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Stop using a large static buffer in getfdpath

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text	   data	    bss	    dec	    hex	filename
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Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2013-03-06 18:24:34 +01:00
parent 7672946e74
commit 61ad0a401c
3 changed files with 18 additions and 15 deletions
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2
defs.h
View File

@ -605,7 +605,7 @@ extern const char *signame(int);
extern int is_restart_error(struct tcb *);
extern void pathtrace_select(const char *);
extern int pathtrace_match(struct tcb *);
extern const char *getfdpath(struct tcb *, int);
extern int getfdpath(struct tcb *, int, char *, unsigned);
extern const char *xlookup(const struct xlat *, int);

25
pathtrace.c
View File

@ -73,9 +73,10 @@ upathmatch(struct tcb *tcp, unsigned long upath)
static int
fdmatch(struct tcb *tcp, int fd)
{
const char *path = getfdpath(tcp, fd);
char path[PATH_MAX + 1];
int n = getfdpath(tcp, fd, path, sizeof(path));
return path && pathmatch(path);
return n >= 0 && pathmatch(path);
}
/*
@ -100,22 +101,24 @@ storepath(const char *path)
/*
* Get path associated with fd.
*/
const char *
getfdpath(struct tcb *tcp, int fd)
int
getfdpath(struct tcb *tcp, int fd, char *buf, unsigned bufsize)
{
static char path[PATH_MAX+1];
char linkpath[sizeof("/proc/%u/fd/%u") + 2 * sizeof(int)*3];
ssize_t n;
if (fd < 0)
return NULL;
return -1;
sprintf(linkpath, "/proc/%u/fd/%u", tcp->pid, fd);
n = readlink(linkpath, path, (sizeof path) - 1);
if (n <= 0)
return NULL;
path[n] = '\0';
return path;
n = readlink(linkpath, buf, bufsize - 1);
/*
* NB: if buf is too small, readlink doesn't fail,
* it returns truncated result (IOW: n == bufsize - 1).
*/
if (n >= 0)
buf[n] = '\0';
return n;
}
/*

6
util.c
View File

@ -353,10 +353,10 @@ printnum_int(struct tcb *tcp, long addr, const char *fmt)
void
printfd(struct tcb *tcp, int fd)
{
const char *p;
char path[PATH_MAX + 1];
if (show_fd_path && (p = getfdpath(tcp, fd)))
tprintf("%d<%s>", fd, p);
if (show_fd_path && getfdpath(tcp, fd, path, sizeof(path)) >= 0)
tprintf("%d<%s>", fd, path);
else
tprintf("%d", fd);
}