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[PATCH] mm: Fix possible deadlock in console_trylock_spinning

by Gu Bowen

kmemleak_scan_thread() invokes scan_block() which may invoke a nomal printk() to print warning message. This can cause a deadlock in the scenario reported below: CPU0 CPU1 ---- ---- lock(kmemleak_lock); lock(&port->lock); lock(kmemleak_lock); lock(console_owner); To solve this problem, switch to printk_safe mode before printing warning message, this will redirect all printk()-s to a special per-CPU buffer, which will be flushed later from a safe context (irq work), and this deadlock problem can be avoided. Our syztester report the following lockdep error: ====================================================== WARNING: possible circular locking dependency detected 5.10.0-22221-gca646a51dd00 #16 Not tainted ------------------------------------------------------ kmemleak/182 is trying to acquire lock: ffffffffaf9e9020 (console_owner){-...}-{0:0}, at: console_trylock_spinning+0xda/0x1d0 kernel/printk/printk.c:1900 but task is already holding lock: ffffffffb007cf58 (kmemleak_lock){-.-.}-{2:2}, at: scan_block+0x3d/0x220 mm/kmemleak.c:1310 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (kmemleak_lock){-.-.}-{2:2}: validate_chain+0x5df/0xac0 kernel/locking/lockdep.c:3729 __lock_acquire+0x514/0x940 kernel/locking/lockdep.c:4958 lock_acquire+0x15a/0x3a0 kernel/locking/lockdep.c:5569 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3b/0x60 kernel/locking/spinlock.c:164 create_object.isra.0+0x36/0x80 mm/kmemleak.c:691 kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] slab_post_alloc_hook mm/slab.h:518 [inline] slab_alloc_node mm/slub.c:2987 [inline] slab_alloc mm/slub.c:2995 [inline] __kmalloc+0x637/0xb60 mm/slub.c:4100 kmalloc include/linux/slab.h:620 [inline] tty_buffer_alloc+0x127/0x140 drivers/tty/tty_buffer.c:176 __tty_buffer_request_room+0x9b/0x110 drivers/tty/tty_buffer.c:276 tty_insert_flip_string_fixed_flag+0x60/0x130 drivers/tty/tty_buffer.c:321 tty_insert_flip_string include/linux/tty_flip.h:36 [inline] tty_insert_flip_string_and_push_buffer+0x3a/0xb0 drivers/tty/tty_buffer.c:578 process_output_block+0xc2/0x2e0 drivers/tty/n_tty.c:592 n_tty_write+0x298/0x540 drivers/tty/n_tty.c:2433 do_tty_write drivers/tty/tty_io.c:1041 [inline] file_tty_write.constprop.0+0x29b/0x4b0 drivers/tty/tty_io.c:1147 redirected_tty_write+0x51/0x90 drivers/tty/tty_io.c:1176 call_write_iter include/linux/fs.h:2117 [inline] do_iter_readv_writev+0x274/0x350 fs/read_write.c:741 do_iter_write+0xbb/0x1f0 fs/read_write.c:867 vfs_writev+0xfa/0x380 fs/read_write.c:940 do_writev+0xd6/0x1d0 fs/read_write.c:983 do_syscall_64+0x2b/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x6c/0xd6 -> #2 (&port->lock){-.-.