| Message ID | 20240530025144.1570865-1-zhaoyang.huang@unisoc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: fix incorrect vbq reference in purge_fragmented_block | expand |
loop Thomas On Thu, May 30, 2024 at 10:52 AM zhaoyang.huang <zhaoyang.huang@unisoc.com> wrote: > > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > Broken vbq->free reported on a v6.6 based system which is caused > by invalid vbq->lock protect over vbq->free in purge_fragmented_block. > This should be introduced by the Fixes below which ignored vbq->lock > matter. > > Fixes: fc1e0d980037 ("mm/vmalloc: prevent stale TLBs in fully utilized blocks") > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > --- > mm/vmalloc.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 22aa63f4ef63..112b50431725 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2614,9 +2614,10 @@ static void free_vmap_block(struct vmap_block *vb) > } > > static bool purge_fragmented_block(struct vmap_block *vb, > - struct vmap_block_queue *vbq, struct list_head *purge_list, > - bool force_purge) > + struct list_head *purge_list, bool force_purge) > { > + struct vmap_block_queue *vbq; > + > if (vb->free + vb->dirty != VMAP_BBMAP_BITS || > vb->dirty == VMAP_BBMAP_BITS) > return false; > @@ -2625,6 +2626,8 @@ static bool purge_fragmented_block(struct vmap_block *vb, > if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) > return false; > > + vbq = container_of(addr_to_vb_xa(vb->va->va_start), > + struct vmap_block_queue, vmap_blocks); > /* prevent further allocs after releasing lock */ > WRITE_ONCE(vb->free, 0); > /* prevent purging it again */ > @@ -2664,7 +2667,7 @@ static void purge_fragmented_blocks(int cpu) > continue; > > spin_lock(&vb->lock); > - purge_fragmented_block(vb, vbq, &purge, true); > + purge_fragmented_block(vb, &purge, true); > spin_unlock(&vb->lock); > } > rcu_read_unlock(); > @@ -2801,7 +2804,7 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) > * not purgeable, check whether there is dirty > * space to be flushed. > */ > - if (!purge_fragmented_block(vb, vbq, &purge_list, false) && > + if (!purge_fragmented_block(vb, &purge_list, false) && > vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { > unsigned long va_start = vb->va->va_start; > unsigned long s, e; > -- > 2.25.1 >
On 05/30/24 at 10:51am, zhaoyang.huang wrote: > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > Broken vbq->free reported on a v6.6 based system which is caused > by invalid vbq->lock protect over vbq->free in purge_fragmented_block. > This should be introduced by the Fixes below which ignored vbq->lock > matter. It will be helpful to provide more details, what's the symptom of the brekage, and in which case vbq->free is broken. > > Fixes: fc1e0d980037 ("mm/vmalloc: prevent stale TLBs in fully utilized blocks") > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > --- > mm/vmalloc.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 22aa63f4ef63..112b50431725 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2614,9 +2614,10 @@ static void free_vmap_block(struct vmap_block *vb) > } > > static bool purge_fragmented_block(struct vmap_block *vb, > - struct vmap_block_queue *vbq, struct list_head *purge_list, > - bool force_purge) > + struct list_head *purge_list, bool force_purge) > { > + struct vmap_block_queue *vbq; > + > if (vb->free + vb->dirty != VMAP_BBMAP_BITS || > vb->dirty == VMAP_BBMAP_BITS) > return false; > @@ -2625,6 +2626,8 @@ static bool purge_fragmented_block(struct vmap_block *vb, > if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) > return false; > > + vbq = container_of(addr_to_vb_xa(vb->va->va_start), > + struct