tracing: fix pointer argument handling in mempool_monitor.py

The BPF code was incorrectly passing pointer variables by value to
bpf_usdt_readarg(), causing the function to fail silently and resulting
in transaction hashes and reason strings displaying as zeros or garbage.

This fix adds the missing reference operator (&) when passing pointer
variables to bpf_usdt_readarg(), allowing the function to properly
write the pointer values and enabling correct display of transaction
hashes and removal/rejection reasons.

Fixes the regression introduced in ec47ba349d where bpf_usdt_readarg_p
was replaced with bpf_usdt_readarg but the calling convention wasn't
properly updated for pointer arguments.
This commit is contained in:
deadmanoz
2025-07-29 07:22:11 +00:00
committed by deadmanoz
parent 321984705d
commit 0ce041ea88

View File

@@ -66,7 +66,7 @@ BPF_PERF_OUTPUT(replaced_events);
int trace_added(struct pt_regs *ctx) { int trace_added(struct pt_regs *ctx) {
struct added_event added = {}; struct added_event added = {};
void *phash = NULL; void *phash = NULL;
bpf_usdt_readarg(1, ctx, phash); bpf_usdt_readarg(1, ctx, &phash);
bpf_probe_read_user(&added.hash, sizeof(added.hash), phash); bpf_probe_read_user(&added.hash, sizeof(added.hash), phash);
bpf_usdt_readarg(2, ctx, &added.vsize); bpf_usdt_readarg(2, ctx, &added.vsize);
bpf_usdt_readarg(3, ctx, &added.fee); bpf_usdt_readarg(3, ctx, &added.fee);
@@ -78,9 +78,9 @@ int trace_added(struct pt_regs *ctx) {
int trace_removed(struct pt_regs *ctx) { int trace_removed(struct pt_regs *ctx) {
struct removed_event removed = {}; struct removed_event removed = {};
void *phash = NULL, *preason = NULL; void *phash = NULL, *preason = NULL;
bpf_usdt_readarg(1, ctx, phash); bpf_usdt_readarg(1, ctx, &phash);
bpf_probe_read_user(&removed.hash, sizeof(removed.hash), phash); bpf_probe_read_user(&removed.hash, sizeof(removed.hash), phash);
bpf_usdt_readarg(2, ctx, preason); bpf_usdt_readarg(2, ctx, &preason);
bpf_probe_read_user_str(&removed.reason, sizeof(removed.reason), preason); bpf_probe_read_user_str(&removed.reason, sizeof(removed.reason), preason);
bpf_usdt_readarg(3, ctx, &removed.vsize); bpf_usdt_readarg(3, ctx, &removed.vsize);
bpf_usdt_readarg(4, ctx, &removed.fee); bpf_usdt_readarg(4, ctx, &removed.fee);
@@ -93,9 +93,9 @@ int trace_removed(struct pt_regs *ctx) {
int trace_rejected(struct pt_regs *ctx) { int trace_rejected(struct pt_regs *ctx) {
struct rejected_event rejected = {}; struct rejected_event rejected = {};
void *phash = NULL, *preason = NULL; void *phash = NULL, *preason = NULL;
bpf_usdt_readarg(1, ctx, phash); bpf_usdt_readarg(1, ctx, &phash);
bpf_probe_read_user(&rejected.hash, sizeof(rejected.hash), phash); bpf_probe_read_user(&rejected.hash, sizeof(rejected.hash), phash);
bpf_usdt_readarg(2, ctx, preason); bpf_usdt_readarg(2, ctx, &preason);
bpf_probe_read_user_str(&rejected.reason, sizeof(rejected.reason), preason); bpf_probe_read_user_str(&rejected.reason, sizeof(rejected.reason), preason);
rejected_events.perf_submit(ctx, &rejected, sizeof(rejected)); rejected_events.perf_submit(ctx, &rejected, sizeof(rejected));
return 0; return 0;
@@ -104,12 +104,12 @@ int trace_rejected(struct pt_regs *ctx) {
int trace_replaced(struct pt_regs *ctx) { int trace_replaced(struct pt_regs *ctx) {
struct replaced_event replaced = {}; struct replaced_event replaced = {};
void *phash_replaced = NULL, *phash_replacement = NULL; void *phash_replaced = NULL, *phash_replacement = NULL;
bpf_usdt_readarg(1, ctx, phash_replaced); bpf_usdt_readarg(1, ctx, &phash_replaced);
bpf_probe_read_user(&replaced.replaced_hash, sizeof(replaced.replaced_hash), phash_replaced); bpf_probe_read_user(&replaced.replaced_hash, sizeof(replaced.replaced_hash), phash_replaced);
bpf_usdt_readarg(2, ctx, &replaced.replaced_vsize); bpf_usdt_readarg(2, ctx, &replaced.replaced_vsize);
bpf_usdt_readarg(3, ctx, &replaced.replaced_fee); bpf_usdt_readarg(3, ctx, &replaced.replaced_fee);
bpf_usdt_readarg(4, ctx, &replaced.replaced_entry_time); bpf_usdt_readarg(4, ctx, &replaced.replaced_entry_time);
bpf_usdt_readarg(5, ctx, phash_replacement); bpf_usdt_readarg(5, ctx, &phash_replacement);
bpf_probe_read_user(&replaced.replacement_hash, sizeof(replaced.replacement_hash), phash_replacement); bpf_probe_read_user(&replaced.replacement_hash, sizeof(replaced.replacement_hash), phash_replacement);
bpf_usdt_readarg(6, ctx, &replaced.replacement_vsize); bpf_usdt_readarg(6, ctx, &replaced.replacement_vsize);
bpf_usdt_readarg(7, ctx, &replaced.replacement_fee); bpf_usdt_readarg(7, ctx, &replaced.replacement_fee);