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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /tools/testing/radix-tree/regression2.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'tools/testing/radix-tree/regression2.c')
| -rw-r--r-- | tools/testing/radix-tree/regression2.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/tools/testing/radix-tree/regression2.c b/tools/testing/radix-tree/regression2.c new file mode 100644 index 000000000..f2c7e640a --- /dev/null +++ b/tools/testing/radix-tree/regression2.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Regression2 + * Description: + * Toshiyuki Okajima describes the following radix-tree bug: + * + * In the following case, we can get a hangup on + * radix_radix_tree_gang_lookup_tag_slot. + * + * 0. The radix tree contains RADIX_TREE_MAP_SIZE items. And the tag of + * a certain item has PAGECACHE_TAG_DIRTY. + * 1. radix_tree_range_tag_if_tagged(, start, end, , PAGECACHE_TAG_DIRTY, + * PAGECACHE_TAG_TOWRITE) is called to add PAGECACHE_TAG_TOWRITE tag + * for the tag which has PAGECACHE_TAG_DIRTY. However, there is no tag with + * PAGECACHE_TAG_DIRTY within the range from start to end. As the result, + * There is no tag with PAGECACHE_TAG_TOWRITE but the root tag has + * PAGECACHE_TAG_TOWRITE. + * 2. An item is added into the radix tree and then the level of it is + * extended into 2 from 1. At that time, the new radix tree node succeeds + * the tag status of the root tag. Therefore the tag of the new radix tree + * node has PAGECACHE_TAG_TOWRITE but there is not slot with + * PAGECACHE_TAG_TOWRITE tag in the child node of the new radix tree node. + * 3. The tag of a certain item is cleared with PAGECACHE_TAG_DIRTY. + * 4. All items within the index range from 0 to RADIX_TREE_MAP_SIZE - 1 are + * released. (Only the item which index is RADIX_TREE_MAP_SIZE exist in the + * radix tree.) As the result, the slot of the radix tree node is NULL but + * the tag which corresponds to the slot has PAGECACHE_TAG_TOWRITE. + * 5. radix_tree_gang_lookup_tag_slot(PAGECACHE_TAG_TOWRITE) calls + * __lookup_tag. __lookup_tag returns with 0. And __lookup_tag doesn't + * change the index that is the input and output parameter. Because the 1st + * slot of the radix tree node is NULL, but the tag which corresponds to + * the slot has PAGECACHE_TAG_TOWRITE. + * Therefore radix_tree_gang_lookup_tag_slot tries to get some items by + * calling __lookup_tag, but it cannot get any items forever. + * + * The fix is to change that radix_tree_tag_if_tagged doesn't tag the root tag + * if it doesn't set any tags within the specified range. + * + * Running: + * This test should run to completion immediately. The above bug would cause it + * to hang indefinitely. + * + * Upstream commit: + * Not yet + */ +#include <linux/kernel.h> +#include <linux/gfp.h> +#include <linux/slab.h> +#include <linux/radix-tree.h> +#include <stdlib.h> +#include <stdio.h> + +#include "regression.h" +#include "test.h" + +#define PAGECACHE_TAG_DIRTY XA_MARK_0 +#define PAGECACHE_TAG_WRITEBACK XA_MARK_1 +#define PAGECACHE_TAG_TOWRITE XA_MARK_2 + +static RADIX_TREE(mt_tree, GFP_KERNEL); +unsigned long page_count = 0; + +struct page { + unsigned long index; +}; + +static struct page *page_alloc(void) +{ + struct page *p; + p = malloc(sizeof(struct page)); + p->index = page_count++; + + return p; +} + +void regression2_test(void) +{ + int i; + struct page *p; + int max_slots = RADIX_TREE_MAP_SIZE; + unsigned long int start, end; + struct page *pages[1]; + + printv(1, "running regression test 2 (should take milliseconds)\n"); + /* 0. */ + for (i = 0; i <= max_slots - 1; i++) { + p = page_alloc(); + radix_tree_insert(&mt_tree, i, p); + } + radix_tree_tag_set(&mt_tree, max_slots - 1, PAGECACHE_TAG_DIRTY); + + /* 1. */ + start = 0; + end = max_slots - 2; + tag_tagged_items(&mt_tree, start, end, 1, + PAGECACHE_TAG_DIRTY, PAGECACHE_TAG_TOWRITE); + + /* 2. */ + p = page_alloc(); + radix_tree_insert(&mt_tree, max_slots, p); + + /* 3. */ + radix_tree_tag_clear(&mt_tree, max_slots - 1, PAGECACHE_TAG_DIRTY); + + /* 4. */ + for (i = max_slots - 1; i >= 0; i--) + free(radix_tree_delete(&mt_tree, i)); + + /* 5. */ + // NOTE: start should not be 0 because radix_tree_gang_lookup_tag_slot + // can return. + start = 1; + end = max_slots - 2; + radix_tree_gang_lookup_tag_slot(&mt_tree, (void ***)pages, start, end, + PAGECACHE_TAG_TOWRITE); + + /* We remove all the remained nodes */ + free(radix_tree_delete(&mt_tree, max_slots)); + + BUG_ON(!radix_tree_empty(&mt_tree)); + + printv(1, "regression test 2, done\n"); +} |
