| Message ID | 20220816163641.2359996-1-elver@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [5.19.y] Revert "mm: kfence: apply kmemleak_ignore_phys on early allocated pool" | expand |
On Tue, 16 Aug 2022 at 18:37, Marco Elver <elver@google.com> wrote: > > This reverts commit 07313a2b29ed1079eaa7722624544b97b3ead84b. > > Commit 0c24e061196c21d5 ("mm: kmemleak: add rbtree and store physical > address for objects allocated with PA") is not yet in 5.19 (but appears > in 6.0). Without 0c24e061196c21d5, kmemleak still stores phys objects > and non-phys objects in the same tree, and ignoring (instead of freeing) > will cause insertions into the kmemleak object tree by the slab > post-alloc hook to conflict with the pool object (see comment). > > Reports such as the following would appear on boot, and effectively > disable kmemleak: > > | kmemleak: Cannot insert 0xffffff806e24f000 into the object search tree (overlaps existing) > | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-v8-0815+ #5 > | Hardware name: Raspberry Pi Compute Module 4 Rev 1.0 (DT) > | Call trace: > | dump_backtrace.part.0+0x1dc/0x1ec > | show_stack+0x24/0x80 > | dump_stack_lvl+0x8c/0xb8 > | dump_stack+0x1c/0x38 > | create_object.isra.0+0x490/0x4b0 > | kmemleak_alloc+0x3c/0x50 > | kmem_cache_alloc+0x2f8/0x450 > | __proc_create+0x18c/0x400 > | proc_create_reg+0x54/0xd0 > | proc_create_seq_private+0x94/0x120 > | init_mm_internals+0x1d8/0x248 > | kernel_init_freeable+0x188/0x388 > | kernel_init+0x30/0x150 > | ret_from_fork+0x10/0x20 > | kmemleak: Kernel memory leak detector disabled > | kmemleak: Object 0xffffff806e24d000 (size 2097152): > | kmemleak: comm "swapper", pid 0, jiffies 4294892296 > | kmemleak: min_count = -1 > | kmemleak: count = 0 > | kmemleak: flags = 0x5 > | kmemleak: checksum = 0 > | kmemleak: backtrace: > | kmemleak_alloc_phys+0x94/0xb0 > | memblock_alloc_range_nid+0x1c0/0x20c > | memblock_alloc_internal+0x88/0x100 > | memblock_alloc_try_nid+0x148/0x1ac > | kfence_alloc_pool+0x44/0x6c > | mm_init+0x28/0x98 > | start_kernel+0x178/0x3e8 > | __primary_switched+0xc4/0xcc > > Reported-by: Max Schulze <max.schulze@online.de> > Signed-off-by: Marco Elver <elver@google.com> The discussion is: Link: https://lore.kernel.org/all/b33b33bc-2d06-1bcd-2df7-43678962b728@online.de/ > --- > mm/kfence/core.c | 18 +++++++++--------- > 1 file changed, 9 insertions(+), 9 deletions(-) > > diff --git a/mm/kfence/core.c b/mm/kfence/core.c > index 6aff49f6b79e..4b5e5a3d3a63 100644 > --- a/mm/kfence/core.c > +++ b/mm/kfence/core.c > @@ -603,6 +603,14 @@ static unsigned long kfence_init_pool(void) > addr += 2 * PAGE_SIZE; > } > > + /* > + * The pool is live and will never be deallocated from this point on. > + * Remove the pool object from the kmemleak object tree, as it would > + * otherwise overlap with allocations returned by kfence_alloc(), which > + * are registered with kmemleak through the slab post-alloc hook. > + */ > + kmemleak_free(__kfence_pool); > + > return 0; > } > > @@ -615,16 +623,8 @@ static bool __init kfence_init_pool_early(void) > > addr = kfence_init_pool(); > > - if (!addr) { > - /* > - * The pool is live and will never be deallocated from this point on. > - * Ignore the pool object from the kmemleak phys object tree, as it would > - * otherwise overlap with allocations returned by kfence_alloc(), which > - * are registered with kmemleak through the slab post-alloc hook. > - */ > - kmemleak_ignore_phys(__pa(__kfence_pool)); > + if (!addr) > return true; > - } > > /* > * Only release unprotected pages, and do not try to go back and change > -- > 2.37.1.595.g718a3a8f04-goog >
On Tue, Aug 16, 2022 at 06:42:46PM +0200, Marco Elver wrote: > On Tue, 16 Aug 2022 at 18:37, Marco Elver <elver@google.com> wrote: > > > > This reverts commit 07313a2b29ed1079eaa7722624544b97b3ead84b. > > > > Commit 0c24e061196c21d5 ("mm: kmemleak: add rbtree and store physical > > address for objects allocated with PA") is not yet in 5.19 (but appears > > in 6.0). Without 0c24e061196c21d5, kmemleak still stores phys objects > > and non-phys objects in the same tree, and ignoring (instead of freeing) > > will cause insertions into the kmemleak object tree by the slab > > post-alloc hook to conflict with the pool object (see comment). > > > > Reports such as the following would appear on boot, and effectively > > disable kmemleak: > > > > | kmemleak: Cannot insert 0xffffff806e24f000 into the object search tree (overlaps existing) > > | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-v8-0815+ #5 > > | Hardware name: Raspberry Pi Compute Module 4 Rev 1.0 (DT) > > | Call trace: > > | dump_backtrace.part.0+0x1dc/0x1ec > > | show_stack+0x24/0x80 > > | dump_stack_lvl+0x8c/0xb8 > > | dump_stack+0x1c/0x38 > > | create_object.isra.0+0x490/0x4b0 > > | kmemleak_alloc+0x3c/0x50 > > | kmem_cache_alloc+0x2f8/0x450 > > | __proc_create+0x18c/0x400 > > | proc_create_reg+0x54/0xd0 > > | proc_create_seq_private+0x94/0x120 > > | init_mm_internals+0x1d8/0x248 > > | kernel_init_freeable+0x188/0x388 > > | kernel_init+0x30/0x150 > > | ret_from_fork+0x10/0x20 > > | kmemleak: Kernel memory leak detector disabled > > | kmemleak: Object 0xffffff806e24d000 (size 2097152): > > | kmemleak: comm "swapper", pid 0, jiffies 4294892296 > > | kmemleak: min_count = -1 > > | kmemleak: count = 0 > > | kmemleak: flags = 0x5 > > | kmemleak: checksum = 0 > > | kmemleak: backtrace: > > | kmemleak_alloc_phys+0x94/0xb0 > > | memblock_alloc_range_nid+0x1c0/0x20c > > | memblock_alloc_internal+0x88/0x100 > > | memblock_alloc_try_nid+0x148/0x1ac > > | kfence_alloc_pool+0x44/0x6c > > | mm_init+0x28/0x98 > > | start_kernel+0x178/0x3e8 > > | __primary_switched+0xc4/0xcc > > > > Reported-by: Max Schulze <max.schulze@online.de> > > Signed-off-by: Marco Elver <elver@google.com> > > The discussion is: > > Link: https://lore.kernel.org/all/b33b33bc-2d06-1bcd-2df7-43678962b728@online.de/ > > > --- > > mm/kfence/core.c | 18 +++++++++--------- > > 1 file changed, 9 insertions(+), 9 deletions(-) > > > > diff --git a/mm/kfence/core.c b/mm/kfence/core.c > > index 6aff49f6b79e..4b5e5a3d3a63 100644 > > --- a/mm/kfence/core.c > > +++ b/mm/kfence/core.c > > @@ -603,6 +603,14 @@ static unsigned long kfence_init_pool(void) > > addr += 2 * PAGE_SIZE; > > } > > > > + /* > > + * The pool is live and will never be deallocated from this point on. > > + * Remove the pool object from the kmemleak object tree, as it would > > + * otherwise overlap with allocations returned by kfence_alloc(), which > > + * are registered with kmemleak through the slab post-alloc hook. > > + */ > > + kmemleak_free(__kfence_pool); > > + > > return 0; > > } > > > > @@ -615,16 +623,8 @@ static bool __init kfence_init_pool_early(void) > > > > addr = kfence_init_pool(); > > > > - if (!addr) { > > - /* > > - * The pool is live and will never be deallocated from this point on. > > - * Ignore the pool object from the kmemleak phys object tree, as it would > > - * otherwise overlap with allocations returned by kfence_alloc(), which > > - * are registered with kmemleak through the slab post-alloc hook. > > - */ > > - kmemleak_ignore_phys(__pa(__kfence_pool)); > > + if (!addr) > > return true; > > - } > > > > /* > > * Only release unprotected pages, and do not try to go back and change > > -- > > 2.37.1.595.g718a3a8f04-goog > > Now queued up, thanks. greg k-h
On Wed, Aug 17, 2022 at 07:23:49PM +0200, gregkh@linuxfoundation.org wrote: > > This is a note to let you know that I've just added the patch titled > > Revert "mm: kfence: apply kmemleak_ignore_phys on early allocated pool" > > to the 4.14-stable tree which can be found at: > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary Oops, wrong branch, this is now dropped, sorry for the noise. greg k-h
diff --git a/mm/kfence/core.c b/mm/kfence/core.c index 6aff49f6b79e..4b5e5a3d3a63 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -603,6 +603,14 @@ static unsigned long kfence_init_pool(void) addr += 2 * PAGE_SIZE; } + /* + * The pool is live and will never be deallocated from this point on. + * Remove the pool object from the kmemleak object tree, as it would + * otherwise overlap with allocations returned by kfence_alloc(), which + * are registered with kmemleak through the slab post-alloc hook. + */ + kmemleak_free(__kfence_pool); + return 0; } @@ -615,16 +623,8 @@ static bool __init kfence_init_pool_early(void) addr = kfence_init_pool(); - if (!addr) { - /* - * The pool is live and will never be deallocated from this point on. - * Ignore the pool object from the kmemleak phys object tree, as it would - * otherwise overlap with allocations returned by kfence_alloc(), which - * are registered with kmemleak through the slab post-alloc hook. - */ - kmemleak_ignore_phys(__pa(__kfence_pool)); + if (!addr) return true; - } /* * Only release unprotected pages, and do not try to go back and change
This reverts commit 07313a2b29ed1079eaa7722624544b97b3ead84b. Commit 0c24e061196c21d5 ("mm: kmemleak: add rbtree and store physical address for objects allocated with PA") is not yet in 5.19 (but appears in 6.0). Without 0c24e061196c21d5, kmemleak still stores phys objects and non-phys objects in the same tree, and ignoring (instead of freeing) will cause insertions into the kmemleak object tree by the slab post-alloc hook to conflict with the pool object (see comment). Reports such as the following would appear on boot, and effectively disable kmemleak: | kmemleak: Cannot insert 0xffffff806e24f000 into the object search tree (overlaps existing) | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-v8-0815+ #5 | Hardware name: Raspberry Pi Compute Module 4 Rev 1.0 (DT) | Call trace: | dump_backtrace.part.0+0x1dc/0x1ec | show_stack+0x24/0x80 | dump_stack_lvl+0x8c/0xb8 | dump_stack+0x1c/0x38 | create_object.isra.0+0x490/0x4b0 | kmemleak_alloc+0x3c/0x50 | kmem_cache_alloc+0x2f8/0x450 | __proc_create+0x18c/0x400 | proc_create_reg+0x54/0xd0 | proc_create_seq_private+0x94/0x120 | init_mm_internals+0x1d8/0x248 | kernel_init_freeable+0x188/0x388 | kernel_init+0x30/0x150 | ret_from_fork+0x10/0x20 | kmemleak: Kernel memory leak detector disabled | kmemleak: Object 0xffffff806e24d000 (size 2097152): | kmemleak: comm "swapper", pid 0, jiffies 4294892296 | kmemleak: min_count = -1 | kmemleak: count = 0 | kmemleak: flags = 0x5 | kmemleak: checksum = 0 | kmemleak: backtrace: | kmemleak_alloc_phys+0x94/0xb0 | memblock_alloc_range_nid+0x1c0/0x20c | memblock_alloc_internal+0x88/0x100 | memblock_alloc_try_nid+0x148/0x1ac | kfence_alloc_pool+0x44/0x6c | mm_init+0x28/0x98 | start_kernel+0x178/0x3e8 | __primary_switched+0xc4/0xcc Reported-by: Max Schulze <max.schulze@online.de> Signed-off-by: Marco Elver <elver@google.com> --- mm/kfence/core.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)