| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <47669EC1.9060605@redhat.com>
Date: Mon, 17 Dec 2007 11:07:29 -0500
From: Masami Hiramatsu <mhiramat@...hat.com>
To: ananth@...ibm.com, Jim Keniston <jkenisto@...ibm.com>,
Roland McGrath <roland@...hat.com>,
Arjan van de Ven <arjan@...radead.org>,
prasanna@...ibm.com, anil.s.keshavamurthy@...el.com,
davem@...emloft.net, Ingo Molnar <mingo@...e.hu>,
Harvey Harrison <harvey.harrison@...il.com>
CC: systemtap-ml <systemtap@...rces.redhat.com>,
LKML <linux-kernel@...r.kernel.org>
Subject: [-mm][PATCH 4/6] return probe-booster for x86-64
This patch adds kretprobe-booster to kprobes_64.c.
- Changes are based on x86-32.
- Rewrite register saving/restoring code
Signed-off-by: Masami Hiramatsu <mhiramat@...hat.com>
---
arch/x86/kernel/kprobes_64.c | 92 ++++++++++++++++++++++++++++++-------------
1 file changed, 65 insertions(+), 27 deletions(-)
Index: 2.6.24-rc4-mm1/arch/x86/kernel/kprobes_64.c
===================================================================
--- 2.6.24-rc4-mm1.orig/arch/x86/kernel/kprobes_64.c
+++ 2.6.24-rc4-mm1/arch/x86/kernel/kprobes_64.c
@@ -28,6 +28,8 @@
* Fixed to handle %rip-relative addressing mode correctly.
* 2005-May Rusty Lynch <rusty.lynch@...el.com>
* Added function return probes functionality
+ * 2007-Dec Masami Hiramatsu <mhiramat@...hat.com> added kprobe-booster
+ * and kretprobe-booster for x86-64
*/
#include <linux/kprobes.h>
@@ -507,21 +509,65 @@ no_kprobe:
}
/*
- * For function-return probes, init_kprobes() establishes a probepoint
- * here. When a retprobed function returns, this probe is hit and
- * trampoline_probe_handler() runs, calling the kretprobe's handler.
+ * When a retprobed function returns, this code saves registers and
+ * calls trampoline_handler() runs, which calls the kretprobe's handler.
*/
- void kretprobe_trampoline_holder(void)
+ void __kprobes kretprobe_trampoline_holder(void)
{
asm volatile ( ".global kretprobe_trampoline\n"
- "kretprobe_trampoline: \n"
- "nop\n");
+ "kretprobe_trampoline: \n"
+ /* We don't bother saving the ss register */
+ " pushq %rsp\n"
+ " pushfq\n"
+ /*
+ * Skip cs, ip, orig_ax.
+ * trampoline_handler() will plug in these values
+ */
+ " subq $24, %rsp\n"
+ " pushq %rdi\n"
+ " pushq %rsi\n"
+ " pushq %rdx\n"
+ " pushq %rcx\n"
+ " pushq %rax\n"
+ " pushq %r8\n"
+ " pushq %r9\n"
+ " pushq %r10\n"
+ " pushq %r11\n"
+ " pushq %rbx\n"
+ " pushq %rbp\n"
+ " pushq %r12\n"
+ " pushq %r13\n"
+ " pushq %r14\n"
+ " pushq %r15\n"
+ " movq %rsp, %rdi\n"
+ " call trampoline_handler\n"
+ /* Replace saved sp with true return address. */
+ " movq %rax, 152(%rsp)\n"
+ " popq %r15\n"
+ " popq %r14\n"
+ " popq %r13\n"
+ " popq %r12\n"
+ " popq %rbp\n"
+ " popq %rbx\n"
+ " popq %r11\n"
+ " popq %r10\n"
+ " popq %r9\n"
+ " popq %r8\n"
+ " popq %rax\n"
+ " popq %rcx\n"
+ " popq %rdx\n"
+ " popq %rsi\n"
+ " popq %rdi\n"
+ /* Skip orig_ax, ip, cs */
+ " addq $24, %rsp\n"
+ " popfq\n"
+ " ret\n");
}
/*
- * Called when we hit the probe point at kretprobe_trampoline
+ * Called from kretprobe_trampoline
*/
-int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
+fastcall void * __kprobes trampoline_handler(struct pt_regs *regs)
{
struct kretprobe_instance *ri = NULL;
struct hlist_head *head, empty_rp;
@@ -532,6 +578,10 @@ int __kprobes trampoline_probe_handler(s
INIT_HLIST_HEAD(&empty_rp);
spin_lock_irqsave(&kretprobe_lock, flags);
head = kretprobe_inst_table_head(current);
+ /* fixup rt_regs */
+ regs->cs = __KERNEL_CS;
+ regs->ip = trampoline_address;
+ regs->orig_ax = 0xffffffffffffffff;
/*
* It is possible to have multiple instances associated with a given
@@ -551,8 +601,12 @@ int __kprobes trampoline_probe_handler(s
/* another task is sharing our hash bucket */
continue;
- if (ri->rp && ri->rp->handler)
+ if (ri->rp && ri->rp->handler) {
+ __get_cpu_var(current_kprobe) = &ri->rp->kp;
+ get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
ri->rp->handler(ri, regs);
+ __get_cpu_var(current_kprobe) = NULL;
+ }
orig_ret_address = (unsigned long)ri->ret_addr;
recycle_rp_inst(ri, &empty_rp);
@@ -567,22 +621,14 @@ int __kprobes trampoline_probe_handler(s
}
kretprobe_assert(ri, orig_ret_address, trampoline_address);
- regs->ip = orig_ret_address;
- reset_current_kprobe();
spin_unlock_irqrestore(&kretprobe_lock, flags);
- preempt_enable_no_resched();
hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
kfree(ri);
}
- /*
- * By returning a non-zero value, we are telling
- * kprobe_handler() that we don't want the post_handler
- * to run (and have re-enabled preemption)
- */
- return 1;
+ return (void *)orig_ret_address;
}
/*
@@ -881,20 +927,12 @@ int __kprobes longjmp_break_handler(stru
return 0;
}
-static struct kprobe trampoline_p = {
- .addr = (kprobe_opcode_t *) &kretprobe_trampoline,
- .pre_handler = trampoline_probe_handler
-};
-
int __init arch_init_kprobes(void)
{
- return register_kprobe(&trampoline_p);
+ return 0;
}
int __kprobes arch_trampoline_kprobe(struct kprobe *p)
{
- if (p->addr == (kprobe_opcode_t *)&kretprobe_trampoline)
- return 1;
-
return 0;
}
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division
e-mail: mhiramat@...hat.com, masami.hiramatsu.pt@...achi.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists