linux/helper-function: Update helper function signatures

A few helper functions have been updated with a new `__bpf_fastcall`
attribute. This commit updates the helper function signatures to reflect
this change in the libbpf headers.

Signed-off-by: Dylan Reimerink <[email protected]>

docs/linux/helper-function/bpf_get_smp_processor_id.md

@@ -20,7 +20,7 @@ Get the SMP (symmetric multiprocessing) processor id. Note that all programs run
 
 The SMP id of the processor running the program.
 
-`#!c static __u32 (* const bpf_get_smp_processor_id)(void) = (void *) 8;`
+`#!c static __bpf_fastcall __u32 (* const bpf_get_smp_processor_id)(void) = (void *) 8;`
 <!-- [/HELPER_FUNC_DEF] -->
 
 ## Usage

docs/linux/helper-function/bpf_kptr_xchg.md

@@ -14,13 +14,13 @@ description: "This page documents the 'bpf_kptr_xchg' eBPF helper function, incl
 
 
 <!-- [HELPER_FUNC_DEF] -->
-Exchange kptr at pointer _map_value_ with _ptr_, and return the old value. _ptr_ can be NULL, otherwise it must be a referenced pointer which will be released when this helper is called.
+Exchange kptr at pointer _dst_ with _ptr_, and return the old value. _dst_ can be map value or local kptr. _ptr_ can be NULL, otherwise it must be a referenced pointer which will be released when this helper is called.
 
 ### Returns
 
 The old value of kptr (which can be NULL). The returned pointer if not NULL, is a reference which must be released using its corresponding release function, or moved into a BPF map before program exit.
 
-`#!c static void *(* const bpf_kptr_xchg)(void *map_value, void *ptr) = (void *) 194;`
+`#!c static void *(* const bpf_kptr_xchg)(void *dst, void *ptr) = (void *) 194;`
 <!-- [/HELPER_FUNC_DEF] -->
 
 ## Usage

docs/linux/helper-function/bpf_loop.md

@@ -16,7 +16,7 @@ description: "This page documents the 'bpf_loop' eBPF helper function, including
 <!-- [HELPER_FUNC_DEF] -->
 For **nr_loops**, call **callback_fn** function with **callback_ctx** as the context parameter. The **callback_fn** should be a static function and the **callback_ctx** should be a pointer to the stack. The **flags** is used to control certain aspects of the helper. Currently, the **flags** must be 0. Currently, nr_loops is limited to 1 << 23 (~8 million) loops.
 
-long (\_callback_fn)(u32 index, void \_ctx);
+long (\_callback_fn)(u64 index, void \_ctx);
 
 where **index** is the current index in the loop. The index is zero-indexed.
 

docs/linux/helper-function/bpf_override_return.md

@@ -20,8 +20,6 @@ This helper works by setting the PC (program counter) to an override function wh
 
 This helper has security implications, and thus is subject to restrictions. It is only available if the kernel was compiled with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration option, and in this case it only works on functions tagged with **ALLOW_ERROR_INJECTION** in the kernel code.
 
-Also, the helper is only available for the architectures having the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing, x86 architecture is the only one to support this feature.
-
 ### Returns
 
 0

docs/linux/helper-function/bpf_setsockopt.md

@@ -26,7 +26,7 @@ This helper actually implements a subset of **setsockopt()**. It supports the fo
 
 * **SOL_SOCKET**, which supports the following _optname_s:
   **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,   **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**,   **SO_BINDTODEVICE**, **SO_KEEPALIVE**, **SO_REUSEADDR**,   **SO_REUSEPORT**, **SO_BINDTOIFINDEX**, **SO_TXREHASH**. * **IPPROTO_TCP**, which supports the following _optname_s:
-  **TCP_CONGESTION**, **TCP_BPF_IW**,   **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**,   **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**,   **TCP_SYNCNT**, **TCP_USER_TIMEOUT**, **TCP_NOTSENT_LOWAT**,   **TCP_NODELAY**, **TCP_MAXSEG**, **TCP_WINDOW_CLAMP**,   **TCP_THIN_LINEAR_TIMEOUTS**, **TCP_BPF_DELACK_MAX**,   **TCP_BPF_RTO_MIN**. * **IPPROTO_IP**, which supports _optname_ **IP_TOS**.
+  **TCP_CONGESTION**, **TCP_BPF_IW**,   **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**,   **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**,   **TCP_SYNCNT**, **TCP_USER_TIMEOUT**, **TCP_NOTSENT_LOWAT**,   **TCP_NODELAY**, **TCP_MAXSEG**, **TCP_WINDOW_CLAMP**,   **TCP_THIN_LINEAR_TIMEOUTS**, **TCP_BPF_DELACK_MAX**,   **TCP_BPF_RTO_MIN**, **TCP_BPF_SOCK_OPS_CB_FLAGS**. * **IPPROTO_IP**, which supports _optname_ **IP_TOS**.
 * **IPPROTO_IPV6**, which supports the following _optname_s:
   **IPV6_TCLASS**, **IPV6_AUTOFLOWLABEL**.