diff options
Diffstat (limited to 'qemu/roms/ipxe/src/core/fnrec.c')
| -rw-r--r-- | qemu/roms/ipxe/src/core/fnrec.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/core/fnrec.c b/qemu/roms/ipxe/src/core/fnrec.c new file mode 100644 index 000000000..3453c8b6a --- /dev/null +++ b/qemu/roms/ipxe/src/core/fnrec.c @@ -0,0 +1,203 @@ +/* + * Copyright (C) 2010 Stefan Hajnoczi <stefanha@gmail.com>. + * + * 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 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., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <ipxe/init.h> +#include <ipxe/uaccess.h> +#include <ipxe/io.h> + +/** @file + * + * Function trace recorder for crash and hang debugging + * + */ + +/** Constant for identifying valid trace buffers */ +#define FNREC_MAGIC ( 'f' << 24 | 'n' << 16 | 'r' << 8 | 'e' ) + +/** Number of trace buffer entries */ +#define FNREC_NUM_ENTRIES 4096 + +/** Trace buffer physical address + * + * Fixed at 17MB + */ +#define FNREC_PHYS_ADDRESS ( 17 * 1024 * 1024 ) + +/** A trace buffer entry */ +struct fnrec_entry { + /** Called function address */ + void *called_fn; + /** Call site */ + void *call_site; + /** Entry count */ + uint16_t entry_count; + /** Exit count */ + uint16_t exit_count; + /** Checksum */ + unsigned long checksum; +}; + +/** A trace buffer */ +struct fnrec_buffer { + /** Constant for identifying valid trace buffers */ + uint32_t magic; + + /** Next trace buffer entry to fill */ + unsigned int idx; + + /** Trace buffer */ + struct fnrec_entry data[FNREC_NUM_ENTRIES] + __attribute__ (( aligned ( 64 ) )); +}; + +/** The trace buffer */ +static struct fnrec_buffer *fnrec_buffer; + +/** + * Test whether the trace buffer is valid + * + * @ret is_valid Buffer is valid + */ +static int fnrec_is_valid ( void ) { + return ( fnrec_buffer && ( fnrec_buffer->magic == FNREC_MAGIC ) ); +} + +/** + * Invalidate the trace buffer + * + */ +static void fnrec_invalidate ( void ) { + fnrec_buffer->magic = 0; +} + +/** + * Reset the trace buffer and clear entries + */ +static void fnrec_reset ( void ) { + memset ( fnrec_buffer, 0, sizeof ( *fnrec_buffer ) ); + fnrec_buffer->magic = FNREC_MAGIC; +} + +/** + * Append an entry to the trace buffer + * + * @v called_fn Called function + * @v call_site Call site + * @ret entry Trace buffer entry + */ +static struct fnrec_entry * fnrec_append ( void *called_fn, void *call_site ) { + struct fnrec_entry *entry; + + /* Re-use existing entry, if possible */ + entry = &fnrec_buffer->data[ fnrec_buffer->idx ]; + if ( ( entry->called_fn == called_fn ) && + ( entry->call_site == call_site ) && + ( entry->entry_count >= entry->exit_count ) ) { + return entry; + } + + /* Otherwise, create a new entry */ + fnrec_buffer->idx = ( ( fnrec_buffer->idx + 1 ) % FNREC_NUM_ENTRIES ); + entry = &fnrec_buffer->data[ fnrec_buffer->idx ]; + entry->called_fn = called_fn; + entry->call_site = call_site; + entry->entry_count = 0; + entry->exit_count = 0; + entry->checksum = ( ( ( unsigned long ) called_fn ) ^ + ( ( unsigned long ) call_site ) ); + return entry; +} + +/** + * Print the contents of the trace buffer in chronological order + */ +static void fnrec_dump ( void ) { + struct fnrec_entry *entry; + unsigned int i; + unsigned int idx; + unsigned long checksum; + + printf ( "fnrec buffer dump:\n" ); + for ( i = 1 ; i <= FNREC_NUM_ENTRIES ; i++ ) { + idx = ( ( fnrec_buffer->idx + i ) % FNREC_NUM_ENTRIES ); + entry = &fnrec_buffer->data[idx]; + if ( ( entry->entry_count == 0 ) && ( entry->exit_count == 0 ) ) + continue; + checksum = ( ( ( ( unsigned long ) entry->called_fn ) ^ + ( ( unsigned long ) entry->call_site ) ) + + entry->entry_count + entry->exit_count ); + printf ( "%p %p %d %d", entry->called_fn, entry->call_site, + entry->entry_count, entry->exit_count ); + if ( entry->checksum != checksum ) { + printf ( " (checksum wrong at phys %08lx)", + virt_to_phys ( entry ) ); + } + printf ( "\n"); + } +} + +/** + * Function tracer initialisation function + */ +static void fnrec_init ( void ) { + + fnrec_buffer = phys_to_virt ( FNREC_PHYS_ADDRESS ); + if ( fnrec_is_valid() ) { + fnrec_invalidate(); + fnrec_dump(); + } else { + printf ( "fnrec buffer not found\n" ); + } + fnrec_reset(); +} + +struct init_fn fnrec_init_fn __init_fn ( INIT_NORMAL ) = { + .initialise = fnrec_init, +}; + +/* + * These functions are called from every C function. The compiler inserts + * these calls when -finstrument-functions is used. + */ +void __cyg_profile_func_enter ( void *called_fn, void *call_site ) { + struct fnrec_entry *entry; + + if ( fnrec_is_valid() ) { + entry = fnrec_append ( called_fn, call_site ); + entry->entry_count++; + entry->checksum++; + mb(); + } +} + +void __cyg_profile_func_exit ( void *called_fn, void *call_site ) { + struct fnrec_entry *entry; + + if ( fnrec_is_valid() ) { + entry = fnrec_append ( called_fn, call_site ); + entry->exit_count++; + entry->checksum++; + mb(); + } +} |