e7b8e675d9
Most implementations of arch_syscall_addr() are the same, so create a default version in common code and move the one piece that differs (the syscall table) to asm/syscall.h. New arch ports don't have to waste time copying & pasting this simple function. The s390/sparc versions need to be different, so document why. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1264498803-17278-1-git-send-email-vapier@gentoo.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
94 lines
1.9 KiB
C
94 lines
1.9 KiB
C
#include <linux/spinlock.h>
|
|
#include <linux/hardirq.h>
|
|
#include <linux/ftrace.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/init.h>
|
|
#include <linux/list.h>
|
|
#include <trace/syscall.h>
|
|
|
|
#include <asm/ftrace.h>
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
static const u32 ftrace_nop = 0x01000000;
|
|
|
|
static u32 ftrace_call_replace(unsigned long ip, unsigned long addr)
|
|
{
|
|
static u32 call;
|
|
s32 off;
|
|
|
|
off = ((s32)addr - (s32)ip);
|
|
call = 0x40000000 | ((u32)off >> 2);
|
|
|
|
return call;
|
|
}
|
|
|
|
static int ftrace_modify_code(unsigned long ip, u32 old, u32 new)
|
|
{
|
|
u32 replaced;
|
|
int faulted;
|
|
|
|
__asm__ __volatile__(
|
|
"1: cas [%[ip]], %[old], %[new]\n"
|
|
" flush %[ip]\n"
|
|
" mov 0, %[faulted]\n"
|
|
"2:\n"
|
|
" .section .fixup,#alloc,#execinstr\n"
|
|
" .align 4\n"
|
|
"3: sethi %%hi(2b), %[faulted]\n"
|
|
" jmpl %[faulted] + %%lo(2b), %%g0\n"
|
|
" mov 1, %[faulted]\n"
|
|
" .previous\n"
|
|
" .section __ex_table,\"a\"\n"
|
|
" .align 4\n"
|
|
" .word 1b, 3b\n"
|
|
" .previous\n"
|
|
: "=r" (replaced), [faulted] "=r" (faulted)
|
|
: [new] "0" (new), [old] "r" (old), [ip] "r" (ip)
|
|
: "memory");
|
|
|
|
if (replaced != old && replaced != new)
|
|
faulted = 2;
|
|
|
|
return faulted;
|
|
}
|
|
|
|
int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
|
|
{
|
|
unsigned long ip = rec->ip;
|
|
u32 old, new;
|
|
|
|
old = ftrace_call_replace(ip, addr);
|
|
new = ftrace_nop;
|
|
return ftrace_modify_code(ip, old, new);
|
|
}
|
|
|
|
int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
|
|
{
|
|
unsigned long ip = rec->ip;
|
|
u32 old, new;
|
|
|
|
old = ftrace_nop;
|
|
new = ftrace_call_replace(ip, addr);
|
|
return ftrace_modify_code(ip, old, new);
|
|
}
|
|
|
|
int ftrace_update_ftrace_func(ftrace_func_t func)
|
|
{
|
|
unsigned long ip = (unsigned long)(&ftrace_call);
|
|
u32 old, new;
|
|
|
|
old = *(u32 *) &ftrace_call;
|
|
new = ftrace_call_replace(ip, (unsigned long)func);
|
|
return ftrace_modify_code(ip, old, new);
|
|
}
|
|
|
|
int __init ftrace_dyn_arch_init(void *data)
|
|
{
|
|
unsigned long *p = data;
|
|
|
|
*p = 0;
|
|
|
|
return 0;
|
|
}
|
|
#endif
|