# gedit arch/arm/kernel/sys_arm.c———————————————————–asmlinkage long sys_arm_fadvise64_64(int fd, int advice, loff_t offset, loff_t len){ return sys_fadvise64_64(fd, offset, len, advice);}
asmlinkage int sys_kmd(unsigned int p_addr){ printk(“p_addr = 0x%x\n”, p_addr); return p_addr;}
# gedit include/asm-arm/unistd.h———————————————————–#define __NR_fallocate (__NR_SYSCALL_BASE+352)#define __NR_kmd (__NR_SYSCALL_BASE+353)
# gedit arch/arm/kernel/calls.S———————————————————– CALL(sys_fallocate) CALL(sys_kmd)
测试提供调用———————————————————–#define _GNU_SOURCE /* or _BSD_SOURCE or _SVID_SOURCE */#include <unistd.h>#include <sys/syscall.h> /* For SYS_xxx definitions */
#define __NR_kmd (__NR_SYSCALL_BASE+353)
int kmd (unsigned int p_addr){ syscall (__NR_kmd, p_addr); return 0;}
int main (){ kmd (0x100000);}
# arm-linux-gcc kmd.c -static# cp a.out /tftpboot/# tftp -g -r a.out 192.168.1.160# ./a.out p_addr = 0x100000
#if 1#define DISP_LINE_LEN (16)#define MAX_LINE_LENGTH_BYTES (64)#define DEFAULT_LINE_LENGTH_BYTES (16)
#define int8_t char#define int16_t short#define int32_t long#define int64_t long long#define uint8_t u_char#define uint16_t u_short#define uint32_t u_long#define uint64_t unsigned long long#define t_scalar_t int#define t_uscalar_t unsigned int#define uintptr_t unsigned long
/** Print data buffer in hex and ascii form to the terminal.** data reads are buffered so that each memory address is only read once.* Useful when displaying the contents of volatile registers.** parameters:* addr: Starting address to display at start of line* data: pointer to data buffer* width: data value width. May be 1, 2, or 4.* count: number of values to display* linelen: Number of values to print per line; specify 0 for default length*/int print_buffer (ulong addr, void *data, uint width, uint count, uint linelen){ uint8_t linebuf[MAX_LINE_LENGTH_BYTES]; uint32_t *uip = (void *) linebuf; uint16_t *usp = (void *) linebuf; uint8_t *ucp = (void *) linebuf; int i; if (linelen * width > MAX_LINE_LENGTH_BYTES) linelen = MAX_LINE_LENGTH_BYTES / width; if (linelen < 1) linelen = DEFAULT_LINE_LENGTH_BYTES / width; while (count) { printk (“%08lx:”, addr);
/* check for overflow condition */ if (count < linelen) linelen = count;
/* Copy from memory into linebuf and print hex values */ for (i = 0; i < linelen; i++) { if (width == 4) { uip[i] = *(volatile uint32_t *) data; printk (” %08x”, (unsigned int)uip[i]); } else if (width == 2) { usp[i] = *(volatile uint16_t *) data; printk (” %04x”, usp[i]); } else { ucp[i] = *(volatile uint8_t *) data; printk (” %02x”, ucp[i]); } data += width; }
#if 0 /* Print data in ASCII characters */ printk (” “); for (i = 0; i < linelen * width; i++) fputc (isprint (ucp[i]) && (ucp[i] < 0x80) ? ucp[i] : ‘.’, stdout);
fputc (‘\n’, stdout);#endif printk(“\n”); /* update references */ addr += linelen * width; count -= linelen; } return 0;}
asmlinkage int sys_kmd(unsigned int v_addr){ ulong length = 64, p_addr = 0, size = 4; if (0 == v_addr) { printk(“v_addr = %x\n”, (unsigned int)v_addr); return -1; } p_addr = virt_to_phys((void *)v_addr); printk(“v_addr <–> p_addr\n”); printk(“%08x <–> %08x\n”, (unsigned int)v_addr, (unsigned int)p_addr); print_buffer (v_addr, (void *) v_addr, size, length, DISP_LINE_LEN / size);
return 0;} #endif
，可偏偏。多么温柔，一出口便是相互指责和嘲讽。
