patch-1.3.22 linux/arch/alpha/kernel/ptrace.c
Next file: linux/arch/alpha/kernel/setup.c
Previous file: linux/arch/alpha/kernel/process.c
Back to the patch index
Back to the overall index
- Lines: 708
- Date:
Tue Aug 29 10:15:48 1995
- Orig file:
v1.3.21/linux/arch/alpha/kernel/ptrace.c
- Orig date:
Sun Aug 13 14:45:27 1995
diff -u --recursive --new-file v1.3.21/linux/arch/alpha/kernel/ptrace.c linux/arch/alpha/kernel/ptrace.c
@@ -2,6 +2,7 @@
/* By Ross Biro 1/23/92 */
/* edited by Linus Torvalds */
/* mangled further by Bob Manson ([email protected]) */
+/* more mutilation by David Mosberger ([email protected]) */
#include <linux/head.h>
#include <linux/kernel.h>
@@ -21,8 +22,9 @@
#ifdef DEBUG
enum {
- DBG_MEM = (1<<0),
- DBG_BPT = (1<<1)
+ DBG_MEM = (1<<0),
+ DBG_BPT = (1<<1),
+ DBG_MEM_ALL = (1<<2)
};
int debug_mask = DBG_BPT;
@@ -35,49 +37,74 @@
#define BREAKINST 0x00000080 /* call_pal bpt */
-/* This was determined via brute force. */
-#define MAGICNUM 496
-
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
-/* A mapping between register number and its offset on the kernel stack.
- * You also need to add MAGICNUM to get past the kernel stack frame
- * to the actual saved user info.
- * The first portion is the switch_stack, then comes the pt_regs.
- * 320 is the size of the switch_stack area.
+/*
+ * Processes always block with the following stack-layout:
+ *
+ * +================================+ --------------------------
+ * | PALcode saved frame (ps, pc, | ^ ^
+ * | gp, a0, a1, a2) | | |
+ * +================================+ | struct pt_regs |
+ * | | | |
+ * | frame generated by SAVE_ALL | | |
+ * | | v | P
+ * +================================+ | A
+ * | | ^ | G
+ * | frame saved by do_switch_stack | | struct switch_stack | E
+ * | | v | _
+ * +================================+ | S
+ * | | | I
+ * | | | Z
+ * / / | E
+ * / / |
+ * | | |
+ * | | |
+ * | | v
+ * +================================+ <-------------------------
+ * task->kernel_stack_page
+ */
+#define PT_REG(reg) (PAGE_SIZE - sizeof(struct pt_regs) \
+ + (long)&((struct pt_regs *)0)->reg)
+#define SW_REG(reg) (PAGE_SIZE - sizeof(struct pt_regs) \
+ - sizeof(struct switch_stack) \
+ + (long)&((struct switch_stack *)0)->reg)
+/*
+ * The following table maps a register index into the stack offset at
+ * which the register is saved. Register indices are 0-31 for integer
+ * regs, 32-63 for fp regs, and 64 for the pc. Notice that sp and
+ * zero have no stack-slot and need to be treated specially (see
+ * get_reg/put_reg below).
