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Jun 3, 2019
Merged

shmat/shmdt additions for patcher #6720

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122 changes: 98 additions & 24 deletions opal/mca/memory/patcher/memory_patcher_component.c
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@
* reserved.
* Copyright (c) 2016-2017 Research Organization for Information Science
* and Technology (RIST). All rights reserved.
* Copyright (c) 2016 IBM Corporation. All rights reserved.
* Copyright (c) 2016-2019 IBM Corporation. All rights reserved.
*
* $COPYRIGHT$
*
Expand Down Expand Up @@ -48,6 +48,9 @@
#if defined(HAVE_LINUX_MMAN_H)
#include <linux/mman.h>
#endif
#if defined(HAVE_SYS_IPC_H)
#include <sys/ipc.h>
#endif

#include "memory_patcher.h"
#undef opal_memory_changed
Expand Down Expand Up @@ -104,15 +107,7 @@ opal_memory_patcher_component_t mca_memory_patcher_component = {
* data. If this can be resolved the two levels can be joined.
*/

/*
* The following block of code is #if 0'ed out because we do not need
* to intercept mmap() any more (mmap() only deals with memory
* protection; it does not invalidate any rcache entries for a given
* region). But if we do someday, this is the code that we'll need.
* It's a little non-trivial, so we might as well keep it (and #if 0
* it out).
*/
#if 0
#if defined (SYS_mmap)

#if defined(HAVE___MMAP) && !HAVE_DECL___MMAP
/* prototype for Apple's internal mmap function */
Expand All @@ -121,12 +116,11 @@ void *__mmap (void *start, size_t length, int prot, int flags, int fd, off_t off

static void *(*original_mmap)(void *, size_t, int, int, int, off_t);

static void *intercept_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
static void *_intercept_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
OPAL_PATCHER_BEGIN;
void *result = 0;

if (prot == PROT_NONE) {
if ((flags & MAP_FIXED) && (start != NULL)) {
opal_mem_hooks_release_hook (start, length, true);
}

Expand All @@ -137,19 +131,20 @@ static void *intercept_mmap(void *start, size_t length, int prot, int flags, int
#else
result = (void*)(intptr_t) memory_patcher_syscall(SYS_mmap, start, length, prot, flags, fd, offset);
#endif

// I thought we had some issue in the past with the above line for IA32,
// like maybe syscall() wouldn't handle that many arguments. But just now
// I used gcc -m32 and it worked on a recent system. But there's a possibility
// that older ia32 systems may need some other code to make the above syscall.
} else {
result = original_mmap (start, length, prot, flags, fd, offset);
}

OPAL_PATCHER_END;
return result;
}

static void *intercept_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
OPAL_PATCHER_BEGIN;
void *result = _intercept_mmap (start, length, prot, flags, fd, offset);
OPAL_PATCHER_END;
return result;
}
#endif

#if defined (SYS_munmap)
Expand Down Expand Up @@ -256,6 +251,9 @@ static int _intercept_madvise (void *start, size_t length, int advice)
int result = 0;

if (advice == MADV_DONTNEED ||
#ifdef MADV_FREE
advice == MADV_FREE ||
#endif
#ifdef MADV_REMOVE
advice == MADV_REMOVE ||
#endif
Expand Down Expand Up @@ -341,7 +339,12 @@ static int intercept_brk (void *addr)

#endif

#if defined(SYS_shmdt) && defined(__linux__)
#define HAS_SHMDT (defined(SYS_shmdt) || \
(defined(IPCOP_shmdt) && defined(SYS_ipc)))
#define HAS_SHMAT (defined(SYS_shmat) || \
(defined(IPCOP_shmat) && defined(SYS_ipc)))

#if (HAS_SHMDT || HAS_SHMAT) && defined(__linux__)

#include <stdio.h>
#include <fcntl.h>
Expand Down Expand Up @@ -404,6 +407,68 @@ static size_t memory_patcher_get_shm_seg_size (const void *shmaddr)
return seg_size;
}

static size_t get_shm_size(int shmid)
{
struct shmid_ds ds;
int ret;

ret = shmctl(shmid, IPC_STAT, &ds);
if (ret < 0) {
return 0;
}

return ds.shm_segsz;
}
#endif

#if HAS_SHMAT && defined(__linux__)
static void *(*original_shmat)(int shmid, const void *shmaddr, int shmflg);

static void *_intercept_shmat(int shmid, const void *shmaddr, int shmflg)
{
void *result = 0;

size_t size = get_shm_size(shmid);

if ((shmflg & SHM_REMAP) && (shmaddr != NULL)) {
// I don't really know what REMAP combined with SHM_RND does, so I'll just
// guess it remaps all the way down to the lower attach_addr, and all the
// way up to the original shmaddr+size
uintptr_t attach_addr = (uintptr_t)shmaddr;

if (shmflg & SHM_RND) {
attach_addr -= ((uintptr_t)shmaddr) % SHMLBA;
size += ((uintptr_t)shmaddr) % SHMLBA;
}
opal_mem_hooks_release_hook ((void*)attach_addr, size, false);
}

if (!original_shmat) {
#if defined(SYS_shmat)
result = memory_patcher_syscall(SYS_shmat, shmid, shmaddr, shmflg);
#else // IPCOP_shmat
unsigned long ret;
ret = memory_patcher_syscall(SYS_ipc, IPCOP_shmat,
shmid, shmflg, &shmaddr, shmaddr);
result = (ret > -(unsigned long)SHMLBA) ? (void *)ret : (void *)shmaddr;
#endif
} else {
result = original_shmat (shmid, shmaddr, shmflg);
}

return result;
}

static void* intercept_shmat (int shmid, const void * shmaddr, int shmflg)
{
OPAL_PATCHER_BEGIN;
void *result = _intercept_shmat (shmid, shmaddr, shmflg);
OPAL_PATCHER_END;
return result;
}
#endif

#if HAS_SHMDT && defined(__linux__)
static int (*original_shmdt) (const void *);

static int _intercept_shmdt (const void *shmaddr)
Expand All @@ -417,7 +482,11 @@ static int _intercept_shmdt (const void *shmaddr)
if (original_shmdt) {
result = original_shmdt (shmaddr);
} else {
#if defined(SYS_shmdt)
result = memory_patcher_syscall (SYS_shmdt, shmaddr);
#else // IPCOP_shmdt
result = memory_patcher_syscall(SYS_ipc, IPCOP_shmdt, 0, 0, 0, shmaddr);
#endif
}

return result;
Expand Down Expand Up @@ -478,9 +547,7 @@ static int patcher_open (void)
/* set memory hooks support level */
opal_mem_hooks_set_support (OPAL_MEMORY_FREE_SUPPORT | OPAL_MEMORY_MUNMAP_SUPPORT);

#if 0
/* See above block to see why mmap() functionality is #if 0'ed
out */
#if defined (SYS_mmap)
rc = opal_patcher->patch_symbol ("mmap", (uintptr_t) intercept_mmap, (uintptr_t *) &original_mmap);
if (OPAL_SUCCESS != rc) {
return rc;
Expand Down Expand Up @@ -508,7 +575,14 @@ static int patcher_open (void)
}
#endif

#if defined(SYS_shmdt) && defined(__linux__)
#if HAS_SHMAT && defined(__linux__)
rc = opal_patcher->patch_symbol ("shmat", (uintptr_t) intercept_shmat, (uintptr_t *) &original_shmat);
if (OPAL_SUCCESS != rc) {
return rc;
}
#endif

#if HAS_SHMDT && defined(__linux__)
rc = opal_patcher->patch_symbol ("shmdt", (uintptr_t) intercept_shmdt, (uintptr_t *) &original_shmdt);
if (OPAL_SUCCESS != rc) {
return rc;
Expand Down