While implementing kprobes on PA-RISC (without kretprobes) compilation
fails when CONFIG_KPROBE_EVENTS is enabled:
kernel/trace/trace_kprobe.o: in function `trace_kprobe_create':
kernel/trace/trace_kprobe.c:666: undefined reference to `kprobe_on_func_entry'
kernel/trace/trace_kprobe.o: in function `trace_kprobe_on_func_entry':
kernel/trace/trace_kprobe.c:167: undefined reference to `kprobe_on_func_entry'
kernel/trace/trace_kprobe.c:167: undefined reference to `kprobe_on_func_entry'
make: *** [Makefile:1029: vmlinux] Error 1
Given the fact that these functions have no dependencies on kretprobes i think
they should be moved out of the #ifdef CONFIG_KRETPROBES block.
Signed-off-by: Sven Schnelle <[email protected]>
Cc: "Naveen N. Rao" <[email protected]>
Cc: Anil S Keshavamurthy <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
---
kernel/kprobes.c | 39 ++++++++++++++++++++-------------------
1 file changed, 20 insertions(+), 19 deletions(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index c83e54727131..10a7e67fea67 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1819,6 +1819,26 @@ unsigned long __weak arch_deref_entry_point(void *entry)
return (unsigned long)entry;
}
+bool __weak arch_kprobe_on_func_entry(unsigned long offset)
+{
+ return !offset;
+}
+
+bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym,
+ unsigned long offset)
+{
+ kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset);
+
+ if (IS_ERR(kp_addr))
+ return false;
+
+ if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset) ||
+ !arch_kprobe_on_func_entry(offset))
+ return false;
+
+ return true;
+}
+
#ifdef CONFIG_KRETPROBES
/*
* This kprobe pre_handler is registered with every kretprobe. When probe
@@ -1875,25 +1895,6 @@ static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs)
}
NOKPROBE_SYMBOL(pre_handler_kretprobe);
-bool __weak arch_kprobe_on_func_entry(unsigned long offset)
-{
- return !offset;
-}
-
-bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset)
-{
- kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset);
-
- if (IS_ERR(kp_addr))
- return false;
-
- if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset) ||
- !arch_kprobe_on_func_entry(offset))
- return false;
-
- return true;
-}
-
int register_kretprobe(struct kretprobe *rp)
{
int ret = 0;
--
2.20.1
Sven Schnelle wrote:
> While implementing kprobes on PA-RISC (without kretprobes) compilation
> fails when CONFIG_KPROBE_EVENTS is enabled:
Thanks for working on that! Is there a specific reason kretprobes is not
being enabled on parisc?
>
> kernel/trace/trace_kprobe.o: in function `trace_kprobe_create':
> kernel/trace/trace_kprobe.c:666: undefined reference to `kprobe_on_func_entry'
> kernel/trace/trace_kprobe.o: in function `trace_kprobe_on_func_entry':
> kernel/trace/trace_kprobe.c:167: undefined reference to `kprobe_on_func_entry'
> kernel/trace/trace_kprobe.c:167: undefined reference to `kprobe_on_func_entry'
> make: *** [Makefile:1029: vmlinux] Error 1
>
> Given the fact that these functions have no dependencies on kretprobes i think
> they should be moved out of the #ifdef CONFIG_KRETPROBES block.
>
> Signed-off-by: Sven Schnelle <[email protected]>
> Cc: "Naveen N. Rao" <[email protected]>
> Cc: Anil S Keshavamurthy <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Masami Hiramatsu <[email protected]>
> ---
> kernel/kprobes.c | 39 ++++++++++++++++++++-------------------
> 1 file changed, 20 insertions(+), 19 deletions(-)
These functions were originally added only for kretprobes, but have
taken on newer uses since then. So, for this patch:
Acked-by: Naveen N. Rao <[email protected]>
However, I wonder if we should simply remove CONFIG_KRETPROBES
altogether. All architectures supporting kprobes today also support
kretprobes. I don't see why anyone would want to only disable
kretprobes.
- Naveen
Hi Naveen,
On Sat, Apr 06, 2019 at 10:52:47PM +0530, Naveen N. Rao wrote:
> Sven Schnelle wrote:
> > While implementing kprobes on PA-RISC (without kretprobes) compilation
> > fails when CONFIG_KPROBE_EVENTS is enabled:
>
> Thanks for working on that! Is there a specific reason kretprobes is not
> being enabled on parisc?
Reason is that i just started to add kprobes support to PA-RISC. I'm planning
doing kretprobes as a second step and have separate patches for kprobe and
kretprobe to keep things small.
Regards
Sven
On Sat, 6 Apr 2019 17:55:43 +0200
Sven Schnelle <[email protected]> wrote:
> While implementing kprobes on PA-RISC (without kretprobes) compilation
> fails when CONFIG_KPROBE_EVENTS is enabled:
>
> kernel/trace/trace_kprobe.o: in function `trace_kprobe_create':
> kernel/trace/trace_kprobe.c:666: undefined reference to `kprobe_on_func_entry'
> kernel/trace/trace_kprobe.o: in function `trace_kprobe_on_func_entry':
> kernel/trace/trace_kprobe.c:167: undefined reference to `kprobe_on_func_entry'
> kernel/trace/trace_kprobe.c:167: undefined reference to `kprobe_on_func_entry'
> make: *** [Makefile:1029: vmlinux] Error 1
>
> Given the fact that these functions have no dependencies on kretprobes i think
> they should be moved out of the #ifdef CONFIG_KRETPROBES block.
Ah, I got it. Yes, this function had been introduced for kretprobe (because
kretprobe must be the entry of functions) but is used for kprobe_event and
bpf now.
It should be moved out of CONFIG_KPROBE_EVENTS.
Acked-by: Masami Hiramatsu <[email protected]>
Thank you,
>
> Signed-off-by: Sven Schnelle <[email protected]>
> Cc: "Naveen N. Rao" <[email protected]>
> Cc: Anil S Keshavamurthy <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Masami Hiramatsu <[email protected]>
> ---
> kernel/kprobes.c | 39 ++++++++++++++++++++-------------------
> 1 file changed, 20 insertions(+), 19 deletions(-)
>
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index c83e54727131..10a7e67fea67 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -1819,6 +1819,26 @@ unsigned long __weak arch_deref_entry_point(void *entry)
> return (unsigned long)entry;
> }
>
> +bool __weak arch_kprobe_on_func_entry(unsigned long offset)
> +{
> + return !offset;
> +}
> +
> +bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym,
> + unsigned long offset)
> +{
> + kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset);
> +
> + if (IS_ERR(kp_addr))
> + return false;
> +
> + if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset) ||
> + !arch_kprobe_on_func_entry(offset))
> + return false;
> +
> + return true;
> +}
> +
> #ifdef CONFIG_KRETPROBES
> /*
> * This kprobe pre_handler is registered with every kretprobe. When probe
> @@ -1875,25 +1895,6 @@ static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs)
> }
> NOKPROBE_SYMBOL(pre_handler_kretprobe);
>
> -bool __weak arch_kprobe_on_func_entry(unsigned long offset)
> -{
> - return !offset;
> -}
> -
> -bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset)
> -{
> - kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset);
> -
> - if (IS_ERR(kp_addr))
> - return false;
> -
> - if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset) ||
> - !arch_kprobe_on_func_entry(offset))
> - return false;
> -
> - return true;
> -}
> -
> int register_kretprobe(struct kretprobe *rp)
> {
> int ret = 0;
> --
> 2.20.1
>
--
Masami Hiramatsu <[email protected]>