// memory/vm related tapset
// Copyright (C) 2005, 2006 IBM Corp.
// Copyright (C) 2006 Intel Corporation.
// Copyright (C) 2010 Red Hat Inc.
//
// This file is part of systemtap, and is free software.  You can
// redistribute it and/or modify it under the terms of the GNU General
// Public License (GPL); either version 2, or (at your option) any
// later version.
// <tapsetdescription>
// This family of probe points is used to probe memory-related events. 
// </tapsetdescription>
%{
#include <linux/mm.h>
%}

global VM_FAULT_OOM=0, VM_FAULT_SIGBUS=1, VM_FAULT_MINOR=2, VM_FAULT_MAJOR=3
global VM_FAULT_NOPAGE=4, VM_FAULT_LOCKED=5, VM_FAULT_ERROR=6
global FAULT_FLAG_WRITE=1

/**
 * sfunction vm_fault_contains - Test return value for page fault reason
 *
 * @value: the fault_type returned by vm.page_fault.return
 * @test: the type of fault to test for (VM_FAULT_OOM or similar)
 */
function vm_fault_contains:long (value:long, test:long)
%{
	int res;
	switch (STAP_ARG_test){
	case 0: res = STAP_ARG_value & VM_FAULT_OOM; break;
	case 1: res = STAP_ARG_value & VM_FAULT_SIGBUS; break;
#if defined(VM_FAULT_MINOR) && VM_FAULT_MINOR == 0
	case 2: /* VM_FAULT_MINOR infered by that flags off */
		res = !((VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_MAJOR) & 
				 STAP_ARG_value);
		break;
#else
	case 2: res = STAP_ARG_value == VM_FAULT_MINOR; break;
#endif
	case 3: res = STAP_ARG_value & VM_FAULT_MAJOR; break;
#ifdef VM_FAULT_NOPAGE
	case 4: res = STAP_ARG_value & VM_FAULT_NOPAGE; break;
#endif
#ifdef VM_FAULT_LOCKED
	case 5: res = STAP_ARG_value & VM_FAULT_LOCKED; break;
#endif
#ifdef VM_FAULT_ERROR
	case 6: res = STAP_ARG_value & VM_FAULT_ERROR; break;
#endif
	default: res = 0; break;
	}
	STAP_RETVALUE = (res != 0);
	return;
%}

/**
 * probe vm.pagefault - Records that a page fault occurred
 *
 * @name: name of the probe point
 * @address: the address of the faulting memory access; i.e. the address that caused the page fault
 * @write_access: indicates whether this was a write or read access; 1 indicates a write, 
 * while 0 indicates a read
 *
 * Context: The process which triggered the fault
 */
probe vm.pagefault = kernel.function("__handle_mm_fault@mm/memory.c") ?,
                     kernel.function("handle_mm_fault@mm/memory.c") ?
{
	name = "pagefault"
	write_access = (@defined($flags)
			? $flags & FAULT_FLAG_WRITE : $write_access)
	address =  $address
}

/**
 * probe vm.pagefault.return - Indicates what type of fault occurred
 *
 * @name: name of the probe point
 * @fault_type: returns either 
 * 0 (VM_FAULT_OOM) for out of memory faults, 
 * 2 (VM_FAULT_MINOR) for minor faults, 3 (VM_FAULT_MAJOR) for 
 * major faults, or 1 (VM_FAULT_SIGBUS) if the fault was neither OOM, minor fault, 
 * nor major fault.
 */
probe vm.pagefault.return =
		kernel.function("__handle_mm_fault@mm/memory.c").return ?,
		kernel.function("handle_mm_fault@mm/memory.c").return ?
{
	name = "pagefault"
	fault_type = $return
}

