- Linux-stable-mirror - lists.linaro.org

[PATCH 6.1.y] drm/amd/display: Fix out-of-bounds access in 'dcn21_link_encoder_create'

by lanbincn＠qq.com

From: Srinivasan Shanmugam <srinivasan.shanmugam(a)amd.com> commit 63de35a8fcfca59ae8750d469a7eb220c7557baf upstream. An issue was identified in the dcn21_link_encoder_create function where an out-of-bounds access could occur when the hpd_source index was used to reference the link_enc_hpd_regs array. This array has a fixed size and the index was not being checked against the array's bounds before accessing it. This fix adds a conditional check to ensure that the hpd_source index is within the valid range of the link_enc_hpd_regs array. If the index is out of bounds, the function now returns NULL to prevent undefined behavior. References: [ 65.920507] ------------[ cut here ]------------ [ 65.920510] UBSAN: array-index-out-of-bounds in drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn21/dcn21_resource.c:1312:29 [ 65.920519] index 7 is out of range for type 'dcn10_link_enc_hpd_registers [5]' [ 65.920523] CPU: 3 PID: 1178 Comm: modprobe Tainted: G OE 6.8.0-cleanershaderfeatureresetasdntipmi200nv2132 #13 [ 65.920525] Hardware name: AMD Majolica-RN/Majolica-RN, BIOS WMJ0429N_Weekly_20_04_2 04/29/2020 [ 65.920527] Call Trace: [ 65.920529] <TASK> [ 65.920532] dump_stack_lvl+0x48/0x70 [ 65.920541] dump_stack+0x10/0x20 [ 65.920543] __ubsan_handle_out_of_bounds+0xa2/0xe0 [ 65.920549] dcn21_link_encoder_create+0xd9/0x140 [amdgpu] [ 65.921009] link_create+0x6d3/0xed0 [amdgpu] [ 65.921355] create_links+0x18a/0x4e0 [amdgpu] [ 65.921679] dc_create+0x360/0x720 [amdgpu] [ 65.921999] ? dmi_matches+0xa0/0x220 [ 65.922004] amdgpu_dm_init+0x2b6/0x2c90 [amdgpu] [ 65.922342] ? console_unlock+0x77/0x120 [ 65.922348] ? dev_printk_emit+0x86/0xb0 [ 65.922354] dm_hw_init+0x15/0x40 [amdgpu] [ 65.922686] amdgpu_device_init+0x26a8/0x33a0 [amdgpu] [ 65.922921] amdgpu_driver_load_kms+0x1b/0xa0 [amdgpu] [ 65.923087] amdgpu_pci_probe+0x1b7/0x630 [amdgpu] [ 65.923087] local_pci_probe+0x4b/0xb0 [ 65.923087] pci_device_probe+0xc8/0x280 [ 65.923087] really_probe+0x187/0x300 [ 65.923087] __driver_probe_device+0x85/0x130 [ 65.923087] driver_probe_device+0x24/0x110 [ 65.923087] __driver_attach+0xac/0x1d0 [ 65.923087] ? __pfx___driver_attach+0x10/0x10 [ 65.923087] bus_for_each_dev+0x7d/0xd0 [ 65.923087] driver_attach+0x1e/0x30 [ 65.923087] bus_add_driver+0xf2/0x200 [ 65.923087] driver_register+0x64/0x130 [ 65.923087] ? __pfx_amdgpu_init+0x10/0x10 [amdgpu] [ 65.923087] __pci_register_driver+0x61/0x70 [ 65.923087] amdgpu_init+0x7d/0xff0 [amdgpu] [ 65.923087] do_one_initcall+0x49/0x310 [ 65.923087] ? kmalloc_trace+0x136/0x360 [ 65.923087] do_init_module+0x6a/0x270 [ 65.923087] load_module+0x1fce/0x23a0 [ 65.923087] init_module_from_file+0x9c/0xe0 [ 65.923087] ? init_module_from_file+0x9c/0xe0 [ 65.923087] idempotent_init_module+0x179/0x230 [ 65.923087] __x64_sys_finit_module+0x5d/0xa0 [ 65.923087] do_syscall_64+0x76/0x120 [ 65.923087] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 65.923087] RIP: 0033:0x7f2d80f1e88d [ 65.923087] Code: 5b 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 b5 0f 00 f7 d8 64 89 01 48 [ 65.923087] RSP: 002b:00007ffc7bc1aa78 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 65.923087] RAX: ffffffffffffffda RBX: 0000564c9c1db130 RCX: 00007f2d80f1e88d [ 65.923087] RDX: 0000000000000000 RSI: 0000564c9c1e5480 RDI: 000000000000000f [ 65.923087] RBP: 0000000000040000 R08: 0000000000000000 R09: 0000000000000002 [ 65.923087] R10: 000000000000000f R11: 0000000000000246 R12: 0000564c9c1e5480 [ 65.923087] R13: 0000564c9c1db260 R14: 0000000000000000 R15: 0000564c9c1e54b0 [ 65.923087] </TASK> [ 65.923927] ---[ end trace ]--- Cc: Tom Chung <chiahsuan.chung(a)amd.com> Cc: Rodrigo Siqueira <Rodrigo.Siqueira(a)amd.com> Cc: Roman Li <roman.li(a)amd.com> Cc: Alex Hung <alex.hung(a)amd.com> Cc: Aurabindo Pillai <aurabindo.pillai(a)amd.com> Cc: Harry Wentland <harry.wentland(a)amd.com> Cc: Hamza Mahfooz <hamza.mahfooz(a)amd.com> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam(a)amd.com> Reviewed-by: Roman Li <roman.li(a)amd.com> Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com> Signed-off-by: Bin Lan <lanbincn(a)qq.com> --- Backport to fix CVE-2024-56608 Link: https://nvd.nist.gov/vuln/detail/CVE-2024-56608 --- drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c index ce6c70e25703..dd71ea2568e2 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c +++ b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c @@ -1340,7 +1340,7 @@ static struct link_encoder *dcn21_link_encoder_create( kzalloc(sizeof(struct dcn21_link_encoder), GFP_KERNEL); int link_regs_id; - if (!enc21) + if (!enc21 || enc_init_data->hpd_source >= ARRAY_SIZE(link_enc_hpd_regs)) return NULL; link_regs_id = -- 2.43.0

