patcher: fix powerpc/power support in patcher/linux

This commit does the following:

 - Move code necessary for powerpc/power support to the patcher
   base. The code is needed by both the overwrite and linux
   components.

 - Move patch structure down to base and move the patch list to
   mca_patcher_base_module_t. The structure has been modified to
   include a function pointer to the function that will unapply the
   patch. This allows the mixing of multiple different types of
   patches in the patch_list.

 - Update linux patching code to keep track of the matching between
   got entry and original (unpatched) address. This allows us to
   completely clean up the patch on finalize.

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>

opal/mca/patcher/base/Makefile.am

@@ -21,4 +21,5 @@
 
 headers += base/base.h
 
-libmca_patcher_la_SOURCES += base/patcher_base_frame.c
+libmca_patcher_la_SOURCES += base/patcher_base_frame.c \
+	base/patcher_base_patch.c

opal/mca/patcher/base/base.h

@@ -30,11 +30,54 @@
 
 BEGIN_C_DECLS
 
+#define MCA_BASE_PATCHER_MAX_PATCH 32
+
+struct mca_patcher_base_patch_t;
+
+typedef void (*mca_patcher_base_restore_fn_t) (struct mca_patcher_base_patch_t *);
+
+struct mca_patcher_base_patch_t {
+    /** patches are list items */
+    opal_list_item_t super;
+    /** name symbol to patch */
+    char            *patch_symbol;
+    /** address of function to call instead */
+    uintptr_t        patch_value;
+    /** original address of function */
+    uintptr_t        patch_orig;
+    /** patch data */
+    unsigned char    patch_data[MCA_BASE_PATCHER_MAX_PATCH];
+    /** original data */
+    unsigned char    patch_orig_data[MCA_BASE_PATCHER_MAX_PATCH];
+    /** size of patch data */
+    unsigned         patch_data_size;
+    /** function to undo the patch */
+    mca_patcher_base_restore_fn_t patch_restore;
+};
+
+typedef struct mca_patcher_base_patch_t mca_patcher_base_patch_t;
+
+OBJ_CLASS_DECLARATION(mca_patcher_base_patch_t);
+
 /**
  * Framework struct declaration for this framework
  */
 OPAL_DECLSPEC extern mca_base_framework_t opal_patcher_base_framework;
 OPAL_DECLSPEC int opal_patcher_base_select (void);
+OPAL_DECLSPEC int mca_patcher_base_patch_hook (mca_patcher_base_module_t *module, uintptr_t hook);
+OPAL_DECLSPEC void mca_base_patcher_patch_apply_binary (mca_patcher_base_patch_t *patch);
+
+static inline uintptr_t mca_patcher_base_addr_text (uintptr_t addr) {
+#if (defined(__PPC64__) || defined(__powerpc64__) || defined(__PPC__)) && _CALL_ELF != 2
+    struct odp_t {
+        uintptr_t text;
+        uintptr_t toc;
+    } *odp = (struct odp_t *) addr;
+    return (odp)?odp->text:0;
+#else
+    return addr;
+#endif
+}
 
 END_C_DECLS
 #endif /* OPAL_BASE_PATCHER_H */

opal/mca/patcher/base/patcher_base_frame.c

@@ -39,6 +39,9 @@ int opal_patcher_base_select (void)
         return rc;
     }
 
+    OBJ_CONSTRUCT(&best_module->patch_list, opal_list_t);
+    OBJ_CONSTRUCT(&best_module->patch_list_mutex, opal_mutex_t);
+
     if (best_module->patch_init) {
         rc = best_module->patch_init ();
         if (OPAL_SUCCESS != rc) {
@@ -53,6 +56,14 @@ int opal_patcher_base_select (void)
 
 static int opal_patcher_base_close (void)
 {
+    mca_patcher_base_patch_t *patch;
+    OPAL_LIST_FOREACH_REV(patch, &opal_patcher->patch_list, mca_patcher_base_patch_t) {
+        patch->patch_restore (patch);
+    }
+
+    OPAL_LIST_DESTRUCT(&opal_patcher->patch_list);
+    OBJ_DESTRUCT(&opal_patcher->patch_list_mutex);
+
     if (opal_patcher->patch_fini) {
         return opal_patcher->patch_fini ();
     }

