October 2025 - Linux-stable-mirror

FAILED: patch "[PATCH] btrfs: fix the incorrect max_bytes value for" failed to apply to 6.12-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x 7b26da407420e5054e3f06c5d13271697add9423 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101522-repugnant-demystify-deee@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7b26da407420e5054e3f06c5d13271697add9423 Mon Sep 17 00:00:00 2001 From: Qu Wenruo <wqu(a)suse.com> Date: Fri, 19 Sep 2025 14:33:23 +0930 Subject: [PATCH] btrfs: fix the incorrect max_bytes value for find_lock_delalloc_range() [BUG] With my local branch to enable bs > ps support for btrfs, sometimes I hit the following ASSERT() inside submit_one_sector(): ASSERT(block_start != EXTENT_MAP_HOLE); Please note that it's not yet possible to hit this ASSERT() in the wild yet, as it requires btrfs bs > ps support, which is not even in the development branch. But on the other hand, there is also a very low chance to hit above ASSERT() with bs < ps cases, so this is an existing bug affect not only the incoming bs > ps support but also the existing bs < ps support. [CAUSE] Firstly that ASSERT() means we're trying to submit a dirty block but without a real extent map nor ordered extent map backing it. Furthermore with extra debugging, the folio triggering such ASSERT() is always larger than the fs block size in my bs > ps case. (8K block size, 4K page size) After some more debugging, the ASSERT() is trigger by the following sequence: extent_writepage() | We got a 32K folio (4 fs blocks) at file offset 0, and the fs block | size is 8K, page size is 4K. | And there is another 8K folio at file offset 32K, which is also | dirty. | So the filemap layout looks like the following: | | "||" is the filio boundary in the filemap. | "//| is the dirty range. | | 0 8K 16K 24K 32K 40K | |////////| |//////////////////////||////////| | |- writepage_delalloc() | |- find_lock_delalloc_range() for [0, 8K) | | Now range [0, 8K) is properly locked. | | | |- find_lock_delalloc_range() for [16K, 40K) | | |- btrfs_find_delalloc_range() returned range [16K, 40K) | | |- lock_delalloc_folios() locked folio 0 successfully | | | | | | The filemap range [32K, 40K) got dropped from filemap. | | | | | |- lock_delalloc_folios() failed with -EAGAIN on folio 32K | | | As the folio at 32K is dropped. | | | | | |- loops = 1; | | |- max_bytes = PAGE_SIZE; | | |- goto again; | | | This will re-do the lookup for dirty delalloc ranges. | | | | | |- btrfs_find_delalloc_range() called with @max_bytes == 4K | | | This is smaller than block size, so | | | btrfs_find_delalloc_range() is unable to return any range. | | \- return false; | | | \- Now only range [0, 8K) has an OE for it, but for dirty range | [16K, 32K) it's dirty without an OE. | This breaks the assumption that writepage_delalloc() will find | and lock all dirty ranges inside the folio. | |- extent_writepage_io() |- submit_one_sector() for [0, 8K) | Succeeded | |- submit_one_sector() for [16K, 24K) Triggering the ASSERT(), as there is no OE, and the original extent map is a hole. Please note that, this also exposed the same problem for bs < ps support. E.g. with 64K page size and 4K block size. If we failed to lock a folio, and falls back into the "loops = 1;" branch, we will re-do the search using 64K as max_bytes. Which may fail again to lock the next folio, and exit early without handling all dirty blocks inside the folio. [FIX] Instead of using the fixed size PAGE_SIZE as @max_bytes, use @sectorsize, so that we are ensured to find and lock any remaining blocks inside the folio. And since we're here, add an extra ASSERT() to before calling btrfs_find_delalloc_range() to make sure the @max_bytes is at least no smaller than a block to avoid false negative. Cc: stable(a)vger.kernel.org # 5.15+ Signed-off-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 0782533aad51..2b6027ebf265 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -393,6 +393,13 @@ noinline_for_stack bool find_lock_delalloc_range(struct inode *inode, /* step one, find a bunch of delalloc bytes starting at start */ delalloc_start = *start; delalloc_end = 0; + + /* + * If @max_bytes is smaller than a block, btrfs_find_delalloc_range() can + * return early without handling any dirty ranges. + */ + ASSERT(max_bytes >= fs_info->sectorsize); + found = btrfs_find_delalloc_range(tree, &delalloc_start, &delalloc_end, max_bytes, &cached_state); if (!found || delalloc_end <= *start || delalloc_start > orig_end) { @@ -423,13 +430,14 @@ noinline_for_stack bool find_lock_delalloc_range(struct inode *inode, delalloc_end); ASSERT(!ret || ret == -EAGAIN); if (ret == -EAGAIN) { - /* some of the folios are gone, lets avoid looping by - * shortening the size of the delalloc range we're searching + /* + * Some of the folios are gone, lets avoid looping by + * shortening the size of the delalloc range we're searching. */ btrfs_free_extent_state(cached_state); cached_state = NULL; if (!loops) { - max_bytes = PAGE_SIZE; + max_bytes = fs_info->sectorsize; loops = 1; goto again; } else {

2 weeks, 2 days

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Re: Patch "clk: at91: peripheral: fix return value" has been added to the 6.17-stable tree

by Brian Masney

Hi Sasha, On Wed, Oct 15, 2025 at 07:36:02AM -0400, Sasha Levin wrote: > This is a note to let you know that I've just added the patch titled > > clk: at91: peripheral: fix return value > > to the 6.17-stable tree which can be found at: > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… > > The filename of the patch is: > clk-at91-peripheral-fix-return-value.patch > and it can be found in the queue-6.17 subdirectory. > > If you, or anyone else, feels it should not be added to the stable tree, > please let <stable(a)vger.kernel.org> know about it. > > > > commit cbddc84a11e6112835fced8f7266d9810efc52f3 > Author: Brian Masney <bmasney(a)redhat.com> > Date: Mon Aug 11 11:17:53 2025 -0400 > > clk: at91: peripheral: fix return value > > [ Upstream commit 47b13635dabc14f1c2fdcaa5468b47ddadbdd1b5 ] > > determine_rate() is expected to return an error code, or 0 on success. > clk_sam9x5_peripheral_determine_rate() has a branch that returns the > parent rate on a certain case. This is the behavior of round_rate(), > so let's go ahead and fix this by setting req->rate. > > Fixes: b4c115c76184f ("clk: at91: clk-peripheral: add support for changeable parent rate") > Reviewed-by: Alexander Sverdlin <alexander.sverdlin(a)gmail.com> > Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com> > Signed-off-by: Brian Masney <bmasney(a)redhat.com> > Signed-off-by: Sasha Levin <sashal(a)kernel.org> Please don't backport any of my round_rate() to determine_rate() migrations to the stable kernels. I have maybe close to 200 of these patches for various clk drivers, and stable can stay on round_rate(). There's no functional change. Stephen mentioned this work on his pull to Linus about how this is all prerequisite work to get to the real task of improving the clk rate setting process. https://lore.kernel.org/linux-clk/20251007051720.11386-1-sboyd@kernel.org/ Thanks, Brian

