xref: /original-bsd/sys/kern/subr_prof.c (revision e59fb703)
1 /*
2  * Copyright (c) 1982, 1986 Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)subr_prof.c	7.10 (Berkeley) 05/07/91
8  */
9 
10 #ifdef GPROF
11 #include "gprof.h"
12 #include "param.h"
13 #include "systm.h"
14 #include "malloc.h"
15 
16 /*
17  * Froms is actually a bunch of unsigned shorts indexing tos
18  */
19 int	profiling = 3;
20 u_short	*froms;
21 struct	tostruct *tos = 0;
22 long	tolimit = 0;
23 char	*s_lowpc = (char *)KERNBASE;
24 extern	char etext;
25 char	*s_highpc = &etext;
26 u_long	s_textsize = 0;
27 int	ssiz;
28 u_short	*sbuf;
29 u_short	*kcount;
30 
31 kmstartup()
32 {
33 	u_long fromssize, tossize;
34 
35 	/*
36 	 * Round lowpc and highpc to multiples of the density we're using
37 	 * so the rest of the scaling (here and in gprof) stays in ints.
38 	 */
39 	s_lowpc = (char *)
40 	    ROUNDDOWN((unsigned)s_lowpc, HISTFRACTION*sizeof (HISTCOUNTER));
41 	s_highpc = (char *)
42 	    ROUNDUP((unsigned)s_highpc, HISTFRACTION*sizeof (HISTCOUNTER));
43 	s_textsize = s_highpc - s_lowpc;
44 	printf("Profiling kernel, s_textsize=%d [%x..%x]\n",
45 		s_textsize, s_lowpc, s_highpc);
46 	ssiz = (s_textsize / HISTFRACTION) + sizeof (struct phdr);
47 	sbuf = (u_short *)malloc(ssiz, M_GPROF, M_WAITOK);
48 	if (sbuf == 0) {
49 		printf("No space for monitor buffer(s)\n");
50 		return;
51 	}
52 	bzero(sbuf, ssiz);
53 	fromssize = s_textsize / HASHFRACTION;
54 	froms = (u_short *)malloc(fromssize, M_GPROF, M_NOWAIT);
55 	if (froms == 0) {
56 		printf("No space for monitor buffer(s)\n");
57 		free(sbuf, M_GPROF);
58 		sbuf = 0;
59 		return;
60 	}
61 	bzero(froms, fromssize);
62 	tolimit = s_textsize * ARCDENSITY / 100;
63 	if (tolimit < MINARCS)
64 		tolimit = MINARCS;
65 	else if (tolimit > (0xffff - 1))
66 		tolimit = 0xffff - 1;
67 	tossize = tolimit * sizeof (struct tostruct);
68 	tos = (struct tostruct *)malloc(tossize, M_GPROF, M_WAITOK);
69 	if (tos == 0) {
70 		printf("No space for monitor buffer(s)\n");
71 		free(sbuf, M_GPROF), sbuf = 0;
72 		free(froms, M_GPROF), froms = 0;
73 		return;
74 	}
75 	bzero(tos, tossize);
76 	tos[0].link = 0;
77 	((struct phdr *)sbuf)->lpc = s_lowpc;
78 	((struct phdr *)sbuf)->hpc = s_highpc;
79 	((struct phdr *)sbuf)->ncnt = ssiz;
80 	kcount = (u_short *)(((int)sbuf) + sizeof (struct phdr));
81 }
82 
83 /*
84  * This routine is massaged so that it may be jsb'ed to on vax.
85  */
86 asm(".text");
87 asm("#the beginning of mcount()");
88 asm(".data");
89 mcount()
90 {
91 	register char *selfpc;			/* r11 => r5 */
92 	register u_short *frompcindex;		/* r10 => r4 */
93 	register struct tostruct *top;		/* r9  => r3 */
94 	register struct tostruct *prevtop;	/* r8  => r2 */
95 	register long toindex;			/* r7  => r1 */
96 	static int s;
97 
98 	asm("	.text");		/* make sure we're in text space */
99 	/*
100 	 * Check that we are profiling.
101 	 */
102 	if (profiling)
103 		goto out;
104 	/*
105 	 * Find the return address for mcount,
106 	 * and the return address for mcount's caller.
107 	 */
108 #ifdef lint
109 	selfpc = (char *)0;
110 	frompcindex = 0;
111 #else
112 	;				/* avoid label botch */
113 #ifdef __GNUC__
114 #if defined(vax)
115 	Fix Me!!
116 #endif
117 #if defined(tahoe)
118 	Fix Me!!
119 #endif
120 #if defined(hp300)
121 	/*
122 	 * selfpc = pc pushed by mcount jsr,
123 	 * frompcindex = pc pushed by jsr into self.
