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Diffstat (limited to 'tools/lib/traceevent/Documentation/libtraceevent-func_apis.txt')
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diff --git a/tools/lib/traceevent/Documentation/libtraceevent-func_apis.txt b/tools/lib/traceevent/Documentation/libtraceevent-func_apis.txt deleted file mode 100644 index f6aca0df2151..000000000000 --- a/tools/lib/traceevent/Documentation/libtraceevent-func_apis.txt +++ /dev/null @@ -1,183 +0,0 @@ -libtraceevent(3) -================ - -NAME ----- -tep_find_function, tep_find_function_address, tep_set_function_resolver, -tep_reset_function_resolver, tep_register_function, tep_register_print_string - -function related tep APIs - -SYNOPSIS --------- -[verse] --- -*#include <event-parse.h>* - -typedef char pass:[*](*tep_func_resolver_t*)(void pass:[*]_priv_, unsigned long long pass:[*]_addrp_, char pass:[**]_modp_); -int *tep_set_function_resolver*(struct tep_handle pass:[*]_tep_, tep_func_resolver_t pass:[*]_func_, void pass:[*]_priv_); -void *tep_reset_function_resolver*(struct tep_handle pass:[*]_tep_); -const char pass:[*]*tep_find_function*(struct tep_handle pass:[*]_tep_, unsigned long long _addr_); -unsigned long long *tep_find_function_address*(struct tep_handle pass:[*]_tep_, unsigned long long _addr_); -int *tep_register_function*(struct tep_handle pass:[*]_tep_, char pass:[*]_name_, unsigned long long _addr_, char pass:[*]_mod_); -int *tep_register_print_string*(struct tep_handle pass:[*]_tep_, const char pass:[*]_fmt_, unsigned long long _addr_); --- - -DESCRIPTION ------------ -Some tools may have already a way to resolve the kernel functions. These APIs -allow them to keep using it instead of duplicating all the entries inside. - -The _tep_func_resolver_t_ type is the prototype of the alternative kernel -functions resolver. This function receives a pointer to its custom context -(set with the _tep_set_function_resolver()_ call ) and the address of a kernel -function, which has to be resolved. In case of success, it should return -the name of the function and its module (if any) in _modp_. - -The _tep_set_function_resolver()_ function registers _func_ as an alternative -kernel functions resolver. The _tep_ argument is trace event parser context. -The _priv_ argument is a custom context of the _func_ function. The function -resolver is used by the APIs _tep_find_function()_, -_tep_find_function_address()_, and _tep_print_func_field()_ to resolve -a function address to a function name. - -The _tep_reset_function_resolver()_ function resets the kernel functions -resolver to the default function. The _tep_ argument is trace event parser -context. - - -These APIs can be used to find function name and start address, by given -address. The given address does not have to be exact, it will select -the function that would contain it. - -The _tep_find_function()_ function returns the function name, which contains the -given address _addr_. The _tep_ argument is the trace event parser context. - -The _tep_find_function_address()_ function returns the function start address, -by given address _addr_. The _addr_ does not have to be exact, it will select -the function that would contain it. The _tep_ argument is the trace event -parser context. - -The _tep_register_function()_ function registers a function name mapped to an -address and (optional) module. This mapping is used in case the function tracer -or events have "%pS" parameter in its format string. It is common to pass in -the kallsyms function names with their corresponding addresses with this -function. The _tep_ argument is the trace event parser context. The _name_ is -the name of the function, the string is copied internally. The _addr_ is the -start address of the function. The _mod_ is the kernel module the function may -be in (NULL for none). - -The _tep_register_print_string()_ function registers a string by the address -it was stored in the kernel. Some strings internal to the kernel with static -address are passed to certain events. The "%s" in the event's format field -which has an address needs to know what string would be at that address. The -tep_register_print_string() supplies the parsing with the mapping between kernel -addresses and those strings. The _tep_ argument is the trace event parser -context. The _fmt_ is the string to register, it is copied internally. -The _addr_ is the address the string was located at. - - -RETURN VALUE ------------- -The _tep_set_function_resolver()_ function returns 0 in case of success, or -1 -in case of an error. - -The _tep_find_function()_ function returns the function name, or NULL in case -it cannot be found. - -The _tep_find_function_address()_ function returns the function start address, -or 0 in case it cannot be found. - -The _tep_register_function()_ function returns 0 in case of success. In case of -an error -1 is returned, and errno is set to the appropriate error number. - -The _tep_register_print_string()_ function returns 0 in case of success. In case -of an error -1 is returned, and errno is set to the appropriate error number. - -EXAMPLE -------- -[source,c] --- -#include <event-parse.h> -... -struct tep_handle *tep = tep_alloc(); -... -char *my_resolve_kernel_addr(void *context, - unsigned long long *addrp, char **modp) -{ - struct db *function_database = context; - struct symbol *sym = sql_lookup(function_database, *addrp); - - if (!sym) - return NULL; - - *modp = sym->module_name; - return sym->name; -} - -void show_function( unsigned long long addr) -{ - unsigned long long fstart; - const char *fname; - - if (tep_set_function_resolver(tep, my_resolve_kernel_addr, - function_database) != 0) { - /* failed to register my_resolve_kernel_addr */ - } - - /* These APIs use my_resolve_kernel_addr() to resolve the addr */ - fname = tep_find_function(tep, addr); - fstart = tep_find_function_address(tep, addr); - - /* - addr is in function named fname, starting at fstart address, - at offset (addr - fstart) - */ - - tep_reset_function_resolver(tep); - -} -... - if (tep_register_function(tep, "kvm_exit", - (unsigned long long) 0x12345678, "kvm") != 0) { - /* Failed to register kvm_exit address mapping */ - } -... - if (tep_register_print_string(tep, "print string", - (unsigned long long) 0x87654321, NULL) != 0) { - /* Failed to register "print string" address mapping */ - } -... --- - -FILES ------ -[verse] --- -*event-parse.h* - Header file to include in order to have access to the library APIs. -*-ltraceevent* - Linker switch to add when building a program that uses the library. --- - -SEE ALSO --------- -_libtraceevent(3)_, _trace-cmd(1)_ - -AUTHOR ------- -[verse] --- -*Steven Rostedt* <rostedt@goodmis.org>, author of *libtraceevent*. -*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>, author of this man page. --- -REPORTING BUGS --------------- -Report bugs to <linux-trace-devel@vger.kernel.org> - -LICENSE -------- -libtraceevent is Free Software licensed under the GNU LGPL 2.1 - -RESOURCES ---------- -https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git |