2 weeks, 2 days

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[PATCH 1/1] firmware: stratix10-svc: fix bug in saving controller data

by Khairul Anuar Romli

Fix the incorrect usage of platform_set_drvdata and dev_set_drvdata. They both are of the same data and overrides each other. This resulted in the rmmod of the svc driver to fail and throw a kernel panic for kthread_stop and fifo free. Fixes: bf0e5bf68a20 ("firmware: stratix10-svc: extend svc to support new RSU features") Signed-off-by: Ang Tien Sung <tiensung.ang(a)altera.com> Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli(a)altera.com> --- drivers/firmware/stratix10-svc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c index e3f990d888d7..00f58e27f6de 100644 --- a/drivers/firmware/stratix10-svc.c +++ b/drivers/firmware/stratix10-svc.c @@ -134,6 +134,7 @@ struct stratix10_svc_data { * @complete_status: state for completion * @svc_fifo_lock: protect access to service message data queue * @invoke_fn: function to issue secure monitor call or hypervisor call + * @svc: manages the list of client svc drivers * * This struct is used to create communication channels for service clients, to * handle secure monitor or hypervisor call. @@ -150,6 +151,7 @@ struct stratix10_svc_controller { struct completion complete_status; spinlock_t svc_fifo_lock; svc_invoke_fn *invoke_fn; + struct stratix10_svc *svc; }; /** @@ -1206,6 +1208,7 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev) ret = -ENOMEM; goto err_free_kfifo; } + controller->svc = svc; svc->stratix10_svc_rsu = platform_device_alloc(STRATIX10_RSU, 0); if (!svc->stratix10_svc_rsu) { @@ -1237,8 +1240,6 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev) if (ret) goto err_unregister_fcs_dev; - dev_set_drvdata(dev, svc); - pr_info("Intel Service Layer Driver Initialized\n"); return 0; @@ -1256,8 +1257,8 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev) static void stratix10_svc_drv_remove(struct platform_device *pdev) { - struct stratix10_svc *svc = dev_get_drvdata(&pdev->dev); struct stratix10_svc_controller *ctrl = platform_get_drvdata(pdev); + struct stratix10_svc *svc = ctrl->svc; of_platform_depopulate(ctrl->dev); -- 2.35.3

