From: Masami Hiramatsu (Google) <mhira...@kernel.org> Instead of allocating traceprobe_parse_context on stack, allocate it dynamically from heap (slab).
This change is likely intended to prevent potential stack overflow issues, which can be a concern in the kernel environment where stack space is limited. Reported-by: kernel test robot <l...@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202506240416.nzihdxoo-...@intel.com/ Signed-off-by: Masami Hiramatsu (Google) <mhira...@kernel.org> --- Changes in v3: - Split #include sorting. Changes in v2: - Sort #include alphabetically. - Just NULL check for freeing traceprobe_parse_context. - Do not change the semantics of traceprobe_parse_context for uprobe event. (alloc/free in loop) --- kernel/trace/trace_eprobe.c | 14 ++++++++------ kernel/trace/trace_fprobe.c | 13 ++++++++----- kernel/trace/trace_kprobe.c | 10 +++++++--- kernel/trace/trace_probe.h | 9 +++++++++ kernel/trace/trace_uprobe.c | 13 ++++++++----- 5 files changed, 40 insertions(+), 19 deletions(-) diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 23e06712bead..7ba3a18be4c5 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -797,18 +797,20 @@ find_and_get_event(const char *system, const char *event_name) static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[], int i) { - struct traceprobe_parse_context ctx = { - .event = ep->event, - .flags = TPARG_FL_KERNEL | TPARG_FL_TEVENT, - }; + struct traceprobe_parse_context *ctx __free(traceprobe_parse_context) = NULL; int ret; - ret = traceprobe_parse_probe_arg(&ep->tp, i, argv[i], &ctx); + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + ctx->event = ep->event; + ctx->flags = TPARG_FL_KERNEL | TPARG_FL_TEVENT; + + ret = traceprobe_parse_probe_arg(&ep->tp, i, argv[i], ctx); /* Handle symbols "@" */ if (!ret) ret = traceprobe_update_arg(&ep->tp.args[i]); - traceprobe_finish_parse(&ctx); return ret; } diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c index add08ffb04d7..610f8d53be8a 100644 --- a/kernel/trace/trace_fprobe.c +++ b/kernel/trace/trace_fprobe.c @@ -1384,14 +1384,17 @@ static int trace_fprobe_create_internal(int argc, const char *argv[], static int trace_fprobe_create_cb(int argc, const char *argv[]) { - struct traceprobe_parse_context ctx = { - .flags = TPARG_FL_KERNEL | TPARG_FL_FPROBE, - }; + struct traceprobe_parse_context *ctx __free(traceprobe_parse_context) = NULL; int ret; + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + ctx->flags = TPARG_FL_KERNEL | TPARG_FL_FPROBE, + trace_probe_log_init("trace_fprobe", argc, argv); - ret = trace_fprobe_create_internal(argc, argv, &ctx); - traceprobe_finish_parse(&ctx); + ret = trace_fprobe_create_internal(argc, argv, ctx); trace_probe_log_clear(); return ret; } diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index cac128a5f7e0..d14b33e205f7 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1065,14 +1065,18 @@ static int trace_kprobe_create_internal(int argc, const char *argv[], static int trace_kprobe_create_cb(int argc, const char *argv[]) { - struct traceprobe_parse_context ctx = { .flags = TPARG_FL_KERNEL }; + struct traceprobe_parse_context *ctx __free(traceprobe_parse_context) = NULL; int ret; + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + ctx->flags = TPARG_FL_KERNEL; + trace_probe_log_init("trace_kprobe", argc, argv); - ret = trace_kprobe_create_internal(argc, argv, &ctx); + ret = trace_kprobe_create_internal(argc, argv, ctx); - traceprobe_finish_parse(&ctx); trace_probe_log_clear(); return ret; } diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 719604855279..842383fbc03b 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -12,6 +12,7 @@ #include <linux/bitops.h> #include <linux/btf.h> +#include <linux/cleanup.h> #include <linux/kprobes.h> #include <linux/limits.h> #include <linux/perf_event.h> @@ -439,6 +440,14 @@ extern void traceprobe_free_probe_arg(struct probe_arg *arg); * this MUST be called for clean up the context and return a resource. */ void traceprobe_finish_parse(struct traceprobe_parse_context *ctx); +static inline void traceprobe_free_parse_ctx(struct traceprobe_parse_context *ctx) +{ + traceprobe_finish_parse(ctx); + kfree(ctx); +} + +DEFINE_FREE(traceprobe_parse_context, struct traceprobe_parse_context *, + if (_T) traceprobe_free_parse_ctx(_T)) extern int traceprobe_split_symbol_offset(char *symbol, long *offset); int traceprobe_parse_event_name(const char **pevent, const char **pgroup, diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 3cc3404b09f0..872dce092e46 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -695,13 +695,16 @@ static int __trace_uprobe_create(int argc, const char **argv) /* parse arguments */ for (i = 0; i < argc; i++) { - struct traceprobe_parse_context ctx = { - .flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER, - }; + struct traceprobe_parse_context *ctx __free(traceprobe_parse_context) + = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) { + ret = -ENOMEM; + goto error; + } + ctx->flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER; trace_probe_log_set_index(i + 2); - ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], &ctx); - traceprobe_finish_parse(&ctx); + ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], ctx); if (ret) goto error; }