*/
-
enum {
- REG_R0 = 0,
- REG_F0 = 32,
- REG_PC = 64
+ REG_R0 = 0, REG_F0 = 32, REG_PC = 64
};
-static int map_reg_to_offset[] = {
- 320+0,320+8,320+16,320+24,320+32,320+40,320+48,320+56,320+64, /* 0-8 */
- 0,8,16,24,32,40,48, /* 9-15 */
- 320+184,320+192,320+200, /* 16-18 */
- 320+72,320+80,320+88,320+96,320+104,320+112,320+120, /* 19-25 */
- 320+128,320+136,320+144,320+176,320+160,-1, /* 26-31*/
-
- /* fp registers below */
- 64,72,80,88,96,104,112,120,128,136,144,152,160,168,176,184,192,
- 200,208,216,224,232,240,248,256,264,272,280,288,296,304,312,
-
- /* 64 = pc */
- 320+168
+static unsigned short regoff[] = {
+ PT_REG( r0), PT_REG( r1), PT_REG( r2), PT_REG( r3),
+ PT_REG( r4), PT_REG( r5), PT_REG( r6), PT_REG( r7),
+ PT_REG( r8), SW_REG( r9), SW_REG( r10), SW_REG( r11),
+ SW_REG( r12), SW_REG( r13), SW_REG( r14), SW_REG( r15),
+ PT_REG( r16), PT_REG( r17), PT_REG( r18), PT_REG( r19),
+ PT_REG( r20), PT_REG( r21), PT_REG( r22), PT_REG( r23),
+ PT_REG( r24), PT_REG( r25), PT_REG( r26), PT_REG( r27),
+ PT_REG( r28), PT_REG( gp), -1, -1,
+ SW_REG(fp[ 0]), SW_REG(fp[ 1]), SW_REG(fp[ 2]), SW_REG(fp[ 3]),
+ SW_REG(fp[ 4]), SW_REG(fp[ 5]), SW_REG(fp[ 6]), SW_REG(fp[ 7]),
+ SW_REG(fp[ 8]), SW_REG(fp[ 9]), SW_REG(fp[10]), SW_REG(fp[11]),
+ SW_REG(fp[12]), SW_REG(fp[13]), SW_REG(fp[14]), SW_REG(fp[15]),
+ SW_REG(fp[16]), SW_REG(fp[17]), SW_REG(fp[18]), SW_REG(fp[19]),
+ SW_REG(fp[20]), SW_REG(fp[21]), SW_REG(fp[22]), SW_REG(fp[23]),
+ SW_REG(fp[24]), SW_REG(fp[25]), SW_REG(fp[26]), SW_REG(fp[27]),
+ SW_REG(fp[28]), SW_REG(fp[29]), SW_REG(fp[30]), SW_REG(fp[31]),
+ PT_REG( pc)
};
-static int offset_of_register(int reg_num)
-{
- if (reg_num < 0 || reg_num > 64) {
- return -1;
- }
- return map_reg_to_offset[reg_num];
-}
+static long zero;
+
/* change a pid into a task struct. */
static inline struct task_struct * get_task(int pid)
@@ -92,36 +119,38 @@
}
/*
- * this routine will get a word off of the processes privileged stack.
- * the offset is how far from the base addr as stored in the TSS.
- * this routine assumes that all the privileged stacks are in our
- * data space.
- * MAGICNUM is the amount to skip to get to the actual user regs. It
- * was determined by brute force & asking BufElves.
- */
-static inline long get_stack_long(struct task_struct *task, unsigned long offset)
+ * Get contents of register REGNO in task TASK.
+ */
+static inline long get_reg(struct task_struct * task, long regno)
{
- unsigned char *stack;
+ long *addr;
- stack = (unsigned char *)task->tss.ksp;
- stack += offset+MAGICNUM;
- return (*((long *)stack));
+ if (regno == 30) {
+ addr = &task->tss.usp;
+ } else if (regno == 31) {
+ zero = 0;
+ addr = &zero;
+ } else {
+ addr = (long *) (task->kernel_stack_page + regoff[regno]);
+ }
+ return *addr;
}
/*
- * this routine will put a word on the processes privileged stack.
- * the offset is how far from the base addr as stored in the TSS.
- * this routine assumes that all the privileged stacks are in our
- * data space.
+ * Write contents of register REGNO in task TASK.