10 months

2
1
0 0

[PATCH 6.1.y] wifi: ath10k: avoid NULL pointer error during sdio remove

by lanbincn＠qq.com

From: Kang Yang <quic_kangyang(a)quicinc.com> commit 95c38953cb1ecf40399a676a1f85dfe2b5780a9a upstream. When running 'rmmod ath10k', ath10k_sdio_remove() will free sdio workqueue by destroy_workqueue(). But if CONFIG_INIT_ON_FREE_DEFAULT_ON is set to yes, kernel panic will happen: Call trace: destroy_workqueue+0x1c/0x258 ath10k_sdio_remove+0x84/0x94 sdio_bus_remove+0x50/0x16c device_release_driver_internal+0x188/0x25c device_driver_detach+0x20/0x2c This is because during 'rmmod ath10k', ath10k_sdio_remove() will call ath10k_core_destroy() before destroy_workqueue(). wiphy_dev_release() will finally be called in ath10k_core_destroy(). This function will free struct cfg80211_registered_device *rdev and all its members, including wiphy, dev and the pointer of sdio workqueue. Then the pointer of sdio workqueue will be set to NULL due to CONFIG_INIT_ON_FREE_DEFAULT_ON. After device release, destroy_workqueue() will use NULL pointer then the kernel panic happen. Call trace: ath10k_sdio_remove ->ath10k_core_unregister …… ->ath10k_core_stop ->ath10k_hif_stop ->ath10k_sdio_irq_disable ->ath10k_hif_power_down ->del_timer_sync(&ar_sdio->sleep_timer) ->ath10k_core_destroy ->ath10k_mac_destroy ->ieee80211_free_hw ->wiphy_free …… ->wiphy_dev_release ->destroy_workqueue Need to call destroy_workqueue() before ath10k_core_destroy(), free the work queue buffer first and then free pointer of work queue by ath10k_core_destroy(). This order matches the error path order in ath10k_sdio_probe(). No work will be queued on sdio workqueue between it is destroyed and ath10k_core_destroy() is called. Based on the call_stack above, the reason is: Only ath10k_sdio_sleep_timer_handler(), ath10k_sdio_hif_tx_sg() and ath10k_sdio_irq_disable() will queue work on sdio workqueue. Sleep timer will be deleted before ath10k_core_destroy() in ath10k_hif_power_down(). ath10k_sdio_irq_disable() only be called in ath10k_hif_stop(). ath10k_core_unregister() will call ath10k_hif_power_down() to stop hif bus, so ath10k_sdio_hif_tx_sg() won't be called anymore. Tested-on: QCA6174 hw3.2 SDIO WLAN.RMH.4.4.1-00189 Signed-off-by: Kang Yang <quic_kangyang(a)quicinc.com> Tested-by: David Ruth <druth(a)chromium.org> Reviewed-by: David Ruth <druth(a)chromium.org> Link: https://patch.msgid.link/20241008022246.1010-1-quic_kangyang@quicinc.com Signed-off-by: Jeff Johnson <quic_jjohnson(a)quicinc.com> Signed-off-by: Bin Lan <lanbincn(a)qq.com> --- drivers/net/wireless/ath/ath10k/sdio.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/ath10k/sdio.c b/drivers/net/wireless/ath/ath10k/sdio.c index 79e09c7a82b3..886070b2a722 100644 --- a/drivers/net/wireless/ath/ath10k/sdio.c +++ b/drivers/net/wireless/ath/ath10k/sdio.c @@ -3,6 +3,7 @@ * Copyright (c) 2004-2011 Atheros Communications Inc. * Copyright (c) 2011-2012,2017 Qualcomm Atheros, Inc. * Copyright (c) 2016-2017 Erik Stromdahl <erik.stromdahl(a)gmail.com> + * Copyright (c) 2022-2024 Qualcomm Innovation Center, Inc. All rights reserved. */ #include <linux/module.h> @@ -2647,9 +2648,9 @@ static void ath10k_sdio_remove(struct sdio_func *func) netif_napi_del(&ar->napi); - ath10k_core_destroy(ar); - destroy_workqueue(ar_sdio->workqueue); + + ath10k_core_destroy(ar); } static const struct sdio_device_id ath10k_sdio_devices[] = { -- 2.43.0

10 months

2
1
0 0

[PATCH 6.6.y] drm/amd/display: Fix out-of-bounds access in 'dcn21_link_encoder_create'