vmap_block_queue, vmap_blocks); > /* prevent further allocs after releasing lock */ > WRITE_ONCE(vb->free, 0); > /* prevent purging it again */ > @@ -2664,7 +2667,7 @@ static void purge_fragmented_blocks(int cpu) > continue; > > spin_lock(&vb->lock); > - purge_fragmented_block(vb, vbq, &purge, true); > + purge_fragmented_block(vb, &purge, true); > spin_unlock(&vb->lock); > } > rcu_read_unlock(); > @@ -2801,7 +2804,7 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) > * not purgeable, check whether there is dirty > * space to be flushed. > */ > - if (!purge_fragmented_block(vb, vbq, &purge_list, false) && > + if (!purge_fragmented_block(vb, &purge_list, false) && > vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { > unsigned long va_start = vb->va->va_start; > unsigned long s, e; > -- > 2.25.1 > >
On Thu, May 30, 2024 at 3:19 PM Baoquan He <bhe@redhat.com> wrote: > > On 05/30/24 at 10:51am, zhaoyang.huang wrote: > > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > > > Broken vbq->free reported on a v6.6 based system which is caused > > by invalid vbq->lock protect over vbq->free in purge_fragmented_block. > > This should be introduced by the Fixes below which ignored vbq->lock > > matter. > > It will be helpful to provide more details, what's the symptom of the > brekage, and in which case vbq->free is broken. Vmalloc area runs out in our ARM64 system during an erofs test as vm_map_ram failed[1]. We find that one vbq->free->next point to vbq->free which makes list_for_each_entry_rcu can not iterate the list and find the BUG. [1] PID: 1 TASK: ffffff80802b4e00 CPU: 6 COMMAND: "init" #0 [ffffffc08006afe0] __switch_to at ffffffc08111d5cc #1 [ffffffc08006b040] __schedule at ffffffc08111dde0 #2 [ffffffc08006b0a0] schedule at ffffffc08111e294 #3 [ffffffc08006b0d0] schedule_preempt_disabled at ffffffc08111e3f0 #4 [ffffffc08006b140] __mutex_lock at ffffffc08112068c #5 [ffffffc08006b180] __mutex_lock_slowpath at ffffffc08111f8f8 #6 [ffffffc08006b1a0] mutex_lock at ffffffc08111f834 #7 [ffffffc08006b1d0] reclaim_and_purge_vmap_areas at ffffffc0803ebc3c #8 [ffffffc08006b290] alloc_vmap_area at ffffffc0803e83fc #9 [ffffffc08006b300] vm_map_ram at ffffffc0803e78c0 #10 [ffffffc08006b420] z_erofs_lz4_decompress at ffffffc0806a49b0 #11 [ffffffc08006b670] z_erofs_decompress_queue at ffffffc0806a8fd0 #12 [ffffffc08006b860] z_erofs_runqueue at ffffffc0806a8744 #13 [ffffffc08006b970] z_erofs_readahead at ffffffc0806a6cfc #14 [ffffffc08006ba00] read_pages at ffffffc08037ed78 #15 [ffffffc08006ba70] page_cache_ra_unbounded at ffffffc08037eb58 #16 [ffffffc08006bb00] page_cache_ra_order at ffffffc08037f42c #17 [ffffffc08006bbb0] do_sync_mmap_readahead at ffffffc080371d3c #18 [ffffffc08006bc40] filemap_fault at ffffffc080371774 #19 [ffffffc08006bd60] handle_mm_fault at ffffffc0803cc118 #20 [ffffffc08006bdc0] do_page_fault at ffffffc08112a618 #21 [ffffffc08006be20] do_translation_fault at ffffffc08112a36c #22 [ffffffc08006be30] do_mem_abort at ffffffc0800bfbf0 #23 [ffffffc08006be70] el0_ia at ffffffc08111583c #24 [ffffffc08006bea0] el0t_64_sync_handler at ffffffc0811156a4 #25 [ffffffc08006bfe0] el0t_64_sync at ffffffc080091584 > > > > > Fixes: fc1e0d980037 ("mm/vmalloc: prevent stale TLBs in fully utilized blocks") > > > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > --- > > mm/vmalloc.c | 11 +++++++---- > > 1 file changed, 7 insertions(+), 4 deletions(-) > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > index 22aa63f4ef63..112b50431725 100644 > > --- a/mm/vmalloc.c > > +++ b/mm/vmalloc.c > > @@ -2614,9 +2614,10 @@ static void free_vmap_block(struct vmap_block *vb) > > } > > > > static bool purge_fragmented_block(struct