gcc/libgcc/config/sol2/gmon.c
Rainer Orth a5046f48b3 Save call-clobbered registers in _mcount on 32-bit Solaris/x86 (PR target/38239)
PR target/38239
	* config/sol2/gmon.c [__i386__] (_mcount): Save and restore
	call-clobbered registers.
	(internal_mcount): Remove __i386__ handling.

From-SVN: r234256
2016-03-16 11:57:02 +00:00

440 lines
13 KiB
C

/*-
* Copyright (c) 1991 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. [rescinded 22 July 1999]
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* Mangled into a form that works on Solaris 2/SPARC by Mark Eichin
* for Cygnus Support, July 1992.
*
* Modified to support Solaris 2/x86 by J.W.Hawtin <oolon@ankh.org>, 14/8/96.
*
* It must be used in conjunction with sol2-gc1.S, which is used to start
* and stop process monitoring.
*/
#include "tconfig.h"
#include "tsystem.h"
#include "auto-target.h"
#include <fcntl.h> /* For creat. */
extern void monstartup (char *, char *);
extern void _mcleanup (void);
static void internal_mcount (char *, unsigned short *) __attribute__ ((used));
static void moncontrol (int);
struct phdr {
char *lpc;
char *hpc;
int ncnt;
};
#define HISTFRACTION 2
#define HISTCOUNTER unsigned short
#define HASHFRACTION 1
#define ARCDENSITY 2
#define MINARCS 50
struct tostruct {
char *selfpc;
long count;
unsigned short link;
};
struct rawarc {
unsigned long raw_frompc;
unsigned long raw_selfpc;
long raw_count;
};
#define ROUNDDOWN(x, y) (((x) / (y)) * (y))
#define ROUNDUP(x, y) ((((x) + (y) - 1) / (y)) * (y))
/* froms is actually a bunch of unsigned shorts indexing tos. */
static int profiling = 3;
static unsigned short *froms;
static struct tostruct *tos = NULL;
static long tolimit = 0;
static char *s_lowpc = NULL;
static char *s_highpc = NULL;
static size_t s_textsize = 0;
static int ssiz;
static char *sbuf;
static int s_scale;
/* See profil(2) where this is describe (incorrectly). */
#define SCALE_1_TO_1 0x10000L
#define MSG "No space for profiling buffer(s)\n"
void
monstartup (char *lowpc, char *highpc)
{
size_t monsize;
char *buffer;
size_t o;
/* Round lowpc and highpc to multiples of the density we're using
so the rest of the scaling (here and in gprof) stays in ints. */
lowpc = (char *) ROUNDDOWN ((size_t) lowpc,
HISTFRACTION * sizeof (HISTCOUNTER));
s_lowpc = lowpc;
highpc = (char *) ROUNDUP ((size_t) highpc,
HISTFRACTION * sizeof (HISTCOUNTER));
s_highpc = highpc;
s_textsize = highpc - lowpc;
monsize = (s_textsize / HISTFRACTION) + sizeof (struct phdr);
buffer = sbrk (monsize);
if (buffer == (void *) -1) {
write (STDERR_FILENO, MSG, sizeof (MSG) - 1);
return;
}
froms = sbrk (s_textsize / HASHFRACTION);
if (froms == (void *) -1) {
write (STDERR_FILENO, MSG, sizeof (MSG) - 1);
froms = NULL;
return;
}
tolimit = s_textsize * ARCDENSITY / 100;
if (tolimit < MINARCS) {
tolimit = MINARCS;
} else if (tolimit > 65534) {
tolimit = 65534;
}
tos = sbrk (tolimit * sizeof (struct tostruct));
if (tos == (void *) -1) {
write (STDERR_FILENO, MSG, sizeof (MSG) - 1);
froms = NULL;
tos = NULL;
return;
}
tos[0].link = 0;
sbuf = buffer;
ssiz = monsize;
((struct phdr *) buffer)->lpc = lowpc;
((struct phdr *) buffer)->hpc = highpc;
((struct phdr *) buffer)->ncnt = ssiz;
monsize -= sizeof (struct phdr);
if (monsize <= 0)
return;
o = highpc - lowpc;
if(monsize < o)
s_scale = ((float) monsize / o) * SCALE_1_TO_1;
else
s_scale = SCALE_1_TO_1;
moncontrol (1);
}
void
_mcleanup (void)
{
int fd;
int fromindex;
int endfrom;
char *frompc;
int toindex;
struct rawarc rawarc;
char *profdir;
const char *proffile;
char *progname;
char buf[PATH_MAX];
