return 0;
}
+#ifdef CONFIG_MPROFILE_KERNEL
+
+#define PACATOC offsetof(struct paca_struct, kernel_toc)
+
+/*
+ * ld r12,PACATOC(r13)
+ * addis r12,r12,<high>
+ * addi r12,r12,<low>
+ * mtctr r12
+ * bctr
+ */
+static u32 stub_insns[] = {
+ PPC_INST_LD | __PPC_RT(R12) | __PPC_RA(R13) | PACATOC,
+ PPC_INST_ADDIS | __PPC_RT(R12) | __PPC_RA(R12),
+ PPC_INST_ADDI | __PPC_RT(R12) | __PPC_RA(R12),
+ PPC_INST_MTCTR | __PPC_RS(R12),
+ PPC_INST_BCTR,
+};
+
+/*
+ * For mprofile-kernel we use a special stub for ftrace_caller() because we
+ * can't rely on r2 containing this module's TOC when we enter the stub.
+ *
+ * That can happen if the function calling us didn't need to use the toc. In
+ * that case it won't have setup r2, and the r2 value will be either the
+ * kernel's toc, or possibly another modules toc.
+ *
+ * To deal with that this stub uses the kernel toc, which is always accessible
+ * via the paca (in r13). The target (ftrace_caller()) is responsible for
+ * saving and restoring the toc before returning.
+ */
+static inline int create_ftrace_stub(struct ppc64_stub_entry *entry,
+ unsigned long addr,
+ struct module *me)
+{
+ long reladdr;
+
+ memcpy(entry->jump, stub_insns, sizeof(stub_insns));
+
+ /* Stub uses address relative to kernel toc (from the paca) */
+ reladdr = addr - kernel_toc_addr();
+ if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
+ pr_err("%s: Address of %ps out of range of kernel_toc.\n",
+ me->name, (void *)addr);
+ return 0;
+ }
+
+ entry->jump[1] |= PPC_HA(reladdr);
+ entry->jump[2] |= PPC_LO(reladdr);
+
+ /* Eventhough we don't use funcdata in the stub, it's needed elsewhere. */
+ entry->funcdata = func_desc(addr);
+ entry->magic = STUB_MAGIC;
+
+ return 1;
+}
+
+static bool is_mprofile_ftrace_call(const char *name)
+{
+ if (!strcmp("_mcount", name))
+ return true;
+#ifdef CONFIG_DYNAMIC_FTRACE
+ if (!strcmp("ftrace_caller", name))
+ return true;
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ if (!strcmp("ftrace_regs_caller", name))
+ return true;
+#endif
+#endif
+
+ return false;
+}
+#else
+static inline int create_ftrace_stub(struct ppc64_stub_entry *entry,
+ unsigned long addr,
+ struct module *me)
+{
+ return 0;
+}
+
+static bool is_mprofile_ftrace_call(const char *name)
+{
+ return false;
+}
+#endif
+
/*
* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this gives the
* value maximum span in an instruction which uses a signed offset). Round down
static inline int create_stub(const Elf64_Shdr *sechdrs,
struct ppc64_stub_entry *entry,
unsigned long addr,
- struct module *me)
+ struct module *me,
+ const char *name)
{
long reladdr;
+ if (is_mprofile_ftrace_call(name))
+ return create_ftrace_stub(entry, addr, me);
+
memcpy(entry->jump, ppc64_stub_insns, sizeof(ppc64_stub_insns));
/* Stub uses address relative to r2. */
stub to set up the TOC ptr (r2) for the function. */
static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
unsigned long addr,
- struct module *me)
+ struct module *me,
+ const char *name)
{
struct ppc64_stub_entry *stubs;
unsigned int i, num_stubs;
return (unsigned long)&stubs[i];
}
- if (!create_stub(sechdrs, &stubs[i], addr, me))
+ if (!create_stub(sechdrs, &stubs[i], addr, me, name))
return 0;
return (unsigned long)&stubs[i];
}
-#ifdef CONFIG_MPROFILE_KERNEL
-static bool is_mprofile_ftrace_call(const char *name)
-{
- if (!strcmp("_mcount", name))
- return true;
-
- return false;
-}
-
-/*
- * In case of _mcount calls, do not save the current callee's TOC (in r2) into
- * the original caller's stack frame. If we did we would clobber the saved TOC
- * value of the original caller.