by lanbincn＠qq.com

From: Srinivasan Shanmugam <srinivasan.shanmugam(a)amd.com> commit 63de35a8fcfca59ae8750d469a7eb220c7557baf upstream. An issue was identified in the dcn21_link_encoder_create function where an out-of-bounds access could occur when the hpd_source index was used to reference the link_enc_hpd_regs array. This array has a fixed size and the index was not being checked against the array's bounds before accessing it. This fix adds a conditional check to ensure that the hpd_source index is within the valid range of the link_enc_hpd_regs array. If the index is out of bounds, the function now returns NULL to prevent undefined behavior. References: [ 65.920507] ------------[ cut here ]------------ [ 65.920510] UBSAN: array-index-out-of-bounds in drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn21/dcn21_resource.c:1312:29 [ 65.920519] index 7 is out of range for type 'dcn10_link_enc_hpd_registers [5]' [ 65.920523] CPU: 3 PID: 1178 Comm: modprobe Tainted: G OE 6.8.0-cleanershaderfeatureresetasdntipmi200nv2132 #13 [ 65.920525] Hardware name: AMD Majolica-RN/Majolica-RN, BIOS WMJ0429N_Weekly_20_04_2 04/29/2020 [ 65.920527] Call Trace: [ 65.920529] <TASK> [ 65.920532] dump_stack_lvl+0x48/0x70 [ 65.920541] dump_stack+0x10/0x20 [ 65.920543] __ubsan_handle_out_of_bounds+0xa2/0xe0 [ 65.920549] dcn21_link_encoder_create+0xd9/0x140 [amdgpu] [ 65.921009] link_create+0x6d3/0xed0 [amdgpu] [ 65.921355] create_links+0x18a/0x4e0 [amdgpu] [ 65.921679] dc_create+0x360/0x720 [amdgpu] [ 65.921999] ? dmi_matches+0xa0/0x220 [ 65.922004] amdgpu_dm_init+0x2b6/0x2c90 [amdgpu] [ 65.922342] ? console_unlock+0x77/0x120 [ 65.922348] ? dev_printk_emit+0x86/0xb0 [ 65.922354] dm_hw_init+0x15/0x40 [amdgpu] [ 65.922686] amdgpu_device_init+0x26a8/0x33a0 [amdgpu] [ 65.922921] amdgpu_driver_load_kms+0x1b/0xa0 [amdgpu] [ 65.923087] amdgpu_pci_probe+0x1b7/0x630 [amdgpu] [ 65.923087] local_pci_probe+0x4b/0xb0 [ 65.923087] pci_device_probe+0xc8/0x280 [ 65.923087] really_probe+0x187/0x300 [ 65.923087] __driver_probe_device+0x85/0x130 [ 65.923087] driver_probe_device+0x24/0x110 [ 65.923087] __driver_attach+0xac/0x1d0 [ 65.923087] ? __pfx___driver_attach+0x10/0x10 [ 65.923087] bus_for_each_dev+0x7d/0xd0 [ 65.923087] driver_attach+0x1e/0x30 [ 65.923087] bus_add_driver+0xf2/0x200 [ 65.923087] driver_register+0x64/0x130 [ 65.923087] ? __pfx_amdgpu_init+0x10/0x10 [amdgpu] [ 65.923087] __pci_register_driver+0x61/0x70 [ 65.923087] amdgpu_init+0x7d/0xff0 [amdgpu] [ 65.923087] do_one_initcall+0x49/0x310 [ 65.923087] ? kmalloc_trace+0x136/0x360 [ 65.923087] do_init_module+0x6a/0x270 [ 65.923087] load_module+0x1fce/0x23a0 [ 65.923087] init_module_from_file+0x9c/0xe0 [ 65.923087] ? init_module_from_file+0x9c/0xe0 [ 65.923087] idempotent_init_module+0x179/0x230 [ 65.923087] __x64_sys_finit_module+0x5d/0xa0 [ 65.923087] do_syscall_64+0x76/0x120 [ 65.923087] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ 65.923087] RIP: 0033:0x7f2d80f1e88d [ 65.923087] Code: 5b 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 b5 0f 00 f7 d8 64 89 01 48 [ 65.923087] RSP: 002b:00007ffc7bc1aa78 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 65.923087] RAX: ffffffffffffffda RBX: 0000564c9c1db130 RCX: 00007f2d80f1e88d [ 65.923087] RDX: 0000000000000000 RSI: 0000564c9c1e5480 RDI: 000000000000000f [ 65.923087] RBP: 0000000000040000 R08: 0000000000000000 R09: 0000000000000002 [ 65.923087] R10: 000000000000000f R11: 0000000000000246 R12: 0000564c9c1e5480 [ 65.923087] R13: 0000564c9c1db260 R14: 0000000000000000 R15: 0000564c9c1e54b0 [ 65.923087] </TASK> [ 65.923927] ---[ end trace ]--- Cc: Tom Chung <chiahsuan.chung(a)amd.com> Cc: Rodrigo Siqueira <Rodrigo.Siqueira(a)amd.com> Cc: Roman Li <roman.li(a)amd.com> Cc: Alex Hung <alex.hung(a)amd.com> Cc: Aurabindo Pillai <aurabindo.pillai(a)amd.com> Cc: Harry Wentland <harry.wentland(a)amd.com> Cc: Hamza Mahfooz <hamza.mahfooz(a)amd.com> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam(a)amd.com> Reviewed-by: Roman Li <roman.li(a)amd.com> Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com> Signed-off-by: Bin Lan <lanbincn(a)qq.com> --- Backport to fix CVE-2024-56608 Link: https://nvd.nist.gov/vuln/detail/CVE-2024-56608 --- drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c index d1a25fe6c44f..8dffa5b6426e 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c +++ b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c @@ -1315,7 +1315,7 @@ static struct link_encoder *dcn21_link_encoder_create( kzalloc(sizeof(struct dcn21_link_encoder), GFP_KERNEL); int link_regs_id; - if (!enc21) + if (!enc21 || enc_init_data->hpd_source >= ARRAY_SIZE(link_enc_hpd_regs)) return NULL; link_regs_id = -- 2.43.0