vmap_block *vb, > > - struct vmap_block_queue *vbq, struct list_head *purge_list, > > - bool force_purge) > > + struct list_head *purge_list, bool force_purge) > > { > > + struct vmap_block_queue *vbq; > > + > > if (vb->free + vb->dirty != VMAP_BBMAP_BITS || > > vb->dirty == VMAP_BBMAP_BITS) > > return false; > > @@ -2625,6 +2626,8 @@ static bool purge_fragmented_block(struct vmap_block *vb, > > if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) > > return false; > > > > + vbq = container_of(addr_to_vb_xa(vb->va->va_start), > > + struct vmap_block_queue, vmap_blocks); > > /* prevent further allocs after releasing lock */ > > WRITE_ONCE(vb->free, 0); > > /* prevent purging it again */ > > @@ -2664,7 +2667,7 @@ static void purge_fragmented_blocks(int cpu) > > continue; > > > > spin_lock(&vb->lock); > > - purge_fragmented_block(vb, vbq, &purge, true); > > + purge_fragmented_block(vb, &purge, true); > > spin_unlock(&vb->lock); > > } > > rcu_read_unlock(); > > @@ -2801,7 +2804,7 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) > > * not purgeable, check whether there is dirty > > * space to be flushed. > > */ > > - if (!purge_fragmented_block(vb, vbq, &purge_list, false) && > > + if (!purge_fragmented_block(vb, &purge_list, false) && > > vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { > > unsigned long va_start = vb->va->va_start; > > unsigned long s, e; > > -- > > 2.25.1 > > > > >
On 05/30/24 at 03:35pm, Zhaoyang Huang wrote: > On Thu, May 30, 2024 at 3:19 PM Baoquan He <bhe@redhat.com> wrote: > > > > On 05/30/24 at 10:51am, zhaoyang.huang wrote: > > > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > > > > > Broken vbq->free reported on a v6.6 based system which is caused > > > by invalid vbq->lock protect over vbq->free in purge_fragmented_block. > > > This should be introduced by the Fixes below which ignored vbq->lock > > > matter. > > > > It will be helpful to provide more details, what's the symptom of the > > brekage, and in which case vbq->free is broken. > Vmalloc area runs out in our ARM64 system during an erofs test as > vm_map_ram failed[1]. We find that one vbq->free->next point to > vbq->free which makes list_for_each_entry_rcu can not iterate the list > and find the BUG. Thanks for these information which are very helpful and important. They need be put in log for easier understanding. I am wondering about the vbq->free list breakage by the run out vmalloc area, could you say more about how it's caused? And do you think we need fix that vbq->free list breakage either? > > [1] > PID: 1 TASK: ffffff80802b4e00 CPU: 6 COMMAND: "init" > #0 [ffffffc08006afe0] __switch_to at ffffffc08111d5cc > #1 [ffffffc08006b040] __schedule at ffffffc08111dde0 > #2 [ffffffc08006b0a0] schedule at ffffffc08111e294 > #3 [ffffffc08006b0d0] schedule_preempt_disabled at ffffffc08111e3f0 > #4 [ffffffc08006b140] __mutex_lock at ffffffc08112068c > #5 [ffffffc08006b180] __mutex_lock_slowpath at ffffffc08111f8f8 > #6 [ffffffc08006b1a0] mutex_lock at ffffffc08111f834 > #7 [ffffffc08006b1d0] reclaim_and_purge_vmap_areas at ffffffc0803ebc3c > #8 [ffffffc08006b290] alloc_vmap_area at ffffffc0803e83fc > #9 [ffffffc08006b300] vm_map_ram at ffffffc0803e78c0 > #10 [ffffffc08006b420] z_erofs_lz4_decompress at ffffffc0806a49b0 > #11 [ffffffc08006b670] z_erofs_decompress_queue at ffffffc0806a8fd0 > #12 [ffffffc08006b860] z_erofs_runqueue at ffffffc0806a8744 > #13 [ffffffc08006b970] z_erofs_readahead at ffffffc0806a6cfc > #14 [ffffffc08006ba00] read_pages at ffffffc08037ed78 > #15 [ffffffc08006ba70] page_cache_ra_unbounded at ffffffc08037eb58 > #16 [ffffffc08006bb00] page_cache_ra_order at ffffffc08037f42c > #17 [ffffffc08006bbb0] do_sync_mmap_readahead at ffffffc080371d3c > #18 [ffffffc08006bc40] filemap_fault at ffffffc080371774 > #19 [ffffffc08006bd60] handle_mm_fault at ffffffc0803cc118 > #20 [ffffffc08006bdc0] do_page_fault at ffffffc08112a618 > #21 [ffffffc08006be20] do_translation_fault at ffffffc08112a36c > #22 [ffffffc08006be30] do_mem_abort at ffffffc0800bfbf0 > #23 [ffffffc08006be70] el0_ia at ffffffc08111583c > #24 [ffffffc08006bea0] el0t_64_sync_handler at ffffffc0811156a4 > #25 [ffffffc08006bfe0] el0t_64_sync at ffffffc080091584 > > > > > > > > > > Fixes: fc1e0d980037 ("mm/vmalloc: prevent stale TLBs in fully utilized blocks") > > > > > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > > --- > > > mm/vmalloc.c | 11 +++++++---- > > > 1 file changed, 7 insertions(+), 4 deletions(-) > > > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > > index 22aa63f4ef63..112b50431725 100644 > > > --- a/mm/vmalloc.c > > > +++ b/mm/vmalloc.c > > > @@ -2614,9 +2614,10 @@ static void free_vmap_block(struct vmap_block *vb) > > > } > > > > > > static bool purge_fragmented_block(struct vmap_block *vb, > > > - struct vmap_block_queue *vbq, struct list_head *purge_list, > > > - bool force_purge) > > > + struct list_head *purge_list, bool force_purge) > > > { > > > + struct vmap_block_queue *vbq; > > > + > > > if (vb->free + vb->dirty != VMAP_BBMAP_BITS || > > > vb->dirty == VMAP_BBMAP_BITS) > > > return false; > > > @@ -2625,6 +2626,8 @@ static bool purge_fragmented_block(struct vmap_block *vb, > > > if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) > > > return false; > > > > > > + vbq = container_of(addr_to_vb_xa(vb->va->va_start), > > > + struct vmap_block_queue, vmap_blocks); > > > /* prevent further allocs after releasing lock */ > > > WRITE_ONCE(vb->free, 0); > > > /* prevent purging it again */ > > > @@ -2664,7 +2667,7 @@ static void purge_fragmented_blocks(int cpu) > > > continue; > > > > > > spin_lock(&vb->lock); > > > - purge_fragmented_block(vb, vbq, &purge, true); > > > + purge_fragmented_block(vb, &purge, true); > > > spin_unlock(&vb->lock); > > > } > > > rcu_read_unlock(); > > > @@ -2801,7 +2804,7 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) > > > * not purgeable, check whether there is dirty > > > * space to be flushed. > > > */ > > > - if (!purge_fragmented_block(vb, vbq, &purge_list, false) && > > > + if (!purge_fragmented_block(vb, &purge_list, false) && > > > vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { > > > unsigned long va_start = vb->va->va_start; > > > unsigned long s, e; > > > -- > > > 2.25.1 > > > > > > > > >
On Thu, May 30, 2024 at 3:54 PM Baoquan He <bhe@redhat.com> wrote: > > On 05/30/24 at 03:35pm, Zhaoyang Huang wrote: > > On Thu, May 30, 2024 at 3:19 PM Baoquan He <bhe@redhat.com> wrote: > > > > > > On 05/30/24 at 10:51am, zhaoyang.huang wrote: > > > > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > > > > > > > Broken vbq->free reported on a v6.6 based system which is caused > > > > by invalid vbq->lock protect over vbq->free in purge_fragmented_block. > > > > This should be introduced by the Fixes below which ignored vbq->lock > > > > matter. > > > > > > It will be helpful to provide more details, what's the symptom of the > > > brekage, and in which case vbq->free is broken. > > Vmalloc area runs out in our ARM64 system during an erofs test as > > vm_map_ram failed[1]. We find that one vbq->free->next point to > > vbq->free which makes list_for_each_entry_rcu can not iterate the list > > and find the BUG. > > Thanks for these information which are very helpful and important. > They need be put in log for easier understanding. ok, I will update the commit message in the next version. > about the vbq->free list breakage by the run out vmalloc area, could vm_map_ram()->vb_alloc() will allocate new vb->va which corresponding to 4MB vmalloc area as list_for_each_entry_rcu returns immediately when vbq->free->next points to vbq->free. That is to say, 65536 times of page fault after the list's broken will run out of the whole vmalloc area. > you say more about how it's caused? And do you think we need fix that > vbq->free list breakage either? IMO, the purge_fragmented_block->list_del_rcu could race with new_vmap_block->list_add_tail_rcu when vbq is wrongly referenced. > > > > > [1] > > PID: 1 TASK: ffffff80802b4e00 CPU: 6 COMMAND: "init" > > #0 [ffffffc08006afe0] __switch_to at ffffffc08111d5cc > > #1 [ffffffc08006b040] __schedule at ffffffc08111dde0 > > #2 [ffffffc08006b0a0] schedule at ffffffc08111e294 > > #3 [ffffffc08006b0d0] schedule_preempt_disabled at ffffffc08111e3f0 > > #4 [ffffffc08006b140] __mutex_lock at ffffffc08112068c > > #5 [ffffffc08006b180] __mutex_lock_slowpath at ffffffc08111f8f8 > > #6 [ffffffc08006b1a0] mutex_lock at ffffffc08111f834 > > #7 [ffffffc08006b1d0] reclaim_and_purge_vmap_areas at ffffffc0803ebc3c > > #8 [ffffffc08006b290] alloc_vmap_area at ffffffc0803e83fc > > #9 [ffffffc08006b300] vm_map_ram at ffffffc0803e78c0 > > #10 [ffffffc08006b420] z_erofs_lz4_decompress at ffffffc0806a49b0 > > #11 [ffffffc08006b670] z_erofs_decompress_queue at ffffffc0806a8fd0 > > #12 [ffffffc08006b860] z_erofs_runqueue at ffffffc0806a8744 > > #13 [ffffffc08006b970] z_erofs_readahead at ffffffc0806a6cfc > > #14 [ffffffc08006ba00] read_pages at ffffffc08037ed78 > > #15 [ffffffc08006ba70] page_cache_ra_unbounded at ffffffc08037eb58 > > #16 [ffffffc08006bb00] page_cache_ra_order at ffffffc08037f42c > > #17 [ffffffc08006bbb0] do_sync_mmap_readahead at ffffffc080371d3c > > #18 [ffffffc08006bc40] filemap_fault at ffffffc080371774 > > #19 [ffffffc08006bd60] handle_mm_fault at ffffffc0803cc118 > > #20 [ffffffc08006bdc0] do_page_fault at ffffffc08112a618 > > #21 [ffffffc08006be20] do_translation_fault at ffffffc08112a36c > > #22 [ffffffc08006be30] do_mem_abort at ffffffc0800bfbf0 > > #23 [ffffffc08006be70] el0_ia at ffffffc08111583c > > #24 [ffffffc08006bea0] el0t_64_sync_handler at ffffffc0811156a4 > > #25 [ffffffc08006bfe0] el0t_64_sync at ffffffc080091584 > > > > > > > > > > > > > > > Fixes: fc1e0d980037 ("mm/vmalloc: prevent stale TLBs in fully utilized blocks") > > > > > > > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > > > --- > > > > mm/vmalloc.c | 11 +++++++---- > > > > 1 file changed, 7 insertions(+), 4 deletions(-) > > > > > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > > > index 22aa63f4ef63..112b50431725 100644 > > > > --- a/mm/vmalloc.c > > > > +++ b/mm/vmalloc.c > > > > @@ -2614,9 +2614,10 @@ static void free_vmap_block(struct vmap_block *vb) > > > > } > > > > > > > > static bool purge_fragmented_block(struct vmap_block *vb, > > > > - struct vmap_block_queue *vbq, struct list_head *purge_list, > > > > - bool force_purge) > > > > + struct list_head *purge_list, bool force_purge) > > > > { > > > > + struct vmap_block_queue *vbq; > > > > + > > > > if (vb->free + vb->dirty != VMAP_BBMAP_BITS || > > > > vb->dirty == VMAP_BBMAP_BITS) > > > > return false; > > > > @@ -2625,6 +2626,8 @@ static bool purge_fragmented_block(struct vmap_block *vb, > > > > if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) > > > > return false; > > > > > > > > + vbq = container_of(addr_to_vb_xa(vb->va->va_start), > > > > + struct vmap_block_queue, vmap_blocks); > > > > /* prevent further allocs after releasing lock */ > > > > WRITE_ONCE(vb->free, 