Add NT_PROCSTAT_KQUEUES core note

Suggested by:	jhb
Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D49372

sys/kern/imgact_elf.c

@@ -1574,6 +1574,7 @@ static void __elfN(note_threadmd)(void *, struct sbuf *, size_t *);
 static void __elfN(note_procstat_auxv)(void *, struct sbuf *, size_t *);
 static void __elfN(note_procstat_proc)(void *, struct sbuf *, size_t *);
 static void __elfN(note_procstat_psstrings)(void *, struct sbuf *, size_t *);
+static void __elfN(note_procstat_kqueues)(void *, struct sbuf *, size_t *);
 static void note_procstat_files(void *, struct sbuf *, size_t *);
 static void note_procstat_groups(void *, struct sbuf *, size_t *);
 static void note_procstat_osrel(void *, struct sbuf *, size_t *);
@@ -1899,6 +1900,8 @@ __elfN(prepare_notes)(struct thread *td, struct note_info_list *list,
 	    __elfN(note_procstat_psstrings), p);
 	size += __elfN(register_note)(td, list, NT_PROCSTAT_AUXV,
 	    __elfN(note_procstat_auxv), p);
+	size += __elfN(register_note)(td, list, NT_PROCSTAT_KQUEUES,
+	    __elfN(note_procstat_kqueues), p);
 
 	*sizep = size;
 }
@@ -2719,6 +2722,54 @@ __elfN(note_procstat_auxv)(void *arg, struct sbuf *sb, size_t *sizep)
 	}
 }
 
+static void
+__elfN(note_procstat_kqueues)(void *arg, struct sbuf *sb, size_t *sizep)
+{
+	struct proc *p;
+	size_t size, sect_sz, i;
+	ssize_t start_len, sect_len;
+	int structsize;
+	bool compat32;
+
+#if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
+	compat32 = true;
+	structsize = sizeof(struct kinfo_knote32);
+#else
+	compat32 = false;
+	structsize = sizeof(struct kinfo_knote);
+#endif
+	p = arg;
+	if (sb == NULL) {
+		size = 0;
+		sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN);
+		sbuf_set_drain(sb, sbuf_count_drain, &size);
+		sbuf_bcat(sb, &structsize, sizeof(structsize));
+		kern_proc_kqueues_out(p, sb, -1, compat32);
+		sbuf_finish(sb);
+		sbuf_delete(sb);
+		*sizep = size;
+	} else {
+		sbuf_start_section(sb, &start_len);
+
+		sbuf_bcat(sb, &structsize, sizeof(structsize));
+		kern_proc_kqueues_out(p, sb, *sizep - sizeof(structsize),
+		    compat32);
+
+		sect_len = sbuf_end_section(sb, start_len, 0, 0);
+		if (sect_len < 0)
+			return;
+		sect_sz = sect_len;
+
+		KASSERT(sect_sz <= *sizep,
+		    ("kern_proc_kqueue_out did not respect maxlen; "
+		     "requested %zu, got %zu", *sizep - sizeof(structsize),
+		     sect_sz - sizeof(structsize)));
+
+		for (i = 0; i < *sizep - sect_sz && sb->s_error == 0; i++)
+			sbuf_putc(sb, 0);
+	}
+}
+
 #define	MAX_NOTES_LOOP	4096
 bool
 __elfN(parse_notes)(const struct image_params *imgp, const Elf_Note *checknote,

sys/kern/kern_event.c

@@ -2940,6 +2940,53 @@ out:
 	return (error);
 }
 
+struct kern_proc_kqueues_out1_cb_args {
+	struct sbuf *s;
+	bool compat32;
+};
+
+static int
+kern_proc_kqueues_out1_cb(struct proc *p, int fd, struct file *fp, void *arg)
+{
+	struct kqueue *kq;
+	struct kern_proc_kqueues_out1_cb_args *a;
+
+	if (fp->f_type != DTYPE_KQUEUE)
+		return (0);
+	a = arg;
+	kq = fp->f_data;
+	return (kern_proc_kqueue_report(a->s, p, fd, kq, a->compat32));
+}
+
+static int
+kern_proc_kqueues_out1(struct thread *td, struct proc *p, struct sbuf *s,
+    bool compat32)
+{
+	struct kern_proc_kqueues_out1_cb_args a;
+
+	MPASS(p == curproc);
+
+	a.s = s;
+	a.compat32 = compat32;
+	return (fget_remote_foreach(td, p, kern_proc_kqueues_out1_cb, &a));
+}
+
+int
+kern_proc_kqueues_out(struct proc *p, struct sbuf *sb, size_t maxlen,
+    bool compat32)
+{
+	struct sbuf *s, sm;
+	int error;
+
+	s = sbuf_new(&sm, NULL, maxlen, SBUF_FIXEDLEN);
+	error = kern_proc_kqueues_out1(curthread, p, s, compat32);
+	sbuf_finish(s);
+	if (error == 0)
+		sbuf_bcat(sb, sbuf_data(s), MIN(sbuf_len(s), maxlen));
+	sbuf_delete(s);
+	return (error);
+}
+
 static int
 sysctl_kern_proc_kqueue(SYSCTL_HANDLER_ARGS)
 {

sys/sys/elf_common.h

@@ -840,6 +840,7 @@ typedef struct {
 #define	NT_PROCSTAT_PSSTRINGS	15	/* Procstat ps_strings data. */
 #define	NT_PROCSTAT_AUXV	16	/* Procstat auxv data. */
 #define	NT_PTLWPINFO		17	/* Thread ptrace miscellaneous info. */
+#define	NT_PROCSTAT_KQUEUES	18	/* Procstat kqueues events. */
 #define	NT_PPC_VMX	0x100	/* PowerPC Altivec/VMX registers */
 #define	NT_PPC_VSX	0x102	/* PowerPC VSX registers */
 #define	NT_X86_SEGBASES	0x200	/* x86 FS/GS base addresses. */

sys/sys/user.h

@@ -721,6 +721,8 @@ int	kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen);
 int	kern_proc_out(struct proc *p, struct sbuf *sb, int flags);
 int	kern_proc_vmmap_out(struct proc *p, struct sbuf *sb, ssize_t maxlen,
 	int flags);
+int	kern_proc_kqueues_out(struct proc *p, struct sbuf *s, size_t maxlen,
+	bool compat32);
 
 int	vntype_to_kinfo(int vtype);
 void	pack_kinfo(struct kinfo_file *kif);