diff options
Diffstat (limited to 'gdb/remote.c')
| -rw-r--r-- | gdb/remote.c | 321 |
1 files changed, 266 insertions, 55 deletions
diff --git a/gdb/remote.c b/gdb/remote.c index cd4eda0a083..e63813628a3 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -280,28 +280,6 @@ static serial_t remote_desc = NULL; to denote that the target is in kernel mode. */ static int cisco_kernel_mode = 0; -/* Maximum number of bytes to read/write at once. The value here - is chosen to fill up a packet (the headers account for the 32). */ -#define MAXBUFBYTES(N) (((N)-32)/2) - -/* Having this larger than 400 causes us to be incompatible with m68k-stub.c - and i386-stub.c. Normally, no one would notice because it only matters - for writing large chunks of memory (e.g. in downloads). Also, this needs - to be more than 400 if required to hold the registers (see below, where - we round it up based on REGISTER_BYTES). */ -/* Round up PBUFSIZ to hold all the registers, at least. */ -#define PBUFSIZ ((REGISTER_BYTES > MAXBUFBYTES (400)) \ - ? (REGISTER_BYTES * 2 + 32) \ - : 400) - - -/* This variable sets the number of bytes to be written to the target - in a single packet. Normally PBUFSIZ is satisfactory, but some - targets need smaller values (perhaps because the receiving end - is slow). */ - -static int remote_write_size; - /* This variable sets the number of bits in an address that are to be sent in a memory ("M" or "m") packet. Normally, after stripping leading zeros, the entire address would be sent. This variable @@ -315,18 +293,226 @@ static int remote_write_size; static int remote_address_size; -/* This is the size (in chars) of the first response to the `g' command. This - is used to limit the size of the memory read and write commands to prevent - stub buffers from overflowing. The size does not include headers and - trailers, it is only the payload size. */ - -static int remote_register_buf_size = 0; - /* Tempoary to track who currently owns the terminal. See target_async_terminal_* for more details. */ static int remote_async_terminal_ours_p; + +/* This is the size (in chars) of the first response to the ``g'' + packet. It is used as a heuristic when determining the maximum + size of memory-read and memory-write packets. A target will + typically only reserve a buffer large enough to hold the ``g'' + packet. The size does not include packet overhead (headers and + trailers). */ + +static long actual_register_packet_size; + +/* This is the maximum size (in chars) of a non read/write packet. It + is also used as a cap on the size of read/write packets. */ + +static long remote_packet_size; +/* compatibility. */ +#define PBUFSIZ (remote_packet_size) + +/* User configurable variables for the number of characters in a + memory read/write packet. MIN (PBUFSIZ, g-packet-size) is the + default. Some targets need smaller values (fifo overruns, et.al.) + and some users need larger values (speed up transfers). The + variables ``preferred_*'' (the user request), ``current_*'' (what + was actually set) and ``forced_*'' (Positive - a soft limit, + negative - a hard limit). */ + +struct memory_packet_config +{ + char *name; + long size; + int fixed_p; +}; + +/* Compute the current size of a read/write packet. Since this makes + use of ``actual_register_packet_size'' the computation is dynamic. */ + +static long +get_memory_packet_size (struct memory_packet_config *config) +{ + /* NOTE: The somewhat arbitrary 16k comes from the knowledge (folk + law?) that some hosts don't cope very well with large alloca() + calls. Eventually the alloca() code will be replaced by calls to + xmalloc() and make_cleanups() allowing this restriction to either + be lifted or removed. */ +#ifndef MAX_REMOTE_PACKET_SIZE +#define MAX_REMOTE_PACKET_SIZE 16384 +#endif + /* NOTE: 16 is just chosen at random. */ +#ifndef MIN_REMOTE_PACKET_SIZE +#define MIN_REMOTE_PACKET_SIZE 16 +#endif + long what_they_get; + if (config->fixed_p) + { + if (config->size <= 0) + what_they_get = MAX_REMOTE_PACKET_SIZE; + else + what_they_get = config->size; + } + else + { + what_they_get = remote_packet_size; + /* Limit the packet to the size specified by the user. */ + if (config->size > 0 + && what_they_get > config->size) + what_they_get = config->size; + /* Limit it to the size of the targets ``g'' response. */ + if (actual_register_packet_size > 0 + && what_they_get > actual_register_packet_size) + what_they_get = actual_register_packet_size; + } + if (what_they_get > MAX_REMOTE_PACKET_SIZE) + what_they_get = MAX_REMOTE_PACKET_SIZE; + if (what_they_get < MIN_REMOTE_PACKET_SIZE) + what_they_get = MIN_REMOTE_PACKET_SIZE; + return what_they_get; +} + +/* Update the size of a read/write packet. If they user wants + something really big then do a sanity check. */ + +static void +set_memory_packet_size (char *args, struct memory_packet_config *config) +{ + int fixed_p = config->fixed_p; + long size = config->size; + if (args == NULL) + error ("Argument required (integer, `fixed' or `limited')."); + else if (strcmp (args, "hard") == 0 + || strcmp (args, "fixed") == 0) + fixed_p = 1; + else if (strcmp (args, "soft") == 0 + || strcmp (args, "limit") == 0) + fixed_p = 0; + else + { + char *end; + size = strtoul (args, &end, 0); + if (args == end) + error ("Invalid %s (bad syntax).", config->name); +#if 0 + /* Instead of explicitly capping the size of a packet to + MAX_REMOTE_PACKET_SIZE or dissallowing it, the user is + instead allowed to set the size to something arbitrarily + large. */ + if (size > MAX_REMOTE_PACKET_SIZE) + error ("Invalid %s (too large).", config->name); +#endif + } + /* Extra checks? */ + if (fixed_p && !config->fixed_p) + { + if (! query ("The target may not be able to correctly handle a %s\n" + "of %ld bytes. Change the packet size? ", + config->name, size)) + error ("Packet size not changed."); + } + /* Update the config. */ + config->fixed_p = fixed_p; + config->size = size; +} + +static void +show_memory_packet_size (struct memory_packet_config *config) +{ + printf_filtered ("The %s is %ld. ", config->name, config->size); + if (config->fixed_p) + printf_filtered ("Packets are fixed at %ld bytes.\n", + get_memory_packet_size (config)); + else + printf_filtered ("Packets are limited to %ld bytes.\n", + get_memory_packet_size (config)); +} + +static struct memory_packet_config memory_write_packet_config = +{ + "memory-write-packet-size", +}; + +static void +set_memory_write_packet_size (char *args, int from_tty) +{ + set_memory_packet_size (args, &memory_write_packet_config); +} + +static void +show_memory_write_packet_size (char *args, int from_tty) +{ + show_memory_packet_size (&memory_write_packet_config); +} + +static long +get_memory_write_packet_size (void) +{ + return get_memory_packet_size (&memory_write_packet_config); +} + +static struct memory_packet_config memory_read_packet_config = +{ + "memory-read-packet-size", +}; + +static void +set_memory_read_packet_size (char *args, int from_tty) +{ + set_memory_packet_size (args, &memory_read_packet_config); +} + +static void +show_memory_read_packet_size (char *args, int from_tty) +{ + show_memory_packet_size (&memory_read_packet_config); +} + +static long +get_memory_read_packet_size (void) +{ + long size = get_memory_packet_size (&memory_read_packet_config); + /* FIXME: cagney/1999-11-07: Functions like getpkt() need to get an + extra buffer size argument before the memory read size can be + increased beyond PBUFSIZ. */ + if (size > PBUFSIZ) + size = PBUFSIZ; + return size; +} + +/* Register packet size initialization. Since the bounds change when + the architecture changes (namely REGISTER_BYTES) this all needs to + be multi-arched. */ + +static void +register_remote_packet_sizes (void) +{ + REGISTER_GDBARCH_SWAP (remote_packet_size); + REGISTER_GDBARCH_SWAP (actual_register_packet_size); +} + +static void +build_remote_packet_sizes (void) +{ + /* Maximum number of characters in a packet. This default m68k-stub.c and + i386-stub.c stubs. */ + remote_packet_size = 400; + /* Should REGISTER_BYTES needs more space than the default, adjust + the size accordingly. Remember that each byte is encoded as two + characters. 32 is the overhead for the packet header / + footer. NOTE: cagney/1999-10-26: I suspect that 8 + (``$NN:G...#NN'') is a better guess, the below has been padded a + little. */ + if (REGISTER_BYTES > ((remote_packet_size - 32) / 2)) + remote_packet_size = (REGISTER_BYTES * 2 + 32); + + /* This one is filled in when a ``g'' packet is received. */ + actual_register_packet_size = 0; +} + /* Generic configuration support for packets the stub optionally supports. Allows the user to specify the use of the packet as well as allowing GDB to auto-detect support in the remote stub. */ @@ -2749,8 +2935,11 @@ remote_fetch_registers (regno) sprintf (buf, "g"); remote_send (buf); - if (remote_register_buf_size == 0) - remote_register_buf_size = strlen (buf); + /* Save the size of the packet sent to us by the target. Its used + as a heuristic when determining the max size of packets that the + target can safely