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yaml
---
r: 44165
b: refs/heads/master
c: f088258
h: refs/heads/master
i:
  44163: dd1b790
v: v3
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David S. Miller committed Dec 10, 2006
1 parent 1775e43 commit e0fd4d5
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Showing 3 changed files with 50 additions and 54 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 2f149228bb30ea08bfde740178f832d5c9081005
refs/heads/master: f0882589666440d573f657cb3a1d5f66f3caa157
91 changes: 43 additions & 48 deletions trunk/arch/sparc64/kernel/kprobes.c
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Original file line number Diff line number Diff line change
Expand Up @@ -45,7 +45,11 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
int __kprobes arch_prepare_kprobe(struct kprobe *p)
{
p->ainsn.insn[0] = *p->addr;
flushi(&p->ainsn.insn[0]);

p->ainsn.insn[1] = BREAKPOINT_INSTRUCTION_2;
flushi(&p->ainsn.insn[1]);

p->opcode = *p->addr;
return 0;
}
Expand Down Expand Up @@ -185,31 +189,41 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
/* If INSN is a relative control transfer instruction,
* return the corrected branch destination value.
*
* The original INSN location was REAL_PC, it actually
* executed at PC and produced destination address NPC.
* regs->tpc and regs->tnpc still hold the values of the
* program counters at the time of trap due to the execution
* of the BREAKPOINT_INSTRUCTION_2 at p->ainsn.insn[1]
*
*/
static unsigned long __kprobes relbranch_fixup(u32 insn, unsigned long real_pc,
unsigned long pc,
unsigned long npc)
static unsigned long __kprobes relbranch_fixup(u32 insn, struct kprobe *p,
struct pt_regs *regs)
{
unsigned long real_pc = (unsigned long) p->addr;

/* Branch not taken, no mods necessary. */
if (npc == pc + 0x4UL)
return real_pc + 0x4UL;
if (regs->tnpc == regs->tpc + 0x4UL)
return real_pc + 0x8UL;

/* The three cases are call, branch w/prediction,
* and traditional branch.
*/
if ((insn & 0xc0000000) == 0x40000000 ||
(insn & 0xc1c00000) == 0x00400000 ||
(insn & 0xc1c00000) == 0x00800000) {
unsigned long ainsn_addr;

ainsn_addr = (unsigned long) &p->ainsn.insn[0];

/* The instruction did all the work for us
* already, just apply the offset to the correct
* instruction location.
*/
return (real_pc + (npc - pc));
return (real_pc + (regs->tnpc - ainsn_addr));
}

return real_pc + 0x4UL;
/* It is jmpl or some other absolute PC modification instruction,
* leave NPC as-is.
*/
return regs->tnpc;
}

/* If INSN is an instruction which writes it's PC location
Expand All @@ -220,12 +234,12 @@ static void __kprobes retpc_fixup(struct pt_regs *regs, u32 insn,
{
unsigned long *slot = NULL;

/* Simplest cast is call, which always uses %o7 */
/* Simplest case is 'call', which always uses %o7 */
if ((insn & 0xc0000000) == 0x40000000) {
slot = &regs->u_regs[UREG_I7];
}

/* Jmpl encodes the register inside of the opcode */
/* 'jmpl' encodes the register inside of the opcode */
if ((insn & 0xc1f80000) == 0x81c00000) {
unsigned long rd = ((insn >> 25) & 0x1f);

Expand All @@ -247,11 +261,11 @@ static void __kprobes retpc_fixup(struct pt_regs *regs, u32 insn,

/*
* Called after single-stepping. p->addr is the address of the
* instruction whose first byte has been replaced by the breakpoint
* instruction which has been replaced by the breakpoint
* instruction. To avoid the SMP problems that can occur when we
* temporarily put back the original opcode to single-step, we
* single-stepped a copy of the instruction. The address of this
* copy is p->ainsn.insn.
* copy is &p->ainsn.insn[0].
*
* This function prepares to return from the post-single-step
* breakpoint trap.
Expand All @@ -261,11 +275,11 @@ static void __kprobes resume_execution(struct kprobe *p,
{
u32 insn = p->ainsn.insn[0];

regs->tnpc = relbranch_fixup(insn, p, regs);

