[RFC PATCH bpf-next 06/17] bpf: Pass image struct to reg/unreg/modify fentry functions

Jiri Olsa
2022-08-08T14:07:44Z

Passing image struct to reg/unreg/modify fentry functions
as a preparation for following change, where we need to
use the whole image in the update logic.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
kernel/bpf/trampoline.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index c0983ff5aa3a..d28070247fa3 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -244,8 +244,9 @@ static void bpf_trampoline_module_put(struct bpf_trampoline *tr)
tr->mod = NULL;
}

-static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr)
+static int unregister_fentry(struct bpf_trampoline *tr, struct bpf_tramp_image *im)
{
+ void *old_addr = im->image;
void *ip = tr->func.addr;
int ret;

@@ -259,9 +260,11 @@ static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr)
return ret;
}

-static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_addr,
+static int modify_fentry(struct bpf_trampoline *tr, struct bpf_tramp_image *im,
bool lock_direct_mutex)
{
+ void *old_addr = tr->cur_image->image;
+ void *new_addr = im->image;
void *ip = tr->func.addr;
int ret;

@@ -277,8 +280,9 @@ static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_ad
}

/* first time registering */
-static int register_fentry(struct bpf_trampoline *tr, void *new_addr)
+static int register_fentry(struct bpf_trampoline *tr, struct bpf_tramp_image *im)
{
+ void *new_addr = im->image;
void *ip = tr->func.addr;
unsigned long faddr;
int ret;
@@ -486,7 +490,7 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut
return PTR_ERR(tprogs);

if (total == 0) {
- err = unregister_fentry(tr, tr->cur_image->image);
+ err = unregister_fentry(tr, tr->cur_image);
bpf_tramp_image_put(tr->cur_image);
tr->cur_image = NULL;
tr->selector = 0;
@@ -532,10 +536,10 @@ static int bpf_trampoline_update(struct bpf_trampoline *tr, bool lock_direct_mut
WARN_ON(!tr->cur_image && tr->selector);
if (tr->cur_image)
/* progs already running at this address */
- err = modify_fentry(tr, tr->cur_image->image, im->image, lock_direct_mutex);
+ err = modify_fentry(tr, im, lock_direct_mutex);
else
/* first time registering */
- err = register_fentry(tr, im->image);
+ err = register_fentry(tr, im);

#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
if (err == -EAGAIN) {
--
2.37.1