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MFD_EXEC is unknown in older Ubuntu linux

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modified:   stub/src/include/linux.h
	modified:   stub/src/upxfd_android.c
This commit is contained in:
John Reiser 2024-07-30 14:18:38 -07:00
parent 05db054fb9
commit 7a3033c150
2 changed files with 21 additions and 2 deletions
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2
src/stub/src/include/linux.h
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@ -568,7 +568,7 @@ off_t lseek(int fd, off_t offset, int whence);
int memfd_create(char const *, unsigned);
int munmap(void *, size_t);
int mprotect(void const *, size_t, int);
int open(char const *, unsigned, unsigned);
int open(char const *, int, int);
int openat(int fd, char const *, unsigned, unsigned);
ssize_t read(int, void *, size_t);
int unlink(char const *);

21
src/stub/src/upxfd_android.c
View File

@ -134,11 +134,13 @@ struct stat { // __NR_stat = 106 + NR_SYSCALL_BASE
#define NO_WANT_OPEN 1
#define NO_WANT_READ 1
#include "include/linux.h" // syscalls; i386 inlines via "int 0x80"
extern int open(char const *, int, int);
extern int fstatat(int dirfd, const char *restrict pathname,
struct stat *restrict statbuf, int flags);
#define ENOENT 2 /* no such name */
#define EINVAL 22 /* invalid arguemnt */
#define ENOSPC 28 /* no space left on device */
#define ENOSYS 38 /* no such system call */
@ -272,6 +274,10 @@ static int strncmplc(char const *s1, char const *s2, unsigned n)
#define ANDROID_TEST 0
#define MFD_EXEC 0x10
//#define O_RDWR 2
#define O_DIRECTORY 0200000 /* 0x010000 */
#define O_TMPFILE 020000000 /* 0x400000 */
extern int memfd_create(char const *name, unsigned flags);
extern int ftruncate(int fd, size_t length);
extern ssize_t write(int fd, void const *buf, size_t length);
@ -287,7 +293,20 @@ unsigned long upx_mmap_and_fd( // returns (mapped_addr | (1+ fd))
unsigned long addr = 0; // for result
// Early 32-bit Android did not implement memfd_create
int fd = (ANDROID_TEST ? -ENOSYS : memfd_create(addr_string("upx"), MFD_EXEC));
int fd = -ENOSYS;
if (!ANDROID_TEST) {
char const *name = addr_string("upx");
fd = memfd_create(name, MFD_EXEC);
if (-EINVAL == fd) { // MFD_EXEC unknown to ubuntu-20.04
fd = memfd_create(name, 0); // try again
}
if (fd < 0) { // last chance for Linux
fd = open(addr_string("/dev/shm"), O_RDWR | O_DIRECTORY | O_TMPFILE, 0700);
if (fd < 0) {
my_bkpt(addr_string("memfd_create"));
}
}
}
#if ANDROID_FRIEND //{
// Varying __NR_ftruncate on Android can hurt even if memfd_create() succeeds.