2 weeks, 2 days

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FAILED: patch "[PATCH] cxl, acpi/hmat: Update CXL access coordinates directly" failed to apply to 6.12-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x 2e454fb8056df6da4bba7d89a57bf60e217463c0 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101518-thriving-lend-6587@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 2e454fb8056df6da4bba7d89a57bf60e217463c0 Mon Sep 17 00:00:00 2001 From: Dave Jiang <dave.jiang(a)intel.com> Date: Fri, 29 Aug 2025 15:29:06 -0700 Subject: [PATCH] cxl, acpi/hmat: Update CXL access coordinates directly instead of through HMAT The current implementation of CXL memory hotplug notifier gets called before the HMAT memory hotplug notifier. The CXL driver calculates the access coordinates (bandwidth and latency values) for the CXL end to end path (i.e. CPU to endpoint). When the CXL region is onlined, the CXL memory hotplug notifier writes the access coordinates to the HMAT target structs. Then the HMAT memory hotplug notifier is called and it creates the access coordinates for the node sysfs attributes. During testing on an Intel platform, it was found that although the newly calculated coordinates were pushed to sysfs, the sysfs attributes for the access coordinates showed up with the wrong initiator. The system has 4 nodes (0, 1, 2, 3) where node 0 and 1 are CPU nodes and node 2 and 3 are CXL nodes. The expectation is that node 2 would show up as a target to node 0: /sys/devices/system/node/node2/access0/initiators/node0 However it was observed that node 2 showed up as a target under node 1: /sys/devices/system/node/node2/access0/initiators/node1 The original intent of the 'ext_updated' flag in HMAT handling code was to stop HMAT memory hotplug callback from clobbering the access coordinates after CXL has injected its calculated coordinates and replaced the generic target access coordinates provided by the HMAT table in the HMAT target structs. However the flag is hacky at best and blocks the updates from other CXL regions that are onlined in the same node later on. Remove the 'ext_updated' flag usage and just update the access coordinates for the nodes directly without touching HMAT target data. The hotplug memory callback ordering is changed. Instead of changing CXL, move HMAT back so there's room for the levels rather than have CXL share the same level as SLAB_CALLBACK_PRI. The change will resulting in the CXL callback to be executed after the HMAT callback. With the change, the CXL hotplug memory notifier runs after the HMAT callback. The HMAT callback will create the node sysfs attributes for access coordinates. The CXL callback will write the access coordinates to the now created node sysfs attributes directly and will not pollute the HMAT target values. A nodemask is introduced to keep track if a node has been updated and prevents further updates. Fixes: 067353a46d8c ("cxl/region: Add memory hotplug notifier for cxl region") Cc: stable(a)vger.kernel.org Tested-by: Marc Herbert <marc.herbert(a)linux.intel.com> Reviewed-by: Dan Williams <dan.j.williams(a)intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron(a)huawei.com> Link: https://patch.msgid.link/20250829222907.1290912-4-dave.jiang@intel.com Signed-off-by: Dave Jiang <dave.jiang(a)intel.com> diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c index 4958301f5417..5d32490dc4ab 100644 --- a/drivers/acpi/numa/hmat.c +++ b/drivers/acpi/numa/hmat.c @@ -74,7 +74,6 @@ struct memory_target { struct node_cache_attrs cache_attrs; u8 gen_port_device_handle[ACPI_SRAT_DEVICE_HANDLE_SIZE]; bool registered; - bool ext_updated; /* externally updated */ }; struct memory_initiator { @@ -391,7 +390,6 @@ int hmat_update_target_coordinates(int nid, struct access_coordinate *coord, coord->read_bandwidth, access); hmat_update_target_access(target, ACPI_HMAT_WRITE_BANDWIDTH, coord->write_bandwidth, access); - target->ext_updated = true; return 0; } @@ -773,10 +771,6 @@ static void hmat_update_target_attrs(struct memory_target *target, u32 best = 0; int i; - /* Don't update if an external agent has changed the data. */ - if (target->ext_updated) - return; - /* Don't update for generic port if there's no device handle */ if ((access == NODE_ACCESS_CLASS_GENPORT_SINK_LOCAL || access == NODE_ACCESS_CLASS_GENPORT_SINK_CPU) && diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c index c0af645425f4..c891fd618cfd 100644 --- a/drivers/cxl/core/cdat.c +++ b/drivers/cxl/core/cdat.c @@ -1081,8 +1081,3 @@ int cxl_update_hmat_access_coordinates(int nid, struct cxl_region *cxlr, { return hmat_update_target_coordinates(nid, &cxlr->coord[access], access); } - -bool cxl_need_node_perf_attrs_update(int nid) -{ - return !acpi_node_backed_by_real_pxm(nid); -} diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h index 2669f251d677..a253d308f3c9 100644 --- a/drivers/cxl/core/core.h +++ b/drivers/cxl/core/core.h @@ -139,7 +139,6 @@ long cxl_pci_get_latency(struct pci_dev *pdev); int cxl_pci_get_bandwidth(struct pci_dev *pdev, struct access_coordinate *c); int cxl_update_hmat_access_coordinates(int nid, struct cxl_region *cxlr, enum access_coordinate_class access); -bool cxl_need_node_perf_attrs_update(int nid); int cxl_port_get_switch_dport_bandwidth(struct cxl_port *port, struct access_coordinate *c); diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 71cc42d05248..0ed95cbc5d5b 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -30,6 +30,12 @@ * 3. Decoder targets */ +/* + * nodemask that sets per node when the access_coordinates for the node has + * been updated by the CXL memory hotplug notifier. + */ +static nodemask_t nodemask_region_seen = NODE_MASK_NONE; + static struct cxl_region *to_cxl_region(struct device *dev); #define __ACCESS_ATTR_RO(_level, _name) { \ @@ -2442,14 +2448,8 @@ static bool cxl_region_update_coordinates(struct cxl_region *cxlr, int nid) for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) { if (cxlr->coord[i].read_bandwidth) { - rc = 0; - if (cxl_need_node_perf_attrs_update(nid)) - node_set_perf_attrs(nid, &cxlr->coord[i], i); - else - rc = cxl_update_hmat_access_coordinates(nid, cxlr, i); - - if (rc == 0) - cset++; + node_update_perf_attrs(nid, &cxlr->coord[i], i); + cset++; } } @@ -2487,6 +2487,10 @@ static int cxl_region_perf_attrs_callback(struct notifier_block *nb, if (nid != region_nid) return NOTIFY_DONE; + /* No action needed if node bit already set */ + if (node_test_and_set(nid, nodemask_region_seen)) + return NOTIFY_DONE; + if (!cxl_region_update_coordinates(cxlr, nid)) return NOTIFY_DONE; diff --git a/include/linux/memory.h b/include/linux/memory.h index 1305102688d0..0b755d1ef1ec 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -120,8 +120,8 @@ struct mem_section; */ #define DEFAULT_CALLBACK_PRI 0 #define SLAB_CALLBACK_PRI 1 -#define HMAT_CALLBACK_PRI 2 #define CXL_CALLBACK_PRI 5 +#define HMAT_CALLBACK_PRI 6 #define MM_COMPUTE_BATCH_PRI 10 #define CPUSET_CALLBACK_PRI 10 #define MEMTIER_HOTPLUG_PRI 100

