git/git-compat-util.h
Shawn O. Pearce c4712e4553 Replace mmap with xmmap, better handling MAP_FAILED.
In some cases we did not even bother to check the return value of
mmap() and just assume it worked.  This is bad, because if we are
out of virtual address space the kernel returned MAP_FAILED and we
would attempt to dereference that address, segfaulting without any
real error output to the user.

We are replacing all calls to mmap() with xmmap() and moving all
MAP_FAILED checking into that single location.  If a mmap call
fails we try to release enough least-recently-used pack windows
to possibly succeed, then retry the mmap() attempt.  If we cannot
mmap even after releasing pack memory then we die() as none of our
callers have any reasonable recovery strategy for a failed mmap.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-29 11:36:45 -08:00

260 lines
5.9 KiB
C

#ifndef GIT_COMPAT_UTIL_H
#define GIT_COMPAT_UTIL_H
#ifndef FLEX_ARRAY
#if defined(__GNUC__) && (__GNUC__ < 3)
#define FLEX_ARRAY 0
#else
#define FLEX_ARRAY /* empty */
#endif
#endif
#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
#if !defined(__APPLE__) && !defined(__FreeBSD__)
#define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
#define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
#endif
#define _GNU_SOURCE
#define _BSD_SOURCE
#include <unistd.h>
#include <stdio.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <sys/param.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/time.h>
#include <time.h>
#include <signal.h>
#include <sys/wait.h>
#include <fnmatch.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <assert.h>
#include <regex.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <pwd.h>
#include <grp.h>
#ifndef NO_ICONV
#include <iconv.h>
#endif
/* On most systems <limits.h> would have given us this, but
* not on some systems (e.g. GNU/Hurd).
*/
#ifndef PATH_MAX
#define PATH_MAX 4096
#endif
#ifdef __GNUC__
#define NORETURN __attribute__((__noreturn__))
#else
#define NORETURN
#ifndef __attribute__
#define __attribute__(x)
#endif
#endif
/* General helper functions */
extern void usage(const char *err) NORETURN;
extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
extern void warn(const char *err, ...) __attribute__((format (printf, 1, 2)));
extern void set_usage_routine(void (*routine)(const char *err) NORETURN);
extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN);
extern void set_error_routine(void (*routine)(const char *err, va_list params));
extern void set_warn_routine(void (*routine)(const char *warn, va_list params));
#ifdef NO_MMAP
#ifndef PROT_READ
#define PROT_READ 1
#define PROT_WRITE 2
#define MAP_PRIVATE 1
#define MAP_FAILED ((void*)-1)
#endif
#define mmap git_mmap
#define munmap git_munmap
extern void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
extern int git_munmap(void *start, size_t length);
#define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
#else /* NO_MMAP */
#include <sys/mman.h>
#define DEFAULT_PACKED_GIT_WINDOW_SIZE (32 * 1024 * 1024)
#endif /* NO_MMAP */
#define DEFAULT_PACKED_GIT_LIMIT (256 * 1024 * 1024)
#ifdef NO_SETENV
#define setenv gitsetenv
extern int gitsetenv(const char *, const char *, int);
#endif
#ifdef NO_UNSETENV
#define unsetenv gitunsetenv
extern void gitunsetenv(const char *);
#endif
#ifdef NO_STRCASESTR
#define strcasestr gitstrcasestr
extern char *gitstrcasestr(const char *haystack, const char *needle);
#endif
#ifdef NO_STRLCPY
#define strlcpy gitstrlcpy
extern size_t gitstrlcpy(char *, const char *, size_t);
#endif
extern void release_pack_memory(size_t);
static inline char* xstrdup(const char *str)
{
char *ret = strdup(str);
if (!ret) {
release_pack_memory(strlen(str) + 1);
ret = strdup(str);
if (!ret)
die("Out of memory, strdup failed");
}
return ret;
}
static inline void *xmalloc(size_t size)
{
void *ret = malloc(size);
if (!ret && !size)
ret = malloc(1);
if (!ret) {
release_pack_memory(size);
ret = malloc(size);
if (!ret && !size)
ret = malloc(1);
if (!ret)
die("Out of memory, malloc failed");
}
#ifdef XMALLOC_POISON
memset(ret, 0xA5, size);
#endif
return ret;
}
static inline void *xrealloc(void *ptr, size_t size)
{
void *ret = realloc(ptr, size);
if (!ret && !size)
ret = realloc(ptr, 1);
if (!ret) {
release_pack_memory(size);
ret = realloc(ptr, size);
if (!ret && !size)
ret = realloc(ptr, 1);
if (!ret)
die("Out of memory, realloc failed");
}
return ret;
}
static inline void *xcalloc(size_t nmemb, size_t size)
{
void *ret = calloc(nmemb, size);
if (!ret && (!nmemb || !size))
ret = calloc(1, 1);
if (!ret) {
release_pack_memory(nmemb * size);
ret = calloc(nmemb, size);
if (!ret && (!nmemb || !size))
ret = calloc(1, 1);
if (!ret)
die("Out of memory, calloc failed");
}
return ret;
}
static inline void *xmmap(void *start, size_t length,
int prot, int flags, int fd, off_t offset)
{
void *ret = mmap(start, length, prot, flags, fd, offset);
if (ret == MAP_FAILED) {
release_pack_memory(length);
ret = mmap(start, length, prot, flags, fd, offset);
if (ret == MAP_FAILED)
die("Out of memory? mmap failed: %s", strerror(errno));
}
return ret;
}
static inline ssize_t xread(int fd, void *buf, size_t len)
{
ssize_t nr;
while (1) {
nr = read(fd, buf, len);
if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
continue;
return nr;
}
}
static inline ssize_t xwrite(int fd, const void *buf, size_t len)
{
ssize_t nr;
while (1) {
nr = write(fd, buf, len);
if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
continue;
return nr;
}
}
static inline int has_extension(const char *filename, const char *ext)
{
size_t len = strlen(filename);
size_t extlen = strlen(ext);
return len > extlen && !memcmp(filename + len - extlen, ext, extlen);
}
/* Sane ctype - no locale, and works with signed chars */
#undef isspace
#undef isdigit
#undef isalpha
#undef isalnum
#undef tolower
#undef toupper
extern unsigned char sane_ctype[256];
#define GIT_SPACE 0x01
#define GIT_DIGIT 0x02
#define GIT_ALPHA 0x04
#define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
#define isspace(x) sane_istest(x,GIT_SPACE)
#define isdigit(x) sane_istest(x,GIT_DIGIT)
#define isalpha(x) sane_istest(x,GIT_ALPHA)
#define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
#define tolower(x) sane_case((unsigned char)(x), 0x20)
#define toupper(x) sane_case((unsigned char)(x), 0)
static inline int sane_case(int x, int high)
{
if (sane_istest(x, GIT_ALPHA))
x = (x & ~0x20) | high;
return x;
}
#endif