*/
-static inline int put_stack_long(struct task_struct *task, unsigned long offset,
- unsigned long data)
+static inline int put_reg(struct task_struct *task, long regno, long data)
{
- unsigned char * stack;
+ long *addr, zero;
- stack = (unsigned char *) task->tss.ksp;
- stack += offset+MAGICNUM;
- *(unsigned long *) stack = data;
+ if (regno == 30) {
+ addr = &task->tss.usp;
+ } else if (regno == 31) {
+ addr = &zero;
+ } else {
+ addr = (long *) (task->kernel_stack_page + regoff[regno]);
+ }
+ *addr = data;
return 0;
}
@@ -138,7 +167,7 @@
pte_t * pgtable;
unsigned long page;
- DBG(DBG_MEM, ("Getting long at 0x%lx\n", addr));
+ DBG(DBG_MEM_ALL, ("getting long at 0x%lx\n", addr));
repeat:
pgdir = pgd_offset(vma->vm_task, addr);
if (pgd_none(*pgdir)) {
@@ -226,11 +255,12 @@
*(unsigned long *) (page + (addr & ~PAGE_MASK)) = data;
/* we're bypassing pagetables, so we have to set the dirty bit ourselves */
/* this should also re-instate whatever read-only mode there was before */
- *pgtable = pte_mkdirty(mk_pte(page, vma->vm_page_prot));
+ set_pte(pgtable, pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
invalidate();
}
-static struct vm_area_struct * find_extend_vma(struct task_struct * tsk, unsigned long addr)
+static struct vm_area_struct * find_extend_vma(struct task_struct * tsk,
+ unsigned long addr)
{
struct vm_area_struct * vma;
@@ -258,57 +288,35 @@
{
struct vm_area_struct * vma = find_extend_vma(tsk, addr);
- DBG(DBG_MEM, ("in read_long\n"));
+ DBG(DBG_MEM_ALL, ("in read_long\n"));
if (!vma) {
printk("Unable to find vma for addr 0x%lx\n",addr);
return -EIO;
}
- if ((addr & ~PAGE_MASK) > (PAGE_SIZE-sizeof(long))) {
- unsigned long low,high;
+ if ((addr & ~PAGE_MASK) > (PAGE_SIZE - sizeof(long))) {
struct vm_area_struct * vma_high = vma;
+ unsigned long low, align;
if (addr + sizeof(long) >= vma->vm_end) {
vma_high = vma->vm_next;
if (!vma_high || vma_high->vm_start != vma->vm_end)
return -EIO;
}
- low = get_long(vma, addr & ~(sizeof(long)-1));
- high = get_long(vma_high, (addr+sizeof(long)) & ~(sizeof(long)-1));
- switch (addr & (sizeof(long)-1)) {
- case 1:
- low >>= 8;
- low |= high << 56;
- break;
- case 2:
- low >>= 16;
- low |= high << 48;
- break;
- case 3:
- low >>= 24;
- low |= high << 40;
- break;
- case 4:
- low >>= 32;
- low |= high << 32;
- break;
- case 5:
- low >>= 40;
- low |= high << 24;
- break;
- case 6:
- low >>= 48;
- low |= high << 16;
- break;
- case 7:
- low >>= 56;
- low |= high << 8;
- break;
+ align = addr & (sizeof(long) - 1);
+ addr -= align;
+ low = get_long(vma, addr);
+ if (align) {
+ unsigned long high;
+
+ high = get_long(vma_high, addr + sizeof(long));
+ low >>= align * 8;
+ low |= high << (64 - align * 8);
}
*result = low;
} else {
- long l =get_long(vma, addr);
+ long l = get_long(vma, addr);
- DBG(DBG_MEM, ("value is 0x%lx\n",l));
+ DBG(DBG_MEM_ALL, ("value is 0x%lx\n", l));
*result = l;
}
return 0;
@@ -326,7 +334,7 @@
if (!vma)
return -EIO;
if ((addr & ~PAGE_MASK) > PAGE_SIZE-sizeof(long)) {
- unsigned long low,high;
+ unsigned long low, high, align;
struct vm_area_struct * vma_high = vma;
if (addr + sizeof(long) >= vma->vm_end) {
@@ -334,58 +342,16 @@
if (!vma_high || vma_high->vm_start != vma->vm_end)
return -EIO;
}
- low = get_long(vma, addr & ~(sizeof(long)-1));
- high = get_long(vma_high, (addr+sizeof(long)) & ~(sizeof(long)-1));
- switch (addr & (sizeof(long)-1)) {
- case 0: /* shouldn't happen, but safety first */
- low = data;
- break;
- case 1:
- low &= 0x00000000000000ffL;
- low |= data << 8;
- high &= ~0x000000000000ffL;
- high |= data >> 56;
- break;
- case 2:
- low &= 0x000000000000ffffL;
- low |= data << 16;
