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-rw-r--r--stap.1.in14
-rw-r--r--stapprobes.3stap.in12
2 files changed, 22 insertions, 4 deletions
diff --git a/stap.1.in b/stap.1.in
index 531b0f88..e1b38878 100644
--- a/stap.1.in
+++ b/stap.1.in
@@ -582,6 +582,10 @@ variables whose names are prefixed with "$". They may be accessed
only if the kernel's compiler preserved them despite optimization.
This is the same constraint that a debugger user faces when working
with optimized code. Some other events have very little context.
+See the
+.IR stapprobes (3stap)
+man pages to see the kinds of context variables available at each kind
+of probe point.
.PP
New probe points may be defined using "aliases". Probe point aliases
look similar to probe definitions, but instead of activating a probe
@@ -819,7 +823,15 @@ as a pointer to a struct/union named
.I type_name
and dereference the
.I member
-value. The optional
+value. Further
+.IR \->subfield
+expressions may be appended to dereference more levels.
+.BR
+NOTE:
+the same dereferencing operator
+.IR \->
+is used to refer to both direct containment or pointer indirection.
+Systemtap automatically determines which. The optional
.I module
tells the translator where to look for information about that type.
Multiple modules may be specified as a list with
diff --git a/stapprobes.3stap.in b/stapprobes.3stap.in
index dbd77ce4..0e1bd66f 100644
--- a/stapprobes.3stap.in
+++ b/stapprobes.3stap.in
@@ -341,9 +341,15 @@ pointers (char *) may be copied to systemtap string values using the
.IR kernel_string " or " user_string
functions.
.TP
-$var\->field
-traversal to a structure's field. The indirection operator
-may be repeated to follow more levels of pointers.
+$var\->field traversal via a structure's or a pointer's field. This
+generalized indirection operator may be repeated to follow more
+levels. Note that the
+.IR .
+operator is not used for plain structure
+members, only
+.IR \->
+for both purposes. (This is because "." is reserved for string
+concatenation.)
.TP
$return
is available in return probes only for functions that are declared