In newer kernel, the event call's "double linked list head of field" is stored in struct ftrace_event_class, and some of them are special defined.
To implement them, we have to emulate them, so this patch emulates the kernel functions: syscall_get_enter_fields() syscall_get_exit_fields() Signed-off-by: Lai Jiangshan <[email protected]> --- diff --git a/extensions/trace.c b/extensions/trace.c index a54e4fa..484c872 100755 --- a/extensions/trace.c +++ b/extensions/trace.c @@ -662,23 +662,127 @@ static void event_generic_print_fmt_print(struct event_type *t, static void event_default_print(struct event_type *t, struct format_context *fc); +static int syscall_get_enter_fields(ulong call, ulong *fields) +{ + static int inited; + static int data_offset; + static int enter_fields_offset; + + ulong metadata; + + if (inited) + goto work; + + inited = 1; + data_offset = MEMBER_OFFSET("ftrace_event_call", "data"); + if (data_offset < 0) + return -1; + + enter_fields_offset = MEMBER_OFFSET("syscall_metadata", "enter_fields"); + if (enter_fields_offset < 0) + return -1; + +work: + if (data_offset < 0 || enter_fields_offset < 0) + return -1; + + if (!readmem(call + data_offset, KVADDR, &metadata, sizeof(metadata), + "read ftrace_event_call data", RETURN_ON_ERROR)) + return -1; + + *fields = metadata + enter_fields_offset; + return 0; +} + +static int syscall_get_exit_fields(ulong call, ulong *fields) +{ + static int inited; + static ulong syscall_exit_fields_value; + + if (!inited) { + struct syment *sp; + + if (!(sp = symbol_search("syscall_exit_fields"))) { + inited = -1; + } else { + syscall_exit_fields_value = sp->value; + inited = 1; + } + } + + if (inited == -1) + return -1; + + *fields = syscall_exit_fields_value; + + return 0; +} + static int ftrace_get_event_type_fields(ulong call, ulong *fields) { static int inited; static int fields_offset; + static int class_offset; + static int get_fields_offset; + static ulong syscall_get_enter_fields_value; + static ulong syscall_get_exit_fields_value; - if (!inited) { - inited = 1; - fields_offset = MEMBER_OFFSET("ftrace_event_call", "fields"); - } + struct syment *sp; + ulong class, get_fields; + if (inited) + goto work; + + inited = 1; + fields_offset = MEMBER_OFFSET("ftrace_event_call", "fields"); + + class_offset = MEMBER_OFFSET("ftrace_event_call", "class"); + if (class_offset < 0) + goto work; + + inited = 2; + fields_offset = MEMBER_OFFSET("ftrace_event_class", "fields"); if (fields_offset < 0) return -1; - *fields = call + fields_offset; + get_fields_offset = MEMBER_OFFSET("ftrace_event_class", "get_fields"); + if ((sp = symbol_search("syscall_get_enter_fields")) != NULL) + syscall_get_enter_fields_value = sp->value; + if ((sp = symbol_search("syscall_get_exit_fields")) != NULL) + syscall_get_exit_fields_value = sp->value; - return 0; +work: + if (fields_offset < 0) + return -1; + + if (inited == 1) { + *fields = call + fields_offset; + return 0; + } + + if (!readmem(call + class_offset, KVADDR, &class, sizeof(class), + "read ftrace_event_call class", RETURN_ON_ERROR)) + return -1; + + if (!readmem(class + get_fields_offset, KVADDR, &get_fields, + sizeof(get_fields), "read ftrace_event_call get_fields", + RETURN_ON_ERROR)) + return -1; + + if (!get_fields) { + *fields = class + fields_offset; + return 0; + } + + if (get_fields == syscall_get_enter_fields_value) + return syscall_get_enter_fields(call, fields); + + if (get_fields == syscall_get_exit_fields_value) + return syscall_get_exit_fields(call, fields); + + fprintf(fp, "Unkown get_fields function\n"); + return -1; } static int ftrace_init_event_type(ulong call, struct event_type *aevent_type) -- Crash-utility mailing list [email protected] https://www.redhat.com/mailman/listinfo/crash-utility