- high &= ~0x0000000000ffffL;
- high |= data >> 48;
- break;
- case 3:
- low &= 0x0000000000ffffffL;
- low |= data << 24;
- high &= ~0x00000000ffffffL;
- high |= data >> 40;
- break;
- case 4:
- low &= 0x00000000ffffffffL;
- low |= data << 32;
- high &= ~0x000000ffffffffL;
- high |= data >> 32;
- break;
-
- case 5:
- low &= 0x000000ffffffffffL;
- low |= data << 40;
- high &= ~0x0000ffffffffffL;
- high |= data >> 24;
- break;
- case 6:
- low &= 0x0000ffffffffffffL;
- low |= data << 48;
- high &= ~0x00ffffffffffffL;
- high |= data >> 16;
- break;
- case 7:
- low &= 0x00ffffffffffffffL;
- low |= data << 56;
- high &= ~0xffffffffffffffL;
- high |= data >> 8;
- break;
- }
- put_long(vma, addr & ~(sizeof(long)-1),low);
- put_long(vma_high, (addr+sizeof(long)) & ~(sizeof(long)-1),high);
+ align = addr & (sizeof(long) - 1);
+ addr -= align;
+ low = get_long(vma, addr);
+ high = get_long(vma_high, addr + sizeof(long));
+ low &= ~0UL >> (64 - align * 8);
+ high &= ~0UL << (align * 8);
+ low |= data << (align * 8);
+ high |= data >> (64 - align * 8);
+ put_long(vma, addr, low);
+ put_long(vma_high, addr + sizeof(long), high);
} else
put_long(vma, addr, data);
return 0;
@@ -394,7 +360,8 @@
/*
* Read a 32bit int from address space TSK.
*/
-static int read_int(struct task_struct * tsk, unsigned long addr, unsigned int *data)
+static int read_int(struct task_struct * tsk, unsigned long addr,
+ unsigned int *data)
{
unsigned long l, align;
int res;
@@ -420,7 +387,8 @@
* For simplicity, do a read-modify-write of the 64bit word that
* contains the 32bit word that we are about to write.
*/
-static int write_int(struct task_struct * tsk, unsigned long addr, unsigned int data)
+static int write_int(struct task_struct * tsk, unsigned long addr,
+ unsigned int data)
{
unsigned long l, align;
int res;
@@ -441,36 +409,15 @@
}
/*
- * Uh, this does ugly stuff. It stores the specified value in the a3
- * register. entry.S will swap a3 and the returned value from
- * sys_ptrace() before returning to the user.
- */
-
-static inline void set_success(struct pt_regs *regs,long resval)
-{
- regs->r19 = resval;
-}
-
-/*
- * This doesn't do diddly, actually--if the value returned from
- * sys_ptrace() is != 0, it sets things up properly.
- */
-
-static inline void set_failure(struct pt_regs *regs, long errcode)
-{
- regs->r19 = 0;
-}
-
-/*
* Set breakpoint.
*/
-static int set_bpt(struct task_struct *child)
+int ptrace_set_bpt(struct task_struct * child)
{
- int displ, i, res, reg_b, off, nsaved = 0;
+ int displ, i, res, reg_b, nsaved = 0;
u32 insn, op_code;
unsigned long pc;
- pc = get_stack_long(child, map_reg_to_offset[REG_PC]);
+ pc = get_reg(child, REG_PC);
res = read_int(child, pc, &insn);
if (res < 0)
return res;
@@ -487,22 +434,12 @@
*/
displ = ((s32)(insn << 11)) >> 9;
child->debugreg[nsaved++] = pc + 4;
- if (displ) /* guard against unoptimized code */
+ if (displ) /* guard against unoptimized code */
child->debugreg[nsaved++] = pc + 4 + displ;
DBG(DBG_BPT, ("execing branch\n"));
} else if (op_code == 0x1a) {
reg_b = (insn >> 16) & 0x1f;
- off = offset_of_register(reg_b);
- if (off >= 0) {
- child->debugreg[nsaved++] = get_stack_long(child, off);
- } else {
- /* $31 (aka zero) doesn't have a stack-slot */
- if (reg_b == 31) {
- child->debugreg[nsaved++] = 0;
- } else {
- return -EIO;
- }
- }
+ child->debugreg[nsaved++] = get_reg(child, reg_b);
DBG(DBG_BPT, ("execing jump\n"));
} else {
child->debugreg[nsaved++] = pc + 4;
@@ -524,7 +461,11 @@
return 0;
}
-int ptrace_cancel_bpt(struct task_struct *child)
+/*
+ * Ensure no single-step breakpoint is pending. Returns non-zero
+ * value if child was being single-stepped.
+ */
+int ptrace_cancel_bpt(struct task_struct * child)
{
int i, nsaved = child->debugreg[4];
@@ -538,56 +479,43 @@
for (i = 0; i < nsaved; ++i) {
write_int(child, child->debugreg[i], child->debugreg[i + 2]);
}
- return nsaved;
+ return (nsaved != 0);
}
-asmlinkage long sys_ptrace(long request, long pid, long addr, long data, int a4, int a5,
- struct pt_regs regs)
+asmlinkage long sys_ptrace(long request, long pid, long addr, long data,
+ int a4, int a5, struct pt_regs regs)
{
struct task_struct *child;
struct user * dummy;
- int res;
dummy = NULL;
- DBG(DBG_MEM, ("request=%ld pid=%ld addr=0x%lx data=0x%lx\n",request,pid,addr,data));
- set_success(®s,0);
+ DBG(DBG_MEM, ("request=%ld pid=%ld addr=0x%lx data=0x%lx\n",
+ request, pid, addr, data));
if (request == PTRACE_TRACEME) {
/* are we already being traced? */
- if (current->flags & PF_PTRACED) {
- set_failure(®s,-EPERM);
+ if (current->flags & PF_PTRACED)
return -EPERM;
- }
/* set the ptrace bit in the process flags. */
current->flags |= PF_PTRACED;
return 0;
}
- if (pid == 1) { /* you may not mess with init */
- set_failure(®s,-EPERM);
+ if (pid == 1) /* you may not mess with init */
return -EPERM;
- }
- if (!(child = get_task(pid))) {
- set_failure(®s,-ESRCH);
+ if (!(child = get_task(pid)))
return -ESRCH;
- }
if (request == PTRACE_ATTACH) {
- if (child == current) {
- set_failure(®s,-EPERM);
+ if (child == current)
return -EPERM;
- }
if ((!child->dumpable ||
(current->uid != child->euid) ||
(current->uid != child->uid) ||
(current->gid != child->egid) ||
- (current->gid != child->gid)) && !suser()) {
- set_failure(®s,-EPERM);
+ (current->gid != child->gid)) && !suser())
return -EPERM;
- }
/* the same process cannot be attached many times */
- if (child->flags & PF_PTRACED) {
- set_failure(®s,-EPERM);
+ if (child->flags & PF_PTRACED)
return -EPERM;
- }
child->flags |= PF_PTRACED;
if (child->p_pptr != current) {
REMOVE_LINKS(child);
@@ -599,97 +527,54 @@
}
if (!(child->flags & PF_PTRACED)) {
DBG(DBG_MEM, ("child not traced\n"));
- set_failure(®s,-ESRCH);
return -ESRCH;
}
if (child->state != TASK_STOPPED) {
DBG(DBG_MEM, ("child process not stopped\n"));
- if (request != PTRACE_KILL) {
- set_failure(®s,-ESRCH);
+ if (request != PTRACE_KILL)
return -ESRCH;
- }
}
if (child->p_pptr != current) {
DBG(DBG_MEM, ("child not parent of this process\n"));
- set_failure(®s,-ESRCH);
return -ESRCH;
}
switch (request) {
/* when I and D space are separate, these will need to be fixed. */
- case PTRACE_PEEKTEXT: /* read word at location addr. */
+ case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA: {
unsigned long tmp;
int res;
- DBG(DBG_MEM, ("doing request at addr 0x%lx\n",addr));
res = read_long(child, addr, &tmp);
- if (res < 0) {
- set_failure(®s,res);
+ DBG(DBG_MEM, ("peek %#lx->%#lx\n", addr, tmp));
+ if (res < 0)
return res;
- } else {
- set_success(®s,tmp);
- return 0;
- }
+ regs.r0 = tmp; /* special return */
+ return -255;
}
- /* read the word at location addr in the USER area. */
- case PTRACE_PEEKUSR: {
- /* We only allow access to registers. */
- unsigned long tmp;
+ /* read register number ADDR. */
+ case PTRACE_PEEKUSR:
+ regs.r0 = get_reg(child, addr);
+ DBG(DBG_MEM, ("peek $%ld=%#lx\n", addr, regs.r0));
