_open("cpu", dir, size, n, &relay_callbacks, NULL);
+}
+
+/* destroy_channel - destroys channel /debug/APP_DIR/cpuXXX */
+static void destroy_channel(void)
+{
+ if (chan) {
+ relay_close(chan);
+ chan = NULL;
+ }
+}
+
+struct remap_trace {
+ struct list_head list;
+ struct kmmio_probe probe;
+};
+static LIST_HEAD(trace_list);
+static DEFINE_SPINLOCK(trace_list_lock);
+
+static void do_ioremap_trace_core(unsigned long offset, unsigned long size,
+ void __iomem *addr)
+{
+ struct remap_trace *trace = kmalloc(sizeof(*trace), GFP_KERNEL);
+ struct mm_io_header_map event = {
+ .header = {
+ .type = MMIO_MAGIC |
+ (MMIO_PROBE << MMIO_OPCODE_SHIFT),
+ .sec = 0,
+ .nsec = 0,
+ .pid = 0,
+ .data_len = sizeof(struct mm_io_map)
+ },
+ .map = {
+ .phys = offset,
+ .addr = (unsigned long)addr,
+ .len = size,
+ .pc = 0
+ }
+ };
+ record_timestamp(&event.header);
+
+ *trace = (struct remap_trace) {
+ .probe = {
+ .addr = (unsigned long)addr,
+ .len = size,
+ .pre_handler = pre,
+ .post_handler = post,
+ }
+ };
+
+ relay_write(chan, &event, sizeof(event));
+ spin_lock(&trace_list_lock);
+ list_add_tail(&trace->list, &trace_list);
+ spin_unlock(&trace_list_lock);
+ if (!nommiotrace)
+ register_kmmio_probe(&trace->probe);
+}
+
+static void ioremap_trace_core(unsigned long offset, unsigned long size,
+ void __iomem *addr)
+{
+ if ((filter_offset) && (offset != filter_offset))
+ return;
+
+ /* Don't trace the low PCI/ISA area, it's always mapped.. */
+ if (!ISA_trace && (offset < ISA_END_ADDRESS) &&
+ (offset + size > ISA_START_ADDRESS)) {
+ printk(KERN_NOTICE MODULE_NAME ": Ignoring map of low "
+ "PCI/ISA area (0x%lx-0x%lx)\n",
+ offset, offset + size);
+ return;
+ }
+ do_ioremap_trace_core(offset, size, addr);
+}
+
+void __iomem *ioremap_cache_trace(unsigned long offset, unsigned long size)
+{
+ void __iomem *p = ioremap_cache(offset, size);
+ printk(KERN_DEBUG MODULE_NAME ": ioremap_cache(0x%lx, 0x%lx) = %p\n",
+ offset, size, p);
+ ioremap_trace_core(offset, size, p);
+ return p;
+}
+EXPORT_SYMBOL(ioremap_cache_trace);
+
+void __iomem *ioremap_nocache_trace(unsigned long offset, unsigned long size)
+{
+ void __iomem *p = ioremap_nocache(offset, size);
+ printk(KERN_DEBUG MODULE_NAME ": ioremap_nocache(0x%lx, 0x%lx) = %p\n",
+ offset, size, p);
+ ioremap_trace_core(offset, size, p);
+ return p;
+}
+EXPORT_SYMBOL(ioremap_nocache_trace);
+
+void iounmap_trace(volatile void __iomem *addr)
+{
+ struct mm_io_header_map event = {
+ .header = {
+ .type = MMIO_MAGIC |
+ (MMIO_UNPROBE << MMIO_OPCODE_SHIFT),
+ .sec = 0,
+ .nsec = 0,
+ .pid = 0,
+ .data_len = sizeof(struct mm_io_map)
+ },
+ .map = {
+ .phys = 0,
+ .addr = (unsigned long)addr,
+ .len = 0,
+ .pc = 0
+ }
+ };
+ struct remap_trace *trace;
+ struct remap_trace *tmp;
+ printk(KERN_DEBUG MODULE_NAME ": Unmapping %p.\n", addr);
+ record_timestamp(&event.header);
+
+ spin_lock(&trace_list_lock);
+ list_for_each_entry_safe(trace, tmp, &trace_list, list) {
+ if ((unsigned long)addr == trace->probe.addr) {
+ if (!nommiotrace)
+ unregister_kmmio_probe(&trace->probe);
+ list_del(&trace->list);
+ kfree(trace);
+ break;
+ }
+ }
+ spin_unlock(&trace_list_lock);
+ relay_write(chan, &event, sizeof(event));
+ iounmap(addr);
+}
+EXPORT_SYMBOL(iounmap_trace);
+
+static void clear_trace_list(void)
+{
+ struct remap_trace *trace;
+ struct remap_trace *tmp;
+
+ spin_lock(&trace_list_lock);
+ list_for_each_entry_safe(trace, tmp, &trace_list, list) {
+ printk(KERN_WARNING MODULE_NAME ": purging non-iounmapped "
+ "trace @0x%08lx, size 0x%lx.\n",
+ trace->probe.addr, trace->probe.len);
+ if (!nommiotrace)
+ unregister_kmmio_probe(&trace->probe);
+ list_del(&trace->list);
+ kfree(trace);
+ break;
+ }
+ spin_unlock(&trace_list_lock);
+}
+
+static int __init init(void)
+{
+ if (n_subbufs < 2)
+ return -EINVAL;
+
+ dir = debugfs_create_dir(APP_DIR, NULL);
+ if (!dir) {
+ printk(KERN_ERR MODULE_NAME
+ ": Couldn't create relay app directory.\n");
+ return -ENOMEM;
+ }
+
+ chan = create_channel(subbuf_size, n_subbufs);
+ if (!chan) {
+ debugfs_remove(dir);
+ printk(KERN_ERR MODULE_NAME
+ ": relay app channel creation failed\n");
+ return -ENOMEM;
+ }
+
+ init_kmmio();
+
+ proc_marker_file = create_proc_entry(MARKER_FILE, 0, NULL);
+ if (proc_marker_file)
+ proc_marker_file->write_proc = write_marker;
+
+ printk(KERN_DEBUG MODULE_NAME ": loaded.\n");
+ if (nommiotrace)
+ printk(KERN_DEBUG MODULE_NAME ": MMIO tracing disabled.\n");
+ if (ISA_trace)
+ printk(KERN_WARNING MODULE_NAME
+ ": Warning! low ISA range will be traced.\n");
+ return 0;
+}
+
+static void __exit cleanup(void)
+{
+ printk(KERN_DEBUG MODULE_NAME ": unload...\n");
+ clear_trace_list();
+ cleanup_kmmio();
+ remove_proc_entry(MARKER_FILE, NULL);
+ destroy_channel();
+ if (dir)
+ debugfs_remove(dir);
+}
+
+module_init(init);
+module_exit(cleanup);
+MODULE_LICENSE("GPL");
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