/**
 * sfunction addr_to_node - Returns which node a given address belongs to within a NUMA system
 *
 * @addr: the address of the faulting memory access
 *
 * Description: This function accepts an address, and returns the 
 * node that the given address belongs to in a NUMA system.
 */
function addr_to_node:long(addr:long) %{ /* pure */ 
	int nid;
	int pfn;
        if (! virt_addr_valid((void*) (uintptr_t) STAP_ARG_addr)) {
            snprintf (CONTEXT->error_buffer, sizeof(CONTEXT->error_buffer),
                      "invalid kernel virtual address 0x%p", (void *) (uintptr_t) STAP_ARG_addr);
            CONTEXT->last_error = CONTEXT->error_buffer;
            goto out;
        }
        pfn = __pa(STAP_ARG_addr) >> PAGE_SHIFT;
#ifdef for_each_online_node
	for_each_online_node(nid)
#else
	for (nid=0; nid<MAX_NUMNODES; nid++)
		if (NODE_DATA(nid)) /* approximately: if (node_online(nid)) */
#endif
		if ( NODE_DATA(nid)->node_start_pfn <= pfn &&
			pfn < (NODE_DATA(nid)->node_start_pfn +
			NODE_DATA(nid)->node_spanned_pages) )
		{
			STAP_RETVALUE = nid;
			break;
		}
%}

// Return whether a page to be copied is a zero page.
function _IS_ZERO_PAGE:long(from:long, vaddr:long) %{ /* pure */
    STAP_RETVALUE = (STAP_ARG_from == (long) ZERO_PAGE(STAP_ARG_vaddr));
%}


/**
 * probe vm.write_shared - Attempts at writing to a shared page
 *
 * @name: name of the probe point
 * @address: the address of the shared write
 *
 * Context:
 *  The context is the process attempting the write.
 *
 *  Fires when a process attempts to write to a shared page. 
 *  If a copy is necessary, this will be followed by a 
 *  vm.write_shared_copy.
 */
probe vm.write_shared = kernel.function("do_wp_page") {
    name = "write_shared"
    address = $address
}

/**
 * probe vm.write_shared_copy - Page copy for shared page write
 *
 * @name: Name of the probe point
 * @address: The address of the shared write
 * @zero: boolean indicating whether it is a zero page
 *         (can do a clear instead of a copy)
 *
 * Context:
 *  The process attempting the write.
 *
 *  Fires when a write to a shared page requires a page copy.  This is
 *  always preceded by a vm.write_shared.
 */
probe vm.write_shared_copy =  kernel.function("cow_user_page") ?,
      kernel.function("copy_cow_page") ?
{
    name = "write_shared_copy"
    if (@defined($va)) {
      address = $va
      zero = _IS_ZERO_PAGE($src, $va);
    } else {
      address = $address
      zero = _IS_ZERO_PAGE($from, $address);
    }
}


/**
 * probe vm.mmap - Fires when an mmap is requested
 *
 * @name: name of the probe point
 * @address: the requested address
 * @length: the length of the memory segment 
 *
 * Context:
 *  The process calling mmap.
 */
probe vm.mmap = kernel.function("vm_mmap")?, kernel.function("do_mmap")?, kernel.function("do_mmap2")?
{
    name = "mmap"
    address = $addr
    length = $len
}


/**
 * probe vm.munmap - Fires when an munmap is requested
 *
 * @name: name of the probe point
 * @address: the requested address
 * @length: the length of the memory segment 
 *
 * Context:
 *  The process calling munmap.
 */
probe vm.munmap = kernel.function("do_munmap") {
    name = "munmap"
    address = $start
    length = $len
}

/**
 * probe vm.brk - Fires when a brk is requested (i.e. the heap will be resized)
 *
 * @name: name of the probe point
 * @address: the requested address
 * @length: the length of the memory segment 
 *
 * Context:
 *  The process calling brk.
 */
probe vm.brk = kernel.function("do_brk") {
    name = "brk"
    address = $addr
    length = $len
}

