diff options
Diffstat (limited to 'util.c')
-rw-r--r-- | util.c | 81 |
1 files changed, 28 insertions, 53 deletions
@@ -155,24 +155,46 @@ out: return p; } +#ifdef USE_MMAP +static void safe_memcpy(void *dest, const void *src, size_t n) +{ +#ifdef USE_SLOW_MEMCPY + size_t i; + + for (i = 0; i < n; i++) + *((u8 *)dest + i) = *((const u8 *)src + i); +#else + memcpy(dest, src, n); +#endif /* USE_SLOW_MEMCPY */ +} +#endif /* USE_MMAP */ + /* * Copy a physical memory chunk into a memory buffer. * This function allocates memory. */ void *mem_chunk(off_t base, size_t len, const char *devmem) { - void *p; + struct stat statbuf; + void *p = NULL; int fd; #ifdef USE_MMAP - struct stat statbuf; off_t mmoffset; void *mmp; #endif - if ((fd = open(devmem, O_RDONLY)) == -1) + /* + * Safety check: if running as root, devmem is expected to be a + * character device file. + */ + if ((fd = open(devmem, O_RDONLY)) == -1 + || fstat(fd, &statbuf) == -1 + || (geteuid() == 0 && !S_ISCHR(statbuf.st_mode))) { - perror(devmem); - return NULL; + fprintf(stderr, "Can't read memory from %s\n", devmem); + if (fd == -1) + return NULL; + goto out; } if ((p = malloc(len)) == NULL) @@ -182,13 +204,6 @@ void *mem_chunk(off_t base, size_t len, const char *devmem) } #ifdef USE_MMAP - if (fstat(fd, &statbuf) == -1) - { - fprintf(stderr, "%s: ", devmem); - perror("stat"); - goto err_free; - } - /* * mmap() will fail with SIGBUS if trying to map beyond the end of * the file. @@ -214,7 +229,7 @@ void *mem_chunk(off_t base, size_t len, const char *devmem) if (mmp == MAP_FAILED) goto try_read; - memcpy(p, (u8 *)mmp + mmoffset, len); + safe_memcpy(p, (u8 *)mmp + mmoffset, len); if (munmap(mmp, mmoffset + len) == -1) { @@ -247,46 +262,6 @@ out: return p; } -int write_dump(size_t base, size_t len, const void *data, const char *dumpfile, int add) -{ - FILE *f; - - f = fopen(dumpfile, add ? "r+b" : "wb"); - if (!f) - { - fprintf(stderr, "%s: ", dumpfile); - perror("fopen"); - return -1; - } - - if (fseek(f, base, SEEK_SET) != 0) - { - fprintf(stderr, "%s: ", dumpfile); - perror("fseek"); - goto err_close; - } - - if (fwrite(data, len, 1, f) != 1) - { - fprintf(stderr, "%s: ", dumpfile); - perror("fwrite"); - goto err_close; - } - - if (fclose(f)) - { - fprintf(stderr, "%s: ", dumpfile); - perror("fclose"); - return -1; - } - - return 0; - -err_close: - fclose(f); - return -1; -} - /* Returns end - start + 1, assuming start < end */ u64 u64_range(u64 start, u64 end) { |