+ return -255; /* special return */
- tmp = 0; /* Default return condition */
- if (addr == 30) {
- /* stack pointer */
- tmp=child->tss.usp;
- } else {
-#ifdef DEBUG
- int reg = addr;
-#endif
- addr = offset_of_register(addr);
- if (addr < 0) {
- set_failure(®s, -EIO);
- return -EIO;
- }
- tmp = get_stack_long(child, addr);
- DBG(DBG_MEM, ("%d = reg 0x%lx=tmp\n",reg,tmp));
- }
- set_success(®s,tmp);
- return 0;
- }
-
- /* when I and D space are separate, this will have to be fixed. */
+ /* when I and D space are separate, this will have to be fixed. */
case PTRACE_POKETEXT: /* write the word at location addr. */
- case PTRACE_POKEDATA: {
- long res = write_long(child,addr,data);
- if (res) {
- set_failure(®s,res);
- }
- return res;
- }
+ case PTRACE_POKEDATA:
+ DBG(DBG_MEM, ("poke %#lx<-%#lx\n", addr, data));
+ return write_long(child, addr, data);
case PTRACE_POKEUSR: /* write the specified register */
- {
- long res;
- addr = offset_of_register(addr);
- if(addr < 0) {
- set_failure(®s,-EIO);
- return -EIO;
- }
- res = put_stack_long(child, addr, data);
- if (res) {
- set_failure(®s,res);
- }
- return res;
- }
+ DBG(DBG_MEM, ("poke $%ld<-%#lx\n", addr, data));
+ return put_reg(child, addr, data);
- case PTRACE_SYSCALL: /* continue and stop at next
+ case PTRACE_SYSCALL: /* continue and stop at next
(return from) syscall */
case PTRACE_CONT: { /* restart after signal. */
- if ((unsigned long) data > NSIG) {
- set_failure(®s,-EIO);
+ if ((unsigned long) data > NSIG)
return -EIO;
- }
if (request == PTRACE_SYSCALL)
child->flags |= PF_TRACESYS;
else
@@ -698,32 +583,28 @@
wake_up_process(child);
/* make sure single-step breakpoint is gone. */
ptrace_cancel_bpt(child);
- set_success(®s,data);
- return 0;
+ return data;
}
/*
- * make the child exit. Best I can do is send it a sigkill.
- * perhaps it should be put in the status that it wants to
+ * make the child exit. Best I can do is send it a sigkill.
+ * perhaps it should be put in the status that it wants to
* exit.
*/
case PTRACE_KILL: {
- wake_up_process(child);
- child->exit_code = SIGKILL;
+ if (child->state != TASK_ZOMBIE) {
+ wake_up_process(child);
+ child->exit_code = SIGKILL;
+ }
/* make sure single-step breakpoint is gone. */
ptrace_cancel_bpt(child);
return 0;
}
- case PTRACE_SINGLESTEP: { /* execute signle instruction. */
- if ((unsigned long) data > NSIG) {
- set_failure(®s,-EIO);
+ case PTRACE_SINGLESTEP: { /* execute single instruction. */
+ if ((unsigned long) data > NSIG)
return -EIO;
- }
- res = set_bpt(child);
- if (res < 0) {
- return res;
- }
+ child->debugreg[4] = -1; /* mark single-stepping */
child->flags &= ~PF_TRACESYS;
wake_up_process(child);
child->exit_code = data;
@@ -732,10 +613,8 @@
}
case PTRACE_DETACH: { /* detach a process that was attached. */
- if ((unsigned long) data > NSIG) {
- set_failure(®s,-EIO);
+ if ((unsigned long) data > NSIG)
return -EIO;
- }
child->flags &= ~(PF_PTRACED|PF_TRACESYS);
wake_up_process(child);
child->exit_code = data;
@@ -748,7 +627,6 @@
}
default:
- set_failure(®s,-EIO);
return -EIO;
}
}
FUNET's LINUX-ADM group, [email protected]
TCL-scripts by Sam Shen, [email protected]
with Sam's (original) version of this