Eliminate MAX_QUALS, make qualifier array dynamic
MAX_QUALS was 2048, even though most arches used less than 500 entries
in it. MAX_QUALS had to be maintained by hand to be higher than syscall
count. It also limited the highest possible fd to track.
This change makes qual_flagsN[] arrays start sized to the required minimum
(number of syscalls) and grow dynamically if user requested
-e read=BIGNUM. As a precaution, BIGNUM should be < 2^15, but this limit
can be raised with no cost for normal strace invocations.
qual_flags is now a define to qual_vec[current_personality].
As a bonus, this patch aliases sysent, errnoent, signalent, ioctlent
names in one-personality arches to their corresponding <foo>0 arrays,
removing one indirection level.
text data bss dec hex filename
244471 700 12928 258099 3f033 strace.t7/strace
244627 680 10860 256167 3e8a7 strace.t8/strace
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/syscall.c b/syscall.c
index b92ddc0..ef14a0a 100644
--- a/syscall.c
+++ b/syscall.c
@@ -118,7 +118,7 @@
#define NF SYSCALL_NEVER_FAILS
#define MA MAX_ARGS
-static const struct_sysent sysent0[] = {
+const struct_sysent sysent0[] = {
#include "syscallent.h"
};
@@ -153,20 +153,19 @@
* in "/usr/include".
*/
-static const char *const errnoent0[] = {
+const char *const errnoent0[] = {
#include "errnoent.h"
};
-static const char *const signalent0[] = {
+const char *const signalent0[] = {
#include "signalent.h"
};
-static const struct_ioctlent ioctlent0[] = {
+const struct_ioctlent ioctlent0[] = {
#include "ioctlent.h"
};
enum { nsyscalls0 = ARRAY_SIZE(sysent0) };
enum { nerrnos0 = ARRAY_SIZE(errnoent0) };
enum { nsignals0 = ARRAY_SIZE(signalent0) };
enum { nioctlents0 = ARRAY_SIZE(ioctlent0) };
-qualbits_t qual_flags0[MAX_QUALS];
#if SUPPORTED_PERSONALITIES > 1
static const char *const errnoent1[] = {
@@ -182,7 +181,6 @@
enum { nerrnos1 = ARRAY_SIZE(errnoent1) };
enum { nsignals1 = ARRAY_SIZE(signalent1) };
enum { nioctlents1 = ARRAY_SIZE(ioctlent1) };
-qualbits_t qual_flags1[MAX_QUALS];
#endif
#if SUPPORTED_PERSONALITIES > 2
@@ -199,18 +197,60 @@
enum { nerrnos2 = ARRAY_SIZE(errnoent2) };
enum { nsignals2 = ARRAY_SIZE(signalent2) };
enum { nioctlents2 = ARRAY_SIZE(ioctlent2) };
-qualbits_t qual_flags2[MAX_QUALS];
#endif
+#if SUPPORTED_PERSONALITIES > 1
const struct_sysent *sysent = sysent0;
const char *const *errnoent = errnoent0;
const char *const *signalent = signalent0;
const struct_ioctlent *ioctlent = ioctlent0;
+#endif
unsigned nsyscalls = nsyscalls0;
unsigned nerrnos = nerrnos0;
unsigned nsignals = nsignals0;
unsigned nioctlents = nioctlents0;
-qualbits_t *qual_flags = qual_flags0;
+
+unsigned num_quals;
+qualbits_t *qual_vec[SUPPORTED_PERSONALITIES];
+
+static const unsigned nsyscall_vec[SUPPORTED_PERSONALITIES] = {
+ nsyscalls0,
+#if SUPPORTED_PERSONALITIES > 1
+ nsyscalls1,
+#endif
+#if SUPPORTED_PERSONALITIES > 2
+ nsyscalls2,
+#endif
+};
+static const struct_sysent *const sysent_vec[SUPPORTED_PERSONALITIES] = {
+ sysent0,
+#if SUPPORTED_PERSONALITIES > 1
+ sysent1,
+#endif
+#if SUPPORTED_PERSONALITIES > 2
+ sysent2,
+#endif
+};
+
+enum {
+ MAX_NSYSCALLS1 = (nsyscalls0
+#if SUPPORTED_PERSONALITIES > 1
+ > nsyscalls1 ? nsyscalls0 : nsyscalls1
+#endif
+ ),
+ MAX_NSYSCALLS2 = (MAX_NSYSCALLS1
+#if SUPPORTED_PERSONALITIES > 2
+ > nsyscalls2 ? MAX_NSYSCALLS1 : nsyscalls2
+#endif
+ ),
+ MAX_NSYSCALLS = MAX_NSYSCALLS2,
+ /* We are ready for arches with up to 255 signals,
+ * even though the largest known signo is on MIPS and it is 128.
