tracing: probeevent: Add symbol type

Add "symbol" type to probeevent, which is an alias of u32 or u64
(depends on BITS_PER_LONG). This shows the result value in
symbol+offset style. This type is only available with kprobe
events.

Link: http://lkml.kernel.org/r/152465882860.26224.14779072294412467338.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst
index 8bfc75c908061710ec3e406c7497000b08a80050..6224ddf345081f9ab77ec43ecae48a7ff16c1a33 100644 (file)
--- a/Documentation/trace/kprobetrace.rst
+++ b/Documentation/trace/kprobetrace.rst
@@ -72,6 +72,8 @@ offset, and container-size (usually 32). The syntax is::
 
  b<bit-width>@<bit-offset>/<container-size>
 
+Symbol type('symbol') is an alias of u32 or u64 type (depends on BITS_PER_LONG)
+which shows given pointer in "symbol+offset" style.
 For $comm, the default type is "string"; any other type is invalid.
 
 

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 147be85235609e47b05745757a2f2ff674334c46..1e3f28b1fa07991a52773908cdd477497996a4fe 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4626,7 +4626,7 @@ static const char readme_msg[] =
        "\t     args: <name>=fetcharg[:type]\n"
        "\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n"
        "\t           $stack<index>, $stack, $retval, $comm\n"
-       "\t     type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string,\n"
+       "\t     type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n"
        "\t           b<bit-width>@<bit-offset>/<container-size>\n"
 #endif
        "  events/\t\t- Directory containing all trace event subsystems:\n"

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index d119bf8c3b4fbb73510b4d1a361de4787c14a7a9..1e7e0618577da685b0872eff8473c7fe26fa6e32 100644 (file)
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -46,6 +46,13 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
 DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
 
+int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent)
+{
+       trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data);
+       return !trace_seq_has_overflowed(s);
+}
+const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS";
+
 /* Print type function for string type */
 int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
 {
@@ -79,6 +86,7 @@ static const struct fetch_type probe_fetch_types[] = {
        ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
        ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
        ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
+       ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
 
        ASSIGN_FETCH_TYPE_END
 };

diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index c4e9d3d3216dec594bdc7917010b30bf86fed78b..469110e0790b8fd6c0fd32588092230495ace538 100644 (file)
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -145,6 +145,7 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
 DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
 
 DECLARE_BASIC_PRINT_TYPE_FUNC(string);
+DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);
 
 /* Default (unsigned long) fetch type */
 #define __DEFAULT_FETCH_TYPE(t) x##t
@@ -152,6 +153,10 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(string);
 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
 
+#define __ADDR_FETCH_TYPE(t) u##t
+#define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t)
+#define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG)
+
 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype)        \
        {.name = _name,                         \
         .size = _size,                                 \
@@ -160,13 +165,14 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(string);
         .fmt = PRINT_TYPE_FMT_NAME(ptype),             \
         .fmttype = _fmttype,                           \
        }
-
+#define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
+       __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype)
 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign)                  \
-       __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
+       _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)
 
 /* If ptype is an alias of atype, use this macro (show atype in format) */
 #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign)             \
-       __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #atype)
+       _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
 
 #define ASSIGN_FETCH_TYPE_END {}