receive. */ + if (actual_register_packet_size == 0) + actual_register_packet_size = strlen (buf); /* Unimplemented registers read as all bits zero. */ memset (regs, 0, REGISTER_BYTES); @@ -3095,9 +3284,7 @@ remote_write_bytes (CORE_ADDR memaddr, char *myaddr, int len) check_binary_download (memaddr); /* Determine the max packet size. */ - max_buf_size = min (remote_write_size, PBUFSIZ); - if (remote_register_buf_size != 0) - max_buf_size = min (max_buf_size, remote_register_buf_size); + max_buf_size = get_memory_write_packet_size (); buf = alloca (max_buf_size + 1); /* Subtract header overhead from max payload size - $M<memaddr>,<len>:#nn */ @@ -3228,15 +3415,13 @@ remote_read_bytes (memaddr, myaddr, len) char *myaddr; int len; { - char *buf = alloca (PBUFSIZ); + char *buf; int max_buf_size; /* Max size of packet output buffer */ int origlen; - /* Chop the transfer down if necessary */ - - max_buf_size = min (remote_write_size, PBUFSIZ); - if (remote_register_buf_size != 0) - max_buf_size = min (max_buf_size, remote_register_buf_size); + /* Create a buffer big enough for this packet. */ + max_buf_size = get_memory_read_packet_size (); + buf = alloca (max_buf_size); origlen = len; while (len > 0) @@ -3477,7 +3662,7 @@ putpkt_binary (buf, cnt) { int i; unsigned char csum = 0; - char *buf2 = alloca (PBUFSIZ); + char *buf2 = alloca (cnt + 6); char *junkbuf = alloca (PBUFSIZ); int ch; @@ -3487,9 +3672,6 @@ putpkt_binary (buf, cnt) /* Copy the packet into buffer BUF2, encapsulating it and giving it a checksum. */ - if (cnt > BUFSIZ - 5) /* Prosanity check */ - abort (); - p = buf2; *p++ = '$'; @@ -5220,7 +5402,11 @@ set_remote_cmd (args, from_tty) static void build_remote_gdbarch_data () { + build_remote_packet_sizes (); + + /* Cisco stuff */ tty_input = xmalloc (PBUFSIZ); + remote_address_size = TARGET_PTR_BIT; } void @@ -5228,16 +5414,16 @@ _initialize_remote () { static struct cmd_list_element *remote_set_cmdlist; static struct cmd_list_element *remote_show_cmdlist; + struct cmd_list_element *tmpcmd; /* architecture specific data */ build_remote_gdbarch_data (); register_gdbarch_swap (&tty_input, sizeof (&tty_input), NULL); + register_remote_packet_sizes (); + register_gdbarch_swap (&remote_address_size, + sizeof (&remote_address_size), NULL); register_gdbarch_swap (NULL, 0, build_remote_gdbarch_data); - /* runtime constants - we retain the value of remote_write_size - across architecture swaps. */ - remote_write_size = PBUFSIZ; - init_remote_ops (); add_target (&remote_ops); @@ -5298,14 +5484,39 @@ terminating `#' character and checksum.", &setlist), &showlist); - add_show_from_set - (add_set_cmd ("remotewritesize", no_class, - var_integer, (char *) &remote_write_size, - "Set the maximum number of bytes per memory write packet.\n", - &setlist), - &showlist); + /* Install commands for configuring memory read/write packets. */ + + add_cmd ("remotewritesize", no_class, set_memory_write_packet_size, + "Set the maximum number of bytes per memory write packet (deprecated).\n", + &setlist); + add_cmd ("remotewritesize", no_class, set_memory_write_packet_size, + "Show the maximum number of bytes per memory write packet (deprecated).\n", + &showlist); + add_cmd ("memory-write-packet-size", no_class, + set_memory_write_packet_size, + "Set the maximum number of bytes per memory-write packet.\n" + "Specify the number of bytes in a packet or 0 (zero) for the\n" + "default packet size. The actual limit is further reduced\n" + "dependent on the target. Specify ``fixed'' to disable the\n" + "further restriction and ``limit'' to enable that restriction\n", + &remote_set_cmdlist); + add_cmd ("memory-read-packet-size", no_class, + set_memory_read_packet_size, + "Set the maximum number of bytes per memory-read packet.\n" + "Specify the number of bytes in a packet or 0 (zero) for the\n" + "default packet size. The actual limit is further reduced\n" + "dependent on the target. Specify ``fixed'' to disable the\n" + "further restriction and ``limit'' to enable that restriction\n", + &remote_set_cmdlist); + add_cmd ("memory-write-packet-size", no_class, + show_memory_write_packet_size, + "Show the maximum number of bytes per memory-write packet.\n", + &remote_show_cmdlist); + add_cmd ("memory-read-packet-size", no_class, + show_memory_read_packet_size, + "Show the maximum number of bytes per memory-read packet.\n", + &remote_show_cmdlist); - remote_address_size = TARGET_PTR_BIT; add_show_from_set (add_set_cmd ("remoteaddresssize", class_obscure, var_integer, (char *) &remote_address_size, |