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yaml
---
r: 100599
b: refs/heads/master
c: bd8ac68
h: refs/heads/master
i:
  100597: fe259af
  100595: 9c3f880
  100591: 2897d33
v: v3
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Pekka Paalanen authored and Thomas Gleixner committed May 24, 2008
1 parent 592b08c commit 308c097
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Showing 7 changed files with 239 additions and 189 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: f984b51e0779a6dd30feedc41404013ca54e5d05
refs/heads/master: bd8ac686c73c7e925fcfe0b02dc4e7b947127864
2 changes: 1 addition & 1 deletion trunk/arch/x86/Kconfig.debug
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Original file line number Diff line number Diff line change
Expand Up @@ -173,7 +173,7 @@ config MMIOTRACE_HOOKS

config MMIOTRACE
bool "Memory mapped IO tracing"
depends on DEBUG_KERNEL && RELAY
depends on DEBUG_KERNEL
select TRACING
select MMIOTRACE_HOOKS
default y
Expand Down
140 changes: 41 additions & 99 deletions trunk/arch/x86/kernel/mmiotrace/mmio-mod.c
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Original file line number Diff line number Diff line change
Expand Up @@ -37,11 +37,6 @@

#define NAME "mmiotrace: "

/* This app's relay channel files will appear in /debug/mmio-trace */
static const char APP_DIR[] = "mmio-trace";
/* the marker injection file in /debug/APP_DIR */
static const char MARKER_FILE[] = "mmio-marker";

struct trap_reason {
unsigned long addr;
unsigned long ip;
Expand All @@ -56,18 +51,15 @@ struct remap_trace {
unsigned long id;
};

static const size_t subbuf_size = 256*1024;

/* Accessed per-cpu. */
static DEFINE_PER_CPU(struct trap_reason, pf_reason);
static DEFINE_PER_CPU(struct mm_io_header_rw, cpu_trace);
static DEFINE_PER_CPU(struct mmiotrace_rw, cpu_trace);

#if 0 /* XXX: no way gather this info anymore */
/* Access to this is not per-cpu. */
static DEFINE_PER_CPU(atomic_t, dropped);
#endif

static struct dentry *dir;
static struct dentry *marker_file;

static DEFINE_MUTEX(mmiotrace_mutex);
Expand All @@ -82,24 +74,21 @@ static LIST_HEAD(trace_list); /* struct remap_trace */
* and trace_lock.
* - Routines depending on is_enabled() must take trace_lock.
* - trace_list users must hold trace_lock.
* - is_enabled() guarantees that chan is valid.
* - is_enabled() guarantees that mmio_trace_record is allowed.
* - pre/post callbacks assume the effect of is_enabled() being true.
*/

/* 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.");
Expand All @@ -110,6 +99,7 @@ static bool is_enabled(void)
return atomic_read(&mmiotrace_enabled);
}

#if 0 /* XXX: needs rewrite */
/*
* Write callback for the debugfs entry:
* Read a marker and write it to the mmio trace log
Expand Down Expand Up @@ -145,6 +135,7 @@ static ssize_t write_marker(struct file *file, const char __user *buffer,
kfree(event);
return len;
}
#endif

static void print_pte(unsigned long address)
{
Expand Down Expand Up @@ -198,9 +189,10 @@ static void pre(struct kmmio_probe *p, struct pt_regs *regs,
unsigned long addr)
{
struct trap_reason *my_reason = &get_cpu_var(pf_reason);
struct mm_io_header_rw *my_trace = &get_cpu_var(cpu_trace);
struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace);
const unsigned long instptr = instruction_pointer(regs);
const enum reason_type type = get_ins_type(instptr);
struct remap_trace *trace = p->user_data;

/* it doesn't make sense to have more than one active trace per cpu */
if (my_reason->active_traces)
Expand All @@ -212,23 +204,17 @@ static void pre(struct kmmio_probe *p, struct pt_regs *regs,
my_reason->addr = addr;
my_reason->ip = instptr;

my_trace->header.type = MMIO_MAGIC;
my_trace->header.pid = 0;
my_trace->header.data_len = sizeof(struct mm_io_rw);
my_trace->rw.address = addr;
/*
* struct remap_trace *trace = p->user_data;
* phys = addr - trace->probe.addr + trace->phys;
*/
my_trace->phys = addr - trace->probe.addr + trace->phys;
my_trace->map_id = trace->id;

/*
* Only record the program counter when requested.
* It may taint clean-room reverse engineering.
*/
if (trace_pc)
my_trace->rw.pc = instptr;
my_trace->pc = instptr;
else
my_trace->rw.pc = 0;
my_trace->pc = 0;

