[DTrace-devel] [PATCH v4 2/7] cg: bump number of TSLOTS to 6
Alan Maguire
alan.maguire at oracle.com
Wed Jul 9 14:46:55 UTC 2025
Because of the ternary operations using inet_ntoa*() in the
TCP translators more temporary string slots are needed.
Signed-off-by: Alan Maguire <alan.maguire at oracle.com>
---
libdtrace/dt_impl.h | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/libdtrace/dt_impl.h b/libdtrace/dt_impl.h
index 2adc1252..a47b6d40 100644
--- a/libdtrace/dt_impl.h
+++ b/libdtrace/dt_impl.h
@@ -203,14 +203,16 @@ typedef struct dt_kern_path {
#define DT_DM_KERN_UNLOADED 0x8 /* module not loaded into the kernel */
/*
- * Why do we need (only) 4 slots? The maximum amount of string arguments to
+ * Why do we need 6 slots? The maximum amount of string arguments to
* any function is 2, and if the result is a string as well, that means we may
* need 3 temporary strings during code generation for that function.
+ * However if operations like inet_ntoa6 are used in ternary operations we need
+ * 2x the number of slots for left and right.
*
* Since string functions can be nested, we can (at most) end up with 1 tstring
* (from a nested function for which we already generated code) along with a
* nested function being processed which needs 3 temporary strings as mentioned
- * above. That brings us to a total of 4.
+ * above.
*
* Each tstring needs to be large enough to hold the largest possible string
* and accomodate the largest known need for tstring space in subroutines.
@@ -222,7 +224,7 @@ typedef struct dt_kern_path {
* - cleanpath() holds a prepended '/' char, a string, an appended '/' char,
* and a terminating NUL char, or STRSZ + 3 chars altogether
*/
-#define DT_TSTRING_SLOTS 4
+#define DT_TSTRING_SLOTS 6
#define DT_TSTRING_SIZE(dtp) \
MAX(P2ROUNDUP((dtp)->dt_options[DTRACEOPT_STRSIZE] + 3, 8), \
72)
--
2.39.3
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