}-{2:2}: validate_chain+0x5df/0xac0 kernel/locking/lockdep.c:3729 __lock_acquire+0x514/0x940 kernel/locking/lockdep.c:4958 lock_acquire+0x15a/0x3a0 kernel/locking/lockdep.c:5569 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3b/0x60 kernel/locking/spinlock.c:164 tty_port_tty_get+0x1f/0xa0 drivers/tty/tty_port.c:289 tty_port_default_wakeup+0xb/0x30 drivers/tty/tty_port.c:48 serial8250_tx_chars+0x259/0x430 drivers/tty/serial/8250/8250_port.c:1906 __start_tx drivers/tty/serial/8250/8250_port.c:1598 [inline] serial8250_start_tx+0x304/0x320 drivers/tty/serial/8250/8250_port.c:1720 uart_write+0x1a1/0x2e0 drivers/tty/serial/serial_core.c:635 do_output_char+0x2c0/0x370 drivers/tty/n_tty.c:444 process_output drivers/tty/n_tty.c:511 [inline] n_tty_write+0x269/0x540 drivers/tty/n_tty.c:2445 do_tty_write drivers/tty/tty_io.c:1041 [inline] file_tty_write.constprop.0+0x29b/0x4b0 drivers/tty/tty_io.c:1147 call_write_iter include/linux/fs.h:2117 [inline] do_iter_readv_writev+0x274/0x350 fs/read_write.c:741 do_iter_write+0xbb/0x1f0 fs/read_write.c:867 vfs_writev+0xfa/0x380 fs/read_write.c:940 do_writev+0xd6/0x1d0 fs/read_write.c:983 do_syscall_64+0x2b/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x6c/0xd6 -> #1 (&port_lock_key){-.-.}-{2:2}: validate_chain+0x5df/0xac0 kernel/locking/lockdep.c:3729 __lock_acquire+0x514/0x940 kernel/locking/lockdep.c:4958 lock_acquire+0x15a/0x3a0 kernel/locking/lockdep.c:5569 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3b/0x60 kernel/locking/spinlock.c:164 serial8250_console_write+0x292/0x320 drivers/tty/serial/8250/8250_port.c:3458 call_console_drivers.constprop.0+0x185/0x240 kernel/printk/printk.c:1988 console_unlock+0x2b4/0x640 kernel/printk/printk.c:2648 register_console.part.0+0x2a1/0x390 kernel/printk/printk.c:3024 univ8250_console_init+0x24/0x2b drivers/tty/serial/8250/8250_core.c:724 console_init+0x188/0x24b kernel/printk/printk.c:3134 start_kernel+0x2b0/0x41e init/main.c:1072 secondary_startup_64_no_verify+0xc3/0xcb -> #0 (console_owner){-...}-{0:0}: check_prev_add+0xfa/0x1380 kernel/locking/lockdep.c:2988 check_prevs_add+0x1d8/0x3c0 kernel/locking/lockdep.c:3113 validate_chain+0x5df/0xac0 kernel/locking/lockdep.c:3729 __lock_acquire+0x514/0x940 kernel/locking/lockdep.c:4958 lock_acquire+0x15a/0x3a0 kernel/locking/lockdep.c:5569 console_trylock_spinning+0x10d/0x1d0 kernel/printk/printk.c:1921 vprintk_emit+0x1a5/0x270 kernel/printk/printk.c:2134 printk+0xb2/0xe7 kernel/printk/printk.c:2183 lookup_object.cold+0xf/0x24 mm/kmemleak.c:405 scan_block+0x1fa/0x220 mm/kmemleak.c:1357 scan_object+0xdd/0x140 mm/kmemleak.c:1415 scan_gray_list+0x8f/0x1c0 mm/kmemleak.c:1453 kmemleak_scan+0x649/0xf30 mm/kmemleak.c:1608 kmemleak_scan_thread+0x94/0xb6 mm/kmemleak.c:1721 kthread+0x1c4/0x210 kernel/kthread.c:328 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:299 other info that might help us debug this: Chain exists of: console_owner --> &port->lock --> kmemleak_lock Cc: stable(a)vger.kernel.org # 5.10 Signed-off-by: Gu Bowen <gubowen5(a)huawei.com> --- mm/kmemleak.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 4801751cb6b6..d322897a1de1 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -390,9 +390,11 @@ static struct kmemleak_object *lookup_object(unsigned long ptr, int alias) else if (object->pointer == ptr || alias) return object; else { + __printk_safe_enter(); kmemleak_warn("Found object by alias at 0x%08lx\n", ptr); dump_object_info(object); + __printk_safe_exit(); break; } } -- 2.25.1