opal/mca/patcher/base/patcher_base_patch.c

@@ -0,0 +1,175 @@
+/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2016      Los Alamos National Security, LLC. All rights
+ *                         reserved.
+ * $COPYRIGHT$
+ *
+ * Additional copyrights may follow
+ *
+ * $HEADER$
+ */
+
+#include "opal_config.h"
+
+#include "opal/mca/patcher/patcher.h"
+#include "opal/mca/patcher/base/base.h"
+#include "opal/util/sys_limits.h"
+#include "opal/prefetch.h"
+#include <sys/mman.h>
+
+static void mca_patcher_base_patch_construct (mca_patcher_base_patch_t *patch)
+{
+    patch->patch_symbol = NULL;
+    patch->patch_data_size = 0;
+}
+
+static void mca_patcher_base_patch_destruct (mca_patcher_base_patch_t *patch)
+{
+    free (patch->patch_symbol);
+}
+
+OBJ_CLASS_INSTANCE(mca_patcher_base_patch_t, opal_list_item_t,
+                   mca_patcher_base_patch_construct,
+                   mca_patcher_base_patch_destruct);
+
+#if defined(__PPC__)
+
+// PowerPC instructions used in patching
+// Reference: "PowerPC User Instruction Set Architecture"
+static unsigned int addis(unsigned int RT, unsigned int RS, unsigned int UI) {
+    return (15<<26) + (RT<<21) + (RS<<16) + (UI&0xffff);
+}
+static unsigned int ori(unsigned int RT, unsigned int RS, unsigned int UI) {
+    return (24<<26) + (RS<<21) + (RT<<16) + (UI&0xffff);
+}
+static unsigned int oris(unsigned int RT, unsigned int RS, unsigned int UI) {
+    return (25<<26) + (RS<<21) + (RT<<16) + (UI&0xffff);
+}
+static unsigned int mtspr(unsigned int SPR, unsigned int RS) {
+    return (31<<26) + (RS<<21) + ((SPR&0x1f)<<16) + ((SPR>>5)<<11) + (467<<1);
+}
+static unsigned int bcctr(unsigned int BO, unsigned int BI, unsigned int BH) {
+    return (19<<26) + (BO<<21) + (BI<<16) + (BH<<11) + (528<<1);
+}
+static unsigned int rldicr(unsigned int RT, unsigned int RS, unsigned int SH, unsigned int MB)
+{
+    return (30<<26) + (RS<<21) + (RT<<16) + ((SH&0x1f)<<11) + ((SH>>5)<<1)
+        + ((MB&0x1f)<<6) + ((MB>>5)<<5) + (1<<2);
+}
+
+static int PatchLoadImm (uintptr_t addr, unsigned int reg, size_t value)
+{
+#if defined(__PPC64__)
+    *(unsigned int *) (addr + 0) = addis ( reg, 0,   (value >> 48));
+    *(unsigned int *) (addr + 4) = ori   ( reg, reg, (value >> 32));
+    *(unsigned int *) (addr + 8) = rldicr( reg, reg, 32, 31);
+    *(unsigned int *) (addr +12) = oris  ( reg, reg, (value >> 16));
+    *(unsigned int *) (addr +16) = ori   ( reg, reg, (value >>  0));
+    return 20;
+#else
+    *(unsigned int *) (addr + 0) = addis ( reg, 0,   (value >> 16));
+    *(unsigned int *) (addr + 4) = ori   ( reg, reg, (value >>  0));
+    return 8;
+#endif
+}
+
+#endif
+
+#if defined(__i386__) || defined(__x86_64__) || defined(__ia64__)
+
+static void flush_and_invalidate_cache (unsigned long  a)
+{
+#if defined(__i386__)
+    /* does not work with AMD processors */
+    __asm__ volatile("mfence;clflush %0;mfence" : :"m" (*(char*)a));
+#elif defined(__x86_64__)
+    __asm__ volatile("mfence;clflush %0;mfence" : :"m" (*(char*)a));
+#elif defined(__ia64__)
+    __asm__ volatile ("fc %0;; sync.i;; srlz.i;;" : : "r"(a) : "memory");
+#endif
+}
+#endif
+
+// modify protection of memory range
+static void ModifyMemoryProtection (uintptr_t addr, size_t length, int prot)
+{
+    long      page_size = opal_getpagesize ();
+    uintptr_t base = (addr & ~(page_size-1));
+    uintptr_t bound = ((addr + length + page_size-1) & ~(page_size-1));
+
+    length = bound - base;
+
+#if defined(__PPC__)
+    /* NTH: is a loop necessary here? */
+    do {
+        if (mprotect((void *)base, page_size, prot))
+            perror("MemHook: mprotect failed");
+        base += page_size;
+    } while (base < addr + length);
+#else
+    if (mprotect((void *) base, length, prot)) {
+            perror("MemHook: mprotect failed");
+    }
+#endif
+}
+
+static inline void apply_patch (unsigned char *patch_data, uintptr_t address, size_t data_size)
+{
+    ModifyMemoryProtection (address, data_size, PROT_EXEC|PROT_READ|PROT_WRITE);
+    memcpy ((void *) address, patch_data, data_size);
+#if defined(__i386__) || defined(__x86_64__) || defined(__ia64__)
+    for (size_t i = 0 ; i < data_size ; i += 16) {
+        flush_and_invalidate_cache (address + i);
+    }
+#endif
+
+    ModifyMemoryProtection (address, data_size, PROT_EXEC|PROT_READ);
+}
+
+static void mca_base_patcher_patch_unapply_binary (mca_patcher_base_patch_t *patch)
+{
+    apply_patch (patch->patch_orig_data, patch->patch_orig, patch->patch_data_size);
+}
+
+void mca_base_patcher_patch_apply_binary (mca_patcher_base_patch_t *patch)
+{
+    memcpy (patch->patch_orig_data, (void *) patch->patch_orig, patch->patch_data_size);
+    apply_patch (patch->patch_data, patch->patch_orig, patch->patch_data_size);
+    patch->patch_restore = mca_base_patcher_patch_unapply_binary;
+}
+
+
+int mca_patcher_base_patch_hook (mca_patcher_base_module_t *module, uintptr_t hook_addr)
+{
+#if defined(__PPC64__) || defined(__powerpc64__) || defined(__PPC__)
+    mca_patcher_base_patch_t *hook_patch;
+    const unsigned int nop = 0x60000000;
+    unsigned int *nop_addr;
+
+    fprintf (stderr, "Patching hook @ 0x%lx\n", hook_addr);
+
+    hook_patch = OBJ_NEW(mca_patcher_base_patch_t);
+    if (OPAL_UNLIKELY(NULL == hook_patch)) {
+        return OPAL_ERR_OUT_OF_RESOURCE;
+    }
+
+    // locate reserved code space in hook function
+    for (nop_addr = (unsigned int *)hook_addr ; ; nop_addr++) {
+        if (nop_addr[0] == nop && nop_addr[1] == nop && nop_addr[2] == nop
+                && nop_addr[3] == nop && nop_addr[4] == nop) {
+            break;
+        }
+    }
+    // generate code to restore TOC
+    register unsigned long toc asm("r2");
+    hook_patch->patch_orig = (uintptr_t) nop_addr;
+    hook_patch->patch_data_size = PatchLoadImm((uintptr_t)hook_patch->patch_data, 2, toc);
+
+    /* put the hook patch on the patch list so it will be undone on finalize */
+    opal_list_append (&module->patch_list, &hook_patch->super);
+
+    mca_base_patcher_patch_apply_binary (hook_patch);
+#endif
+
+    return OPAL_SUCCESS;
+}

