From: "Steven Rostedt (VMware)" <rost...@goodmis.org>

Add "unsigned" to the format processing to creating dynamic function based
events. For example: "unsigned long" now works.

Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org>
---
 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:
     <idle>-0     [003] ..s3   904.075848: 
__netif_receive_skb_core->ip_rcv(skb=ffff88011396e800, skb=52, 
dev=ffff880115204000)
     <idle>-0     [003] ..s3   904.725486: 
__netif_receive_skb_core->ip_rcv(skb=ffff88011396e800, skb=194, 
dev=ffff880115204000)
     <idle>-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 8c9d4a92deab..9548b93eb8cd 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,
@@ -198,7 +199,7 @@ 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;
@@ -211,13 +212,18 @@ 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;
@@ -232,12 +238,14 @@ 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 */
@@ -262,13 +270,20 @@ 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


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