10 months

2
1
0 0

[PATCH v2 7/7] ima: Reset IMA_NONACTION_RULE_FLAGS after post_setattr

by Roberto Sassu

From: Roberto Sassu <roberto.sassu(a)huawei.com> Commit 11c60f23ed13 ("integrity: Remove unused macro IMA_ACTION_RULE_FLAGS") removed the IMA_ACTION_RULE_FLAGS mask, due to it not being used after commit 0d73a55208e9 ("ima: re-introduce own integrity cache lock"). However, it seems that the latter commit mistakenly used the wrong mask when moving the code from ima_inode_post_setattr() to process_measurement(). There is no mention in the commit message about this change and it looks quite important, since changing from IMA_ACTIONS_FLAGS (later renamed to IMA_NONACTION_FLAGS) to IMA_ACTION_RULE_FLAGS was done by commit 42a4c603198f0 ("ima: fix ima_inode_post_setattr"). Restore the original change, but with new mask 0xfb000000 since the policy-specific flags changed meanwhile, and rename IMA_ACTION_RULE_FLAGS to IMA_NONACTION_RULE_FLAGS, to be consistent with IMA_NONACTION_FLAGS. Cc: stable(a)vger.kernel.org # v4.16.x Fixes: 11c60f23ed13 ("integrity: Remove unused macro IMA_ACTION_RULE_FLAGS") Signed-off-by: Roberto Sassu <roberto.sassu(a)huawei.com> --- security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_main.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 22c3b87cfcac..32ffef2cc92a 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -141,6 +141,7 @@ struct ima_kexec_hdr { /* IMA iint policy rule cache flags */ #define IMA_NONACTION_FLAGS 0xff000000 +#define IMA_NONACTION_RULE_FLAGS 0xfb000000 #define IMA_DIGSIG_REQUIRED 0x01000000 #define IMA_PERMIT_DIRECTIO 0x02000000 #define IMA_NEW_FILE 0x04000000 diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 712c3a522e6c..83e467ad18d4 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -277,7 +277,7 @@ static int process_measurement(struct file *file, const struct cred *cred, /* reset appraisal flags if ima_inode_post_setattr was called */ iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED | IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK | - IMA_NONACTION_FLAGS); + IMA_NONACTION_RULE_FLAGS); /* * Re-evaulate the file if either the xattr has changed or the -- 2.47.0.118.gfd3785337b

10 months

2
1
0 0

patch "iio: dac: ad3552r-hs: clear reset status flag" added to char-misc-next

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled iio: dac: ad3552r-hs: clear reset status flag to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-next branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will also be merged in the next major kernel release during the merge window. If you have any questions about this process, please let me know. From 012b8276f08a67b9f2e2fd0f35363ae4a75e5267 Mon Sep 17 00:00:00 2001 From: Angelo Dureghello <adureghello(a)baylibre.com> Date: Wed, 8 Jan 2025 18:29:16 +0100 Subject: iio: dac: ad3552r-hs: clear reset status flag Clear reset status flag, to keep error status register clean after reset (ad3552r manual, rev B table 38). Reset error flag was left to 1, so debugging registers, the "Error Status Register" was dirty (0x01). It is important to clear this bit, so if there is any reset event over normal working mode, it is possible to detect it. Fixes: 0b4d9fe58be8 ("iio: dac: ad3552r: add high-speed platform driver") Signed-off-by: Angelo Dureghello <adureghello(a)baylibre.com> Reviewed-by: David Lechner <dlechner(a)baylibre.com> Link: https://patch.msgid.link/20250108-wip-bl-ad3552r-axi-v0-iio-testing-carlos-… Cc: <Stable(a)vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com> --- drivers/iio/dac/ad3552r-hs.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/iio/dac/ad3552r-hs.c b/drivers/iio/dac/ad3552r-hs.c index 216c634f3eaf..8974df625670 100644 --- a/drivers/iio/dac/ad3552r-hs.c +++ b/drivers/iio/dac/ad3552r-hs.c @@ -329,6 +329,12 @@ static int ad3552r_hs_setup(struct ad3552r_hs_state *st) dev_info(st->dev, "Chip ID error. Expected 0x%x, Read 0x%x\n", AD3552R_ID, id); + /* Clear reset error flag, see ad3552r manual, rev B table 38. */ + ret = st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_ERR_STATUS, + AD3552R_MASK_RESET_STATUS, 1); + if (ret) + return ret; + ret = st->data->bus_reg_write(st->back, AD3552R_REG_ADDR_SH_REFERENCE_CONFIG, 0, 1); -- 2.48.1

10 months

1
0
0 0

patch "iio: chemical: bme680: Fix uninitialized variable in" added to char-misc-next

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled iio: chemical: bme680: Fix uninitialized variable in to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-next branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will also be merged in the next major kernel release during the merge window. If you have any questions about this process, please let me know. From 20eb1fae4145bc45717aa8a6d05fcd6a64ed856a Mon Sep 17 00:00:00 2001 From: Dan Carpenter <dan.carpenter(a)linaro.org> Date: Wed, 8 Jan 2025 12:37:22 +0300 Subject: iio: chemical: bme680: Fix uninitialized variable in __bme680_read_raw() The bme680_read_temp() function takes a pointer to s16 but we're passing an int pointer to it. This will not work on big endian systems and it also means that the other 16 bits are uninitialized. Pass an s16 type variable. Fixes: f51171ce2236 ("iio: chemical: bme680: Add SCALE and RAW channels") Signed-off-by: Dan Carpenter <dan.carpenter(a)linaro.org> Acked-by: Vasileios Amoiridis <vassilisamir(a)gmail.com> Link: https://patch.msgid.link/4addb68c-853a-49fc-8d40-739e78db5fa1@stanley.mount… Cc: <stable(a)vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com> --- drivers/iio/chemical/bme680_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iio/chemical/bme680_core.c b/drivers/iio/chemical/bme680_core.c index d12270409c8a..a2949daf9467 100644 --- a/drivers/iio/chemical/bme680_core.c +++ b/drivers/iio/chemical/bme680_core.c @@ -874,11 +874,11 @@ static int bme680_read_raw(struct iio_dev *indio_dev, case IIO_CHAN_INFO_RAW: switch (chan->type) { case IIO_TEMP: - ret = bme680_read_temp(data, (s16 *)&chan_val); + ret = bme680_read_temp(data, &temp_chan_val); if (ret) return ret; - *val = chan_val; + *val = temp_chan_val; return IIO_VAL_INT; case IIO_PRESSURE: ret = bme680_read_press(data, &chan_val); -- 2.48.1