extern char **___Argv;
moncontrol (0);
if ((profdir = getenv ("PROFDIR")) != NULL) {
/* If PROFDIR contains a null value, no profiling output is produced. */
if (*profdir == '\0') {
return;
}
progname = strrchr (___Argv[0], '/');
if (progname == NULL)
progname = ___Argv[0];
else
progname++;
sprintf (buf, "%s/%ld.%s", profdir, (long) getpid (), progname);
proffile = buf;
} else {
proffile = "gmon.out";
}
fd = creat (proffile, 0666);
if (fd < 0) {
perror (proffile);
return;
}
#ifdef DEBUG
fprintf (stderr, "[mcleanup] sbuf %#x ssiz %d\n", sbuf, ssiz);
#endif /* DEBUG */
write (fd, sbuf, ssiz);
endfrom = s_textsize / (HASHFRACTION * sizeof (*froms));
for (fromindex = 0; fromindex < endfrom; fromindex++) {
if (froms[fromindex] == 0) {
continue;
}
frompc = s_lowpc + (fromindex * HASHFRACTION * sizeof (*froms));
for (toindex = froms[fromindex];
toindex != 0;
toindex = tos[toindex].link) {
#ifdef DEBUG
fprintf (stderr, "[mcleanup] frompc %#x selfpc %#x count %d\n",
frompc, tos[toindex].selfpc, tos[toindex].count);
#endif /* DEBUG */
rawarc.raw_frompc = (unsigned long) frompc;
rawarc.raw_selfpc = (unsigned long) tos[toindex].selfpc;
rawarc.raw_count = tos[toindex].count;
write (fd, &rawarc, sizeof (rawarc));
}
}
close (fd);
}
/* Solaris 2 libraries use _mcount. */
#if defined __i386__
asm(".globl _mcount\n"
" .type _mcount, @function\n"
"_mcount:\n"
/* Save and restore the call-clobbered registers. */
" pushl %eax\n"
" pushl %ecx\n"
" pushl %edx\n"
" movl 12(%esp), %edx\n"
" movl 4(%ebp), %eax\n"
" call internal_mcount\n"
" popl %edx\n"
" popl %ecx\n"
" popl %eax\n"
" ret\n");
#elif defined __x86_64__
/* See GLIBC for additional information about this technique. */
asm(".globl _mcount\n"
" .type _mcount, @function\n"
"_mcount:\n"
/* The compiler calls _mcount after the prologue, and does not
save any of the registers. Therefore we must preserve all
seven registers which may contain function arguments. */
" subq $0x38, %rsp\n"
" movq %rax, (%rsp)\n"
" movq %rcx, 0x08(%rsp)\n"
" movq %rdx, 0x10(%rsp)\n"
" movq %rsi, 0x18(%rsp)\n"
" movq %rdi, 0x20(%rsp)\n"
" movq %r8, 0x28(%rsp)\n"
" movq %r9, 0x30(%rsp)\n"
/* Get SELFPC (pushed by the call to this function) and
FROMPCINDEX (via the frame pointer). */
" movq 0x38(%rsp), %rdi\n"
" movq 0x8(%rbp), %rsi\n"
" call internal_mcount\n"
/* Restore the saved registers. */
" movq 0x30(%rsp), %r9\n"
" movq 0x28(%rsp), %r8\n"
" movq 0x20(%rsp), %rdi\n"
" movq 0x18(%rsp), %rsi\n"
" movq 0x10(%rsp), %rdx\n"
" movq 0x08(%rsp), %rcx\n"
" movq (%rsp), %rax\n"
" addq $0x38, %rsp\n"
" retq\n");
#elif defined __sparc__
/* The SPARC stack frame is only held together by the frame pointers
in the register windows. According to the SVR4 SPARC ABI
Supplement, Low Level System Information/Operating System
Interface/Software Trap Types, a type 3 trap will flush all of the
register windows to the stack, which will make it possible to walk
the frames and find the return addresses.
However, it seems awfully expensive to incur a trap (system
call) for every function call. It turns out that "call" simply puts
the return address in %o7 expecting the "save" in the procedure to
shift it into %i7; this means that before the "save" occurs, %o7
contains the address of the call to mcount, and %i7 still contains
the caller above that. The asm mcount here simply saves those
registers in argument registers and branches to internal_mcount,
simulating a call with arguments.
Kludges:
1) the branch to internal_mcount is hard coded; it should be
possible to tell asm to use the assembler-name of a symbol.
