[PATCHv8 bpf-next 06/29] bpf: Move trampoline image setup into bpf_trampoline_ops callbacks
From: Jiri Olsa <jolsa@kernel.org>
Date: 2026-06-06 12:41:01
Also in:
bpf
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Moving trampoline image setup into bpf_trampoline_ops callbacks, so we can have different image handling for multi attachment which is coming in following changes. Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- kernel/bpf/trampoline.c | 66 ++++++++++++++++++++++++----------------- 1 file changed, 38 insertions(+), 28 deletions(-)
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index 5c943832fb9d..1006031ea021 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c@@ -60,11 +60,10 @@ static void trampoline_unlock(struct bpf_trampoline *tr) } struct bpf_trampoline_ops { - int (*register_fentry)(struct bpf_trampoline *tr, void *new_addr, void *data); - int (*unregister_fentry)(struct bpf_trampoline *tr, u32 orig_flags, void *old_addr, - void *data); - int (*modify_fentry)(struct bpf_trampoline *tr, u32 orig_flags, void *old_addr, - void *new_addr, bool lock_direct_mutex, void *data); + int (*register_fentry)(struct bpf_trampoline *tr, struct bpf_tramp_image *im, void *data); + int (*unregister_fentry)(struct bpf_trampoline *tr, u32 orig_flags, void *data); + int (*modify_fentry)(struct bpf_trampoline *tr, u32 orig_flags, struct bpf_tramp_image *im, + bool lock_direct_mutex, void *data); }; #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
@@ -426,9 +425,11 @@ static int bpf_trampoline_update_fentry(struct bpf_trampoline *tr, u32 orig_flag return bpf_arch_text_poke(ip, old_t, new_t, old_addr, new_addr); } -static int unregister_fentry(struct bpf_trampoline *tr, u32 orig_flags, - void *old_addr, void *data __maybe_unused) +static void bpf_tramp_image_put(struct bpf_tramp_image *im); + +static int unregister_fentry(struct bpf_trampoline *tr, u32 orig_flags, void *data __maybe_unused) { + void *old_addr = tr->cur_image->image; int ret; if (tr->func.ftrace_managed)
@@ -436,13 +437,19 @@ static int unregister_fentry(struct bpf_trampoline *tr, u32 orig_flags, else ret = bpf_trampoline_update_fentry(tr, orig_flags, old_addr, NULL); - return ret; + if (ret) + return ret; + + bpf_tramp_image_put(tr->cur_image); + tr->cur_image = NULL; + return 0; } -static int modify_fentry(struct bpf_trampoline *tr, u32 orig_flags, - void *old_addr, void *new_addr, +static int modify_fentry(struct bpf_trampoline *tr, u32 orig_flags, struct bpf_tramp_image *im, bool lock_direct_mutex, void *data __maybe_unused) { + void *old_addr = tr->cur_image->image; + void *new_addr = im->image; int ret; if (tr->func.ftrace_managed) {
@@ -451,12 +458,20 @@ static int modify_fentry(struct bpf_trampoline *tr, u32 orig_flags, ret = bpf_trampoline_update_fentry(tr, orig_flags, old_addr, new_addr); } - return ret; + + if (ret) + return ret; + + bpf_tramp_image_put(tr->cur_image); + tr->cur_image = im; + return 0; } /* first time registering */ -static int register_fentry(struct bpf_trampoline *tr, void *new_addr, void *data __maybe_unused) +static int register_fentry(struct bpf_trampoline *tr, struct bpf_tramp_image *im, + void *data __maybe_unused) { + void *new_addr = im->image; void *ip = tr->func.addr; unsigned long faddr; int ret;
@@ -474,7 +489,11 @@ static int register_fentry(struct bpf_trampoline *tr, void *new_addr, void *data ret = bpf_trampoline_update_fentry(tr, 0, NULL, new_addr); } - return ret; + if (ret) + return ret; + + tr->cur_image = im; + return 0; } static const struct bpf_trampoline_ops trampoline_ops = {
@@ -664,9 +683,7 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut return PTR_ERR(tlinks); if (total == 0) { - err = ops->unregister_fentry(tr, orig_flags, tr->cur_image->image, data); - bpf_tramp_image_put(tr->cur_image); - tr->cur_image = NULL; + err = ops->unregister_fentry(tr, orig_flags, data); goto out; }
@@ -734,11 +751,10 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut if (tr->cur_image) /* progs already running at this address */ - err = ops->modify_fentry(tr, orig_flags, tr->cur_image->image, - im->image, lock_direct_mutex, data); + err = ops->modify_fentry(tr, orig_flags, im, lock_direct_mutex, data); else /* first time registering */ - err = ops->register_fentry(tr, im->image, data); + err = ops->register_fentry(tr, im, data); #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS if (err == -EAGAIN) {
@@ -750,22 +766,16 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut goto again; } #endif - if (err) - goto out_free; - if (tr->cur_image) - bpf_tramp_image_put(tr->cur_image); - tr->cur_image = im; +out_free: + if (err) + bpf_tramp_image_free(im); out: /* If any error happens, restore previous flags */ if (err) tr->flags = orig_flags; kfree(tlinks); return err; - -out_free: - bpf_tramp_image_free(im); - goto out; } static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(struct bpf_prog *prog)
--
2.54.0