Skip to content

Fix: task_struct backwards-compatibility with kernel versions < 5.14 (2) #55

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
tanelpoder merged 1 commit into from
Dec 14, 2024
Merged

Fix: task_struct backwards-compatibility with kernel versions < 5.14 (2) #55

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
26 changes: 11 additions & 15 deletions bin/xcapture-bpf.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,14 @@
#define __BCC__
#endif

// workaround for rename of task->state to task->__state in kernel 5.14
// (this change has been backported to rhel8 kernel 4.18 as well)
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 14, 0) || RHEL_MAJOR >= 8
#define STATE_FIELD __state
#else
#define STATE_FIELD state
#endif

// don't need EIP value for basic stack trace analysis (deduplicate some stackids)
// unfortunately SKIP_FRAMES 1 "skips" both the EIP value and one stack frame...
// #define SKIP_FRAMES (1 & BPF_F_SKIP_FIELD_MASK)
Expand Down Expand Up @@ -160,11 +168,7 @@ int update_cpu_stack_profile(struct bpf_perf_event_data *ctx) {
t->tid = tid;
t->pid = pid;
t->uid = (s32) (bpf_get_current_uid_gid() & 0xFFFFFFFF);
#if LINUX_VERSION_MAJOR >= 5 && LINUX_VERSION_PATCHLEVEL >= 14
t->state = curtask->__state;
#else
t->state = curtask->state;
#endif
t->state = curtask->STATE_FIELD;
bpf_probe_read_str(t->comm, sizeof(t->comm), (struct task_struct *)curtask->comm);

#ifdef CMDLINE
Expand Down Expand Up @@ -271,11 +275,7 @@ RAW_TRACEPOINT_PROBE(sched_switch) {
bool *preempt = (bool *)ctx->args[0];
struct task_struct *prev = (struct task_struct *)ctx->args[1];
struct task_struct *next = (struct task_struct *)ctx->args[2];
#if LINUX_VERSION_MAJOR >= 5 && LINUX_VERSION_PATCHLEVEL >= 14
unsigned int prev_state = prev->__state; // ctx->args[3] won't work in older configs due to breaking change in sched_switch tracepoint
#else
unsigned int prev_state = prev->state;
#endif
unsigned int prev_state = prev->STATE_FIELD; // ctx->args[3] won't work in older configs due to breaking change in sched_switch tracepoint

s32 prev_tid = prev->pid; // task (tid in user tools)
s32 prev_pid = prev->tgid; // tgid (pid in user tools)
Expand Down Expand Up @@ -334,11 +334,7 @@ RAW_TRACEPOINT_PROBE(sched_switch) {
//if (!t_next->comm[0])
bpf_probe_read_str(t_next->comm, sizeof(t_next->comm), next->comm);

#if LINUX_VERSION_MAJOR >= 5 && LINUX_VERSION_PATCHLEVEL >= 14
t_next->state = next->__state;
#else
t_next->state = next->state;
#endif
t_next->state = next->STATE_FIELD;
t_next->in_sched_migrate = 0;
t_next->in_sched_waking = 0;
t_next->in_sched_wakeup = 0;
Expand Down