#include <trace/syscall.h>
#include <asm/asm-offsets.h>
#include <asm/cacheflush.h>
+#include <asm/ftrace.lds.h>
+#include <asm/nospec-branch.h>
#include <asm/set_memory.h>
#include "entry.h"
+#include "ftrace.h"
/*
* To generate function prologue either gcc's hotpatch feature (since gcc 4.8)
*/
void *ftrace_func __read_mostly = ftrace_stub;
-unsigned long ftrace_plt;
+struct ftrace_insn {
+ u16 opc;
+ s32 disp;
+} __packed;
+
+asm(
+ " .align 16\n"
+ "ftrace_shared_hotpatch_trampoline_br:\n"
+ " lmg %r0,%r1,2(%r1)\n"
+ " br %r1\n"
+ "ftrace_shared_hotpatch_trampoline_br_end:\n"
+);
+
+#ifdef CONFIG_EXPOLINE
+asm(
+ " .align 16\n"
+ "ftrace_shared_hotpatch_trampoline_ex:\n"
+ " lmg %r0,%r1,2(%r1)\n"
+ " ex %r0," __stringify(__LC_BR_R1) "(%r0)\n"
+ " j .\n"
+ "ftrace_shared_hotpatch_trampoline_ex_end:\n"
+);
+
+asm(
+ " .align 16\n"
+ "ftrace_shared_hotpatch_trampoline_exrl:\n"
+ " lmg %r0,%r1,2(%r1)\n"
+ " .insn ril,0xc60000000000,%r0,0f\n" /* exrl */
+ " j .\n"
+ "0: br %r1\n"
+ "ftrace_shared_hotpatch_trampoline_exrl_end:\n"
+);
+#endif /* CONFIG_EXPOLINE */
+
+#ifdef CONFIG_MODULES
+static char *ftrace_plt;
+
+asm(
+ " .data\n"
+ "ftrace_plt_template:\n"
+ " basr %r1,%r0\n"
+ " lg %r1,0f-.(%r1)\n"
+ " br %r1\n"
+ "0: .quad ftrace_caller\n"
+ "ftrace_plt_template_end:\n"
+ " .previous\n"
+);
+#endif /* CONFIG_MODULES */
+
+static const char *ftrace_shared_hotpatch_trampoline(const char **end)
+{
+ const char *tstart, *tend;
+
+ tstart = ftrace_shared_hotpatch_trampoline_br;
+ tend = ftrace_shared_hotpatch_trampoline_br_end;
+#ifdef CONFIG_EXPOLINE
+ if (!nospec_disable) {
+ tstart = ftrace_shared_hotpatch_trampoline_ex;
+ tend = ftrace_shared_hotpatch_trampoline_ex_end;
+ if (test_facility(35)) { /* exrl */
+ tstart = ftrace_shared_hotpatch_trampoline_exrl;
+ tend = ftrace_shared_hotpatch_trampoline_exrl_end;
+ }
+ }
+#endif /* CONFIG_EXPOLINE */
+ if (end)
+ *end = tend;
+ return tstart;
+}
+
+bool ftrace_need_init_nop(void)
+{
+ return ftrace_shared_hotpatch_trampoline(NULL);
+}
+
+int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
+{
+ static struct ftrace_hotpatch_trampoline *next_vmlinux_trampoline =
+ __ftrace_hotpatch_trampolines_start;
+ static const char orig[6] = { 0xc0, 0x04, 0x00, 0x00, 0x00, 0x00 };
+ static struct ftrace_hotpatch_trampoline *trampoline;
+ struct ftrace_hotpatch_trampoline **next_trampoline;
+ struct ftrace_hotpatch_trampoline *trampolines_end;
+ struct ftrace_hotpatch_trampoline tmp;
+ struct ftrace_insn *insn;
+ const char *shared;
+ s32 disp;
+
+ BUILD_BUG_ON(sizeof(struct ftrace_hotpatch_trampoline) !=
+ SIZEOF_FTRACE_HOTPATCH_TRAMPOLINE);
+
+ next_trampoline = &next_vmlinux_trampoline;
+ trampolines_end = __ftrace_hotpatch_trampolines_end;
+ shared = ftrace_shared_hotpatch_trampoline(NULL);
+#ifdef CONFIG_MODULES
+ if (mod) {
+ next_trampoline = &mod->arch.next_trampoline;
+ trampolines_end = mod->arch.trampolines_end;
+ shared = ftrace_plt;
+ }
+#endif
+
+ if (WARN_ON_ONCE(*next_trampoline >= trampolines_end))
+ return -ENOMEM;
+ trampoline = (*next_trampoline)++;
+
+ /* Check for the compiler-generated fentry nop (brcl 0, .). */
+ if (WARN_ON_ONCE(memcmp((const void *)rec->ip, &orig, sizeof(orig))))
+ return -EINVAL;
+
+ /* Generate the trampoline. */
+ tmp.brasl_opc = 0xc015; /* brasl %r1, shared */
+ tmp.brasl_disp = (shared - (const char *)&trampoline->brasl_opc) / 2;
+ tmp.interceptor = FTRACE_ADDR;
+ tmp.rest_of_intercepted_function = rec->ip + sizeof(struct ftrace_insn);
