From 7f1fa63204f0607ae82ac90cdd5de3f8f33612d5 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 9 Jan 2024 10:36:31 -0500 Subject: [PATCH] Inline implementation of task_prio() The task_prio() function has been implemented as "return p->prio - MAX_RT_PRIO;" since at least kernel v3.0, so inline it into lttng-modules rather than using kallsyms to call the kernel implementation. Signed-off-by: Mathieu Desnoyers Change-Id: I7dd482a2da72a005c16b3e5864767b47d7bc3fd3 --- include/lttng/events-internal.h | 1 - src/lttng-context-prio.c | 32 +++++++------------------------- src/lttng-events.c | 3 --- 3 files changed, 7 insertions(+), 29 deletions(-) diff --git a/include/lttng/events-internal.h b/include/lttng/events-internal.h index 8f5b702a..a91a659e 100644 --- a/include/lttng/events-internal.h +++ b/include/lttng/events-internal.h @@ -611,7 +611,6 @@ int lttng_add_pid_to_ctx(struct lttng_kernel_ctx **ctx); int lttng_add_cpu_id_to_ctx(struct lttng_kernel_ctx **ctx); int lttng_add_procname_to_ctx(struct lttng_kernel_ctx **ctx); int lttng_add_prio_to_ctx(struct lttng_kernel_ctx **ctx); -int wrapper_task_prio_init(void); int lttng_add_nice_to_ctx(struct lttng_kernel_ctx **ctx); int lttng_add_vpid_to_ctx(struct lttng_kernel_ctx **ctx); int lttng_add_tid_to_ctx(struct lttng_kernel_ctx **ctx); diff --git a/src/lttng-context-prio.c b/src/lttng-context-prio.c index aac10a63..cbe94800 100644 --- a/src/lttng-context-prio.c +++ b/src/lttng-context-prio.c @@ -14,34 +14,16 @@ #include #include #include -#include #include -static -int (*wrapper_task_prio_sym)(struct task_struct *t); - -int wrapper_task_prio_init(void) -{ - wrapper_task_prio_sym = (void *) kallsyms_lookup_funcptr("task_prio"); - if (!wrapper_task_prio_sym) { - printk(KERN_WARNING "LTTng: task_prio symbol lookup failed.\n"); - return -EINVAL; - } - return 0; -} -EXPORT_SYMBOL_GPL(wrapper_task_prio_init); - /* - * Canary function to check for 'task_prio()' at compile time. - * - * From 'include/linux/sched.h': - * - * extern int task_prio(const struct task_struct *p); + * task_prio() has been implemented as p->prio - MAX_RT_PRIO since at + * least kernel v3.0. */ -__attribute__((unused)) static -int __canary__task_prio(const struct task_struct *p) +static +int wrapper_task_prio(struct task_struct *p) { - return task_prio(p); + return p->prio - MAX_RT_PRIO; } static @@ -61,7 +43,7 @@ void prio_record(void *priv, struct lttng_kernel_probe_ctx *probe_ctx, { int prio; - prio = wrapper_task_prio_sym(current); + prio = wrapper_task_prio(current); chan->ops->event_write(ctx, &prio, sizeof(prio), lttng_alignof(prio)); } @@ -70,7 +52,7 @@ void prio_get_value(void *priv, struct lttng_kernel_probe_ctx *lttng_probe_ctx, struct lttng_ctx_value *value) { - value->u.s64 = wrapper_task_prio_sym(current); + value->u.s64 = wrapper_task_prio(current); } static const struct lttng_kernel_ctx_field *ctx_field = lttng_kernel_static_ctx_field( diff --git a/src/lttng-events.c b/src/lttng-events.c index 0107b790..3c9251a0 100644 --- a/src/lttng-events.c +++ b/src/lttng-events.c @@ -4365,9 +4365,6 @@ static int __init lttng_events_init(void) if (ret) return ret; ret = wrapper_get_pageblock_flags_mask_init(); - if (ret) - return ret; - ret = wrapper_task_prio_init(); if (ret) return ret; ret = lttng_probes_init(); -- 2.34.1