alistair23-linux/kernel/trace/trace_entries.h
Frederic Weisbecker 24f1e32c60 hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events
This patch rebase the implementation of the breakpoints API on top of
perf events instances.

Each breakpoints are now perf events that handle the
register scheduling, thread/cpu attachment, etc..

The new layering is now made as follows:

       ptrace       kgdb      ftrace   perf syscall
          \          |          /         /
           \         |         /         /
                                        /
            Core breakpoint API        /
                                      /
                     |               /
                     |              /

              Breakpoints perf events

                     |
                     |

               Breakpoints PMU ---- Debug Register constraints handling
                                    (Part of core breakpoint API)
                     |
                     |

             Hardware debug registers

Reasons of this rewrite:

- Use the centralized/optimized pmu registers scheduling,
  implying an easier arch integration
- More powerful register handling: perf attributes (pinned/flexible
  events, exclusive/non-exclusive, tunable period, etc...)

Impact:

- New perf ABI: the hardware breakpoints counters
- Ptrace breakpoints setting remains tricky and still needs some per
  thread breakpoints references.

Todo (in the order):

- Support breakpoints perf counter events for perf tools (ie: implement
  perf_bpcounter_event())
- Support from perf tools

Changes in v2:

- Follow the perf "event " rename
- The ptrace regression have been fixed (ptrace breakpoint perf events
  weren't released when a task ended)
- Drop the struct hw_breakpoint and store generic fields in
  perf_event_attr.
- Separate core and arch specific headers, drop
  asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h
- Use new generic len/type for breakpoint
- Handle off case: when breakpoints api is not supported by an arch

Changes in v3:

- Fix broken CONFIG_KVM, we need to propagate the breakpoint api
  changes to kvm when we exit the guest and restore the bp registers
  to the host.

Changes in v4:

- Drop the hw_breakpoint_restore() stub as it is only used by KVM
- EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a
  module
- Restore the breakpoints unconditionally on kvm guest exit:
  TIF_DEBUG_THREAD doesn't anymore cover every cases of running
  breakpoints and vcpu->arch.switch_db_regs might not always be
  set when the guest used debug registers.
  (Waiting for a reliable optimization)

Changes in v5:

- Split-up the asm-generic/hw-breakpoint.h moving to
  linux/hw_breakpoint.h into a separate patch
- Optimize the breakpoints restoring while switching from kvm guest
  to host. We only want to restore the state if we have active
  breakpoints to the host, otherwise we don't care about messed-up
  address registers.
- Add asm/hw_breakpoint.h to Kbuild
- Fix bad breakpoint type in trace_selftest.c

Changes in v6:

- Fix wrong header inclusion in trace.h (triggered a build
  error with CONFIG_FTRACE_SELFTEST

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jan Kiszka <jan.kiszka@web.de>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
2009-11-08 15:34:42 +01:00