2 weeks, 2 days

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FAILED: patch "[PATCH] cxl, acpi/hmat: Update CXL access coordinates directly" failed to apply to 6.17-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.17-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.17.y git checkout FETCH_HEAD git cherry-pick -x 2e454fb8056df6da4bba7d89a57bf60e217463c0 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101516-stowaway-bogged-2173@gregkh' --subject-prefix 'PATCH 6.17.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 2e454fb8056df6da4bba7d89a57bf60e217463c0 Mon Sep 17 00:00:00 2001 From: Dave Jiang <dave.jiang(a)intel.com> Date: Fri, 29 Aug 2025 15:29:06 -0700 Subject: [PATCH] cxl, acpi/hmat: Update CXL access coordinates directly instead of through HMAT The current implementation of CXL memory hotplug notifier gets called before the HMAT memory hotplug notifier. The CXL driver calculates the access coordinates (bandwidth and latency values) for the CXL end to end path (i.e. CPU to endpoint). When the CXL region is onlined, the CXL memory hotplug notifier writes the access coordinates to the HMAT target structs. Then the HMAT memory hotplug notifier is called and it creates the access coordinates for the node sysfs attributes. During testing on an Intel platform, it was found that although the newly calculated coordinates were pushed to sysfs, the sysfs attributes for the access coordinates showed up with the wrong initiator. The system has 4 nodes (0, 1, 2, 3) where node 0 and 1 are CPU nodes and node 2 and 3 are CXL nodes. The expectation is that node 2 would show up as a target to node 0: /sys/devices/system/node/node2/access0/initiators/node0 However it was observed that node 2 showed up as a target under node 1: /sys/devices/system/node/node2/access0/initiators/node1 The original intent of the 'ext_updated' flag in HMAT handling code was to stop HMAT memory hotplug callback from clobbering the access coordinates after CXL has injected its calculated coordinates and replaced the generic target access coordinates provided by the HMAT table in the HMAT target structs. However the flag is hacky at best and blocks the updates from other CXL regions that are onlined in the same node later on. Remove the 'ext_updated' flag usage and just update the access coordinates for the nodes directly without touching HMAT target data. The hotplug memory callback ordering is changed. Instead of changing CXL, move HMAT back so there's room for the levels rather than have CXL share the same level as SLAB_CALLBACK_PRI. The change will resulting in the CXL callback to be executed after the HMAT callback. With the change, the CXL hotplug memory notifier runs after the HMAT callback. The HMAT callback will create the node sysfs attributes for access coordinates. The CXL callback will write the access coordinates to the now created node sysfs attributes directly and will not pollute the HMAT target values. A nodemask is introduced to keep track if a node has been updated and prevents further updates. Fixes: 067353a46d8c ("cxl/region: Add memory hotplug notifier for cxl region") Cc: stable(a)vger.kernel.org Tested-by: Marc Herbert <marc.herbert(a)linux.intel.com> Reviewed-by: Dan Williams <dan.j.williams(a)intel.com> Reviewed-by: Jonathan Cameron <jonathan.cameron(a)huawei.com> Link: https://patch.msgid.link/20250829222907.1290912-4-dave.jiang@intel.com Signed-off-by: Dave Jiang <dave.jiang(a)intel.com> diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c index 4958301f5417..5d32490dc4ab 100644 --- a/drivers/acpi/numa/hmat.c +++ b/drivers/acpi/numa/hmat.c @@ -74,7 +74,6 @@ struct memory_target { struct node_cache_attrs cache_attrs; u8 gen_port_device_handle[ACPI_SRAT_DEVICE_HANDLE_SIZE]; bool registered; - bool ext_updated; /* externally updated */ }; struct memory_initiator { @@ -391,7 +390,6 @@ int hmat_update_target_coordinates(int nid, struct access_coordinate *coord, coord->read_bandwidth, access); hmat_update_target_access(target, ACPI_HMAT_WRITE_BANDWIDTH, coord->write_bandwidth, access); - target->ext_updated = true; return 0; } @@ -773,10 +771,6 @@ static void hmat_update_target_attrs(struct memory_target *target, u32 best = 0; int i; - /* Don't update if an external agent has changed the data. */ - if (target->ext_updated) - return; - /* Don't update for generic port if there's no device handle */ if ((access == NODE_ACCESS_CLASS_GENPORT_SINK_LOCAL || access == NODE_ACCESS_CLASS_GENPORT_SINK_CPU) && diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c index c0af645425f4..c891fd618cfd 100644 --- a/drivers/cxl/core/cdat.c +++ b/drivers/cxl/core/cdat.c @@ -1081,8 +1081,3 @@ int cxl_update_hmat_access_coordinates(int nid, struct cxl_region *cxlr, { return hmat_update_target_coordinates(nid, &cxlr->coord[access], access); } - -bool cxl_need_node_perf_attrs_update(int nid) -{ - return !acpi_node_backed_by_real_pxm(nid); -} diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h index 2669f251d677..a253d308f3c9 100644 --- a/drivers/cxl/core/core.h +++ b/drivers/cxl/core/core.h @@ -139,7 +139,6 @@ long cxl_pci_get_latency(struct pci_dev *pdev); int cxl_pci_get_bandwidth(struct pci_dev *pdev, struct access_coordinate *c); int cxl_update_hmat_access_coordinates(int nid, struct cxl_region *cxlr, enum access_coordinate_class access); -bool cxl_need_node_perf_attrs_update(int nid); int cxl_port_get_switch_dport_bandwidth(struct cxl_port *port, struct access_coordinate *c); diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 71cc42d05248..0ed95cbc5d5b 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -30,6 +30,12 @@ * 3. Decoder targets */ +/* + * nodemask that sets per node when the access_coordinates for the node has + * been updated by the CXL memory hotplug notifier. + */ +static nodemask_t nodemask_region_seen = NODE_MASK_NONE; + static struct cxl_region *to_cxl_region(struct device *dev); #define __ACCESS_ATTR_RO(_level, _name) { \ @@ -2442,14 +2448,8 @@ static bool cxl_region_update_coordinates(struct cxl_region *cxlr, int nid) for (int i = 0; i < ACCESS_COORDINATE_MAX; i++) { if (cxlr->coord[i].read_bandwidth) { - rc = 0; - if (cxl_need_node_perf_attrs_update(nid)) - node_set_perf_attrs(nid, &cxlr->coord[i], i); - else - rc = cxl_update_hmat_access_coordinates(nid, cxlr, i); - - if (rc == 0) - cset++; + node_update_perf_attrs(nid, &cxlr->coord[i], i); + cset++; } } @@ -2487,6 +2487,10 @@ static int cxl_region_perf_attrs_callback(struct notifier_block *nb, if (nid != region_nid) return NOTIFY_DONE; + /* No action needed if node bit already set */ + if (node_test_and_set(nid, nodemask_region_seen)) + return NOTIFY_DONE; + if (!cxl_region_update_coordinates(cxlr, nid)) return NOTIFY_DONE; diff --git a/include/linux/memory.h b/include/linux/memory.h index 1305102688d0..0b755d1ef1ec 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -120,8 +120,8 @@ struct mem_section; */ #define DEFAULT_CALLBACK_PRI 0 #define SLAB_CALLBACK_PRI 1 -#define HMAT_CALLBACK_PRI 2 #define CXL_CALLBACK_PRI 5 +#define HMAT_CALLBACK_PRI 6 #define MM_COMPUTE_BATCH_PRI 10 #define CPUSET_CALLBACK_PRI 10 #define MEMTIER_HOTPLUG_PRI 100

