Merge branch 'perf-probes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-probes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Issue at least one memory barrier in stop_machine_text_poke()
  perf probe: Correct probe syntax on command line help
  perf probe: Add lazy line matching support
  perf probe: Show more lines after last line
  perf probe: Check function address range strictly in line finder
  perf probe: Use libdw callback routines
  perf probe: Use elfutils-libdw for analyzing debuginfo
  perf probe: Rename probe finder functions
  perf probe: Fix bugs in line range finder
  perf probe: Update perf probe document
  perf probe: Do not show --line option without dwarf support
  kprobes: Add documents of jump optimization
  kprobes/x86: Support kprobes jump optimization on x86
  x86: Add text_poke_smp for SMP cross modifying code
  kprobes/x86: Cleanup save/restore registers
  kprobes/x86: Boost probes when reentering
  kprobes: Jump optimization sysctl interface
  kprobes: Introduce kprobes jump optimization
  kprobes: Introduce generic insn_slot framework
  kprobes/x86: Cleanup RELATIVEJUMP_INSTRUCTION to RELATIVEJUMP_OPCODE
This commit is contained in:
Linus Torvalds
2010-03-05 10:50:22 -08:00
18 changed files with 2091 additions and 863 deletions

View File

@ -7,6 +7,7 @@
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/memory.h>
#include <linux/stop_machine.h>
#include <asm/alternative.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
@ -572,3 +573,62 @@ void *__kprobes text_poke(void *addr, const void *opcode, size_t len)
local_irq_restore(flags);
return addr;
}
/*
* Cross-modifying kernel text with stop_machine().
* This code originally comes from immediate value.
*/
static atomic_t stop_machine_first;
static int wrote_text;
struct text_poke_params {
void *addr;
const void *opcode;
size_t len;
};
static int __kprobes stop_machine_text_poke(void *data)
{
struct text_poke_params *tpp = data;
if (atomic_dec_and_test(&stop_machine_first)) {
text_poke(tpp->addr, tpp->opcode, tpp->len);
smp_wmb(); /* Make sure other cpus see that this has run */
wrote_text = 1;
} else {
while (!wrote_text)
cpu_relax();
smp_mb(); /* Load wrote_text before following execution */
}
flush_icache_range((unsigned long)tpp->addr,
(unsigned long)tpp->addr + tpp->len);
return 0;
}
/**
* text_poke_smp - Update instructions on a live kernel on SMP
* @addr: address to modify
* @opcode: source of the copy
* @len: length to copy
*
* Modify multi-byte instruction by using stop_machine() on SMP. This allows
* user to poke/set multi-byte text on SMP. Only non-NMI/MCE code modifying
* should be allowed, since stop_machine() does _not_ protect code against
* NMI and MCE.
*
* Note: Must be called under get_online_cpus() and text_mutex.
*/
void *__kprobes text_poke_smp(void *addr, const void *opcode, size_t len)
{
struct text_poke_params tpp;
tpp.addr = addr;
tpp.opcode = opcode;
tpp.len = len;
atomic_set(&stop_machine_first, 1);
wrote_text = 0;
stop_machine(stop_machine_text_poke, (void *)&tpp, NULL);
return addr;
}