+ * The number of existing syscalls on all arches is
+ * larger that 255 anyway, so it is just a pedantic matter.
+ */
+ MIN_QUALS = MAX_NSYSCALLS > 255 ? MAX_NSYSCALLS : 255
+};
#if SUPPORTED_PERSONALITIES > 1
unsigned current_personality;
@@ -229,42 +269,36 @@
void
set_personality(int personality)
{
+ nsyscalls = nsyscall_vec[personality];
+ sysent = sysent_vec[personality];
+
switch (personality) {
case 0:
errnoent = errnoent0;
nerrnos = nerrnos0;
- sysent = sysent0;
- nsyscalls = nsyscalls0;
ioctlent = ioctlent0;
nioctlents = nioctlents0;
signalent = signalent0;
nsignals = nsignals0;
- qual_flags = qual_flags0;
break;
case 1:
errnoent = errnoent1;
nerrnos = nerrnos1;
- sysent = sysent1;
- nsyscalls = nsyscalls1;
ioctlent = ioctlent1;
nioctlents = nioctlents1;
signalent = signalent1;
nsignals = nsignals1;
- qual_flags = qual_flags1;
break;
# if SUPPORTED_PERSONALITIES > 2
case 2:
errnoent = errnoent2;
nerrnos = nerrnos2;
- sysent = sysent2;
- nsyscalls = nsyscalls2;
ioctlent = ioctlent2;
nioctlents = nioctlents2;
signalent = signalent2;
nsignals = nsignals2;
- qual_flags = qual_flags2;
break;
# endif
}
@@ -349,71 +383,62 @@
};
static void
+reallocate_qual(int n)
+{
+ unsigned p;
+ qualbits_t *qp;
+ for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
+ qp = qual_vec[p] = realloc(qual_vec[p], n * sizeof(qualbits_t));
+ if (!qp)
+ die_out_of_memory();
+ memset(&qp[num_quals], 0, (n - num_quals) * sizeof(qualbits_t));
+ }
+ num_quals = n;
+}
+
+static void
qualify_one(int n, int bitflag, int not, int pers)
{
- if (pers == 0 || pers < 0) {
- if (not)
- qual_flags0[n] &= ~bitflag;
- else
- qual_flags0[n] |= bitflag;
- }
+ unsigned p;
-#if SUPPORTED_PERSONALITIES > 1
- if (pers == 1 || pers < 0) {
- if (not)
- qual_flags1[n] &= ~bitflag;
- else
- qual_flags1[n] |= bitflag;
- }
-#endif
+ if (num_quals <= n)
+ reallocate_qual(n + 1);
-#if SUPPORTED_PERSONALITIES > 2
- if (pers == 2 || pers < 0) {
- if (not)
- qual_flags2[n] &= ~bitflag;
- else
- qual_flags2[n] |= bitflag;
+ for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
+ if (pers == p || pers < 0) {
+ if (not)
+ qual_vec[p][n] &= ~bitflag;
+ else
+ qual_vec[p][n] |= bitflag;
+ }
}
-#endif
}
static int
qual_syscall(const char *s, int bitflag, int not)
{
- int i;
+ unsigned p;
+ unsigned i;
int rc = -1;
if (*s >= '0' && *s <= '9') {
- int i = string_to_uint(s);
- if (i < 0 || i >= MAX_QUALS)
+ i = string_to_uint(s);
+ if (i > MAX_NSYSCALLS)
return -1;
qualify_one(i, bitflag, not, -1);
return 0;
}
- for (i = 0; i < nsyscalls0; i++)
- if (sysent0[i].sys_name &&
- strcmp(s, sysent0[i].sys_name) == 0) {
- qualify_one(i, bitflag, not, 0);