2 weeks, 2 days

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FAILED: patch "[PATCH] rseq: Protect event mask against membarrier IPI" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 6eb350a2233100a283f882c023e5ad426d0ed63b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101556-district-timid-1eda@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 6eb350a2233100a283f882c023e5ad426d0ed63b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx(a)linutronix.de> Date: Wed, 13 Aug 2025 17:02:30 +0200 Subject: [PATCH] rseq: Protect event mask against membarrier IPI rseq_need_restart() reads and clears task::rseq_event_mask with preemption disabled to guard against the scheduler. But membarrier() uses an IPI and sets the PREEMPT bit in the event mask from the IPI, which leaves that RMW operation unprotected. Use guard(irq) if CONFIG_MEMBARRIER is enabled to fix that. Fixes: 2a36ab717e8f ("rseq/membarrier: Add MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ") Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Reviewed-by: Boqun Feng <boqun.feng(a)gmail.com> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Cc: stable(a)vger.kernel.org diff --git a/include/linux/rseq.h b/include/linux/rseq.h index bc8af3eb5598..1fbeb61babeb 100644 --- a/include/linux/rseq.h +++ b/include/linux/rseq.h @@ -7,6 +7,12 @@ #include <linux/preempt.h> #include <linux/sched.h> +#ifdef CONFIG_MEMBARRIER +# define RSEQ_EVENT_GUARD irq +#else +# define RSEQ_EVENT_GUARD preempt +#endif + /* * Map the event mask on the user-space ABI enum rseq_cs_flags * for direct mask checks. @@ -41,9 +47,8 @@ static inline void rseq_handle_notify_resume(struct ksignal *ksig, static inline void rseq_signal_deliver(struct ksignal *ksig, struct pt_regs *regs) { - preempt_disable(); - __set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask); - preempt_enable(); + scoped_guard(RSEQ_EVENT_GUARD) + __set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask); rseq_handle_notify_resume(ksig, regs); } diff --git a/kernel/rseq.c b/kernel/rseq.c index b7a1ec327e81..2452b7366b00 100644 --- a/kernel/rseq.c +++ b/kernel/rseq.c @@ -342,12 +342,12 @@ static int rseq_need_restart(struct task_struct *t, u32 cs_flags) /* * Load and clear event mask atomically with respect to - * scheduler preemption. + * scheduler preemption and membarrier IPIs. */ - preempt_disable(); - event_mask = t->rseq_event_mask; - t->rseq_event_mask = 0; - preempt_enable(); + scoped_guard(RSEQ_EVENT_GUARD) { + event_mask = t->rseq_event_mask; + t->rseq_event_mask = 0; + } return !!event_mask; }

2 weeks, 2 days

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FAILED: patch "[PATCH] rseq: Protect event mask against membarrier IPI" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 6eb350a2233100a283f882c023e5ad426d0ed63b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101556-riches-vivacious-ee8f@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 6eb350a2233100a283f882c023e5ad426d0ed63b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx(a)linutronix.de> Date: Wed, 13 Aug 2025 17:02:30 +0200 Subject: [PATCH] rseq: Protect event mask against membarrier IPI rseq_need_restart() reads and clears task::rseq_event_mask with preemption disabled to guard against the scheduler. But membarrier() uses an IPI and sets the PREEMPT bit in the event mask from the IPI, which leaves that RMW operation unprotected. Use guard(irq) if CONFIG_MEMBARRIER is enabled to fix that. Fixes: 2a36ab717e8f ("rseq/membarrier: Add MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ") Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Reviewed-by: Boqun Feng <boqun.feng(a)gmail.com> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Cc: stable(a)vger.kernel.org diff --git a/include/linux/rseq.h b/include/linux/rseq.h index bc8af3eb5598..1fbeb61babeb 100644 --- a/include/linux/rseq.h +++ b/include/linux/rseq.h @@ -7,6 +7,12 @@ #include <linux/preempt.h> #include <linux/sched.h> +#ifdef CONFIG_MEMBARRIER +# define RSEQ_EVENT_GUARD irq +#else +# define RSEQ_EVENT_GUARD preempt +#endif + /* * Map the event mask on the user-space ABI enum rseq_cs_flags * for direct mask checks. @@ -41,9 +47,8 @@ static inline void rseq_handle_notify_resume(struct ksignal *ksig, static inline void rseq_signal_deliver(struct ksignal *ksig, struct pt_regs *regs) { - preempt_disable(); - __set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask); - preempt_enable(); + scoped_guard(RSEQ_EVENT_GUARD) + __set_bit(RSEQ_EVENT_SIGNAL_BIT, &current->rseq_event_mask); rseq_handle_notify_resume(ksig, regs); } diff --git a/kernel/rseq.c b/kernel/rseq.c index b7a1ec327e81..2452b7366b00 100644 --- a/kernel/rseq.c +++ b/kernel/rseq.c @@ -342,12 +342,12 @@ static int rseq_need_restart(struct task_struct *t, u32 cs_flags) /* * Load and clear event mask atomically with respect to - * scheduler preemption. + * scheduler preemption and membarrier IPIs. */ - preempt_disable(); - event_mask = t->rseq_event_mask; - t->rseq_event_mask = 0; - preempt_enable(); + scoped_guard(RSEQ_EVENT_GUARD) { + event_mask = t->rseq_event_mask; + t->rseq_event_mask = 0; + } return !!event_mask; }

