module: refactor load_module

I'd start from the trivial stuff. There's a fair amount of straight-line
code that just makes the function hard to read just because you have to
page up and down so far. Some of it is trivial to just create a helper
function for.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/kernel/module.c b/kernel/module.c
index 404e722..12905ed 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2107,6 +2107,71 @@ static inline void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
 }
 #endif
 
+static void find_module_sections(struct module *mod, Elf_Ehdr *hdr,
+                                Elf_Shdr *sechdrs, const char *secstrings)
+{
+       mod->kp = section_objs(hdr, sechdrs, secstrings, "__param",
+                              sizeof(*mod->kp), &mod->num_kp);
+       mod->syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab",
+                                sizeof(*mod->syms), &mod->num_syms);
+       mod->crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab");
+       mod->gpl_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_gpl",
+                                    sizeof(*mod->gpl_syms),
+                                    &mod->num_gpl_syms);
+       mod->gpl_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_gpl");
+       mod->gpl_future_syms = section_objs(hdr, sechdrs, secstrings,
+                                           "__ksymtab_gpl_future",
+                                           sizeof(*mod->gpl_future_syms),
+                                           &mod->num_gpl_future_syms);
+       mod->gpl_future_crcs = section_addr(hdr, sechdrs, secstrings,
+                                           "__kcrctab_gpl_future");
+
+#ifdef CONFIG_UNUSED_SYMBOLS
+       mod->unused_syms = section_objs(hdr, sechdrs, secstrings,
+                                       "__ksymtab_unused",
+                                       sizeof(*mod->unused_syms),
+                                       &mod->num_unused_syms);
+       mod->unused_crcs = section_addr(hdr, sechdrs, secstrings,
+                                       "__kcrctab_unused");
+       mod->unused_gpl_syms = section_objs(hdr, sechdrs, secstrings,
+                                           "__ksymtab_unused_gpl",
+                                           sizeof(*mod->unused_gpl_syms),
+                                           &mod->num_unused_gpl_syms);
+       mod->unused_gpl_crcs = section_addr(hdr, sechdrs, secstrings,
+                                           "__kcrctab_unused_gpl");
+#endif
+#ifdef CONFIG_CONSTRUCTORS
+       mod->ctors = section_objs(hdr, sechdrs, secstrings, ".ctors",
+                                 sizeof(*mod->ctors), &mod->num_ctors);
+#endif
+
+#ifdef CONFIG_TRACEPOINTS
+       mod->tracepoints = section_objs(hdr, sechdrs, secstrings,
+                                       "__tracepoints",
+                                       sizeof(*mod->tracepoints),
+                                       &mod->num_tracepoints);
+#endif
+#ifdef CONFIG_EVENT_TRACING
+       mod->trace_events = section_objs(hdr, sechdrs, secstrings,
+                                        "_ftrace_events",
+                                        sizeof(*mod->trace_events),
+                                        &mod->num_trace_events);
+       /*
+        * This section contains pointers to allocated objects in the trace
+        * code and not scanning it leads to false positives.
+        */
+       kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
+                          mod->num_trace_events, GFP_KERNEL);
+#endif
+#ifdef CONFIG_FTRACE_MCOUNT_RECORD
+       /* sechdrs[0].sh_size is always zero */
+       mod->ftrace_callsites = section_objs(hdr, sechdrs, secstrings,
+                                            "__mcount_loc",
+                                            sizeof(*mod->ftrace_callsites),
+                                            &mod->num_ftrace_callsites);
+#endif
+}
+
 /* Allocate and load the module: note that size of section 0 is always
    zero, and we rely on this for optional sections. */
 static noinline struct module *load_module(void __user *umod,
@@ -2147,7 +2212,7 @@ static noinline struct module *load_module(void __user *umod,
        }
 