10 months

1
0
0 0

patch "iio: dac: ad3552r-common: fix ad3541/2r ranges" added to char-misc-next

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled iio: dac: ad3552r-common: fix ad3541/2r ranges to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-next branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will also be merged in the next major kernel release during the merge window. If you have any questions about this process, please let me know. From 1e758b613212b6964518a67939535910b5aee831 Mon Sep 17 00:00:00 2001 From: Angelo Dureghello <adureghello(a)baylibre.com> Date: Wed, 8 Jan 2025 18:29:15 +0100 Subject: iio: dac: ad3552r-common: fix ad3541/2r ranges Fix ad3541/2r voltage ranges to be as per ad3542r datasheet, rev. C, table 38 (page 57). The wrong ad354xr ranges was generating erroneous Vpp output. In more details: - fix wrong number of ranges, they are 5 ranges, not 6, - remove non-existent 0-3V range, - adjust order, since ad3552r_find_range() get a wrong index, producing a wrong Vpp as output. Retested all the ranges on real hardware, EVALAD3542RFMCZ: adi,output-range-microvolt (fdt): <(000000) (2500000)>; ok (Rfbx1, switch 10) <(000000) (5000000)>; ok (Rfbx1, switch 10) <(000000) (10000000)>; ok (Rfbx1, switch 10) <(-5000000) (5000000)>; ok (Rfbx2, switch +/- 5) <(-2500000) (7500000)>; ok (Rfbx2, switch -2.5/7.5) Fixes: 8f2b54824b28 ("drivers:iio:dac: Add AD3552R driver support") Signed-off-by: Angelo Dureghello <adureghello(a)baylibre.com> Reviewed-by: David Lechner <dlechner(a)baylibre.com> Link: https://patch.msgid.link/20250108-wip-bl-ad3552r-axi-v0-iio-testing-carlos-… Cc: <Stable(a)vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com> --- drivers/iio/dac/ad3552r-common.c | 5 ++--- drivers/iio/dac/ad3552r.h | 8 +++----- 2 files changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/iio/dac/ad3552r-common.c b/drivers/iio/dac/ad3552r-common.c index 0f495df2e5ce..03e0864f5084 100644 --- a/drivers/iio/dac/ad3552r-common.c +++ b/drivers/iio/dac/ad3552r-common.c @@ -22,11 +22,10 @@ EXPORT_SYMBOL_NS_GPL(ad3552r_ch_ranges, "IIO_AD3552R"); const s32 ad3542r_ch_ranges[AD3542R_MAX_RANGES][2] = { [AD3542R_CH_OUTPUT_RANGE_0__2P5V] = { 0, 2500 }, - [AD3542R_CH_OUTPUT_RANGE_0__3V] = { 0, 3000 }, [AD3542R_CH_OUTPUT_RANGE_0__5V] = { 0, 5000 }, [AD3542R_CH_OUTPUT_RANGE_0__10V] = { 0, 10000 }, - [AD3542R_CH_OUTPUT_RANGE_NEG_2P5__7P5V] = { -2500, 7500 }, - [AD3542R_CH_OUTPUT_RANGE_NEG_5__5V] = { -5000, 5000 } + [AD3542R_CH_OUTPUT_RANGE_NEG_5__5V] = { -5000, 5000 }, + [AD3542R_CH_OUTPUT_RANGE_NEG_2P5__7P5V] = { -2500, 7500 } }; EXPORT_SYMBOL_NS_GPL(ad3542r_ch_ranges, "IIO_AD3552R"); diff --git a/drivers/iio/dac/ad3552r.h b/drivers/iio/dac/ad3552r.h index fd5a3dfd1d1c..4b5581039ae9 100644 --- a/drivers/iio/dac/ad3552r.h +++ b/drivers/iio/dac/ad3552r.h @@ -131,7 +131,7 @@ #define AD3552R_CH1_ACTIVE BIT(1) #define AD3552R_MAX_RANGES 5 -#define AD3542R_MAX_RANGES 6 +#define AD3542R_MAX_RANGES 5 #define AD3552R_QUAD_SPI 2 extern const s32 ad3552r_ch_ranges[AD3552R_MAX_RANGES][2]; @@ -189,16 +189,14 @@ enum ad3552r_ch_vref_select { enum ad3542r_ch_output_range { /* Range from 0 V to 2.5 V. Requires Rfb1x connection */ AD3542R_CH_OUTPUT_RANGE_0__2P5V, - /* Range from 0 V to 3 V. Requires Rfb1x connection */ - AD3542R_CH_OUTPUT_RANGE_0__3V, /* Range from 0 V to 5 V. Requires Rfb1x connection */ AD3542R_CH_OUTPUT_RANGE_0__5V, /* Range from 0 V to 10 V. Requires Rfb2x connection */ AD3542R_CH_OUTPUT_RANGE_0__10V, - /* Range from -2.5 V to 7.5 V. Requires Rfb2x connection */ - AD3542R_CH_OUTPUT_RANGE_NEG_2P5__7P5V, /* Range from -5 V to 5 V. Requires Rfb2x connection */ AD3542R_CH_OUTPUT_RANGE_NEG_5__5V, + /* Range from -2.5 V to 7.5 V. Requires Rfb2x connection */ + AD3542R_CH_OUTPUT_RANGE_NEG_2P5__7P5V, }; enum ad3552r_ch_output_range { -- 2.48.1