- rc = 0;
- }
-#if SUPPORTED_PERSONALITIES > 1
- for (i = 0; i < nsyscalls1; i++)
- if (sysent1[i].sys_name &&
- strcmp(s, sysent1[i].sys_name) == 0) {
- qualify_one(i, bitflag, not, 1);
- rc = 0;
+ for (p = 0; p < SUPPORTED_PERSONALITIES; p++) {
+ for (i = 0; i < nsyscall_vec[p]; i++) {
+ if (sysent_vec[p][i].sys_name
+ && strcmp(s, sysent_vec[p][i].sys_name) == 0
+ ) {
+ qualify_one(i, bitflag, not, 0);
+ rc = 0;
+ }
}
-#endif
-
-#if SUPPORTED_PERSONALITIES > 2
- for (i = 0; i < nsyscalls2; i++)
- if (sysent2[i].sys_name &&
- strcmp(s, sysent2[i].sys_name) == 0) {
- qualify_one(i, bitflag, not, 2);
- rc = 0;
- }
-#endif
+ }
return rc;
}
@@ -425,7 +450,7 @@
if (*s >= '0' && *s <= '9') {
int signo = string_to_uint(s);
- if (signo < 0 || signo >= MAX_QUALS)
+ if (signo < 0 || signo > 255)
return -1;
qualify_one(signo, bitflag, not, -1);
return 0;
@@ -446,7 +471,7 @@
{
if (*s >= '0' && *s <= '9') {
int desc = string_to_uint(s);
- if (desc < 0 || desc >= MAX_QUALS)
+ if (desc < 0 || desc > 0x7fff) /* paranoia */
return -1;
qualify_one(desc, bitflag, not, -1);
return 0;
@@ -483,6 +508,9 @@
const char *p;
int i, n;
+ if (num_quals == 0)
+ reallocate_qual(MIN_QUALS);
+
opt = &qual_options[0];
for (i = 0; (p = qual_options[i].option_name); i++) {
n = strlen(p);
@@ -502,12 +530,12 @@
s = "all";
}
if (strcmp(s, "all") == 0) {
- for (i = 0; i < MAX_QUALS; i++) {
+ for (i = 0; i < num_quals; i++) {
qualify_one(i, opt->bitflag, not, -1);
}
return;
}
- for (i = 0; i < MAX_QUALS; i++) {
+ for (i = 0; i < num_quals; i++) {
qualify_one(i, opt->bitflag, !not, -1);
}
copy = strdup(s);
@@ -515,22 +543,12 @@
die_out_of_memory();
for (p = strtok(copy, ","); p; p = strtok(NULL, ",")) {
if (opt->bitflag == QUAL_TRACE && (n = lookup_class(p)) > 0) {
- for (i = 0; i < nsyscalls0; i++)
- if (sysent0[i].sys_flags & n)
- qualify_one(i, opt->bitflag, not, 0);
-
-#if SUPPORTED_PERSONALITIES > 1
- for (i = 0; i < nsyscalls1; i++)
- if (sysent1[i].sys_flags & n)
- qualify_one(i, opt->bitflag, not, 1);
-#endif
-
-#if SUPPORTED_PERSONALITIES > 2
- for (i = 0; i < nsyscalls2; i++)
- if (sysent2[i].sys_flags & n)
- qualify_one(i, opt->bitflag, not, 2);
-#endif
-
+ unsigned pers;
+ for (pers = 0; pers < SUPPORTED_PERSONALITIES; pers++) {
+ for (i = 0; i < nsyscall_vec[pers]; i++)
+ if (sysent_vec[pers][i].sys_flags & n)
+ qualify_one(i, opt->bitflag, not, 0);
+ }
continue;
}
if (opt->qualify(p, opt->bitflag, not)) {
@@ -2336,7 +2354,7 @@
if (syserror(tcp))
return;
- if ((unsigned long) tcp->u_arg[0] >= MAX_QUALS)
+ if ((unsigned long) tcp->u_arg[0] >= num_quals)
return;
func = tcp->s_ent->sys_func;
if (func == printargs)