        /* Sanity checks against insmoding binaries or wrong arch,
-           weird elf version */
+          weird elf version */
        if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
            || hdr->e_type != ET_REL
            || !elf_check_arch(hdr)
@@ -2326,7 +2391,8 @@ static noinline struct module *load_module(void __user *umod,
                               sechdrs[i].sh_size);
                /* Update sh_addr to point to copy in image. */
                sechdrs[i].sh_addr = (unsigned long)dest;
-               DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
+               DEBUGP("\t0x%lx %s\n",
+                      sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
        }
        /* Module has been moved. */
        mod = (void *)sechdrs[modindex].sh_addr;
@@ -2368,66 +2434,8 @@ static noinline struct module *load_module(void __user *umod,
 
        /* Now we've got everything in the final locations, we can
         * find optional sections. */
-       mod->kp = section_objs(hdr, sechdrs, secstrings, "__param",
-                              sizeof(*mod->kp), &mod->num_kp);
-       mod->syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab",
-                                sizeof(*mod->syms), &mod->num_syms);
-       mod->crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab");
-       mod->gpl_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_gpl",
-                                    sizeof(*mod->gpl_syms),
-                                    &mod->num_gpl_syms);
-       mod->gpl_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_gpl");
-       mod->gpl_future_syms = section_objs(hdr, sechdrs, secstrings,
-                                           "__ksymtab_gpl_future",
-                                           sizeof(*mod->gpl_future_syms),
-                                           &mod->num_gpl_future_syms);
-       mod->gpl_future_crcs = section_addr(hdr, sechdrs, secstrings,
-                                           "__kcrctab_gpl_future");
+       find_module_sections(mod, hdr, sechdrs, secstrings);
 
-#ifdef CONFIG_UNUSED_SYMBOLS
-       mod->unused_syms = section_objs(hdr, sechdrs, secstrings,
-                                       "__ksymtab_unused",
-                                       sizeof(*mod->unused_syms),
-                                       &mod->num_unused_syms);
-       mod->unused_crcs = section_addr(hdr, sechdrs, secstrings,
-                                       "__kcrctab_unused");
-       mod->unused_gpl_syms = section_objs(hdr, sechdrs, secstrings,
-                                           "__ksymtab_unused_gpl",
-                                           sizeof(*mod->unused_gpl_syms),
-                                           &mod->num_unused_gpl_syms);
-       mod->unused_gpl_crcs = section_addr(hdr, sechdrs, secstrings,
-                                           "__kcrctab_unused_gpl");
-#endif
-#ifdef CONFIG_CONSTRUCTORS
-       mod->ctors = section_objs(hdr, sechdrs, secstrings, ".ctors",
-                                 sizeof(*mod->ctors), &mod->num_ctors);
-#endif
-
-#ifdef CONFIG_TRACEPOINTS
-       mod->tracepoints = section_objs(hdr, sechdrs, secstrings,
-                                       "__tracepoints",
-                                       sizeof(*mod->tracepoints),
-                                       &mod->num_tracepoints);
-#endif
-#ifdef CONFIG_EVENT_TRACING
-       mod->trace_events = section_objs(hdr, sechdrs, secstrings,
-                                        "_ftrace_events",
-                                        sizeof(*mod->trace_events),
-                                        &mod->num_trace_events);
-       /*
-        * This section contains pointers to allocated objects in the trace
-        * code and not scanning it leads to false positives.
-        */
-       kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
-                          mod->num_trace_events, GFP_KERNEL);
-#endif
-#ifdef CONFIG_FTRACE_MCOUNT_RECORD
-       /* sechdrs[0].sh_size is always zero */
-       mod->ftrace_callsites = section_objs(hdr, sechdrs, secstrings,
-                                            "__mcount_loc",
-                                            sizeof(*mod->ftrace_callsites),
-                                            &mod->num_ftrace_callsites);
-#endif
 #ifdef CONFIG_MODVERSIONS
        if ((mod->num_syms && !mod->crcs)
            || (mod->num_gpl_syms && !mod->gpl_crcs)