124 	 * In GCC the caller's stack frame has already been built so we
125 	 * have to chase a6 to find caller's raddr.  This assumes that all
126 	 * routines we are profiling were built with GCC and that all
127 	 * profiled routines use link/unlk.
128 	 */
129 	asm("movl a6@(4),%0" : "=r" (selfpc));
130 	asm("movl a6@(0)@(4),%0" : "=r" (frompcindex));
131 #endif
132 #else
133 #if defined(vax)
134 	asm("	movl (sp), r11");	/* selfpc = ... (jsb frame) */
135 	asm("	movl 16(fp), r10");	/* frompcindex =     (calls frame) */
136 #endif
137 #if defined(tahoe)
138 	asm("	movl -8(fp),r12");	/* selfpc = callf frame */
139 	asm("	movl (fp),r11");
140 	asm("	movl -8(r11),r11");	/* frompcindex = 1 callf frame back */
141 #endif
142 #if defined(hp300)
143 	Fix Me!!
144 #endif
145 #endif /* not __GNUC__ */
146 #endif /* not lint */
147 	/*
148 	 * Insure that we cannot be recursively invoked.
149 	 * this requires that splhigh() and splx() below
150 	 * do NOT call mcount!
151 	 */
152 #if defined(hp300)
153 	asm("movw	sr,%0" : "=g" (s));
154 	asm("movw	#0x2700,sr");
155 #else
156 	s = splhigh();
157 #endif
158 	/*
159 	 * Check that frompcindex is a reasonable pc value.
160 	 * For example:	signal catchers get called from the stack,
161 	 *	not from text space.  too bad.
162 	 */
163 	frompcindex = (u_short *)((long)frompcindex - (long)s_lowpc);
164 	if ((u_long)frompcindex > s_textsize)
165 		goto done;
166 	frompcindex =
167 	    &froms[((long)frompcindex) / (HASHFRACTION * sizeof (*froms))];
168 	toindex = *frompcindex;
169 	if (toindex == 0) {
170 		/*
171 		 * First time traversing this arc
172 		 */
173 		toindex = ++tos[0].link;
174 		if (toindex >= tolimit)
175 			goto overflow;
176 		*frompcindex = toindex;
177 		top = &tos[toindex];
178 		top->selfpc = selfpc;
179 		top->count = 1;
180 		top->link = 0;
181 		goto done;
182 	}
183 	top = &tos[toindex];
184 	if (top->selfpc == selfpc) {
185 		/*
186 		 * Arc at front of chain; usual case.
187 		 */
188 		top->count++;
189 		goto done;
190 	}
191 	/*
192 	 * Have to go looking down chain for it.
193 	 * Top points to what we are looking at,
194 	 * prevtop points to previous top.
195 	 * We know it is not at the head of the chain.
196 	 */
197 	for (; /* goto done */; ) {
198 		if (top->link == 0) {
199 			/*
200 			 * Top is end of the chain and none of the chain
201 			 * had top->selfpc == selfpc.
202 			 * So we allocate a new tostruct
203 			 * and link it to the head of the chain.
204 			 */
205 			toindex = ++tos[0].link;
206 			if (toindex >= tolimit)
207 				goto overflow;
208 			top = &tos[toindex];
209 			top->selfpc = selfpc;
210 			top->count = 1;
211 			top->link = *frompcindex;
212 			*frompcindex = toindex;
213 			goto done;
214 		}
215 		/*
216 		 * Otherwise, check the next arc on the chain.
217 		 */
218 		prevtop = top;
219 		top = &tos[top->link];
220 		if (top->selfpc == selfpc) {
221 			/*
222 			 * There it is, increment its count and
223 			 * move it to the head of the chain.
224 			 */
225 			top->count++;
226 			toindex = prevtop->link;
227 			prevtop->link = top->link;
228 			top->link = *frompcindex;
229 			*frompcindex = toindex;
230 			goto done;
231 		}
232 
233 	}
234 done:
235 #if defined(hp300)
236 	asm("movw	%0,sr" : : "g" (s));
237 #else
238 	splx(s);
239 #endif
240 	/* and fall through */
241 out:
242 #if defined(vax)
243 	asm("	rsb");
244 #endif
245 	return;
246 overflow:
247 	profiling = 3;
248 	printf("mcount: tos overflow\n");
249 	goto out;
250 }
251 asm(".text");
252 asm("#the end of mcount()");
253 asm(".data");
254 #endif
255