383 lines
9.1 KiB
C

/*
* This file defines the trace event structures that go into the ring
* buffer directly. They are created via macros so that changes for them
* appear in the format file. Using macros will automate this process.
*
* The macro used to create a ftrace data structure is:
*
* FTRACE_ENTRY( name, struct_name, id, structure, print )
*
* @name: the name used the event name, as well as the name of
* the directory that holds the format file.
*
* @struct_name: the name of the structure that is created.
*
* @id: The event identifier that is used to detect what event
* this is from the ring buffer.
*
* @structure: the structure layout
*
* - __field( type, item )
* This is equivalent to declaring
* type item;
* in the structure.
* - __array( type, item, size )
* This is equivalent to declaring
* type item[size];
* in the structure.
*
* * for structures within structures, the format of the internal
* structure is layed out. This allows the internal structure
* to be deciphered for the format file. Although these macros
* may become out of sync with the internal structure, they
* will create a compile error if it happens. Since the
* internel structures are just tracing helpers, this is not
* an issue.
*
* When an internal structure is used, it should use:
*
* __field_struct( type, item )
*
* instead of __field. This will prevent it from being shown in
* the output file. The fields in the structure should use.
*
* __field_desc( type, container, item )
* __array_desc( type, container, item, len )
*
* type, item and len are the same as __field and __array, but
* container is added. This is the name of the item in
* __field_struct that this is describing.
*
*
* @print: the print format shown to users in the format file.
*/
/*
* Function trace entry - function address and parent function addres:
*/
FTRACE_ENTRY(function, ftrace_entry,
TRACE_FN,
F_STRUCT(
__field( unsigned long, ip )
__field( unsigned long, parent_ip )
),
F_printk(" %lx <-- %lx", __entry->ip, __entry->parent_ip)
);
/* Function call entry */
FTRACE_ENTRY(funcgraph_entry, ftrace_graph_ent_entry,
TRACE_GRAPH_ENT,
F_STRUCT(
__field_struct( struct ftrace_graph_ent, graph_ent )
__field_desc( unsigned long, graph_ent, func )
__field_desc( int, graph_ent, depth )
),
F_printk("--> %lx (%d)", __entry->func, __entry->depth)
);
/* Function return entry */
FTRACE_ENTRY(funcgraph_exit, ftrace_graph_ret_entry,
TRACE_GRAPH_RET,
F_STRUCT(
__field_struct( struct ftrace_graph_ret, ret )
__field_desc( unsigned long, ret, func )
__field_desc( unsigned long long, ret, calltime)
__field_desc( unsigned long long, ret, rettime )
__field_desc( unsigned long, ret, overrun )
__field_desc( int, ret, depth )
),
F_printk("<-- %lx (%d) (start: %llx end: %llx) over: %d",
__entry->func, __entry->depth,
__entry->calltime, __entry->rettime,
__entry->depth)
);
/*
* Context switch trace entry - which task (and prio) we switched from/to:
*
* This is used for both wakeup and context switches. We only want
* to create one structure, but we need two outputs for it.
*/
#define FTRACE_CTX_FIELDS \
__field( unsigned int, prev_pid ) \
__field( unsigned char, prev_prio ) \
__field( unsigned char, prev_state ) \
__field( unsigned int, next_pid ) \
__field( unsigned char, next_prio ) \
__field( unsigned char, next_state ) \
__field( unsigned int, next_cpu )
FTRACE_ENTRY(context_switch, ctx_switch_entry,
TRACE_CTX,
F_STRUCT(
FTRACE_CTX_FIELDS
),
F_printk("%u:%u:%u ==> %u:%u:%u [%03u]",
__entry->prev_pid, __entry->prev_prio, __entry->prev_state,
__entry->next_pid, __entry->next_prio, __entry->next_state,
__entry->next_cpu
)
);
/*
* FTRACE_ENTRY_DUP only creates the format file, it will not
* create another structure.
*/
FTRACE_ENTRY_DUP(wakeup, ctx_switch_entry,
TRACE_WAKE,
F_STRUCT(
FTRACE_CTX_FIELDS
),
F_printk("%u:%u:%u ==+ %u:%u:%u [%03u]",
__entry->prev_pid, __entry->prev_prio, __entry->prev_state,
__entry->next_pid, __entry->next_prio, __entry->next_state,
__entry->next_cpu
)
);
/*
* Special (free-form) trace entry:
*/
FTRACE_ENTRY(special, special_entry,
TRACE_SPECIAL,
F_STRUCT(
__field( unsigned long, arg1 )
__field( unsigned long, arg2 )
__field( unsigned long, arg3 )
),
F_printk("(%08lx) (%08lx) (%08lx)",
__entry->arg1, __entry->arg2, __entry->arg3)
);
/*
* Stack-trace entry:
*/
#define FTRACE_STACK_ENTRIES 8
FTRACE_ENTRY(kernel_stack, stack_entry,
TRACE_STACK,
F_STRUCT(