/* This assignment must occur after relbranch_fixup() */
regs->tpc = kcb->kprobe_orig_tnpc;
regs->tnpc = relbranch_fixup(insn,
(unsigned long) p->addr,
(unsigned long) &p->ainsn.insn[0],
regs->tnpc);

retpc_fixup(regs, insn, (unsigned long) p->addr);

regs->tstate = ((regs->tstate & ~TSTATE_PIL) |
Expand Down Expand Up @@ -430,17 +444,8 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
struct jprobe *jp = container_of(p, struct jprobe, kp);
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();

kcb->jprobe_saved_regs_location = regs;
memcpy(&(kcb->jprobe_saved_regs), regs, sizeof(*regs));

/* Save a whole stack frame, this gets arguments
* pushed onto the stack after using up all the
* arg registers.
*/
memcpy(&(kcb->jprobe_saved_stack),
(char *) (regs->u_regs[UREG_FP] + STACK_BIAS),
sizeof(kcb->jprobe_saved_stack));

regs->tpc = (unsigned long) jp->entry;
regs->tnpc = ((unsigned long) jp->entry) + 0x4UL;
regs->tstate |= TSTATE_PIL;
Expand All @@ -450,10 +455,19 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)

void __kprobes jprobe_return(void)
{
__asm__ __volatile__(
".globl jprobe_return_trap_instruction\n"
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
register unsigned long orig_fp asm("g1");

orig_fp = kcb->jprobe_saved_regs.u_regs[UREG_FP];
__asm__ __volatile__("\n"
"1: cmp %%sp, %0\n\t"
"blu,a,pt %%xcc, 1b\n\t"
" restore\n\t"
".globl jprobe_return_trap_instruction\n"
"jprobe_return_trap_instruction:\n\t"
"ta 0x70");
"ta 0x70"
: /* no outputs */
: "r" (orig_fp));
}

extern void jprobe_return_trap_instruction(void);
Expand All @@ -466,26 +480,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();

if (addr == (u32 *) jprobe_return_trap_instruction) {
if (kcb->jprobe_saved_regs_location != regs) {
printk("JPROBE: Current regs (%p) does not match "
"saved regs (%p).\n",
regs, kcb->jprobe_saved_regs_location);
printk("JPROBE: Saved registers\n");
__show_regs(kcb->jprobe_saved_regs_location);
printk("JPROBE: Current registers\n");
__show_regs(regs);
BUG();
}
/* Restore old register state. Do pt_regs
* first so that UREG_FP is the original one for
* the stack frame restore.
*/
memcpy(regs, &(kcb->jprobe_saved_regs), sizeof(*regs));

memcpy((char *) (regs->u_regs[UREG_FP] + STACK_BIAS),
&(kcb->jprobe_saved_stack),
sizeof(kcb->jprobe_saved_stack));

preempt_enable_no_resched();
return 1;
}
Expand Down
11 changes: 6 additions & 5 deletions trunk/include/asm-sparc64/kprobes.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,11 @@ typedef u32 kprobe_opcode_t;
#define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)pentry
#define arch_remove_kprobe(p) do {} while (0)
#define ARCH_INACTIVE_KPROBE_COUNT 0
#define flush_insn_slot(p) do { } while (0)

#define flush_insn_slot(p) \
do { flushi(&(p)->ainsn.insn[0]); \
flushi(&(p)->ainsn.insn[1]); \
} while (0)

/* Architecture specific copy of original instruction*/
struct arch_specific_insn {
Expand All @@ -23,7 +27,7 @@ struct arch_specific_insn {

struct prev_kprobe {
struct kprobe *kp;
unsigned int status;
unsigned long status;
unsigned long orig_tnpc;
unsigned long orig_tstate_pil;
};
Expand All @@ -33,10 +37,7 @@ struct kprobe_ctlblk {
unsigned long kprobe_status;
unsigned long kprobe_orig_tnpc;
unsigned long kprobe_orig_tstate_pil;
long *jprobe_saved_esp;
struct pt_regs jprobe_saved_regs;
struct pt_regs *jprobe_saved_regs_location;
struct sparc_stackf jprobe_saved_stack;
struct prev_kprobe prev_kprobe;
};

Expand Down

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