2 weeks, 2 days

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FAILED: patch "[PATCH] arm64: map [_text, _stext) virtual address range" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 5973a62efa34c80c9a4e5eac1fca6f6209b902af # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101551-unsealed-whisking-8514@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5973a62efa34c80c9a4e5eac1fca6f6209b902af Mon Sep 17 00:00:00 2001 From: Omar Sandoval <osandov(a)fb.com> Date: Fri, 19 Sep 2025 14:27:51 -0700 Subject: [PATCH] arm64: map [_text, _stext) virtual address range non-executable+read-only Since the referenced fixes commit, the kernel's .text section is only mapped starting from _stext; the region [_text, _stext) is omitted. As a result, other vmalloc/vmap allocations may use the virtual addresses nominally in the range [_text, _stext). This address reuse confuses multiple things: 1. crash_prepare_elf64_headers() sets up a segment in /proc/vmcore mapping the entire range [_text, _end) to [__pa_symbol(_text), __pa_symbol(_end)). Reading an address in [_text, _stext) from /proc/vmcore therefore gives the incorrect result. 2. Tools doing symbolization (either by reading /proc/kallsyms or based on the vmlinux ELF file) will incorrectly identify vmalloc/vmap allocations in [_text, _stext) as kernel symbols. In practice, both of these issues affect the drgn debugger. Specifically, there were cases where the vmap IRQ stacks for some CPUs were allocated in [_text, _stext). As a result, drgn could not get the stack trace for a crash in an IRQ handler because the core dump contained invalid data for the IRQ stack address. The stack addresses were also symbolized as being in the _text symbol. Fix this by bringing back the mapping of [_text, _stext), but now make it non-executable and read-only. This prevents other allocations from using it while still achieving the original goal of not mapping unpredictable data as executable. Other than the changed protection, this is effectively a revert of the fixes commit. Fixes: e2a073dde921 ("arm64: omit [_text, _stext) from permanent kernel mapping") Cc: stable(a)vger.kernel.org Signed-off-by: Omar Sandoval <osandov(a)fb.com> Signed-off-by: Will Deacon <will(a)kernel.org> diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c index e6d35eff1486..e8ddbde31a83 100644 --- a/arch/arm64/kernel/pi/map_kernel.c +++ b/arch/arm64/kernel/pi/map_kernel.c @@ -78,6 +78,12 @@ static void __init map_kernel(u64 kaslr_offset, u64 va_offset, int root_level) twopass |= enable_scs; prot = twopass ? data_prot : text_prot; + /* + * [_stext, _text) isn't executed after boot and contains some + * non-executable, unpredictable data, so map it non-executable. + */ + map_segment(init_pg_dir, &pgdp, va_offset, _text, _stext, data_prot, + false, root_level); map_segment(init_pg_dir, &pgdp, va_offset, _stext, _etext, prot, !twopass, root_level); map_segment(init_pg_dir, &pgdp, va_offset, __start_rodata, diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 77c7926a4df6..23c05dc7a8f2 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -214,7 +214,7 @@ static void __init request_standard_resources(void) unsigned long i = 0; size_t res_size; - kernel_code.start = __pa_symbol(_stext); + kernel_code.start = __pa_symbol(_text); kernel_code.end = __pa_symbol(__init_begin - 1); kernel_data.start = __pa_symbol(_sdata); kernel_data.end = __pa_symbol(_end - 1); @@ -280,7 +280,7 @@ u64 cpu_logical_map(unsigned int cpu) void __init __no_sanitize_address setup_arch(char **cmdline_p) { - setup_initial_init_mm(_stext, _etext, _edata, _end); + setup_initial_init_mm(_text, _etext, _edata, _end); *cmdline_p = boot_command_line; diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 70c2ca813c18..524d34a0e921 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -279,7 +279,7 @@ void __init arm64_memblock_init(void) * Register the kernel text, kernel data, initrd, and initial * pagetables with memblock. */ - memblock_reserve(__pa_symbol(_stext), _end - _stext); + memblock_reserve(__pa_symbol(_text), _end - _text); if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) { /* the generic initrd code expects virtual addresses */ initrd_start = __phys_to_virt(phys_initrd_start); diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 0ba1a15e7e74..10c258099581 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -965,8 +965,8 @@ void __init mark_linear_text_alias_ro(void) /* * Remove the write permissions from the linear alias of .text/.rodata */ - update_mapping_prot(__pa_symbol(_stext), (unsigned long)lm_alias(_stext), - (unsigned long)__init_begin - (unsigned long)_stext, + update_mapping_prot(__pa_symbol(_text), (unsigned long)lm_alias(_text), + (unsigned long)__init_begin - (unsigned long)_text, PAGE_KERNEL_RO); } @@ -1037,7 +1037,7 @@ static inline bool force_pte_mapping(void) static void __init map_mem(pgd_t *pgdp) { static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN); - phys_addr_t kernel_start = __pa_symbol(_stext); + phys_addr_t kernel_start = __pa_symbol(_text); phys_addr_t kernel_end = __pa_symbol(__init_begin); phys_addr_t start, end; phys_addr_t early_kfence_pool; @@ -1086,7 +1086,7 @@ static void __init map_mem(pgd_t *pgdp) } /* - * Map the linear alias of the [_stext, __init_begin) interval + * Map the linear alias of the [_text, __init_begin) interval * as non-executable now, and remove the write permission in * mark_linear_text_alias_ro() below (which will be called after * alternative patching has completed). This makes the contents @@ -1113,6 +1113,10 @@ void mark_rodata_ro(void) WRITE_ONCE(rodata_is_rw, false); update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata, section_size, PAGE_KERNEL_RO); + /* mark the range between _text and _stext as read only. */ + update_mapping_prot(__pa_symbol(_text), (unsigned long)_text, + (unsigned long)_stext - (unsigned long)_text, + PAGE_KERNEL_RO); } static void __init declare_vma(struct vm_struct *vma, @@ -1183,7 +1187,7 @@ static void __init declare_kernel_vmas(void) { static struct vm_struct vmlinux_seg[KERNEL_SEGMENT_COUNT]; - declare_vma(&vmlinux_seg[0], _stext, _etext, VM_NO_GUARD); + declare_vma(&vmlinux_seg[0], _text, _etext, VM_NO_GUARD); declare_vma(&vmlinux_seg[1], __start_rodata, __inittext_begin, VM_NO_GUARD); declare_vma(&vmlinux_seg[2], __inittext_begin, __inittext_end, VM_NO_GUARD); declare_vma(&vmlinux_seg[3], __initdata_begin, __initdata_end, VM_NO_GUARD);