+ s390_kernel_write(trampoline, &tmp, sizeof(tmp));
+
+ /* Generate a jump to the trampoline. */
+ disp = ((char *)trampoline - (char *)rec->ip) / 2;
+ insn = (struct ftrace_insn *)rec->ip;
+ s390_kernel_write(&insn->disp, &disp, sizeof(disp));
+
+ return 0;
+}
int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
unsigned long addr)
return 0;
}
+static void ftrace_generate_nop_insn(struct ftrace_insn *insn)
+{
+ /* brcl 0,0 */
+ insn->opc = 0xc004;
+ insn->disp = 0;
+}
+
+static void ftrace_generate_call_insn(struct ftrace_insn *insn,
+ unsigned long ip)
+{
+ unsigned long target;
+
+ /* brasl r0,ftrace_caller */
+ target = FTRACE_ADDR;
+#ifdef CONFIG_MODULES
+ if (is_module_addr((void *)ip))
+ target = (unsigned long)ftrace_plt;
+#endif /* CONFIG_MODULES */
+ insn->opc = 0xc005;
+ insn->disp = (target - ip) / 2;
+}
+
+static void brcl_disable(void *brcl)
+{
+ u8 op = 0x04; /* set mask field to zero */
+
+ s390_kernel_write((char *)brcl + 1, &op, sizeof(op));
+}
+
int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
unsigned long addr)
{
struct ftrace_insn orig, new, old;
+ if (ftrace_shared_hotpatch_trampoline(NULL)) {
+ brcl_disable((void *)rec->ip);
+ return 0;
+ }
+
if (copy_from_kernel_nofault(&old, (void *) rec->ip, sizeof(old)))
return -EFAULT;
/* Replace ftrace call with a nop. */
return 0;
}
+static void brcl_enable(void *brcl)
+{
+ u8 op = 0xf4; /* set mask field to all ones */
+
+ s390_kernel_write((char *)brcl + 1, &op, sizeof(op));
+}
+
int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
struct ftrace_insn orig, new, old;
+ if (ftrace_shared_hotpatch_trampoline(NULL)) {
+ brcl_enable((void *)rec->ip);
+ return 0;
+ }
+
if (copy_from_kernel_nofault(&old, (void *) rec->ip, sizeof(old)))
return -EFAULT;
/* Replace nop with an ftrace call. */
return 0;
}
+void arch_ftrace_update_code(int command)
+{
+ if (ftrace_shared_hotpatch_trampoline(NULL))
+ ftrace_modify_all_code(command);
+ else
+ ftrace_run_stop_machine(command);
+}
+
+static void __ftrace_sync(void *dummy)
+{
+}
+
+int ftrace_arch_code_modify_post_process(void)
+{
+ if (ftrace_shared_hotpatch_trampoline(NULL)) {
+ /* Send SIGP to the other CPUs, so they see the new code. */
+ smp_call_function(__ftrace_sync, NULL, 1);
+ }
+ return 0;
+}
+
#ifdef CONFIG_MODULES
static int __init ftrace_plt_init(void)
{
- unsigned int *ip;
+ const char *start, *end;
- ftrace_plt = (unsigned long) module_alloc(PAGE_SIZE);
+ ftrace_plt = module_alloc(PAGE_SIZE);
if (!ftrace_plt)
panic("cannot allocate ftrace plt\n");
- ip = (unsigned int *) ftrace_plt;
- ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */
- ip[1] = 0x100a0004;
- ip[2] = 0x07f10000;
- ip[3] = FTRACE_ADDR >> 32;
- ip[4] = FTRACE_ADDR & 0xffffffff;
- set_memory_ro(ftrace_plt, 1);
+
+ start = ftrace_shared_hotpatch_trampoline(&end);
+ if (!start) {
+ start = ftrace_plt_template;
+ end = ftrace_plt_template_end;
+ }
+ memcpy(ftrace_plt, start, end - start);
+ set_memory_ro((unsigned long)ftrace_plt, 1);
return 0;
}
device_initcall(ftrace_plt_init);
*/
int ftrace_enable_ftrace_graph_caller(void)
{
- u8 op = 0x04; /* set mask field to zero */
-
- s390_kernel_write(__va(ftrace_graph_caller)+1, &op, sizeof(op));
+ brcl_disable(__va(ftrace_graph_caller));
return 0;
}
int ftrace_disable_ftrace_graph_caller(void)
{
- u8 op = 0xf4; /* set mask field to all ones */
-
- s390_kernel_write(__va(ftrace_graph_caller)+1, &op, sizeof(op));
+ brcl_enable(__va(ftrace_graph_caller));
return 0;
}
projects / linux-2.6-microblaze.git / blobdiff