opal/mca/patcher/linux/patcher_linux.h

@@ -20,35 +20,25 @@
 #include "opal/class/opal_list.h"
 #include "opal/threads/mutex.h"
 
-struct mca_patcher_linux_patch_t {
-    /** patches are list items */
+struct mca_patcher_linux_patch_got_t {
     opal_list_item_t super;
-    /** name symbol to patch */
-    char *symbol;
-    /** address of function to call instead */
-    uintptr_t value;
-    /** original address of function */
-    uintptr_t orig;
+    void **got_entry;
+    void *got_orig;
 };
 
-typedef struct mca_patcher_linux_patch_t mca_patcher_linux_patch_t;
-
-OBJ_CLASS_DECLARATION(mca_patcher_linux_patch_t);
+typedef struct mca_patcher_linux_patch_got_t mca_patcher_linux_patch_got_t;
 
-struct mca_patcher_linux_module_t {
-    mca_patcher_base_module_t super;
+OBJ_CLASS_DECLARATION(mca_patcher_linux_patch_got_t);
 
-    opal_list_t patch_list;
-    opal_mutex_t patch_list_mutex;
+struct mca_patcher_linux_patch_t {
+    mca_patcher_base_patch_t super;
+    opal_list_t patch_got_list;
 };
 
-typedef struct mca_patcher_linux_module_t mca_patcher_linux_module_t;
+typedef struct mca_patcher_linux_patch_t mca_patcher_linux_patch_t;
 
-extern mca_patcher_linux_module_t mca_patcher_linux_module;
+OBJ_CLASS_DECLARATION(mca_patcher_linux_patch_t);
 
-int mca_patcher_linux_install_dlopen (void);
-int mca_patcher_linux_remove_dlopen (void);
-int mca_patcher_linux_patch_symbol (const char *symbol_name, uintptr_t replacement, uintptr_t *orig);
-int mca_patcher_linux_remove_patch (mca_patcher_linux_patch_t *patch);
+extern mca_patcher_base_module_t mca_patcher_linux_module;
 
 #endif /* !defined(OPAL_PATCHER_LINUX_H) */

opal/mca/patcher/linux/patcher_linux_component.c

@@ -13,7 +13,7 @@
 
 static int mca_patcher_linux_query (mca_base_module_t **module, int *priority)
 {
-    *module = &mca_patcher_linux_module.super.super;
+    *module = &mca_patcher_linux_module.super;
     *priority = 37;
     return OPAL_SUCCESS;
 }