Hi Mahesh,
On Wed, 18 May 2011 01:34:15 +0530
Mahesh J Salgaonkar <mahesh at linux.vnet.ibm.com> wrote:
>
> This patch enables to makedumpfile to read and process filter commands from
> specified config file. It builds a list of filter info consisting of memory
> address (paddr) and size to be filtered out. This list is used during
> read_pfn() function to filter out user specified kernel data from vmcore
> before writing it to compressed DUMPFILE. The filtered memory locations are
> filled with 'X' (0x58) character.
>
> The filter command syntax is:
> erase <Symbol>[.member[...]] [size <SizeValue>[K|M]]
> erase <Symbol>[.member[...]] [size <SizeSymbol>]
> erase <Symbol>[.member[...]] [nullify]
>
> Below are the examples how filter commands in config file look like:
>
> erase modules
> erase cred_jar.name size 10
> erase vmlist.addr nullify
Thank you for the work.
I tested this feature by the above example, and confirmed the feature
works fine. Nice work :-)
There are some comments in the below lines.
Can you check them ?
> +/*
> + * Read the non-terminal's which are in the form of <Symbol>[.member[...]]
> + */
> +struct config_entry *
> +create_config_entry(const char *token, unsigned short flag, int line)
> +{
> + struct config_entry *ce = NULL, *ptr, *prev_ce;
> + char *str, *cur, *next;
> + long len;
> + int depth = 0;
> +
> + if (!token)
> + return NULL;
> +
> + cur = str = strdup(token);
> + prev_ce = ptr = NULL;
> + while (cur != NULL) {
> + if ((next = strchr(cur, '.')) != NULL) {
> + *next++ = '\0';
> + }
> + if (!strlen(cur)) {
> + cur = next;
> + continue;
> + }
> +
> + if ((ptr = calloc(1, sizeof(struct config_entry))) == NULL) {
> + ERRMSG("Can't allocate memory for config_entry\n");
> + goto err_out;
> + }
> + ptr->line = line;
> + ptr->flag |= flag;
> + if (depth == 0) {
> + /* First node is always a symbol name */
> + ptr->flag |= SYMBOL_ENTRY;
> + }
> + if (flag & FILTER_ENTRY) {
> + ptr->name = strdup(cur);
> + }
> + if (flag & SIZE_ENTRY) {
> + char ch = '\0';
> + int n = 0;
> + /* See if absolute length is provided */
> + if ((depth == 0) &&
> + ((n = sscanf(cur, "%zd%c", &len, &ch)) > 0)) {
> + if (len < 0) {
> + ERRMSG("Config error at %d: size "
> + "value must be positive.\n",
> + line);
> + goto err_out;
> + }
> + ptr->size = len;
> + ptr->flag |= ENTRY_RESOLVED;
> + if (n == 2) {
> + /* Handle suffix.
> + * K = Kilobytes
> + * M = Megabytes
> + */
> + switch (ch) {
> + case 'M':
> + case 'm':
> + ptr->size *= 1024;
> + case 'K':
> + case 'k':
> + ptr->size *= 1024;
> + break;
> + }
> + }
> + }
> + else
> + ptr->name = strdup(cur);
> + }
> + if (prev_ce) {
> + prev_ce->next = ptr;
> + prev_ce = ptr;
> + }
> + else
> + ce = prev_ce = ptr;
> + cur = next;
> + depth++;
> + ptr = NULL;
> + }
> + free(str);
> + return ce;
> +
> +err_out:
> + if (ce)
> + free_config_entry(ce);
> + if (ptr)
> + free_config_entry(ptr);
"free(str);" is necessary.
> + return NULL;
> +}
[..]
> +/*
> + * read filter config file and return each string token. If the parameter
> + * expected_token is non-NULL, then return the current token if it matches
> + * with expected_token otherwise save the current token and return NULL.
> + * At start of every module section filter_config.new_section is set to 1 and
> + * subsequent function invocations return NULL untill filter_config.new_section
> + * is reset to 0 by passing @flag = CONFIG_NEW_CMD (0x02).
> + *
> + * Parameters:
> + * @expected_token INPUT
> + * Token string to match with currnet token.
> + * =NULL - return the current available token.
> + *
> + * @flag INPUT
> + * =0x01 - Skip to next module section.
> + * =0x02 - Treat the next token as next filter command and reset.
> + *
> + * @line OUTPUT
> + * Line number of current token in filter config file.
> + *
> + * @cur_mod OUTPUT
> + * Points to current module section name on non-NULL return value.
> + *
> + * @eof OUTPUT
> + * set to -1 when end of file is reached.
> + * set to -2 when end of section is reached.
> + */
> +static char *
> +get_config_token(char *expected_token, unsigned char flag, int *line,
> + char **cur_mod, int *eof)
> +{
> + char *p;
> + struct filter_config *fc = &filter_config;
> + int skip = flag & CONFIG_SKIP_SECTION;
CONFIG_SKIP_SECTION is used only here, and we need to fix get_config()
for the readability. Please check my comment in get_config().
[..]
> +/*
> + * Configuration file 'makedumpfile.conf' contains filter commands.
> + * Every individual filter command is considered as a config entry. A config
> + * entry can be provided on a single line or multiple lines.
> + */
> +struct config *
> +get_config(int skip)
> +{
> + struct config *config;
> + char *token = NULL;
> + static int line_count = 0;
> + char *cur_module = NULL;
> + int eof = 0;
> + unsigned char flag = CONFIG_NEW_CMD | skip;
We need to change the above:
unsigned char flag = CONFIG_NEW_CMD;
if (skip)
flag |= CONFIG_SKIP_SECTION;
> +
> + if ((config = calloc(1, sizeof(struct config))) == NULL)
> + return NULL;
> +
> + if (get_config_token("erase", flag, &line_count, &cur_module, &eof)) {
> + if (cur_module)
> + config->module_name = strdup(cur_module);
> +
> + if (!read_filter_entry(config, line_count))
> + goto err_out;
> + }
> + else {
> + if (!eof) {
> + token = get_config_token(NULL, 0, &line_count,
> + NULL, NULL);
> + ERRMSG("Config error at %d: Invalid token '%s'.\n",
> + line_count, token);
> + }
> + goto err_out;
> + }
> + return config;
> +err_out:
> + if (config)
> + free_config(config);
> + return NULL;
> +}
BTW makedumpfile.c has become a large file which is bigger than 10KLine,
and I will separate it to some files for the maintenance.
Thanks
Ken'ichi Ohmichi