- */
-static void squash_toc_save_inst(const char *name, unsigned long addr)
-{
- struct ppc64_stub_entry *stub = (struct ppc64_stub_entry *)addr;
-
- /* Only for calls to _mcount */
- if (strcmp("_mcount", name) != 0)
- return;
-
- stub->jump[2] = PPC_INST_NOP;
-}
-#else
-static void squash_toc_save_inst(const char *name, unsigned long addr) { }
-
-static bool is_mprofile_ftrace_call(const char *name)
-{
- return false;
-}
-#endif
-
/* We expect a noop next: if it is, replace it with instruction to
restore r2. */
static int restore_r2(const char *name, u32 *instruction, struct module *me)
if (sym->st_shndx == SHN_UNDEF ||
sym->st_shndx == SHN_LIVEPATCH) {
/* External: go via stub */
- value = stub_for_addr(sechdrs, value, me);
+ value = stub_for_addr(sechdrs, value, me,
+ strtab + sym->st_name);
if (!value)
return -ENOENT;
if (!restore_r2(strtab + sym->st_name,
(u32 *)location + 1, me))
return -ENOEXEC;
-
- squash_toc_save_inst(strtab + sym->st_name, value);
} else
value += local_entry_offset(sym);
return 0;
}
-#ifdef CONFIG_MPROFILE_KERNEL
-
-#define PACATOC offsetof(struct paca_struct, kernel_toc)
-
-/*
- * For mprofile-kernel we use a special stub for ftrace_caller() because we
- * can't rely on r2 containing this module's TOC when we enter the stub.
- *
- * That can happen if the function calling us didn't need to use the toc. In
- * that case it won't have setup r2, and the r2 value will be either the
- * kernel's toc, or possibly another modules toc.
- *
- * To deal with that this stub uses the kernel toc, which is always accessible
- * via the paca (in r13). The target (ftrace_caller()) is responsible for
- * saving and restoring the toc before returning.
- */
-static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs,
- struct module *me, unsigned long addr)
-{
- struct ppc64_stub_entry *entry;
- unsigned int i, num_stubs;
- /*
- * ld r12,PACATOC(r13)
- * addis r12,r12,<high>
- * addi r12,r12,<low>
- * mtctr r12
- * bctr
- */
- static u32 stub_insns[] = {
- PPC_INST_LD | __PPC_RT(R12) | __PPC_RA(R13) | PACATOC,
- PPC_INST_ADDIS | __PPC_RT(R12) | __PPC_RA(R12),
- PPC_INST_ADDI | __PPC_RT(R12) | __PPC_RA(R12),
- PPC_INST_MTCTR | __PPC_RS(R12),
- PPC_INST_BCTR,
- };
- long reladdr;
-
- num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*entry);
-
- /* Find the next available stub entry */
- entry = (void *)sechdrs[me->arch.stubs_section].sh_addr;
- for (i = 0; i < num_stubs && stub_func_addr(entry->funcdata); i++, entry++);
-
- if (i >= num_stubs) {
- pr_err("%s: Unable to find a free slot for ftrace stub.\n", me->name);
- return 0;
- }
-
- memcpy(entry->jump, stub_insns, sizeof(stub_insns));
-
- /* Stub uses address relative to kernel toc (from the paca) */
- reladdr = addr - kernel_toc_addr();
- if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
- pr_err("%s: Address of %ps out of range of kernel_toc.\n",
- me->name, (void *)addr);
- return 0;
- }
-
- entry->jump[1] |= PPC_HA(reladdr);
- entry->jump[2] |= PPC_LO(reladdr);
-
- /* Eventhough we don't use funcdata in the stub, it's needed elsewhere. */
- entry->funcdata = func_desc(addr);
- entry->magic = STUB_MAGIC;
-
- return (unsigned long)entry;
-}
-#else
-static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs,
- struct module *me, unsigned long addr)
-{
- return stub_for_addr(sechdrs, addr, me);
-}
-#endif
-
int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs)
{
- mod->arch.tramp = create_ftrace_stub(sechdrs, mod,
- (unsigned long)ftrace_caller);
+ mod->arch.tramp = stub_for_addr(sechdrs,
+ (unsigned long)ftrace_caller,
+ mod,
+ "ftrace_caller");
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
- mod->arch.tramp_regs = create_ftrace_stub(sechdrs, mod,
- (unsigned long)ftrace_regs_caller);
+ mod->arch.tramp_regs = stub_for_addr(sechdrs,
+ (unsigned long)ftrace_regs_caller,
+ mod,
+ "ftrace_regs_caller");
if (!mod->arch.tramp_regs)
return -ENOENT;
#endif
projects / users / hch / configfs.git / commitdiff