/**
 * probe vm.oom_kill - Fires when a thread is selected for termination by the OOM killer
 *
 * @name: name of the probe point
 * @task: the task being killed
 *
 * Context:
 *  The process that tried to consume excessive memory, and thus
 *  triggered the OOM.
 */
probe vm.oom_kill = kernel.function("oom_kill_process") !,
		    kernel.function("__oom_kill_task")
{
    name = "oom_kill"
    task = $p
}

function GFP_KERNEL:long()
%{ /* pure */ /* unprivileged */
	STAP_RETVALUE = GFP_KERNEL;
%}

function __gfp_flag_str:string(gfp_flag:long)
%{
	long gfp_flag = STAP_ARG_gfp_flag;
	STAP_RETVALUE[0] = '\0';

/* Older kernels < 2.6.32 didn't have some of these GFP defines yet. */
#ifndef __GFP_DMA32
#define __GFP_DMA32	((__force gfp_t)0x04u)
#endif
#ifndef GFP_DMA32
#define GFP_DMA32	__GFP_DMA32
#endif

#ifndef __GFP_MOVABLE
#define __GFP_MOVABLE  ((__force gfp_t)0x08u)  /* Page is movable */
#endif

#ifndef GFP_ZONEMASK
#define GFP_ZONEMASK   (__GFP_DMA|__GFP_HIGHMEM|__GFP_DMA32|__GFP_MOVABLE)
#endif

#ifndef __GFP_NOTRACK
#ifdef CONFIG_KMEMCHECK
#define __GFP_NOTRACK  ((__force gfp_t)0x200000u)  /* Don't track with kmemcheck */
#else
#define __GFP_NOTRACK  ((__force gfp_t)0)
#endif
#endif

#ifndef __GFP_THISNODE
#define __GFP_THISNODE  ((__force gfp_t)0x40000u)
#endif

#ifndef __GFP_RECLAIMABLE
#define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u)
#endif

#ifndef __GFP_ZERO
#define __GFP_ZERO	((__force gfp_t)0x8000u)
#endif

#ifndef __GFP_NOMEMALLOC
#define __GFP_NOMEMALLOC ((__force gfp_t)0x10000u)
#endif

#ifndef __GFP_HARDWALL
#define __GFP_HARDWALL   ((__force gfp_t)0x20000u)
#endif

#ifndef GFP_TEMPORARY
#define GFP_TEMPORARY  (__GFP_WAIT | __GFP_IO | __GFP_FS | \
                        __GFP_RECLAIMABLE)
#endif

#ifndef GFP_HIGHUSER_MOVABLE
#define GFP_HIGHUSER_MOVABLE   (__GFP_WAIT | __GFP_IO | __GFP_FS | \
                                __GFP_HARDWALL | __GFP_HIGHMEM | \
                                __GFP_MOVABLE)
#endif

#ifndef GFP_THISNODE
#ifdef CONFIG_NUMA
#define GFP_THISNODE    (__GFP_THISNODE | __GFP_NOWARN | __GFP_NORETRY)
#else
#define GFP_THISNODE    ((__force gfp_t)0)
#endif
#endif

/* Macro for GFP Bitmasks. */
/* The resulted GFP_FLAGS may be either single or concatenation of the multiple bitmasks. */


#define __GFP_BITMASKS(FLAG)  if(gfp_flag & FLAG) { if(STAP_RETVALUE[0] != '\0') \
                strlcat(STAP_RETVALUE, " | "#FLAG, MAXSTRINGLEN); \
                else strlcat(STAP_RETVALUE, #FLAG, MAXSTRINGLEN); }


/* Macro for Composite Flags. */
/* Each Composite GFP_FLAG is the combination of multiple bitmasks. */


#define __GFP_COMPOSITE_FLAG(FLAG)  if(gfp_flag == FLAG) { \
                strlcat(STAP_RETVALUE, #FLAG, MAXSTRINGLEN); return; }


/* Composite GFP FLAGS of the BitMasks. */

	__GFP_COMPOSITE_FLAG(GFP_ZONEMASK)
	__GFP_COMPOSITE_FLAG(GFP_ATOMIC)
	__GFP_COMPOSITE_FLAG(GFP_NOIO)
	__GFP_COMPOSITE_FLAG(GFP_NOFS)
	__GFP_COMPOSITE_FLAG(GFP_KERNEL)
	__GFP_COMPOSITE_FLAG(GFP_TEMPORARY)
	__GFP_COMPOSITE_FLAG(GFP_USER)
	__GFP_COMPOSITE_FLAG(GFP_HIGHUSER)
	__GFP_COMPOSITE_FLAG(GFP_HIGHUSER_MOVABLE)
	__GFP_COMPOSITE_FLAG(GFP_THISNODE)
	__GFP_COMPOSITE_FLAG(GFP_DMA)
	__GFP_COMPOSITE_FLAG(GFP_DMA32)

/* GFP BitMasks */

	__GFP_BITMASKS(__GFP_DMA)
	__GFP_BITMASKS(__GFP_HIGHMEM)
	__GFP_BITMASKS(__GFP_MOVABLE)
	__GFP_BITMASKS(__GFP_WAIT)
	__GFP_BITMASKS(__GFP_HIGH)
	__GFP_BITMASKS(__GFP_IO)
	__GFP_BITMASKS(__GFP_FS)
	__GFP_BITMASKS(__GFP_COLD)
	__GFP_BITMASKS(__GFP_NOWARN)
	__GFP_BITMASKS(__GFP_REPEAT)
	__GFP_BITMASKS(__GFP_NOFAIL)
	__GFP_BITMASKS(__GFP_COMP)
	__GFP_BITMASKS(__GFP_ZERO)
	__GFP_BITMASKS(__GFP_NOMEMALLOC)
	__GFP_BITMASKS(__GFP_HARDWALL)
	__GFP_BITMASKS(__GFP_THISNODE)
	__GFP_BITMASKS(__GFP_RECLAIMABLE)
	__GFP_BITMASKS(__GFP_NOTRACK)


#undef __GFP_BITMASKS
#undef __GFP_COMPOSITE_FLAG
%}

/* The Formal Parameters will be displayed if available, otherwise \
		 "0" or "unknown" will be displayed */

probe __vm.kmalloc.tp = kernel.trace("kmalloc")
{
	call_site = $call_site
	caller_function = symname(call_site)
	bytes_req = $bytes_req
	bytes_alloc = $bytes_alloc
	gfp_flags = $gfp_flags
	gfp_flag_name = __gfp_flag_str($gfp_flags)
	ptr = $ptr
}

/*
 * It is unsafe to invoke __builtin_return_address() presently (to get
 * call_site for kprobe based probes) and that it can be improved
 * later when fix for bugs bz#6961 and bz#6580 is available.
 */ 

probe __vm.kmalloc.kp = kernel.function("kmem_cache_alloc_notrace").return !,
			kernel.function("kmem_cache_alloc").return
{
	call_site = 0
	caller_function = "unknown"
	// Note that 'bytes_req' could be wrong.  By the time
	// kmem_cache_alloc* gets called the requested size could have
	// rounded up to the nearest cache alloc size.
	if (@defined($s)) {
		bytes_req = $s->size
		bytes_alloc = $s->size
	}
	else if (@defined($cachep->buffer_size)) {
		bytes_req = $cachep->buffer_size
		bytes_alloc = $cachep->buffer_size
	}
	else {
		bytes_req = $cachep->objsize
		bytes_alloc = $cachep->objsize
	}
	if (@defined($gfpflags)) {
		gfp_flags = $gfpflags
		gfp_flag_name = __gfp_flag_str($gfpflags)
	}
	else {
		gfp_flags = $flags
		gfp_flag_name = __gfp_flag_str($flags)
	}
	ptr = $return
}

/**
 * probe vm.kmalloc - Fires when kmalloc is requested
 *
 * @name: name of the probe point
 * @call_site: address of the kmemory function
 * @caller_function: name of the caller function
 * @bytes_req: requested Bytes
 * @bytes_alloc: allocated Bytes
 * @gfp_flags: type of kmemory to allocate
 * @gfp_flag_name: type of kmemory to allocate (in String format)
 * @ptr: pointer to the kmemory allocated
 */
probe vm.kmalloc = __vm.kmalloc.tp !, __vm.kmalloc.kp
{
	name = "kmalloc"
}


probe __vm.kmem_cache_alloc.tp = kernel.trace("kmem_cache_alloc")
{
	call_site = $call_site
	caller_function = symname(call_site)
	bytes_req = $bytes_req
	bytes_alloc = $bytes_alloc
	gfp_flags = $gfp_flags
	gfp_flag_name = __gfp_flag_str($gfp_flags)
	ptr = $ptr
}

probe __vm.kmem_cache_alloc.kp = kernel.function("kmem_cache_alloc").return
{
	call_site = 0
	caller_function = "unknown"
	// Note that 'bytes_req' could be wrong.  By the time
	// kmem_cache_alloc* gets called the requested size could have
	// rounded up to the nearest cache alloc size.
	if (@defined($s)) {
		bytes_req = $s->size
		bytes_alloc = $s->size
	}
	else if (@defined($cachep->buffer_size)) {
		bytes_req = $cachep->buffer_size
		bytes_alloc = $cachep->buffer_size
	}
	else {
		bytes_req = $cachep->objsize
		bytes_alloc = $cachep->objsize
	}
	if (@defined($gfpflags)) {
		gfp_flags = $gfpflags
		gfp_flag_name = __gfp_flag_str($gfpflags)
	}
	else {
		gfp_flags = $flags
		gfp_flag_name = __gfp_flag_str($flags)
	}
	ptr = $return
}

/**
 * probe vm.kmem_cache_alloc - Fires when kmem_cache_alloc is requested
 *
 * @name: name of the probe point
 * @call_site: address of the function calling this kmemory function.
 * @caller_function: name of the caller function.
 * @bytes_req: requested Bytes
 * @bytes_alloc: allocated Bytes
 * @gfp_flags: type of kmemory to allocate
 * @gfp_flag_name: type of kmemory to allocate(in string format)
 * @ptr: pointer to the kmemory allocated
 */

probe vm.kmem_cache_alloc = __vm.kmem_cache_alloc.tp !,
			    __vm.kmem_cache_alloc.kp
{
	name = "kmem_cache_alloc"
}

probe __vm.kmalloc_node.tp = kernel.trace("kmalloc_node") ?
{
	call_site = $call_site
	caller_function = symname(call_site)
	bytes_req = $bytes_req
	bytes_alloc = $bytes_alloc
	gfp_flags = $gfp_flags
	gfp_flag_name = __gfp_flag_str($gfp_flags)
	ptr = $ptr
}

probe __vm.kmalloc_node.kp = kernel.function("kmalloc_node").return ?
{
	call_site = 0
	caller_function = "unknown"
	bytes_req = $size
	bytes_alloc = bytes_req // pretend they are always the same

	# Unfortunately, on i686 f11 (2.6.29.4-167.fc11.i686.PAE), we
	# can't see the '$flags' argument (even though we can see the
	# '$size' argument above).  Note that we can see the '$flags'
	# argument on x86_64 f11 (2.6.29.4-167.fc11.x86_64).  So, the
	# best we can do here is just use 0 when $flags isn't defined.
	gfp_flags = @choose_defined($flags, 0)
	gfp_flag_name = __gfp_flag_str(@choose_defined($flags, 0))

	ptr = $return
}

/**
 * probe vm.kmalloc_node - Fires when kmalloc_node is requested
 *
 * @name: name of the probe point
 * @call_site: address of the function caling this  kmemory function
 * @caller_function: name of the caller function
 * @bytes_req: requested Bytes
 * @bytes_alloc: allocated Bytes
 * @gfp_flags: type of kmemory to allocate
 * @gfp_flag_name: type of kmemory to allocate(in string format)
 * @ptr: pointer to the kmemory allocated
 */
probe vm.kmalloc_node = __vm.kmalloc_node.tp !, __vm.kmalloc_node.kp ?
{
	name = "kmalloc_node"
}

probe __vm.kmem_cache_alloc_node.tp = kernel.trace("kmem_cache_alloc_node") ?
{
	call_site = $call_site
	caller_function = symname(call_site)
	bytes_req = $bytes_req
	bytes_alloc = $bytes_alloc
	gfp_flags = $gfp_flags
	gfp_flag_name = __gfp_flag_str($gfp_flags)
	ptr = $ptr
}

probe __vm.kmem_cache_alloc_node.kp =
		kernel.function("kmem_cache_alloc_node").return ?
{
	call_site = 0
	caller_function = "unknown"
	// Note that 'bytes_req' could be wrong.  By the time
	// kmem_cache_alloc* gets called the requested size could have
	// rounded up to the nearest cache alloc size.
	if (@defined($s)) {
		bytes_req = $s->size
		bytes_alloc = $s->size
	}
	else if (@defined($cachep->buffer_size)) {
		bytes_req = $cachep->buffer_size
		bytes_alloc = $cachep->buffer_size
	}
	else {
		bytes_req = $cachep->objsize
		bytes_alloc = $cachep->objsize
	}

	// kmem_cache_alloc_node() doesn't get a flags argument.  But,
	// internally it uses GFP_KERNEL().
	gfp_flags = GFP_KERNEL()
	gfp_flag_name = __gfp_flag_str(gfp_flags)
	ptr = $return
}

/**
 * probe vm.kmem_cache_alloc_node - Fires when kmem_cache_alloc_node is requested
 *
 * @name: name of the probe point
 * @call_site: address of the function calling this kmemory function
 * @caller_function: name of the caller function
 * @bytes_req: requested Bytes
 * @bytes_alloc: allocated Bytes
 * @gfp_flags: type of kmemory to allocate
 * @gfp_flag_name: type of kmemory to allocate(in string format)
 * @ptr: pointer to the kmemory allocated
 */
probe vm.kmem_cache_alloc_node = __vm.kmem_cache_alloc_node.tp !,
				 __vm.kmem_cache_alloc_node.kp ?
{
	name = "kmem_cache_alloc_node"
}

probe __vm.kfree.tp = kernel.trace("kfree")
{
	call_site = $call_site
	caller_function = symname(call_site)
	ptr = $ptr
}

probe __vm.kfree.kp = kernel.function("kfree").return
{
	call_site = 0
	caller_function = "unknown"
	ptr = @choose_defined($x, $objp)
}

/**
 * probe vm.kfree - Fires when kfree is requested
 *
 * @name: name of the probe point
 * @call_site: address of the function calling this kmemory function
 * @caller_function: name of the caller function.
 * @ptr: pointer to the kmemory allocated which is returned by kmalloc
 */
probe vm.kfree = __vm.kfree.tp !, __vm.kfree.kp
{
	name = "kfree"
}

probe __vm.kmem_cache_free.tp = kernel.trace("kmem_cache_free")
{
	call_site = $call_site
	caller_function = symname(call_site)
	ptr = $ptr
}
probe __vm.kmem_cache_free.kp = kernel.function("kmem_cache_free").return
{
	call_site = 0
	caller_function = "unknown"
	ptr = @choose_defined($x, $objp)
}

/**
 * probe vm.kmem_cache_free - Fires when kmem_cache_free is requested
 *
 * @name: Name of the probe point
 * @call_site: Address of the function calling this kmemory function
 * @caller_function: Name of the caller function.
 * @ptr: Pointer to the kmemory allocated which is returned by kmem_cache
 */
probe vm.kmem_cache_free = __vm.kmem_cache_free.tp !, __vm.kmem_cache_free.kp
{
	name = "kmem_cache_free"
}