__array( unsigned long, caller, FTRACE_STACK_ENTRIES )
),
F_printk("\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n"
"\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n",
__entry->caller[0], __entry->caller[1], __entry->caller[2],
__entry->caller[3], __entry->caller[4], __entry->caller[5],
__entry->caller[6], __entry->caller[7])
);
FTRACE_ENTRY(user_stack, userstack_entry,
TRACE_USER_STACK,
F_STRUCT(
__field( unsigned int, tgid )
__array( unsigned long, caller, FTRACE_STACK_ENTRIES )
),
F_printk("\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n"
"\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n",
__entry->caller[0], __entry->caller[1], __entry->caller[2],
__entry->caller[3], __entry->caller[4], __entry->caller[5],
__entry->caller[6], __entry->caller[7])
);
/*
* trace_printk entry:
*/
FTRACE_ENTRY(bprint, bprint_entry,
TRACE_BPRINT,
F_STRUCT(
__field( unsigned long, ip )
__field( const char *, fmt )
__dynamic_array( u32, buf )
),
F_printk("%08lx fmt:%p",
__entry->ip, __entry->fmt)
);
FTRACE_ENTRY(print, print_entry,
TRACE_PRINT,
F_STRUCT(
__field( unsigned long, ip )
__dynamic_array( char, buf )
),
F_printk("%08lx %s",
__entry->ip, __entry->buf)
);
FTRACE_ENTRY(mmiotrace_rw, trace_mmiotrace_rw,
TRACE_MMIO_RW,
F_STRUCT(
__field_struct( struct mmiotrace_rw, rw )
__field_desc( resource_size_t, rw, phys )
__field_desc( unsigned long, rw, value )
__field_desc( unsigned long, rw, pc )
__field_desc( int, rw, map_id )
__field_desc( unsigned char, rw, opcode )
__field_desc( unsigned char, rw, width )
),
F_printk("%lx %lx %lx %d %x %x",
(unsigned long)__entry->phys, __entry->value, __entry->pc,
__entry->map_id, __entry->opcode, __entry->width)
);
FTRACE_ENTRY(mmiotrace_map, trace_mmiotrace_map,
TRACE_MMIO_MAP,
F_STRUCT(
__field_struct( struct mmiotrace_map, map )
__field_desc( resource_size_t, map, phys )
__field_desc( unsigned long, map, virt )
__field_desc( unsigned long, map, len )
__field_desc( int, map, map_id )
__field_desc( unsigned char, map, opcode )
),
F_printk("%lx %lx %lx %d %x",
(unsigned long)__entry->phys, __entry->virt, __entry->len,
__entry->map_id, __entry->opcode)
);
FTRACE_ENTRY(boot_call, trace_boot_call,
TRACE_BOOT_CALL,
F_STRUCT(
__field_struct( struct boot_trace_call, boot_call )
__field_desc( pid_t, boot_call, caller )
__array_desc( char, boot_call, func, KSYM_SYMBOL_LEN)
),
F_printk("%d %s", __entry->caller, __entry->func)
);
FTRACE_ENTRY(boot_ret, trace_boot_ret,
TRACE_BOOT_RET,
F_STRUCT(
__field_struct( struct boot_trace_ret, boot_ret )
__array_desc( char, boot_ret, func, KSYM_SYMBOL_LEN)
__field_desc( int, boot_ret, result )
__field_desc( unsigned long, boot_ret, duration )
),
F_printk("%s %d %lx",
__entry->func, __entry->result, __entry->duration)
);
#define TRACE_FUNC_SIZE 30
#define TRACE_FILE_SIZE 20
FTRACE_ENTRY(branch, trace_branch,
TRACE_BRANCH,
F_STRUCT(
__field( unsigned int, line )
__array( char, func, TRACE_FUNC_SIZE+1 )
__array( char, file, TRACE_FILE_SIZE+1 )
__field( char, correct )
),
F_printk("%u:%s:%s (%u)",
__entry->line,
__entry->func, __entry->file, __entry->correct)
);
FTRACE_ENTRY(hw_branch, hw_branch_entry,
TRACE_HW_BRANCHES,
F_STRUCT(
__field( u64, from )
__field( u64, to )
),
F_printk("from: %llx to: %llx", __entry->from, __entry->to)
);
FTRACE_ENTRY(kmem_alloc, kmemtrace_alloc_entry,
TRACE_KMEM_ALLOC,
F_STRUCT(
__field( enum kmemtrace_type_id, type_id )
__field( unsigned long, call_site )
__field( const void *, ptr )
__field( size_t, bytes_req )
__field( size_t, bytes_alloc )
__field( gfp_t, gfp_flags )
__field( int, node )
),
F_printk("type:%u call_site:%lx ptr:%p req:%zi alloc:%zi"
" flags:%x node:%d",
__entry->type_id, __entry->call_site, __entry->ptr,
__entry->bytes_req, __entry->bytes_alloc,
__entry->gfp_flags, __entry->node)
);
FTRACE_ENTRY(kmem_free, kmemtrace_free_entry,
TRACE_KMEM_FREE,
F_STRUCT(
__field( enum kmemtrace_type_id, type_id )
__field( unsigned long, call_site )
__field( const void *, ptr )
),
F_printk("type:%u call_site:%lx ptr:%p",
__entry->type_id, __entry->call_site, __entry->ptr)
);
FTRACE_ENTRY(ksym_trace, ksym_trace_entry,
TRACE_KSYM,
F_STRUCT(
__field( unsigned long, ip )
__field( unsigned char, type )
__array( char , cmd, TASK_COMM_LEN )
__field( unsigned long, addr )
),
F_printk("ip: %pF type: %d ksym_name: %pS cmd: %s",
(void *)__entry->ip, (unsigned int)__entry->type,
(void *)__entry->addr, __entry->cmd)
);