From: Alan Maguire <alan.maguire@oracle.com>
To: dtrace@lists.linux.dev
Cc: dtrace-devel@oss.oracle.com, Alan Maguire <alan.maguire@oracle.com>
Subject: [PATCH v3 2/7] cg: bump number of TSLOTS to 6
Date: Wed, 9 Jul 2025 15:09:43 +0100 [thread overview]
Message-ID: <20250709140948.15090-3-alan.maguire@oracle.com> (raw)
In-Reply-To: <20250709140948.15090-1-alan.maguire@oracle.com>
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@oracle.com>
---
libdtrace/dt_impl.h | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/libdtrace/dt_impl.h b/libdtrace/dt_impl.h
index 2adc1252..b8c0f94c 100644
--- a/libdtrace/dt_impl.h
+++ b/libdtrace/dt_impl.h
@@ -203,14 +203,17 @@ 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 8 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. That brings us to a total of 4, but since the ternary case requires
+ * 2x we need 8 in total.
*
* 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 +225,7 @@ 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 8
#define DT_TSTRING_SIZE(dtp) \
MAX(P2ROUNDUP((dtp)->dt_options[DTRACEOPT_STRSIZE] + 3, 8), \
72)
--
2.39.3
next prev parent reply other threads:[~2025-07-09 14:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-09 14:09 [PATCH v3 0/7] DTrace TCP provider Alan Maguire
2025-07-09 14:09 ` [PATCH v3 1/7] cg: move get_member() to dt_cg.c Alan Maguire
2025-07-21 20:37 ` [DTrace-devel] " Kris Van Hees
2025-07-09 14:09 ` Alan Maguire [this message]
2025-07-21 20:39 ` [DTrace-devel] [PATCH v3 2/7] cg: bump number of TSLOTS to 6 Kris Van Hees
2025-07-09 14:09 ` [PATCH v3 3/7] test/operators: extend ternary tests to cover inet_ntoa*()s Alan Maguire
2025-07-09 14:09 ` [PATCH v3 4/7] providers: move network-generic definitions to net.d Alan Maguire
2025-07-09 14:09 ` [PATCH v3 5/7] tcp: new provider Alan Maguire
2025-07-09 14:09 ` [PATCH v3 6/7] dlibs: sync ip.d, net.d and tcp.d Alan Maguire
2025-07-09 14:09 ` [PATCH v3 7/7] unittest/tcp: update test.x Alan Maguire
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