openmpi/opal/mca/patcher/overwrite/patcher_overwrite_module.c

/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
/*
 * Copyright (c) 2016-2018 Los Alamos National Security, LLC. All rights
 *                         reserved.
 * Copyright (c) 2016      IBM Corporation.  All rights reserved.
 * Copyright (c) 2017      Research Organization for Information Science
 *                         and Technology (RIST). All rights reserved.
 * $COPYRIGHT$
 *
 * Additional copyrights may follow
 *
 * $HEADER$
 */

#include "patcher_overwrite.h"

#include "opal/mca/patcher/base/base.h"

#include "opal/constants.h"
#include "opal/util/sys_limits.h"
#include "opal/util/output.h"
#include "opal/prefetch.h"

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <string.h>
#include <sys/mman.h>
#include <dlfcn.h>
#include <assert.h>

#if (OPAL_ASSEMBLY_ARCH == OPAL_IA32) || (OPAL_ASSEMBLY_ARCH == OPAL_X86_64)

static int mca_patcher_overwrite_apply_patch (mca_patcher_base_patch_t *patch)
{
    uintptr_t func_new_addr = patch->patch_value;

    {
#if (OPAL_ASSEMBLY_ARCH == OPAL_IA32)
        patch->patch_data_size = 5;
        *(unsigned char *)(patch->patch_data+0) = 0xe9;
        *(unsigned int *) (patch->patch_data+1) = (unsigned int)(func_new_addr - patch->patch_orig - 5);
#elif (OPAL_ASSEMBLY_ARCH == OPAL_X86_64)
        patch->patch_data_size = 13;
        *(unsigned short*)(patch->patch_data + 0) = 0xbb49;
        *(unsigned long* )(patch->patch_data + 2) = (unsigned long) func_new_addr;
        *(unsigned char*) (patch->patch_data +10) = 0x41;
        *(unsigned char*) (patch->patch_data +11) = 0xff;
        *(unsigned char*) (patch->patch_data +12) = 0xe3;
#endif
    }

    mca_base_patcher_patch_apply_binary (patch);

    return OPAL_SUCCESS;
}

/* end of #if defined(__i386__) || defined(__x86_64__) || defined(__ia64__) */
// ------------------------------------------------- PPC equivalent:
#elif (OPAL_ASSEMBLY_ARCH == OPAL_POWERPC32) || (OPAL_ASSEMBLY_ARCH == OPAL_POWERPC64)

// 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 (OPAL_ASSEMBLY_ARCH == OPAL_POWERPC64)
    *(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
}


static int mca_patcher_overwrite_apply_patch (mca_patcher_base_patch_t *patch)
{
    uintptr_t sys_addr, hook_addr;
    int offset, rc;

    // get system function address
    sys_addr = mca_patcher_base_addr_text(patch->patch_orig);
    hook_addr = mca_patcher_base_addr_text(patch->patch_value);

// Patch for hook function:
#if (OPAL_ASSEMBLY_ARCH == OPAL_POWERPC64)
    rc = mca_patcher_base_patch_hook (&mca_patcher_overwrite_module, hook_addr);
    if (OPAL_SUCCESS != rc) {
        return rc;
    }

#if defined(_CALL_ELF) && (_CALL_ELF == 2)
    sys_addr += 8;
    hook_addr += 8;
#endif /* _CALL_ELF == 2*/
#endif

    // Patch for system function:
    // generate patch code
    // r11 is a volatile register according to PowerPC EABI
    const unsigned int gr = 11;
    offset = PatchLoadImm ((uintptr_t) patch->patch_data, gr, hook_addr);
    *(unsigned int *) (patch->patch_data + offset + 0) = mtspr (9, gr);   // 9 = CTR
    *(unsigned int *) (patch->patch_data + offset + 4) = bcctr (20, 0, 0);// 20 = always
    patch->patch_data_size = offset + 8;
    patch->patch_orig = sys_addr;

    mca_base_patcher_patch_apply_binary (patch);

    return OPAL_SUCCESS;
}

#elif defined(__aarch64__)

/**
 * @brief Generate a mov immediate instruction
 *
 * @param[in] reg   register number (0-31)
 * @param[in] shift shift amount (0-3) * 16-bits
 * @param[in] value immediate value
 */
static uint32_t mov (unsigned int reg, uint16_t shift, uint16_t value)
{
    return (0x1a5 << 23) + ((uint32_t) shift << 21) + ((uint32_t) value << 5) + reg;
}