2 weeks, 2 days

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FAILED: patch "[PATCH] arm64: map [_text, _stext) virtual address range" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 5973a62efa34c80c9a4e5eac1fca6f6209b902af # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101549-slurp-darkened-955a@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5973a62efa34c80c9a4e5eac1fca6f6209b902af Mon Sep 17 00:00:00 2001 From: Omar Sandoval <osandov(a)fb.com> Date: Fri, 19 Sep 2025 14:27:51 -0700 Subject: [PATCH] arm64: map [_text, _stext) virtual address range non-executable+read-only Since the referenced fixes commit, the kernel's .text section is only mapped starting from _stext; the region [_text, _stext) is omitted. As a result, other vmalloc/vmap allocations may use the virtual addresses nominally in the range [_text, _stext). This address reuse confuses multiple things: 1. crash_prepare_elf64_headers() sets up a segment in /proc/vmcore mapping the entire range [_text, _end) to [__pa_symbol(_text), __pa_symbol(_end)). Reading an address in [_text, _stext) from /proc/vmcore therefore gives the incorrect result. 2. Tools doing symbolization (either by reading /proc/kallsyms or based on the vmlinux ELF file) will incorrectly identify vmalloc/vmap allocations in [_text, _stext) as kernel symbols. In practice, both of these issues affect the drgn debugger. Specifically, there were cases where the vmap IRQ stacks for some CPUs were allocated in [_text, _stext). As a result, drgn could not get the stack trace for a crash in an IRQ handler because the core dump contained invalid data for the IRQ stack address. The stack addresses were also symbolized as being in the _text symbol. Fix this by bringing back the mapping of [_text, _stext), but now make it non-executable and read-only. This prevents other allocations from using it while still achieving the original goal of not mapping unpredictable data as executable. Other than the changed protection, this is effectively a revert of the fixes commit. Fixes: e2a073dde921 ("arm64: omit [_text, _stext) from permanent kernel mapping") Cc: stable(a)vger.kernel.org Signed-off-by: Omar Sandoval <osandov(a)fb.com> Signed-off-by: Will Deacon <will(a)kernel.org> diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c index e6d35eff1486..e8ddbde31a83 100644 --- a/arch/arm64/kernel/pi/map_kernel.c +++ b/arch/arm64/kernel/pi/map_kernel.c @@ -78,6 +78,12 @@ static void __init map_kernel(u64 kaslr_offset, u64 va_offset, int root_level) twopass |= enable_scs; prot = twopass ? data_prot : text_prot; + /* + * [_stext, _text) isn't executed after boot and contains some + * non-executable, unpredictable data, so map it non-executable. + */ + map_segment(init_pg_dir, &pgdp, va_offset, _text, _stext, data_prot, + false, root_level); map_segment(init_pg_dir, &pgdp, va_offset, _stext, _etext, prot, !twopass, root_level); map_segment(init_pg_dir, &pgdp, va_offset, __start_rodata, diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 77c7926a4df6..23c05dc7a8f2 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -214,7 +214,7 @@ static void __init request_standard_resources(void) unsigned long i = 0; size_t res_size; - kernel_code.start = __pa_symbol(_stext); + kernel_code.start = __pa_symbol(_text); kernel_code.end = __pa_symbol(__init_begin - 1); kernel_data.start = __pa_symbol(_sdata); kernel_data.end = __pa_symbol(_end - 1); @@ -280,7 +280,7 @@ u64 cpu_logical_map(unsigned int cpu) void __init __no_sanitize_address setup_arch(char **cmdline_p) { - setup_initial_init_mm(_stext, _etext, _edata, _end); + setup_initial_init_mm(_text, _etext, _edata, _end); *cmdline_p = boot_command_line; diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 70c2ca813c18..524d34a0e921 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -279,7 +279,7 @@ void __init arm64_memblock_init(void) * Register the kernel text, kernel data, initrd, and initial * pagetables with memblock. */ - memblock_reserve(__pa_symbol(_stext), _end - _stext); + memblock_reserve(__pa_symbol(_text), _end - _text); if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) { /* the generic initrd code expects virtual addresses */ initrd_start = __phys_to_virt(phys_initrd_start); diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 0ba1a15e7e74..10c258099581 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -965,8 +965,8 @@ void __init mark_linear_text_alias_ro(void) /* * Remove the write permissions from the linear alias of .text/.rodata */ - update_mapping_prot(__pa_symbol(_stext), (unsigned long)lm_alias(_stext), - (unsigned long)__init_begin - (unsigned long)_stext, + update_mapping_prot(__pa_symbol(_text), (unsigned long)lm_alias(_text), + (unsigned long)__init_begin - (unsigned long)_text, PAGE_KERNEL_RO); } @@ -1037,7 +1037,7 @@ static inline bool force_pte_mapping(void) static void __init map_mem(pgd_t *pgdp) { static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN); - phys_addr_t kernel_start = __pa_symbol(_stext); + phys_addr_t kernel_start = __pa_symbol(_text); phys_addr_t kernel_end = __pa_symbol(__init_begin); phys_addr_t start, end; phys_addr_t early_kfence_pool; @@ -1086,7 +1086,7 @@ static void __init map_mem(pgd_t *pgdp) } /* - * Map the linear alias of the [_stext, __init_begin) interval + * Map the linear alias of the [_text, __init_begin) interval * as non-executable now, and remove the write permission in * mark_linear_text_alias_ro() below (which will be called after * alternative patching has completed). This makes the contents @@ -1113,6 +1113,10 @@ void mark_rodata_ro(void) WRITE_ONCE(rodata_is_rw, false); update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata, section_size, PAGE_KERNEL_RO); + /* mark the range between _text and _stext as read only. */ + update_mapping_prot(__pa_symbol(_text), (unsigned long)_text, + (unsigned long)_stext - (unsigned long)_text, + PAGE_KERNEL_RO); } static void __init declare_vma(struct vm_struct *vma, @@ -1183,7 +1187,7 @@ static void __init declare_kernel_vmas(void) { static struct vm_struct vmlinux_seg[KERNEL_SEGMENT_COUNT]; - declare_vma(&vmlinux_seg[0], _stext, _etext, VM_NO_GUARD); + declare_vma(&vmlinux_seg[0], _text, _etext, VM_NO_GUARD); declare_vma(&vmlinux_seg[1], __start_rodata, __inittext_begin, VM_NO_GUARD); declare_vma(&vmlinux_seg[2], __inittext_begin, __inittext_end, VM_NO_GUARD); declare_vma(&vmlinux_seg[3], __initdata_begin, __initdata_end, VM_NO_GUARD);

