linux_dsm_epyc7002/arch/sparc/kernel/ftrace.c
Mike Frysinger e7b8e675d9 tracing: Unify arch_syscall_addr() implementations
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>
2010-02-17 13:07:21 +01:00

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