From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/arch/powerpc/kernel/kprobes.c | 196 +++++++++++++++++-------------------------------
1 files changed, 69 insertions(+), 127 deletions(-)
diff --git a/kernel/arch/powerpc/kernel/kprobes.c b/kernel/arch/powerpc/kernel/kprobes.c
index ccf16bc..00fafc8 100644
--- a/kernel/arch/powerpc/kernel/kprobes.c
+++ b/kernel/arch/powerpc/kernel/kprobes.c
@@ -1,19 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Kernel Probes (KProbes)
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) IBM Corporation, 2002, 2004
*
@@ -36,6 +23,7 @@
#include <asm/cacheflush.h>
#include <asm/sstep.h>
#include <asm/sections.h>
+#include <asm/inst.h>
#include <linux/uaccess.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
@@ -118,13 +106,26 @@
int arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
- kprobe_opcode_t insn = *p->addr;
+ struct kprobe *prev;
+ struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->addr);
if ((unsigned long)p->addr & 0x03) {
printk("Attempt to register kprobe at an unaligned address\n");
ret = -EINVAL;
} else if (IS_MTMSRD(insn) || IS_RFID(insn) || IS_RFI(insn)) {
printk("Cannot register a kprobe on rfi/rfid or mtmsr[d]\n");
+ ret = -EINVAL;
+ } else if ((unsigned long)p->addr & ~PAGE_MASK &&
+ ppc_inst_prefixed(ppc_inst_read((struct ppc_inst *)(p->addr - 1)))) {
+ printk("Cannot register a kprobe on the second word of prefixed instruction\n");
+ ret = -EINVAL;
+ }
+ preempt_disable();
+ prev = get_kprobe(p->addr - 1);
+ preempt_enable_no_resched();
+ if (prev &&
+ ppc_inst_prefixed(ppc_inst_read((struct ppc_inst *)prev->ainsn.insn))) {
+ printk("Cannot register a kprobe on the second word of prefixed instruction\n");
ret = -EINVAL;
}
@@ -137,11 +138,8 @@
}
if (!ret) {
- memcpy(p->ainsn.insn, p->addr,
- MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
- p->opcode = *p->addr;
- flush_icache_range((unsigned long)p->ainsn.insn,
- (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t));
+ patch_instruction((struct ppc_inst *)p->ainsn.insn, insn);
+ p->opcode = ppc_inst_val(insn);
}
p->ainsn.boostable = 0;
@@ -151,13 +149,13 @@
void arch_arm_kprobe(struct kprobe *p)
{
- patch_instruction(p->addr, BREAKPOINT_INSTRUCTION);
+ patch_instruction((struct ppc_inst *)p->addr, ppc_inst(BREAKPOINT_INSTRUCTION));
}
NOKPROBE_SYMBOL(arch_arm_kprobe);
void arch_disarm_kprobe(struct kprobe *p)
{
- patch_instruction(p->addr, p->opcode);
+ patch_instruction((struct ppc_inst *)p->addr, ppc_inst(p->opcode));
}
NOKPROBE_SYMBOL(arch_disarm_kprobe);
@@ -220,6 +218,7 @@
void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
{
ri->ret_addr = (kprobe_opcode_t *)regs->link;
+ ri->fp = NULL;
/* Replace the return addr with trampoline addr */
regs->link = (unsigned long)kretprobe_trampoline;
@@ -229,7 +228,7 @@
static int try_to_emulate(struct kprobe *p, struct pt_regs *regs)
{
int ret;
- unsigned int insn = *p->ainsn.insn;
+ struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->ainsn.insn);
/* regs->nip is also adjusted if emulate_step returns 1 */
ret = emulate_step(regs, insn);
@@ -246,7 +245,7 @@
* So, we should never get here... but, its still
* good to catch them, just in case...
*/
- printk("Can't step on instruction %x\n", insn);
+ printk("Can't step on instruction %s\n", ppc_inst_as_str(insn));
BUG();
} else {
/*
@@ -288,64 +287,20 @@
preempt_disable();
kcb = get_kprobe_ctlblk();
- /* Check we're not actually recursing */
- if (kprobe_running()) {
- p = get_kprobe(addr);
- if (p) {
- kprobe_opcode_t insn = *p->ainsn.insn;
- if (kcb->kprobe_status == KPROBE_HIT_SS &&
- is_trap(insn)) {
- /* Turn off 'trace' bits */
- regs->msr &= ~MSR_SINGLESTEP;
- regs->msr |= kcb->kprobe_saved_msr;
- goto no_kprobe;
- }
- /* We have reentered the kprobe_handler(), since
- * another probe was hit while within the handler.
- * We here save the original kprobes variables and
- * just single step on the instruction of the new probe
- * without calling any user handlers.
