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[PATCH v3 4/7] trace2: remove use of ALLOC_ARRAY()

From
Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>
Date
Aug 31, 2026, 17:25 UTC
Message-ID
<5bf6ab91f37cd80dba5e50eee85f9f3258f34be3.1788197143.git.gitgitgadget@gmail.com>
In-Reply-To
<pull.2178.v3.git.1788197143.gitgitgadget@gmail.com>
From: Derrick Stolee <stolee@gmail.com>

The banned-die.h header is used to prevent use of helper methods that call die(). Remove use of the ALLOC_ARRAY() helper, which calls die() on allocation failures. Replace the use in trace2.c with a more direct allocation and soft failure when allocation fails. This prevents die() recursion loops when memory allocation fails and trace2 logs are enabled.

The tricky part about this change is how to handle the results from redact_arg(), which is a 'const char *' result because it might be a pointer directly to the externally-controlled argument. When it is different from the argument, then it is indeed a newly-allocated string that we need to free before returning. This requires using a (char *) cast to allow a change.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
---
 banned-die.h |  3 +++
 trace2.c     | 16 ++++++++++++++--
 2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/banned-die.h b/banned-die.h
index bf16ec5ba9..0ad9a6c492 100644
--- a/banned-die.h
+++ b/banned-die.h
@@ -17,4 +17,7 @@
 #undef xstrdup
 #define xstrdup(str) BANNED(xstrdup)
 
+#undef ALLOC_ARRAY
+#define ALLOC_ARRAY(x, alloc) BANNED(ALLOC_ARRAY)
+
 #endif /* BANNED_DIE_H */
diff --git a/trace2.c b/trace2.c
index 8c974dee87..ea021c602e 100644
--- a/trace2.c
+++ b/trace2.c
@@ -305,7 +305,11 @@ static const char **redact_argv(const char **argv)
 	for (j = 0; argv[j]; j++)
 		; /* keep counting */
 
-	ALLOC_ARRAY(ret, j + 1);
+	ret = calloc(j + 1, sizeof(*ret));
+	if (!ret) {
+		free((char *)redacted);
+		return NULL;
+	}
 	ret[j] = NULL;
 
 	for (j = 0; j < i; j++)
@@ -346,6 +350,8 @@ void trace2_cmd_start_fl(const char *file, int line, const char **argv)
 	us_elapsed_absolute = tr2tls_absolute_elapsed(us_now);
 
 	redacted = redact_argv(argv);
+	if (!redacted)
+		return;
 
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_start_fl)
@@ -514,6 +520,7 @@ void trace2_child_start_fl(const char *file, int line,
 	uint64_t us_now;
 	uint64_t us_elapsed_absolute;
 	const char **orig_argv = cmd->args.v;
+	const char **redacted;
 
 	if (!trace2_enabled)
 		return;
@@ -531,7 +538,10 @@ void trace2_child_start_fl(const char *file, int line,
 	 * temporarily replace the original argv (inside the `strvec`)
 	 * with a possibly redacted version.
 	 */
-	cmd->args.v = redact_argv(orig_argv);
+	redacted = redact_argv(orig_argv);
+	if (!redacted)
+		return;
+	cmd->args.v = redacted;
 
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_child_start_fl)
@@ -623,6 +633,8 @@ int trace2_exec_fl(const char *file, int line, const char *exe,
 	exec_id = tr2tls_locked_increment(&tr2_next_exec_id);
 
 	redacted = redact_argv(argv);
+	if (!redacted)
+		return exec_id;
 
 	for_each_wanted_builtin (j, tgt_j)
 		if (tgt_j->pfn_exec_fl)
-- 
gitgitgadget
Previous: Derrick Stolee via GitGitGadgetNext: Derrick Stolee via GitGitGadget
Message 39 of 43 in “trace2: tolerate failed timestamp formatting”
  1. trace2: tolerate failed timestamp formattingDerrick Stolee via GitGitGadget, Jul 15, 2026
  2. Taylor BlauJul 17, 2026
  3. Derrick StoleeJul 18, 2026
  4. Junio C HamanoJul 20, 2026
  5. Taylor BlauJul 20, 2026
  6. Junio C HamanoJul 29, 2026
  7. Derrick StoleeJul 31, 2026
  8. Junio C HamanoJul 31, 2026
  9. 0/7 trace2: stop allowing die()Derrick Stolee via GitGitGadget, Aug 25, 2026
  10. 1/7 banned-die: create header for banning of functionsDerrick Stolee via GitGitGadget, Aug 25, 2026
  11. Junio C HamanoAug 25, 2026
  12. Derrick StoleeAug 31, 2026
  13. Patrick SteinhardtAug 31, 2026
  14. Elijah NewrenAug 25, 2026
  15. Derrick StoleeAug 31, 2026
  16. Jeff KingAug 27, 2026
  17. Derrick StoleeAug 31, 2026
  18. 2/7 trace2: tolerate failed timestamp formattingDerrick Stolee via GitGitGadget, Aug 25, 2026
  19. 3/7 trace2: remove use of xstrdup()Derrick Stolee via GitGitGadget, Aug 25, 2026
  20. Elijah NewrenAug 25, 2026
  21. Derrick StoleeAug 31, 2026
  22. 4/7 trace2: remove use of ALLOC_ARRAY()Derrick Stolee via GitGitGadget, Aug 25, 2026
  23. 5/7 trace2: remove use of xstrfmt()Derrick Stolee via GitGitGadget, Aug 25, 2026
  24. Elijah NewrenAug 25, 2026
  25. Junio C HamanoAug 25, 2026
  26. Derrick StoleeAug 31, 2026
  27. 6/7 trace2: remove use of ALLOC_GROW()Derrick Stolee via GitGitGadget, Aug 25, 2026
  28. Elijah NewrenAug 25, 2026
  29. 7/7 trace2: remove use of xcalloc()Derrick Stolee via GitGitGadget, Aug 25, 2026
  30. Jeff KingAug 27, 2026
  31. Derrick StoleeAug 31, 2026
  32. Jeff KingSep 1, 2026
  33. Jeff KingSep 1, 2026
  34. Derrick StoleeSep 1, 2026
  35. 0/7 trace2: stop allowing die()Derrick Stolee via GitGitGadget, Aug 31, 2026
  36. 1/7 banned-die: create header for banning of functionsDerrick Stolee via GitGitGadget, Aug 31, 2026
  37. 2/7 trace2: tolerate failed timestamp formattingDerrick Stolee via GitGitGadget, Aug 31, 2026
  38. 3/7 trace2: remove use of xstrdup()Derrick Stolee via GitGitGadget, Aug 31, 2026
  39. 4/7 trace2: remove use of ALLOC_ARRAY()Derrick Stolee via GitGitGadget, Aug 31, 2026
  40. 5/7 trace2: remove use of xstrfmt()Derrick Stolee via GitGitGadget, Aug 31, 2026
  41. 6/7 trace2: remove use of ALLOC_GROW()Derrick Stolee via GitGitGadget, Aug 31, 2026
  42. 7/7 trace2: remove use of xcalloc()Derrick Stolee via GitGitGadget, Aug 31, 2026
  43. Derrick StoleeOct 6, 2026

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