linux: update ptrace_syscall_info struct

Add new flags field and reserveds.
Rename wrongly named field `sval` to `rval`.

Author: Marcondiro

libc-test/build.rs

@@ -4683,7 +4683,9 @@ fn test_linux(target: &str) {
                 true
             }
             // the `u` field is in fact an anonymous union
-            ("ptrace_syscall_info", "u" | "pad") if gnu => true,
+            ("ptrace_syscall_info", "u") if gnu => true,
+            // FIXME(linux): `flags` requires >= 6.16 kernel headers
+            ("ptrace_syscall_info", "flags") if gnu => true,
             // the vregs field is a `__uint128_t` C's type.
             ("user_fpsimd_struct", "vregs") => true,
             // Linux >= 5.11 tweaked the `svm_zero` field of the `sockaddr_vm` struct.

src/unix/linux_like/linux/gnu/mod.rs

@@ -171,19 +171,21 @@ s! {
     }
 
     pub struct __c_anonymous_ptrace_syscall_info_exit {
-        pub sval: crate::__s64,
+        pub rval: crate::__s64,
         pub is_error: crate::__u8,
     }
 
     pub struct __c_anonymous_ptrace_syscall_info_seccomp {
         pub nr: crate::__u64,
         pub args: [crate::__u64; 6],
         pub ret_data: crate::__u32,
+        reserved2: Padding<crate::__u32>,
     }
 
     pub struct ptrace_syscall_info {
         pub op: crate::__u8,
-        pub pad: [crate::__u8; 3],
+        reserved: Padding<crate::__u8>,
+        pub flags: crate::__u16,
         pub arch: crate::__u32,
         pub instruction_pointer: crate::__u64,
         pub stack_pointer: crate::__u64,