On Thu, Feb 01, 2024 at 12:52:24PM +0000, Puranjay Mohan wrote:
> This will be used by bpf_throw() to unwind till the program marked as
> exception boundary and run the callback with the stack of the main
> program.
>
> This is required for supporting BPF exceptions on ARM64.
>
> Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx>
> ---
> arch/arm64/kernel/stacktrace.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
> index 7f88028a00c0..66cffc5fc0be 100644
> --- a/arch/arm64/kernel/stacktrace.c
> +++ b/arch/arm64/kernel/stacktrace.c
> @@ -7,6 +7,7 @@
> #include <linux/kernel.h>
> #include <linux/efi.h>
> #include <linux/export.h>
> +#include <linux/filter.h>
> #include <linux/ftrace.h>
> #include <linux/kprobes.h>
> #include <linux/sched.h>
> @@ -266,6 +267,31 @@ noinline noinstr void arch_stack_walk(stack_trace_consume_fn consume_entry,
> kunwind_stack_walk(arch_kunwind_consume_entry, &data, task, regs);
> }
>
> +struct bpf_unwind_consume_entry_data {
> + bool (*consume_entry)(void *cookie, u64 ip, u64 sp, u64 fp);
> + void *cookie;
> +};
> +
> +static bool
> +arch_bpf_unwind_consume_entry(const struct kunwind_state *state, void *cookie)
> +{
> + struct bpf_unwind_consume_entry_data *data = cookie;
> +
> + return data->consume_entry(data->cookie, state->common.pc, 0,
> + state->common.fp);
> +}
> +
> +noinline noinstr void arch_bpf_stack_walk(bool (*consume_entry)(void *cookie, u64 ip, u64 sp,
> + u64 fp), void *cookie)
> +{
> + struct bpf_unwind_consume_entry_data data = {
> + .consume_entry = consume_entry,
> + .cookie = cookie,
> + };
> +
> + kunwind_stack_walk(arch_bpf_unwind_consume_entry, &data, current, NULL);
> +}
Too many "cookies", I found reading this confusing. If you ever respin,
please use some different "cookie" names.
I guess you want this to be merged via the bpf tree?
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