10 months

1
0
0 0

[tip: timers/urgent] hrtimers: Handle CPU state correctly on hotplug

by tip-bot2 for Koichiro Den

The following commit has been merged into the timers/urgent branch of tip: Commit-ID: 2f8dea1692eef2b7ba6a256246ed82c365fdc686 Gitweb: https://git.kernel.org/tip/2f8dea1692eef2b7ba6a256246ed82c365fdc686 Author: Koichiro Den <koichiro.den(a)canonical.com> AuthorDate: Fri, 20 Dec 2024 22:44:21 +09:00 Committer: Thomas Gleixner <tglx(a)linutronix.de> CommitterDate: Thu, 16 Jan 2025 13:06:14 +01:00 hrtimers: Handle CPU state correctly on hotplug Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to CPUHP_ONLINE: Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set to 1 throughout. However, during a CPU unplug operation, the tick and the clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online state, for instance CFS incorrectly assumes that the hrtick is already active, and the chance of the clockevent device to transition to oneshot mode is also lost forever for the CPU, unless it goes back to a lower state than CPUHP_HRTIMERS_PREPARE once. This round-trip reveals another issue; cpu_base.online is not set to 1 after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer(). Aside of that, the bulk of the per CPU state is not reset either, which means there are dangling pointers in the worst case. Address this by adding a corresponding startup() callback, which resets the stale per CPU state and sets the online flag. [ tglx: Make the new callback unconditionally available, remove the online modification in the prepare() callback and clear the remaining state in the starting callback instead of the prepare callback ] Fixes: 5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier") Signed-off-by: Koichiro Den <koichiro.den(a)canonical.com> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/all/20241220134421.3809834-1-koichiro.den@canonical… --- include/linux/hrtimer.h | 1 + kernel/cpu.c | 2 +- kernel/time/hrtimer.c | 11 ++++++++++- 3 files changed, 12 insertions(+), 2 deletions(-) diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 7ef5f7e..f7bfdcf 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -386,6 +386,7 @@ extern void __init hrtimers_init(void); extern void sysrq_timer_list_show(void); int hrtimers_prepare_cpu(unsigned int cpu); +int hrtimers_cpu_starting(unsigned int cpu); #ifdef CONFIG_HOTPLUG_CPU int hrtimers_cpu_dying(unsigned int cpu); #else diff --git a/kernel/cpu.c b/kernel/cpu.c index b605334..0509a97 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -2179,7 +2179,7 @@ static struct cpuhp_step cpuhp_hp_states[] = { }, [CPUHP_AP_HRTIMERS_DYING] = { .name = "hrtimers:dying", - .startup.single = NULL, + .startup.single = hrtimers_cpu_starting, .teardown.single = hrtimers_cpu_dying, }, [CPUHP_AP_TICK_DYING] = { diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 80fe374..030426c 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -2202,6 +2202,15 @@ int hrtimers_prepare_cpu(unsigned int cpu) } cpu_base->cpu = cpu; + hrtimer_cpu_base_init_expiry_lock(cpu_base); + return 0; +} + +int hrtimers_cpu_starting(unsigned int cpu) +{ + struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); + + /* Clear out any left over state from a CPU down operation */ cpu_base->active_bases = 0; cpu_base->hres_active = 0; cpu_base->hang_detected = 0; @@ -2210,7 +2219,6 @@ int hrtimers_prepare_cpu(unsigned int cpu) cpu_base->expires_next = KTIME_MAX; cpu_base->softirq_expires_next = KTIME_MAX; cpu_base->online = 1; - hrtimer_cpu_base_init_expiry_lock(cpu_base); return 0; } @@ -2286,5 +2294,6 @@ int hrtimers_cpu_dying(unsigned int dying_cpu) void __init hrtimers_init(void) { hrtimers_prepare_cpu(smp_processor_id()); + hrtimers_cpu_starting(smp_processor_id()); open_softirq(HRTIMER_SOFTIRQ, hrtimer_run_softirq); }

10 months

1
0
0 0

[tip: timers/urgent] timers/migration: Fix another race between hotplug and idle entry/exit