0); > > > > /* prevent purging it again */ > > > > @@ -2664,7 +2667,7 @@ static void purge_fragmented_blocks(int cpu) > > > > continue; > > > > > > > > spin_lock(&vb->lock); > > > > - purge_fragmented_block(vb, vbq, &purge, true); > > > > + purge_fragmented_block(vb, &purge, true); > > > > spin_unlock(&vb->lock); > > > > } > > > > rcu_read_unlock(); > > > > @@ -2801,7 +2804,7 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) > > > > * not purgeable, check whether there is dirty > > > > * space to be flushed. > > > > */ > > > > - if (!purge_fragmented_block(vb, vbq, &purge_list, false) && > > > > + if (!purge_fragmented_block(vb, &purge_list, false) && > > > > vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { > > > > unsigned long va_start = vb->va->va_start; > > > > unsigned long s, e; > > > > -- > > > > 2.25.1 > > > > > > > > > > > > > >
zhaoyang.huang <zhaoyang.huang@unisoc.com> 于2024年5月30日周四 10:52写道： > > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > Broken vbq->free reported on a v6.6 based system which is caused > by invalid vbq->lock protect over vbq->free in purge_fragmented_block. > This should be introduced by the Fixes below which ignored vbq->lock > matter. > > Fixes: fc1e0d980037 ("mm/vmalloc: prevent stale TLBs in fully utilized blocks") > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > --- > mm/vmalloc.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 22aa63f4ef63..112b50431725 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2614,9 +2614,10 @@ static void free_vmap_block(struct vmap_block *vb) > } > > static bool purge_fragmented_block(struct vmap_block *vb, > - struct vmap_block_queue *vbq, struct list_head *purge_list, > - bool force_purge) > + struct list_head *purge_list, bool force_purge) > { > + struct vmap_block_queue *vbq; > + > if (vb->free + vb->dirty != VMAP_BBMAP_BITS || > vb->dirty == VMAP_BBMAP_BITS) > return false; > @@ -2625,6 +2626,8 @@ static bool purge_fragmented_block(struct vmap_block *vb, > if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) > return false; > > + vbq = container_of(addr_to_vb_xa(vb->va->va_start), > + struct vmap_block_queue, vmap_blocks); This seems to be the same as before fix :), the vbq found by addr_to_vb_xa is still added to the xarray vbq, not necessarily to the free_list vbq, These two vbqs may not be the same, we need to find the vbq when added to free_list. For example: We add vb to vbq1's xarray and vbq2's free_list, and we need to find vbq2 instead of vbq1. So I feel like this place isn't really fixed？ > /* prevent further allocs after releasing lock */ > WRITE_ONCE(vb->free, 0); > /* prevent purging it again */ > @@ -2664,7 +2667,7 @@ static void purge_fragmented_blocks(int cpu) > continue; > > spin_lock(&vb->lock); > - purge_fragmented_block(vb, vbq, &purge, true); > + purge_fragmented_block(vb, &purge, true); > spin_unlock(&vb->lock); > } > rcu_read_unlock(); > @@ -2801,7 +2804,7 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) > * not purgeable, check whether there is dirty > * space to be flushed. > */ > - if (!purge_fragmented_block(vb, vbq, &purge_list, false) && > + if (!purge_fragmented_block(vb, &purge_list, false) && > vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { > unsigned long va_start = vb->va->va_start; > unsigned long s, e; > -- > 2.25.1 > >