3 months, 3 weeks

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Re: Patch "ARM: s3c/gpio: complete the conversion to new GPIO value setters" has been added to the 6.16-stable tree

by Bartosz Golaszewski

On Mon, 11 Aug 2025 at 16:18, Sasha Levin <sashal(a)kernel.org> wrote: > > This is a note to let you know that I've just added the patch titled > > ARM: s3c/gpio: complete the conversion to new GPIO value setters > > to the 6.16-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: > arm-s3c-gpio-complete-the-conversion-to-new-gpio-val.patch > and it can be found in the queue-6.16 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. > This is not something we should backport. This is a refactoring targeting v6.17. Bartosz > > > commit c09ce1148e4748b856b6d13a8b9fa568a1e687a2 > Author: Bartosz Golaszewski <bartosz.golaszewski(a)linaro.org> > Date: Wed Jul 30 09:14:43 2025 +0200 > > ARM: s3c/gpio: complete the conversion to new GPIO value setters > > [ Upstream commit 3dca3d51b933beb3f35a60472ed2110d1bd7046a ] > > Commit fb52f3226cab ("ARM: s3c/gpio: use new line value setter > callbacks") correctly changed the assignment of the callback but missed > the check one liner higher. Change it now too to using the recommended > callback as the legacy one is going away soon. > > Fixes: fb52f3226cab ("ARM: s3c/gpio: use new line value setter callbacks") > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski(a)linaro.org> > Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> > Signed-off-by: Sasha Levin <sashal(a)kernel.org> > > diff --git a/arch/arm/mach-s3c/gpio-samsung.c b/arch/arm/mach-s3c/gpio-samsung.c > index 206a492fbaf5..3ee4ad969cc2 100644 > --- a/arch/arm/mach-s3c/gpio-samsung.c > +++ b/arch/arm/mach-s3c/gpio-samsung.c > @@ -516,7 +516,7 @@ static void __init samsung_gpiolib_add(struct samsung_gpio_chip *chip) > gc->direction_input = samsung_gpiolib_2bit_input; > if (!gc->direction_output) > gc->direction_output = samsung_gpiolib_2bit_output; > - if (!gc->set) > + if (!gc->set_rv) > gc->set_rv = samsung_gpiolib_set; > if (!gc->get) > gc->get = samsung_gpiolib_get;

3 months, 3 weeks

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[PATCH V4 mm-hotfixes 1/3] mm: move page table sync declarations to linux/pgtable.h

by Harry Yoo

Move ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to linux/pgtable.h so that they can be used outside of vmalloc and ioremap. Cc: <stable(a)vger.kernel.org> Fixes: 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges") Signed-off-by: Harry Yoo <harry.yoo(a)oracle.com> --- include/linux/pgtable.h | 16 ++++++++++++++++ include/linux/vmalloc.h | 16 ---------------- 2 files changed, 16 insertions(+), 16 deletions(-) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 4c035637eeb7..ba699df6ef69 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -1467,6 +1467,22 @@ static inline void modify_prot_commit_ptes(struct vm_area_struct *vma, unsigned } #endif +/* + * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values + * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings() + * needs to be called. + */ +#ifndef ARCH_PAGE_TABLE_SYNC_MASK +#define ARCH_PAGE_TABLE_SYNC_MASK 0 +#endif + +/* + * There is no default implementation for arch_sync_kernel_mappings(). It is + * relied upon the compiler to optimize calls out if ARCH_PAGE_TABLE_SYNC_MASK + * is 0. + */ +void arch_sync_kernel_mappings(unsigned long start, unsigned long end); + #endif /* CONFIG_MMU */ /* diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index fdc9aeb74a44..2759dac6be44 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -219,22 +219,6 @@ extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, int vmap_pages_range(unsigned long addr, unsigned long end, pgprot_t prot, struct page **pages, unsigned int page_shift); -/* - * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values - * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings() - * needs to be called. - */ -#ifndef ARCH_PAGE_TABLE_SYNC_MASK -#define ARCH_PAGE_TABLE_SYNC_MASK 0 -#endif - -/* - * There is no default implementation for arch_sync_kernel_mappings(). It is - * relied upon the compiler to optimize calls out if ARCH_PAGE_TABLE_SYNC_MASK - * is 0. - */ -void arch_sync_kernel_mappings(unsigned long start, unsigned long end); - /* * Lowlevel-APIs (not for driver use!) */ -- 2.43.0