- */
- save_previous_kprobe(kcb);
- set_current_kprobe(p, regs, kcb);
- kprobes_inc_nmissed_count(p);
- kcb->kprobe_status = KPROBE_REENTER;
- if (p->ainsn.boostable >= 0) {
- ret = try_to_emulate(p, regs);
-
- if (ret > 0) {
- restore_previous_kprobe(kcb);
- preempt_enable_no_resched();
- return 1;
- }
- }
- prepare_singlestep(p, regs);
- return 1;
- } else if (*addr != BREAKPOINT_INSTRUCTION) {
- /* If trap variant, then it belongs not to us */
- kprobe_opcode_t cur_insn = *addr;
-
- if (is_trap(cur_insn))
- goto no_kprobe;
- /* The breakpoint instruction was removed by
- * another cpu right after we hit, no further
- * handling of this interrupt is appropriate
- */
- ret = 1;
- }
- goto no_kprobe;
- }
-
p = get_kprobe(addr);
if (!p) {
- if (*addr != BREAKPOINT_INSTRUCTION) {
+ unsigned int instr;
+
+ if (get_kernel_nofault(instr, addr))
+ goto no_kprobe;
+
+ if (instr != BREAKPOINT_INSTRUCTION) {
/*
* PowerPC has multiple variants of the "trap"
* instruction. If the current instruction is a
* trap variant, it could belong to someone else
*/
- kprobe_opcode_t cur_insn = *addr;
- if (is_trap(cur_insn))
+ if (is_trap(instr))
goto no_kprobe;
/*
* The breakpoint instruction was removed right
@@ -358,6 +313,39 @@
}
/* Not one of ours: let kernel handle it */
goto no_kprobe;
+ }
+
+ /* Check we're not actually recursing */
+ if (kprobe_running()) {
+ kprobe_opcode_t insn = *p->ainsn.insn;
+ if (kcb->kprobe_status == KPROBE_HIT_SS && is_trap(insn)) {
+ /* Turn off 'trace' bits */
+ regs->msr &= ~MSR_SINGLESTEP;
+ regs->msr |= kcb->kprobe_saved_msr;
+ goto no_kprobe;
+ }
+
+ /*
+ * We have reentered the kprobe_handler(), since another probe
+ * was hit while within the handler. We here save the original
+ * kprobes variables and just single step on the instruction of
+ * the new probe without calling any user handlers.
+ */
+ save_previous_kprobe(kcb);
+ set_current_kprobe(p, regs, kcb);
+ kprobes_inc_nmissed_count(p);
+ kcb->kprobe_status = KPROBE_REENTER;
+ if (p->ainsn.boostable >= 0) {
+ ret = try_to_emulate(p, regs);
+
+ if (ret > 0) {
+ restore_previous_kprobe(kcb);
+ preempt_enable_no_resched();
+ return 1;
+ }
+ }
+ prepare_singlestep(p, regs);
+ return 1;
}
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
@@ -410,50 +398,9 @@
*/
static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
{
- struct kretprobe_instance *ri = NULL;
- struct hlist_head *head, empty_rp;
- struct hlist_node *tmp;
- unsigned long flags, orig_ret_address = 0;
- unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline;
+ unsigned long orig_ret_address;
- INIT_HLIST_HEAD(&empty_rp);
- kretprobe_hash_lock(current, &head, &flags);
-
- /*
- * It is possible to have multiple instances associated with a given
- * task either because an multiple functions in the call path
- * have a return probe installed on them, and/or more than one return
- * return probe was registered for a target function.
- *
- * We can handle this because:
- * - instances are always inserted at the head of the list
- * - when multiple return probes are registered for the same
- * function, the first instance's ret_addr will point to the
- * real return address, and all the rest will point to
- * kretprobe_trampoline
- */
- hlist_for_each_entry_safe(ri, tmp, head, hlist) {
- if (ri->task != current)
- /* another task is sharing our hash bucket */
- continue;
-
- if (ri->rp && ri->rp->handler)
- ri->rp->handler(ri, regs);
-
- orig_ret_address = (unsigned long)ri->ret_addr;
- recycle_rp_inst(ri, &empty_rp);
-
- if (orig_ret_address != trampoline_address)
- /*
- * This is the real return address. Any other
- * instances associated with this task are for
- * other calls deeper on the call stack
- */
- break;
- }
-
- kretprobe_assert(ri, orig_ret_address, trampoline_address);
-
+ orig_ret_address = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL);
/*
* We get here through one of two paths:
* 1. by taking a trap -> kprobe_handler() -> here
@@ -472,13 +419,6 @@
regs->nip = orig_ret_address - 4;
regs->link = orig_ret_address;
- kretprobe_hash_unlock(current, &flags);
-
- hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
- hlist_del(&ri->hlist);
- kfree(ri);
- }
-
return 0;
}
NOKPROBE_SYMBOL(trampoline_probe_handler);
@@ -493,14 +433,16 @@
*/
int kprobe_post_handler(struct pt_regs *regs)
{
+ int len;
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
if (!cur || user_mode(regs))
return 0;
+ len = ppc_inst_len(ppc_inst_read((struct ppc_inst *)cur->ainsn.insn));
/* make sure we got here for instruction we have a kprobe on */
- if (((unsigned long)cur->ainsn.insn + 4) != regs->nip)
+ if (((unsigned long)cur->ainsn.insn + len) != regs->nip)
return 0;
if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
@@ -509,7 +451,7 @@
}
/* Adjust nip to after the single-stepped instruction */
- regs->nip = (unsigned long)cur->addr + 4;
+ regs->nip = (unsigned long)cur->addr + len;
regs->msr |= kcb->kprobe_saved_msr;
/*Restore back the original saved kprobes variables and continue. */
--
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