by tip-bot2 for Frederic Weisbecker

The following commit has been merged into the timers/urgent branch of tip: Commit-ID: b729cc1ec21a5899b7879ccfbe1786664928d597 Gitweb: https://git.kernel.org/tip/b729cc1ec21a5899b7879ccfbe1786664928d597 Author: Frederic Weisbecker <frederic(a)kernel.org> AuthorDate: Wed, 15 Jan 2025 00:15:04 +01:00 Committer: Thomas Gleixner <tglx(a)linutronix.de> CommitterDate: Thu, 16 Jan 2025 12:47:11 +01:00 timers/migration: Fix another race between hotplug and idle entry/exit Commit 10a0e6f3d3db ("timers/migration: Move hierarchy setup into cpuhotplug prepare callback") fixed a race between idle exit and CPU hotplug up leading to a wrong "0" value migrator assigned to the top level. However there is still a situation that remains unhandled: [GRP0:0] migrator = TMIGR_NONE active = NONE groupmask = 0 / \ \ 0 1 2..7 idle idle idle 0) The system is fully idle. [GRP0:0] migrator = CPU 0 active = CPU 0 groupmask = 0 / \ \ 0 1 2..7 active idle idle 1) CPU 0 is activating. It has done the cmpxchg on the top's ->migr_state but it hasn't yet returned to __walk_groups(). [GRP0:0] migrator = CPU 0 active = CPU 0, CPU 1 groupmask = 0 / \ \ 0 1 2..7 active active idle 2) CPU 1 is activating. CPU 0 stays the migrator (still stuck in __walk_groups(), delayed by #VMEXIT for example). [GRP1:0] migrator = TMIGR_NONE active = NONE groupmask = 0 / \ [GRP0:0] [GRP0:1] migrator = CPU 0 migrator = TMIGR_NONE active = CPU 0, CPU1 active = NONE groupmask = 2 groupmask = 1 / \ \ 0 1 2..7 8 active active idle !online 3) CPU 8 is preparing to boot. CPUHP_TMIGR_PREPARE is being ran by CPU 1 which has created the GRP0:1 and the new top GRP1:0 connected to GRP0:1 and GRP0:0. The groupmask of GRP0:0 is now 2. CPU 1 hasn't yet propagated its activation up to GRP1:0. [GRP1:0] migrator = 0 (!!!) active = NONE groupmask = 0 / \ [GRP0:0] [GRP0:1] migrator = CPU 0 migrator = TMIGR_NONE active = CPU 0, CPU1 active = NONE groupmask = 2 groupmask = 1 / \ \ 0 1 2..7 8 active active idle !online 4) CPU 0 finally resumed after its #VMEXIT. It's in __walk_groups() returning from tmigr_cpu_active(). The new top GRP1:0 is visible and fetched but the freshly updated groupmask of GRP0:0 may not be visible due to lack of ordering! As a result tmigr_active_up() is called to GRP0:0 with a child's groupmask of "0". This buggy "0" groupmask then becomes the migrator for GRP1:0 forever. As a result, timers on a fully idle system get ignored. One possible fix would be to define TMIGR_NONE as "0" so that such a race would have no effect. And after all TMIGR_NONE doesn't need to be anything else. However this would leave an uncomfortable state machine where gears happen not to break by chance but are vulnerable to future modifications. Keep TMIGR_NONE as is instead and pre-initialize to "1" the groupmask of any newly created top level. This groupmask is guaranteed to be visible upon fetching the corresponding group for the 1st time: _ By the upcoming CPU thanks to CPU hotplug synchronization between the control CPU (BP) and the booting one (AP). _ By the control CPU since the groupmask and parent pointers are initialized locally. _ By all CPUs belonging to the same group than the control CPU because they must wait for it to ever become idle before needing to walk to the new top. The cmpcxhg() on ->migr_state then makes sure its groupmask is visible. With this pre-initialization, it is guaranteed that if a future top level is linked to an old one, it is walked through with a valid groupmask. Fixes: 10a0e6f3d3db ("timers/migration: Move hierarchy setup into cpuhotplug prepare callback") Signed-off-by: Frederic Weisbecker <frederic(a)kernel.org> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/all/20250114231507.21672-2-frederic@kernel.org --- kernel/time/timer_migration.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/kernel/time/timer_migration.c b/kernel/time/timer_migration.c index 8d57f76..c8a8ea2 100644 --- a/kernel/time/timer_migration.c +++ b/kernel/time/timer_migration.c @@ -1487,6 +1487,21 @@ static void tmigr_init_group(struct tmigr_group *group, unsigned int lvl, s.seq = 0; atomic_set(&group->migr_state, s.state); + /* + * If this is a new top-level, prepare its groupmask in advance. + * This avoids accidents where yet another new top-level is + * created in the future and made visible before the current groupmask. + */ + if (list_empty(&tmigr_level_list[lvl])) { + group->groupmask = BIT(0); + /* + * The previous top level has prepared its groupmask already, + * simply account it as the first child. + */ + if (lvl > 0) + group->num_children = 1; + } + timerqueue_init_head(&group->events); timerqueue_init(&group->groupevt.nextevt); group->groupevt.nextevt.expires = KTIME_MAX; @@ -1550,8 +1565,20 @@ static void tmigr_connect_child_parent(struct tmigr_group *child, raw_spin_lock_irq(&child->lock); raw_spin_lock_nested(&parent->lock, SINGLE_DEPTH_NESTING); + if (activate) { + /* + * @child is the old top and @parent the new one. In this + * case groupmask is pre-initialized and @child already + * accounted, along with its new sibling corresponding to the + * CPU going up. + */ + WARN_ON_ONCE(child->groupmask != BIT(0) || parent->num_children != 2); + } else { + /* Adding @child for the CPU going up to @parent. */ + child->groupmask = BIT(parent->num_children++); + } + child->parent = parent; - child->groupmask = BIT(parent->num_children++); raw_spin_unlock(&parent->lock); raw_spin_unlock_irq(&child->lock);

10 months

1
0
0 0

[tip: timers/urgent] timers/migration: Enforce group initialization visibility to tree walkers