On Thu, May 30, 2024 at 5:16 PM Chuanhua Han <chuanhuahan@gmail.com> wrote: > > zhaoyang.huang <zhaoyang.huang@unisoc.com> 于2024年5月30日周四 10:52写道： > > > > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > > > Broken vbq->free reported on a v6.6 based system which is caused > > by invalid vbq->lock protect over vbq->free in purge_fragmented_block. > > This should be introduced by the Fixes below which ignored vbq->lock > > matter. > > > > Fixes: fc1e0d980037 ("mm/vmalloc: prevent stale TLBs in fully utilized blocks") > > > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > --- > > mm/vmalloc.c | 11 +++++++---- > > 1 file changed, 7 insertions(+), 4 deletions(-) > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > index 22aa63f4ef63..112b50431725 100644 > > --- a/mm/vmalloc.c > > +++ b/mm/vmalloc.c > > @@ -2614,9 +2614,10 @@ static void free_vmap_block(struct vmap_block *vb) > > } > > > > static bool purge_fragmented_block(struct vmap_block *vb, > > - struct vmap_block_queue *vbq, struct list_head *purge_list, > > - bool force_purge) > > + struct list_head *purge_list, bool force_purge) > > { > > + struct vmap_block_queue *vbq; > > + > > if (vb->free + vb->dirty != VMAP_BBMAP_BITS || > > vb->dirty == VMAP_BBMAP_BITS) > > return false; > > @@ -2625,6 +2626,8 @@ static bool purge_fragmented_block(struct vmap_block *vb, > > if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) > > return false; > > > > + vbq = container_of(addr_to_vb_xa(vb->va->va_start), > > + struct vmap_block_queue, vmap_blocks); > This seems to be the same as before fix :), the vbq found by > addr_to_vb_xa is still added to the xarray vbq, not necessarily to the > free_list vbq, Yes, my fault. Should we expand the vmap_block_queue by introducing a cpu_id which I actually do in my local regression. > These two vbqs may not be the same, we need to find the vbq when added > to free_list. > > For example: > We add vb to vbq1's xarray and vbq2's free_list, and we need to find > vbq2 instead of vbq1. > So I feel like this place isn't really fixed？ > > /* prevent further allocs after releasing lock */ > > WRITE_ONCE(vb->free, 0); > > /* prevent purging it again */ > > @@ -2664,7 +2667,7 @@ static void purge_fragmented_blocks(int cpu) > > continue; > > > > spin_lock(&vb->lock); > > - purge_fragmented_block(vb, vbq, &purge, true); > > + purge_fragmented_block(vb, &purge, true); > > spin_unlock(&vb->lock); > > } > > rcu_read_unlock(); > > @@ -2801,7 +2804,7 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) > > * not purgeable, check whether there is dirty > > * space to be flushed. > > */ > > - if (!purge_fragmented_block(vb, vbq, &purge_list, false) && > > + if (!purge_fragmented_block(vb, &purge_list, false) && > > vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { > > unsigned long va_start = vb->va->va_start; > > unsigned long s, e; > > -- > > 2.25.1 > > > > > > > -- > Thanks, > Chuanhua
Zhaoyang Huang <huangzhaoyang@gmail.com> 于2024年5月30日周四 17:25写道： > > On Thu, May 30, 2024 at 5:16 PM Chuanhua Han <chuanhuahan@gmail.com> wrote: > > > > zhaoyang.huang <zhaoyang.huang@unisoc.com> 于2024年5月30日周四 10:52写道： > > > > > > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > > > > > Broken vbq->free reported on a v6.6 based system which is caused > > > by invalid vbq->lock protect over vbq->free in purge_fragmented_block. > > > This should be introduced by the Fixes below which ignored vbq->lock > > > matter. > > > > > > Fixes: fc1e0d980037 ("mm/vmalloc: prevent stale TLBs in fully utilized blocks") > > > > > > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com> > > > --- > > > mm/vmalloc.c | 11 +++++++---- > > > 1 file changed, 7 insertions(+), 4 deletions(-) > > > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > > index 22aa63f4ef63..112b50431725 100644 > > > --- a/mm/vmalloc.c > > > +++ b/mm/vmalloc.c > > > @@ -2614,9 +2614,10 @@ static void free_vmap_block(struct vmap_block *vb) > > > } > > > > > > static bool purge_fragmented_block(struct vmap_block *vb, > > > - struct vmap_block_queue *vbq, struct list_head *purge_list, > > > - bool force_purge) > > > + struct list_head *purge_list, bool force_purge) > > > { > > > + struct vmap_block_queue *vbq; > > > + > > > if (vb->free + vb->dirty != VMAP_BBMAP_BITS || > > > vb->dirty == VMAP_BBMAP_BITS) > > > return false; > > > @@ -2625,6 +2626,8 @@ static bool purge_fragmented_block(struct vmap_block *vb, > > > if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) > > > return false; > > > > > > + vbq = container_of(addr_to_vb_xa(vb->va->va_start), > > > + struct vmap_block_queue, vmap_blocks); > > This seems to be the same as before fix :), the vbq found by > > addr_to_vb_xa is still added to the xarray vbq, not necessarily to the > > free_list vbq, > Yes, my fault. Should we expand the vmap_block_queue by introducing a > cpu_id which I actually do in my local regression. You may need to embed a cpu_id in vb, and then use cpu_id to get the vbq where the free_list is located > > > These two vbqs may not be the same, we need to find the vbq when added > > to free_list. > > > > For example: > > We add vb to vbq1's xarray and vbq2's free_list, and we need to find > > vbq2 instead of vbq1. > > So I feel like this place isn't really fixed？ > > > /* prevent further allocs after releasing lock */ > > > WRITE_ONCE(vb->free, 0); > > > /* prevent purging it again */ > > > @@ -2664,7 +2667,7 @@ static void purge_fragmented_blocks(int cpu) > > > continue; > > > > > > spin_lock(&vb->lock); > > > - purge_fragmented_block(vb, vbq, &purge, true); > > > + purge_fragmented_block(vb, &purge, true); > > > spin_unlock(&vb->lock); > > > } > > > rcu_read_unlock(); > > > @@ -2801,7 +2804,7 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) > > > * not purgeable, check whether there is dirty > > > * space to be flushed. > > > */ > > > - if (!purge_fragmented_block(vb, vbq, &purge_list, false) && > > > + if (!purge_fragmented_block(vb, &purge_list, false) && > > > vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { > > > unsigned long va_start = vb->va->va_start; > > > unsigned long s, e; > > > -- > > > 2.25.1 > > > > > > > > > > > > -- > > Thanks, > > Chuanhua
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 22aa63f4ef63..112b50431725 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2614,9 +2614,10 @@ static void free_vmap_block(struct vmap_block *vb) } static bool purge_fragmented_block(struct vmap_block *vb, - struct vmap_block_queue *vbq, struct list_head *purge_list, - bool force_purge) + struct list_head *purge_list, bool force_purge) { + struct vmap_block_queue *vbq; + if (vb->free + vb->dirty != VMAP_BBMAP_BITS || vb->dirty == VMAP_BBMAP_BITS) return false; @@ -2625,6 +2626,8 @@ static bool purge_fragmented_block(struct vmap_block *vb, if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) return false; + vbq = container_of(addr_to_vb_xa(vb->va->va_start), + struct vmap_block_queue, vmap_blocks); /* prevent further allocs after releasing lock */ WRITE_ONCE(vb->free, 0); /* prevent purging it again */ @@ -2664,7 +2667,7 @@ static void purge_fragmented_blocks(int cpu) continue; spin_lock(&vb->lock); - purge_fragmented_block(vb, vbq, &purge, true); + purge_fragmented_block(vb, &purge, true); spin_unlock(&vb->lock); } rcu_read_unlock(); @@ -2801,7 +2804,7 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) * not purgeable, check whether there is dirty * space to be flushed. */ - if (!purge_fragmented_block(vb, vbq, &purge_list, false) && + if (!purge_fragmented_block(vb, &purge_list, false) && vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { unsigned long va_start = vb->va->va_start; unsigned long s, e;