From: "Steven Rostedt (VMware)" Add "unsigned" to the format processing to creating dynamic function based events. For example: "unsigned long" now works. Signed-off-by: Steven Rostedt (VMware) --- Documentation/trace/function-based-events.rst | 47 ++++++++++++++++++++++++++- kernel/trace/trace_event_ftrace.c | 23 ++++++++++--- 2 files changed, 65 insertions(+), 5 deletions(-) diff --git a/Documentation/trace/function-based-events.rst b/Documentation/trace/function-based-events.rst index 2a002c8a500b..72e3e7730d63 100644 --- a/Documentation/trace/function-based-events.rst +++ b/Documentation/trace/function-based-events.rst @@ -93,7 +93,7 @@ as follows: ARG := TYPE FIELD | ARG '|' ARG - TYPE := ATOM + TYPE := ATOM | 'unsigned' ATOM ATOM := 'u8' | 'u16' | 'u32' | 'u64' | 's8' | 's16' | 's32' | 's64' | @@ -176,3 +176,48 @@ an argument: -0 [003] ..s3 904.075848: __netif_receive_skb_core->ip_rcv(skb=ffff88011396e800, skb=52, dev=ffff880115204000) -0 [003] ..s3 904.725486: __netif_receive_skb_core->ip_rcv(skb=ffff88011396e800, skb=194, dev=ffff880115204000) -0 [003] ..s3 905.152537: __netif_receive_skb_core->ip_rcv(skb=ffff88011396f200, skb=88, dev=ffff880115204000) + + +Unsigned usage +============== + +One can also use "unsigned" to make some types unsigned. It works against +"long", "int", "short" and "char". It doesn't error against other types but +may not make any sense. + + # echo 'ip_rcv(int skb[32])' > function_events + # cat events/functions/ip_rcv/format +name: ip_rcv +ID: 1397 +format: + field:unsigned short common_type; offset:0; size:2; signed:0; + field:unsigned char common_flags; offset:2; size:1; signed:0; + field:unsigned char common_preempt_count; offset:3; size:1; signed:0; + field:int common_pid; offset:4; size:4; signed:1; + + field:unsigned long __parent_ip; offset:8; size:8; signed:0; + field:unsigned long __ip; offset:16; size:8; signed:0; + field:int skb; offset:24; size:4; signed:1; + +print fmt: "%pS->%pS(skb=%d)", REC->__ip, REC->__parent_ip, REC->skb + + +Notice that REC->skb is printed with "%d". By adding "unsigned" + + # echo 'ip_rcv(unsigned int skb[32])' > function_events + # cat events/functions/ip_rcv/format +name: ip_rcv +ID: 1398 +format: + field:unsigned short common_type; offset:0; size:2; signed:0; + field:unsigned char common_flags; offset:2; size:1; signed:0; + field:unsigned char common_preempt_count; offset:3; size:1; signed:0; + field:int common_pid; offset:4; size:4; signed:1; + + field:unsigned long __parent_ip; offset:8; size:8; signed:0; + field:unsigned long __ip; offset:16; size:8; signed:0; + field:unsigned int skb; offset:24; size:4; signed:0; + +print fmt: "%pS->%pS(skb=%u)", REC->__ip, REC->__parent_ip, REC->skb + +It is now printed with a "%u". diff --git a/kernel/trace/trace_event_ftrace.c b/kernel/trace/trace_event_ftrace.c index 666edd76b70f..8327346799eb 100644 --- a/kernel/trace/trace_event_ftrace.c +++ b/kernel/trace/trace_event_ftrace.c @@ -60,6 +60,7 @@ enum func_states { FUNC_STATE_BRACKET, FUNC_STATE_BRACKET_END, FUNC_STATE_INDIRECT, + FUNC_STATE_UNSIGNED, FUNC_STATE_PIPE, FUNC_STATE_TYPE, FUNC_STATE_VAR, @@ -200,7 +201,7 @@ static char *next_token(char **ptr, char *last) return arg; } -static int add_arg(struct func_event *fevent, int ftype) +static int add_arg(struct func_event *fevent, int ftype, int unsign) { struct func_type *func_type = &func_types[ftype]; struct func_arg *arg; @@ -213,13 +214,18 @@ static int add_arg(struct func_event *fevent, int ftype) if (!arg) return -ENOMEM; - arg->type = kstrdup(func_type->name, GFP_KERNEL); + if (unsign) + arg->type = kasprintf(GFP_KERNEL, "unsigned %s", + func_type->name); + else + arg->type = kstrdup(func_type->name, GFP_KERNEL); if (!arg->type) { kfree(arg); return -ENOMEM; } arg->size = func_type->size; - arg->sign = func_type->sign; + if (!unsign) + arg->sign = func_type->sign; arg->offset = ALIGN(fevent->arg_offset, arg->size); arg->arg = fevent->arg_cnt; fevent->arg_offset = arg->offset + arg->size; @@ -234,12 +240,14 @@ static int add_arg(struct func_event *fevent, int ftype) static enum func_states process_event(struct func_event *fevent, const char *token, enum func_states state) { + static int unsign; long val; int ret; int i; switch (state) { case FUNC_STATE_INIT: + unsign = 0; if (!isalpha(token[0])) break; /* Do not allow wild cards */ @@ -264,13 +272,20 @@ process_event(struct func_event *fevent, const char *token, enum func_states sta /* Fall through */ case FUNC_STATE_COMMA: comma: + if (strcmp(token, "unsigned") == 0) { + unsign = 2; + return FUNC_STATE_UNSIGNED; + } + /* Fall through */ + case FUNC_STATE_UNSIGNED: for (i = 0; func_types[i].size; i++) { if (strcmp(token, func_types[i].name) == 0) break; } if (!func_types[i].size) break; - ret = add_arg(fevent, i); + ret = add_arg(fevent, i, unsign); + unsign = 0; if (ret < 0) break; return FUNC_STATE_TYPE; -- 2.15.1