by tip-bot2 for Frederic Weisbecker

The following commit has been merged into the timers/urgent branch of tip: Commit-ID: de3ced72a79280fefd680e5e101d8b9f03cfa1d7 Gitweb: https://git.kernel.org/tip/de3ced72a79280fefd680e5e101d8b9f03cfa1d7 Author: Frederic Weisbecker <frederic(a)kernel.org> AuthorDate: Wed, 15 Jan 2025 00:15:05 +01:00 Committer: Thomas Gleixner <tglx(a)linutronix.de> CommitterDate: Thu, 16 Jan 2025 12:47:11 +01:00 timers/migration: Enforce group initialization visibility to tree walkers Commit 2522c84db513 ("timers/migration: Fix another race between hotplug and idle entry/exit") fixed yet another race between idle exit and CPU hotplug up leading to a wrong "0" value migrator assigned to the top level. However there is yet another situation that remains unhandled: [GRP0:0] migrator = TMIGR_NONE active = NONE groupmask = 1 / \ \ 0 1 2..7 idle idle idle 0) The system is fully idle. [GRP0:0] migrator = CPU 0 active = CPU 0 groupmask = 1 / \ \ 0 1 2..7 active idle idle 1) CPU 0 is activating. It has done the cmpxchg on the top's ->migr_state but it hasn't yet returned to __walk_groups(). [GRP0:0] migrator = CPU 0 active = CPU 0, CPU 1 groupmask = 1 / \ \ 0 1 2..7 active active idle 2) CPU 1 is activating. CPU 0 stays the migrator (still stuck in __walk_groups(), delayed by #VMEXIT for example). [GRP1:0] migrator = TMIGR_NONE active = NONE groupmask = 1 / \ [GRP0:0] [GRP0:1] migrator = CPU 0 migrator = TMIGR_NONE active = CPU 0, CPU1 active = NONE groupmask = 1 groupmask = 2 / \ \ 0 1 2..7 8 active active idle !online 3) CPU 8 is preparing to boot. CPUHP_TMIGR_PREPARE is being ran by CPU 1 which has created the GRP0:1 and the new top GRP1:0 connected to GRP0:1 and GRP0:0. CPU 1 hasn't yet propagated its activation up to GRP1:0. [GRP1:0] migrator = GRP0:0 active = GRP0:0 groupmask = 1 / \ [GRP0:0] [GRP0:1] migrator = CPU 0 migrator = TMIGR_NONE active = CPU 0, CPU1 active = NONE groupmask = 1 groupmask = 2 / \ \ 0 1 2..7 8 active active idle !online 4) CPU 0 finally resumed after its #VMEXIT. It's in __walk_groups() returning from tmigr_cpu_active(). The new top GRP1:0 is visible and fetched and the pre-initialized groupmask of GRP0:0 is also visible. As a result tmigr_active_up() is called to GRP1:0 with GRP0:0 as active and migrator. CPU 0 is returning to __walk_groups() but suffers again a #VMEXIT. [GRP1:0] migrator = GRP0:0 active = GRP0:0 groupmask = 1 / \ [GRP0:0] [GRP0:1] migrator = CPU 0 migrator = TMIGR_NONE active = CPU 0, CPU1 active = NONE groupmask = 1 groupmask = 2 / \ \ 0 1 2..7 8 active active idle !online 5) CPU 1 propagates its activation of GRP0:0 to GRP1:0. This has no effect since CPU 0 did it already. [GRP1:0] migrator = GRP0:0 active = GRP0:0, GRP0:1 groupmask = 1 / \ [GRP0:0] [GRP0:1] migrator = CPU 0 migrator = CPU 8 active = CPU 0, CPU1 active = CPU 8 groupmask = 1 groupmask = 2 / \ \ \ 0 1 2..7 8 active active idle active 6) CPU 1 links CPU 8 to its group. CPU 8 boots and goes through CPUHP_AP_TMIGR_ONLINE which propagates activation. [GRP2:0] migrator = TMIGR_NONE active = NONE groupmask = 1 / \ [GRP1:0] [GRP1:1] migrator = GRP0:0 migrator = TMIGR_NONE active = GRP0:0, GRP0:1 active = NONE groupmask = 1 groupmask = 2 / \ [GRP0:0] [GRP0:1] [GRP0:2] migrator = CPU 0 migrator = CPU 8 migrator = TMIGR_NONE active = CPU 0, CPU1 active = CPU 8 active = NONE groupmask = 1 groupmask = 2 groupmask = 0 / \ \ \ 0 1 2..7 8 64 active active idle active !online 7) CPU 64 is booting. CPUHP_TMIGR_PREPARE is being ran by CPU 1 which has created the GRP1:1, GRP0:2 and the new top GRP2:0 connected to GRP1:1 and GRP1:0. CPU 1 hasn't yet propagated its activation up to GRP2:0. [GRP2:0] migrator = 0 (!!!) active = NONE groupmask = 1 / \ [GRP1:0] [GRP1:1] migrator = GRP0:0 migrator = TMIGR_NONE active = GRP0:0, GRP0:1 active = NONE groupmask = 1 groupmask = 2 / \ [GRP0:0] [GRP0:1] [GRP0:2] migrator = CPU 0 migrator = CPU 8 migrator = TMIGR_NONE active = CPU 0, CPU1 active = CPU 8 active = NONE groupmask = 1 groupmask = 2 groupmask = 0 / \ \ \ 0 1 2..7 8 64 active active idle active !online 8) CPU 0 finally resumed after its #VMEXIT. It's in __walk_groups() returning from tmigr_cpu_active(). The new top GRP2:0 is visible and fetched but the pre-initialized groupmask of GRP1:0 is not because no ordering made its initialization visible. As a result tmigr_active_up() may be called to GRP2:0 with a "0" child's groumask. Leaving the timers ignored for ever when the system is fully idle. The race is highly theoretical and perhaps impossible in practice but the groupmask of the child is not the only concern here as the whole initialization of the child is not guaranteed to be visible to any tree walker racing against hotplug (idle entry/exit, remote handling, etc...). Although the current code layout seem to be resilient to such hazards, this doesn't tell much about the future. Fix this with enforcing address dependency between group initialization and the write/read to the group's parent's pointer. Fortunately that doesn't involve any barrier addition in the fast paths. Fixes: 10a0e6f3d3db ("timers/migration: Move hierarchy setup into cpuhotplug prepare callback") Signed-off-by: Frederic Weisbecker <frederic(a)kernel.org> Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/all/20250114231507.21672-3-frederic@kernel.org --- kernel/time/timer_migration.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/kernel/time/timer_migration.c b/kernel/time/timer_migration.c index c8a8ea2..371a62a 100644 --- a/kernel/time/timer_migration.c +++ b/kernel/time/timer_migration.c @@ -534,8 +534,13 @@ static void __walk_groups(up_f up, struct tmigr_walk *data, break; child = group; - group = group->parent; + /* + * Pairs with the store release on group connection + * to make sure group initialization is visible. + */ + group = READ_ONCE(group->parent); data->childmask = child->groupmask; + WARN_ON_ONCE(!data->childmask); } while (group); } @@ -1578,7 +1583,12 @@ static void tmigr_connect_child_parent(struct tmigr_group *child, child->groupmask = BIT(parent->num_children++); } - child->parent = parent; + /* + * Make sure parent initialization is visible before publishing it to a + * racing CPU entering/exiting idle. This RELEASE barrier enforces an + * address dependency that pairs with the READ_ONCE() in __walk_groups(). + */ + smp_store_release(&child->parent, parent); raw_spin_unlock(&parent->lock); raw_spin_unlock_irq(&child->lock);

10 months

1
0
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror