linux-stable/include/linux/bpfptr.h
Suren Baghdasaryan 2c321f3f70 mm: change inlined allocation helpers to account at the call site
Main goal of memory allocation profiling patchset is to provide accounting
that is cheap enough to run in production.  To achieve that we inject
counters using codetags at the allocation call sites to account every time
allocation is made.  This injection allows us to perform accounting
efficiently because injected counters are immediately available as opposed
to the alternative methods, such as using _RET_IP_, which would require
counter lookup and appropriate locking that makes accounting much more
expensive.  This method requires all allocation functions to inject
separate counters at their call sites so that their callers can be
individually accounted.  Counter injection is implemented by allocation
hooks which should wrap all allocation functions.

Inlined functions which perform allocations but do not use allocation
hooks are directly charged for the allocations they perform.  In most
cases these functions are just specialized allocation wrappers used from
multiple places to allocate objects of a specific type.  It would be more
useful to do the accounting at their call sites instead.  Instrument these
helpers to do accounting at the call site.  Simple inlined allocation
wrappers are converted directly into macros.  More complex allocators or
allocators with documentation are converted into _noprof versions and
allocation hooks are added.  This allows memory allocation profiling
mechanism to charge allocations to the callers of these functions.

Link: https://lkml.kernel.org/r/20240415020731.1152108-1-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Jan Kara <jack@suse.cz>		[jbd2]
Cc: Anna Schumaker <anna@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:59 -07:00

90 lines
2.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/* A pointer that can point to either kernel or userspace memory. */
#ifndef _LINUX_BPFPTR_H
#define _LINUX_BPFPTR_H
#include <linux/mm.h>
#include <linux/sockptr.h>
typedef sockptr_t bpfptr_t;
static inline bool bpfptr_is_kernel(bpfptr_t bpfptr)
{
return bpfptr.is_kernel;
}
static inline bpfptr_t KERNEL_BPFPTR(void *p)
{
return (bpfptr_t) { .kernel = p, .is_kernel = true };
}
static inline bpfptr_t USER_BPFPTR(void __user *p)
{
return (bpfptr_t) { .user = p };
}
static inline bpfptr_t make_bpfptr(u64 addr, bool is_kernel)
{
if (is_kernel)
return KERNEL_BPFPTR((void*) (uintptr_t) addr);
else
return USER_BPFPTR(u64_to_user_ptr(addr));
}
static inline bool bpfptr_is_null(bpfptr_t bpfptr)
{
if (bpfptr_is_kernel(bpfptr))
return !bpfptr.kernel;
return !bpfptr.user;
}
static inline void bpfptr_add(bpfptr_t *bpfptr, size_t val)
{
if (bpfptr_is_kernel(*bpfptr))
bpfptr->kernel += val;
else
bpfptr->user += val;
}
static inline int copy_from_bpfptr_offset(void *dst, bpfptr_t src,
size_t offset, size_t size)
{
if (!bpfptr_is_kernel(src))
return copy_from_user(dst, src.user + offset, size);
return copy_from_kernel_nofault(dst, src.kernel + offset, size);
}
static inline int copy_from_bpfptr(void *dst, bpfptr_t src, size_t size)
{
return copy_from_bpfptr_offset(dst, src, 0, size);
}
static inline int copy_to_bpfptr_offset(bpfptr_t dst, size_t offset,
const void *src, size_t size)
{
return copy_to_sockptr_offset((sockptr_t) dst, offset, src, size);
}
static inline void *kvmemdup_bpfptr_noprof(bpfptr_t src, size_t len)
{
void *p = kvmalloc_noprof(len, GFP_USER | __GFP_NOWARN);
if (!p)
return ERR_PTR(-ENOMEM);
if (copy_from_bpfptr(p, src, len)) {
kvfree(p);
return ERR_PTR(-EFAULT);
}
return p;
}
#define kvmemdup_bpfptr(...) alloc_hooks(kvmemdup_bpfptr_noprof(__VA_ARGS__))
static inline long strncpy_from_bpfptr(char *dst, bpfptr_t src, size_t count)
{
if (bpfptr_is_kernel(src))
return strncpy_from_kernel_nofault(dst, src.kernel, count);
return strncpy_from_user(dst, src.user, count);
}
#endif /* _LINUX_BPFPTR_H */