/**
 * @brief Generate a mov immediate with keep instruction
 *
 * @param[in] reg   register number (0-31)
 * @param[in] shift shift amount (0-3) * 16-bits
 * @param[in] value immediate value
 */
static uint32_t movk (unsigned int reg, uint16_t shift, uint16_t value)
{
    return (0x1e5 << 23) + ((uint32_t) shift << 21) + ((uint32_t) value << 5) + reg;
}

static uint32_t br (unsigned int reg)
{
    return (0xd61f << 16) + (reg << 5);
}

static int
PatchLoadImm(uintptr_t addr, unsigned int reg, uint64_t value)
{
    *(uint32_t *) (addr +  0) = mov(reg, 3, value >> 48);
    *(uint32_t *) (addr +  4) = movk(reg, 2, value >> 32);
    *(uint32_t *) (addr +  8) = movk(reg, 1, value >> 16);
    *(uint32_t *) (addr + 12) = movk(reg, 0, value);
    return 16;
}

static int mca_patcher_overwrite_apply_patch (mca_patcher_base_patch_t *patch)
{
    uintptr_t sys_addr, hook_addr;
    int offset, rc;

    /* get system function address */
    sys_addr = mca_patcher_base_addr_text(patch->patch_orig);
    hook_addr = mca_patcher_base_addr_text(patch->patch_value);

    /* Patch for hook function: */
    rc = mca_patcher_base_patch_hook (&mca_patcher_overwrite_module, hook_addr);
    if (OPAL_SUCCESS != rc) {
        return rc;
    }

    /* Patch for system function:
     * generate patch code
     * r15 is the highest numbered temporary register. I am assuming this one is safe
     * to use. */
    const unsigned int gr = 15;
    offset = PatchLoadImm ((uintptr_t) patch->patch_data, gr, hook_addr);
    *(uint32_t *) (patch->patch_data + offset) = br(gr);
    patch->patch_data_size = offset + 4;
    patch->patch_orig = sys_addr;

    mca_base_patcher_patch_apply_binary (patch);

    return OPAL_SUCCESS;
}

#endif

static int mca_patcher_overwrite_patch_address (uintptr_t sys_addr, uintptr_t hook_addr)
{
    mca_patcher_base_patch_t *patch;
    int rc;

    patch = OBJ_NEW(mca_patcher_base_patch_t);
    if (OPAL_UNLIKELY(NULL == patch)) {
        return OPAL_ERR_OUT_OF_RESOURCE;
    }

    patch->patch_orig = sys_addr;
    patch->patch_value = hook_addr;

    opal_mutex_lock (&mca_patcher_overwrite_module.patch_list_mutex);
    do {
        rc = mca_patcher_overwrite_apply_patch (patch);
        if (OPAL_SUCCESS != rc) {
            break;
        }

        opal_list_append (&mca_patcher_overwrite_module.patch_list, &patch->super);
    } while (0);

    opal_mutex_unlock (&mca_patcher_overwrite_module.patch_list_mutex);

    return OPAL_SUCCESS;
}

static int mca_patcher_overwrite_patch_symbol (const char *func_symbol_name, uintptr_t func_new_addr,
                                               uintptr_t *func_old_addr)
{
    void *sym_addr;
    char *error;
    uintptr_t old_addr;

    /* NTH: might want to update opal/mca/dl to handle lookups in the default
     * handle. */
    sym_addr = dlsym (RTLD_NEXT, func_symbol_name);
    if (NULL == sym_addr) {
        sym_addr = dlsym(RTLD_DEFAULT, func_symbol_name);
        if ( (sym_addr == NULL) && ((error = dlerror()) != NULL) )  {
            opal_output(0, "error locating symbol %s to patch. %s", func_symbol_name,
                        error);
            return OPAL_ERR_NOT_FOUND;
        }
    }

    old_addr = (unsigned long)sym_addr;

    if (func_old_addr) {
        /* we will be overwritting part of the original function. do not return
         * its address */
        *func_old_addr = 0;
    }

    return mca_patcher_overwrite_patch_address (old_addr, func_new_addr);
}

mca_patcher_base_module_t mca_patcher_overwrite_module = {
    .patch_symbol = mca_patcher_overwrite_patch_symbol,
    .patch_address = mca_patcher_overwrite_patch_address,
};