/*
* XXX: the timestamp recorded will be *after* the tracing has been
Expand All @@ -238,28 +224,25 @@ static void pre(struct kmmio_probe *p, struct pt_regs *regs,

switch (type) {
case REG_READ:
my_trace->header.type |=
(MMIO_READ << MMIO_OPCODE_SHIFT) |
(get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT);
my_trace->opcode = MMIO_READ;
my_trace->width = get_ins_mem_width(instptr);
break;
case REG_WRITE:
my_trace->header.type |=
(MMIO_WRITE << MMIO_OPCODE_SHIFT) |
(get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT);
my_trace->rw.value = get_ins_reg_val(instptr, regs);
my_trace->opcode = MMIO_WRITE;
my_trace->width = get_ins_mem_width(instptr);
my_trace->value = get_ins_reg_val(instptr, regs);
break;
case IMM_WRITE:
my_trace->header.type |=
(MMIO_WRITE << MMIO_OPCODE_SHIFT) |
(get_ins_mem_width(instptr) << MMIO_WIDTH_SHIFT);
my_trace->rw.value = get_ins_imm_val(instptr);
my_trace->opcode = MMIO_WRITE;
my_trace->width = get_ins_mem_width(instptr);
my_trace->value = get_ins_imm_val(instptr);
break;
default:
{
unsigned char *ip = (unsigned char *)instptr;
my_trace->header.type |=
(MMIO_UNKNOWN_OP << MMIO_OPCODE_SHIFT);
my_trace->rw.value = (*ip) << 16 | *(ip + 1) << 8 |
my_trace->opcode = MMIO_UNKNOWN_OP;
my_trace->width = 0;
my_trace->value = (*ip) << 16 | *(ip + 1) << 8 |
*(ip + 2);
}
}
Expand All @@ -271,7 +254,7 @@ static void post(struct kmmio_probe *p, unsigned long condition,
struct pt_regs *regs)
{
struct trap_reason *my_reason = &get_cpu_var(pf_reason);
struct mm_io_header_rw *my_trace = &get_cpu_var(cpu_trace);
struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace);

/* this should always return the active_trace count to 0 */
my_reason->active_traces--;
Expand All @@ -282,20 +265,13 @@ static void post(struct kmmio_probe *p, unsigned long condition,

switch (my_reason->type) {
case REG_READ:
my_trace->rw.value = get_ins_reg_val(my_reason->ip, regs);
my_trace->value = get_ins_reg_val(my_reason->ip, regs);
break;
default:
break;
}

/*
* XXX: Several required values are ignored:
* - mapping id
* - program counter
* Also the address should be physical, not virtual.
*/
mmio_trace_record(my_trace->header.type, my_trace->rw.address,
my_trace->rw.value);
mmio_trace_rw(my_trace);
put_cpu_var(cpu_trace);
put_cpu_var(pf_reason);
}
Expand All @@ -305,21 +281,11 @@ static void ioremap_trace_core(unsigned long offset, unsigned long size,
{
static atomic_t next_id;
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
}
struct mmiotrace_map map = {
.phys = offset,
.virt = (unsigned long)addr,
.len = size,
.opcode = MMIO_PROBE
};

if (!trace) {
Expand All @@ -338,15 +304,13 @@ static void ioremap_trace_core(unsigned long offset, unsigned long size,
.phys = offset,
.id = atomic_inc_return(&next_id)
};
map.map_id = trace->id;

spin_lock_irq(&trace_lock);
if (!is_enabled())
goto not_enabled;

/*
* XXX: Insufficient data recorded!
*/
mmio_trace_record(event.header.type, event.map.addr, event.map.len);
mmio_trace_mapping(&map);
list_add_tail(&trace->list, &trace_list);
if (!nommiotrace)
register_kmmio_probe(&trace->probe);
Expand All @@ -369,21 +333,11 @@ mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr)

static void iounmap_trace_core(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 mmiotrace_map map = {
.phys = 0,
.virt = (unsigned long)addr,
.len = 0,
.opcode = MMIO_UNPROBE
};
struct remap_trace *trace;
struct remap_trace *tmp;
Expand All @@ -404,8 +358,8 @@ static void iounmap_trace_core(volatile void __iomem *addr)
break;
}
}
mmio_trace_record(event.header.type, event.map.addr,
found_trace ? found_trace->id : -1);
map.map_id = (found_trace) ? found_trace->id : -1;
mmio_trace_mapping(&map);

not_enabled:
spin_unlock_irq(&trace_lock);
Expand Down Expand Up @@ -448,10 +402,12 @@ static void clear_trace_list(void)
}
}

#if 0 /* XXX: out of order */
static struct file_operations fops_marker = {
.owner = THIS_MODULE,
.write = write_marker
};
#endif

void enable_mmiotrace(void)
{
Expand All @@ -464,9 +420,9 @@ void enable_mmiotrace(void)
#if 0 /* XXX: tracing does not support text entries */
marker_file = debugfs_create_file("marker", 0660, dir, NULL,
&fops_marker);
#endif
if (!marker_file)
pr_err(NAME "marker file creation failed.\n");
#endif

if (nommiotrace)
pr_info(NAME "MMIO tracing disabled.\n");
Expand Down Expand Up @@ -502,17 +458,3 @@ void disable_mmiotrace(void)
out:
mutex_unlock(&mmiotrace_mutex);
}

int __init init_mmiotrace(void)
{
pr_debug(NAME "load...\n");
if (n_subbufs < 2)
return -EINVAL;

dir = debugfs_create_dir(APP_DIR, NULL);
if (!dir) {
pr_err(NAME "Couldn't create relay app directory.\n");
return -ENOMEM;
}
return 0;
}
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