2) in theory, the function calling mcount could have saved %i7
somewhere and reused the register; in practice, I *think* this will
break longjmp (and maybe the debugger) but I'm not certain. (I take
some comfort in the knowledge that it will break the native mcount
as well.)
3) if builtin_return_address worked, this could be portable.
However, it would really have to be optimized for arguments of 0
and 1 and do something like what we have here in order to avoid the
trap per function call performance hit.
4) the atexit and monsetup calls prevent this from simply
being a leaf routine that doesn't do a "save" (and would thus have
access to %o7 and %i7 directly) but the call to write() at the end
would have also prevented this.
-- [eichin:19920702.1107EST] */
asm(".global _mcount\n"
"_mcount:\n"
/* i7 == last ret, -> frompcindex. */
" mov %i7, %o1\n"
/* o7 == current ret, -> selfpc. */
" mov %o7, %o0\n"
" b,a internal_mcount\n");
#endif
static void
internal_mcount (char *selfpc, unsigned short *frompcindex)
{
struct tostruct *top;
struct tostruct *prevtop;
long toindex;
static char already_setup;
/* Only necessary without the Solaris CRTs or a proper gcrt1.o, otherwise
crtpg.o or gcrt1.o take care of that.
FIXME: What about _init vs. _start on sparc? */
#ifndef HAVE_SOLARIS_CRTS
if(!already_setup) {
extern char etext[];
already_setup = 1;
#if defined __i386__
/* <sys/vmparam.h> USERSTACK. */
monstartup ((char *) 0x8048000, etext);
#elif defined __x86_64__
monstartup (NULL, etext);
#elif defined __sparc__
{
extern char _start[];
extern char _init[];
monstartup (_start < _init ? _start : _init, etext);
}
#endif
atexit (_mcleanup);
}
#endif /* !HAVE_SOLARIS_CRTS */
/* Check that we are profiling and that we aren't recursively invoked. */
if (profiling) {
goto out;
}
profiling++;
/* Check that frompcindex is a reasonable pc value. For example: signal
catchers get called from the stack, not from text space. too bad. */
frompcindex = (unsigned short *) ((long) frompcindex - (long) s_lowpc);
if ((unsigned long) frompcindex > s_textsize) {
goto done;
}
frompcindex = &froms[((long) frompcindex) / (HASHFRACTION * sizeof (*froms))];
toindex = *frompcindex;
if (toindex == 0) {
/* First time traversing this arc. */
toindex = ++tos[0].link;
if (toindex >= tolimit) {
goto overflow;
}
*frompcindex = toindex;
top = &tos[toindex];
top->selfpc = selfpc;
top->count = 1;
top->link = 0;
goto done;
}
top = &tos[toindex];
if (top->selfpc == selfpc) {
/* arc at front of chain; usual case. */
top->count++;
goto done;
}
/* Have to go looking down chain for it. Top points to what we are
looking at, prevtop points to previous top. We know it is not at the
head of the chain. */
for (; /* goto done */; ) {
if (top->link == 0) {
/* top is end of the chain and none of the chain had top->selfpc ==
selfpc, so we allocate a new tostruct and link it to the head of
the chain. */
toindex = ++tos[0].link;
if (toindex >= tolimit) {
goto overflow;
}
top = &tos[toindex];
top->selfpc = selfpc;
top->count = 1;
top->link = *frompcindex;
*frompcindex = toindex;
goto done;
}
/* Otherwise, check the next arc on the chain. */
prevtop = top;
top = &tos[top->link];
if (top->selfpc == selfpc) {
/* There it is. Increment its count move it to the head of the
chain. */
top->count++;
toindex = prevtop->link;
prevtop->link = top->link;
top->link = *frompcindex;
*frompcindex = toindex;
goto done;
}
}
done:
profiling--;
/* ... and fall through. */
out:
/* Normal return restores saved registers. */
return;
overflow:
/* Halt further profiling. */
profiling++;
#define TOLIMIT "mcount: tos overflow\n"
write (STDERR_FILENO, TOLIMIT, sizeof (TOLIMIT) - 1);
goto out;
}
/* Control profiling. Profiling is what mcount checks to see if all the
data structures are ready. */
static void
moncontrol (int mode)
{
if (mode) {
/* Start. */
profil ((unsigned short *) (sbuf + sizeof (struct phdr)),
ssiz - sizeof (struct phdr), (size_t) s_lowpc, s_scale);
profiling = 0;
} else {
/* Stop. */
profil ((unsigned short *) 0, 0, 0, 0);
profiling = 3;
}
}