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FAILED: patch "[PATCH] arm64: map [_text, _stext) virtual address range" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 5973a62efa34c80c9a4e5eac1fca6f6209b902af # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101548-stiffly-eagle-d9a5@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 5973a62efa34c80c9a4e5eac1fca6f6209b902af Mon Sep 17 00:00:00 2001 From: Omar Sandoval <osandov(a)fb.com> Date: Fri, 19 Sep 2025 14:27:51 -0700 Subject: [PATCH] arm64: map [_text, _stext) virtual address range non-executable+read-only Since the referenced fixes commit, the kernel's .text section is only mapped starting from _stext; the region [_text, _stext) is omitted. As a result, other vmalloc/vmap allocations may use the virtual addresses nominally in the range [_text, _stext). This address reuse confuses multiple things: 1. crash_prepare_elf64_headers() sets up a segment in /proc/vmcore mapping the entire range [_text, _end) to [__pa_symbol(_text), __pa_symbol(_end)). Reading an address in [_text, _stext) from /proc/vmcore therefore gives the incorrect result. 2. Tools doing symbolization (either by reading /proc/kallsyms or based on the vmlinux ELF file) will incorrectly identify vmalloc/vmap allocations in [_text, _stext) as kernel symbols. In practice, both of these issues affect the drgn debugger. Specifically, there were cases where the vmap IRQ stacks for some CPUs were allocated in [_text, _stext). As a result, drgn could not get the stack trace for a crash in an IRQ handler because the core dump contained invalid data for the IRQ stack address. The stack addresses were also symbolized as being in the _text symbol. Fix this by bringing back the mapping of [_text, _stext), but now make it non-executable and read-only. This prevents other allocations from using it while still achieving the original goal of not mapping unpredictable data as executable. Other than the changed protection, this is effectively a revert of the fixes commit. Fixes: e2a073dde921 ("arm64: omit [_text, _stext) from permanent kernel mapping") Cc: stable(a)vger.kernel.org Signed-off-by: Omar Sandoval <osandov(a)fb.com> Signed-off-by: Will Deacon <will(a)kernel.org> diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c index e6d35eff1486..e8ddbde31a83 100644 --- a/arch/arm64/kernel/pi/map_kernel.c +++ b/arch/arm64/kernel/pi/map_kernel.c @@ -78,6 +78,12 @@ static void __init map_kernel(u64 kaslr_offset, u64 va_offset, int root_level) twopass |= enable_scs; prot = twopass ? data_prot : text_prot; + /* + * [_stext, _text) isn't executed after boot and contains some + * non-executable, unpredictable data, so map it non-executable. + */ + map_segment(init_pg_dir, &pgdp, va_offset, _text, _stext, data_prot, + false, root_level); map_segment(init_pg_dir, &pgdp, va_offset, _stext, _etext, prot, !twopass, root_level); map_segment(init_pg_dir, &pgdp, va_offset, __start_rodata, diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 77c7926a4df6..23c05dc7a8f2 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -214,7 +214,7 @@ static void __init request_standard_resources(void) unsigned long i = 0; size_t res_size; - kernel_code.start = __pa_symbol(_stext); + kernel_code.start = __pa_symbol(_text); kernel_code.end = __pa_symbol(__init_begin - 1); kernel_data.start = __pa_symbol(_sdata); kernel_data.end = __pa_symbol(_end - 1); @@ -280,7 +280,7 @@ u64 cpu_logical_map(unsigned int cpu) void __init __no_sanitize_address setup_arch(char **cmdline_p) { - setup_initial_init_mm(_stext, _etext, _edata, _end); + setup_initial_init_mm(_text, _etext, _edata, _end); *cmdline_p = boot_command_line; diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 70c2ca813c18..524d34a0e921 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -279,7 +279,7 @@ void __init arm64_memblock_init(void) * Register the kernel text, kernel data, initrd, and initial * pagetables with memblock. */ - memblock_reserve(__pa_symbol(_stext), _end - _stext); + memblock_reserve(__pa_symbol(_text), _end - _text); if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) { /* the generic initrd code expects virtual addresses */ initrd_start = __phys_to_virt(phys_initrd_start); diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 0ba1a15e7e74..10c258099581 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -965,8 +965,8 @@ void __init mark_linear_text_alias_ro(void) /* * Remove the write permissions from the linear alias of .text/.rodata */ - update_mapping_prot(__pa_symbol(_stext), (unsigned long)lm_alias(_stext), - (unsigned long)__init_begin - (unsigned long)_stext, + update_mapping_prot(__pa_symbol(_text), (unsigned long)lm_alias(_text), + (unsigned long)__init_begin - (unsigned long)_text, PAGE_KERNEL_RO); } @@ -1037,7 +1037,7 @@ static inline bool force_pte_mapping(void) static void __init map_mem(pgd_t *pgdp) { static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN); - phys_addr_t kernel_start = __pa_symbol(_stext); + phys_addr_t kernel_start = __pa_symbol(_text); phys_addr_t kernel_end = __pa_symbol(__init_begin); phys_addr_t start, end; phys_addr_t early_kfence_pool; @@ -1086,7 +1086,7 @@ static void __init map_mem(pgd_t *pgdp) } /* - * Map the linear alias of the [_stext, __init_begin) interval + * Map the linear alias of the [_text, __init_begin) interval * as non-executable now, and remove the write permission in * mark_linear_text_alias_ro() below (which will be called after * alternative patching has completed). This makes the contents @@ -1113,6 +1113,10 @@ void mark_rodata_ro(void) WRITE_ONCE(rodata_is_rw, false); update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata, section_size, PAGE_KERNEL_RO); + /* mark the range between _text and _stext as read only. */ + update_mapping_prot(__pa_symbol(_text), (unsigned long)_text, + (unsigned long)_stext - (unsigned long)_text, + PAGE_KERNEL_RO); } static void __init declare_vma(struct vm_struct *vma, @@ -1183,7 +1187,7 @@ static void __init declare_kernel_vmas(void) { static struct vm_struct vmlinux_seg[KERNEL_SEGMENT_COUNT]; - declare_vma(&vmlinux_seg[0], _stext, _etext, VM_NO_GUARD); + declare_vma(&vmlinux_seg[0], _text, _etext, VM_NO_GUARD); declare_vma(&vmlinux_seg[1], __start_rodata, __inittext_begin, VM_NO_GUARD); declare_vma(&vmlinux_seg[2], __inittext_begin, __inittext_end, VM_NO_GUARD); declare_vma(&vmlinux_seg[3], __initdata_begin, __initdata_end, VM_NO_GUARD);

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