3 months, 3 weeks

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[PATCH] PCI: rcar-gen4: Fix PHY initialization

by Marek Vasut

R-Car V4H Reference Manual R19UH0186EJ0130 Rev.1.30 Apr. 21, 2025 page 4581 Figure 104.3b Initial Setting of PCIEC(example) middle of the figure indicates that fourth write into register 0x148 [2:0] is 0x3 or GENMASK(1, 0). The current code writes GENMASK(11, 0) which is a typo. Fix the typo. Fixes: faf5a975ee3b ("PCI: rcar-gen4: Add support for R-Car V4H") Cc: <stable(a)vger.kernel.org> Signed-off-by: Marek Vasut <marek.vasut+renesas(a)mailbox.org> --- Cc: "Krzysztof Wilczyński" <kwilczynski(a)kernel.org> Cc: Bjorn Helgaas <bhelgaas(a)google.com> Cc: Geert Uytterhoeven <geert+renesas(a)glider.be> Cc: Lorenzo Pieralisi <lpieralisi(a)kernel.org> Cc: Magnus Damm <magnus.damm(a)gmail.com> Cc: Manivannan Sadhasivam <mani(a)kernel.org> Cc: Rob Herring <robh(a)kernel.org> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh(a)renesas.com> Cc: linux-pci(a)vger.kernel.org Cc: linux-renesas-soc(a)vger.kernel.org --- drivers/pci/controller/dwc/pcie-rcar-gen4.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/controller/dwc/pcie-rcar-gen4.c b/drivers/pci/controller/dwc/pcie-rcar-gen4.c index f256ba12b84f..0ef95005b0f5 100644 --- a/drivers/pci/controller/dwc/pcie-rcar-gen4.c +++ b/drivers/pci/controller/dwc/pcie-rcar-gen4.c @@ -703,7 +703,7 @@ static int rcar_gen4_pcie_ltssm_control(struct rcar_gen4_pcie *rcar, bool enable rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x148, GENMASK(23, 22), BIT(22)); rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x148, GENMASK(18, 16), GENMASK(17, 16)); rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x148, GENMASK(7, 6), BIT(6)); - rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x148, GENMASK(2, 0), GENMASK(11, 0)); + rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x148, GENMASK(2, 0), GENMASK(1, 0)); rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x1d4, GENMASK(16, 15), GENMASK(16, 15)); rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x514, BIT(26), BIT(26)); rcar_gen4_pcie_phy_reg_update_bits(rcar, 0x0f8, BIT(16), 0); -- 2.47.2

3 months, 3 weeks

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[PATCH 4/4] smb: client: fix potential UAF in cifs_stats_proc_write()

by Chanho Min

From: Paulo Alcantara <pc(a)manguebit.com> commit d3da25c5ac84430f89875ca7485a3828150a7e0a upstream. Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF. Cc: stable(a)vger.kernel.org # 5.4 Signed-off-by: Paulo Alcantara (Red Hat) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> [ chanho: Backported to v5.4.y, cifs_debug.c was moved from fs/cifs to fs/smb/client ] Signed-off-by: Chanho Min <chanho.min(a)lge.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- fs/cifs/cifs_debug.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c index df3dfa611c352..47190e676aa25 100644 --- a/fs/cifs/cifs_debug.c +++ b/fs/cifs/cifs_debug.c @@ -470,6 +470,8 @@ static ssize_t cifs_stats_proc_write(struct file *file, } #endif /* CONFIG_CIFS_STATS2 */ list_for_each(tmp2, &server->smb_ses_list) { + if (cifs_ses_exiting(ses)) + continue; ses = list_entry(tmp2, struct cifs_ses, smb_ses_list); list_for_each(tmp3, &ses->tcon_list) {

3 months, 3 weeks

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[PATCH 3/4] smb: client: fix potential UAF in smb2_is_valid_lease_break()

by Chanho Min

From: Paulo Alcantara <pc(a)manguebit.com> Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF. Cc: stable(a)vger.kernel.org # 5.4 Signed-off-by: Paulo Alcantara (Red Hat) <pc(a)manguebit.com> [ chanho: Backported to v5.4.y, smb2misc.c was moved from fs/cifs to fs/smb/client ] Signed-off-by: Chanho Min <chanho.min(a)lge.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> --- fs/cifs/smb2misc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index d7cbf1b07126c..c47927d257635 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -611,7 +611,8 @@ smb2_is_valid_lease_break(char *buffer) list_for_each(tmp1, &server->smb_ses_list) { ses = list_entry(tmp1, struct cifs_ses, smb_ses_list); - + if (cifs_ses_exiting(ses)) + continue; list_for_each(tmp2, &ses->tcon_list) { tcon = list_entry(tmp2, struct cifs_tcon, tcon_list);

3 months, 3 weeks

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[PATCH 2/4] smb: client: fix potential UAF in is_valid_oplock_break()

by Chanho Min

From: Paulo Alcantara <pc(a)manguebit.com> commit 69ccf040acddf33a3a85ec0f6b45ef84b0f7ec29 upstream. Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF. Cc: stable(a)vger.kernel.org # 5.4 Signed-off-by: Paulo Alcantara (Red Hat) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> [ chanho: Backported to v5.4.y, misc.c was moved from fs/cifs to fs/smb/client ] Signed-off-by: Chanho Min <chanho.min(a)lge.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- fs/cifs/misc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index db1fcdedf289a..4d838d7db7b57 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -473,6 +473,8 @@ is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv) spin_lock(&cifs_tcp_ses_lock); list_for_each(tmp, &srv->smb_ses_list) { ses = list_entry(tmp, struct cifs_ses, smb_ses_list); + if (cifs_ses_exiting(ses)) + continue; list_for_each(tmp1, &ses->tcon_list) { tcon = list_entry(tmp1, struct cifs_tcon, tcon_list); if (tcon->tid != buf->Tid)

3 months, 3 weeks

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[PATCH 1/4] smb: client: fix potential UAF in cifs_debug_files_proc_show()

by Chanho Min

From: Paulo Alcantara <pc(a)manguebit.com> commit ca545b7f0823f19db0f1148d59bc5e1a56634502 upstream. Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF. Cc: stable(a)vger.kernel.org # 5.4 Signed-off-by: Paulo Alcantara (Red Hat) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> [ This patch removes lock/unlock operation in routine cifs_ses_exiting() for ses_lock is not present in v5.10 and not ported yet. ses->status is protected by a global lock, cifs_tcp_ses_lock, in v5.10. ] Signed-off-by: Jianqi Ren <jianqi.ren.cn(a)windriver.com> Signed-off-by: He Zhe <zhe.he(a)windriver.com> [ chanho: Backport to v5.4.y from v5.10.y's commit 8f8718afd44 ] Signed-off-by: Chanho Min <chanho.min(a)lge.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- fs/cifs/cifs_debug.c | 2 ++ fs/cifs/cifsglob.h | 8 ++++++++ 2 files changed, 10 insertions(+) diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c index efb2928ff6c89..df3dfa611c352 100644 --- a/fs/cifs/cifs_debug.c +++ b/fs/cifs/cifs_debug.c @@ -162,6 +162,8 @@ static int cifs_debug_files_proc_show(struct seq_file *m, void *v) tcp_ses_list); list_for_each(tmp, &server->smb_ses_list) { ses = list_entry(tmp, struct cifs_ses, smb_ses_list); + if (cifs_ses_exiting(ses)) + continue; list_for_each(tmp1, &ses->tcon_list) { tcon = list_entry(tmp1, struct cifs_tcon, tcon_list); spin_lock(&tcon->open_file_lock); diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 253321adc2664..5f545a240afa6 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -2027,4 +2027,12 @@ static inline struct scatterlist *cifs_sg_set_buf(struct scatterlist *sg, return sg; } +static inline bool cifs_ses_exiting(struct cifs_ses *ses) +{ + bool ret; + + ret = ses->status == CifsExiting; + return ret; +} + #endif /* _CIFS_GLOB_H */

3 months, 3 weeks

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[PATCH v2 1/3] drm/i915/gt: Relocate compression repacking WA for JSL/EHL

by Sebastian Brzezinka

CACHE_MODE_0 registers should be saved and restored as part of the context, not during engine reset. Move the related workaround (Disable Repacking for Compression) from rcs_engine_wa_init() to icl_ctx_workarounds_init() for Jasper Lake and Elkhart Lake platforms. This ensures the WA is applied during context initialisation. BSPEC: 11322 Signed-off-by: Sebastian Brzezinka <sebastian.brzezinka(a)intel.com> Reviewed-by: Andi Shyti <andi.shyti(a)linux.intel.com> Reviewed-by: Krzysztof Karas <krzysztof.karas(a)intel.com> Fixes: 0ddae025ab6c ("drm/i915: Disable compression tricks on JSL") Closes: Fixes: 0ddae025ab6c ("drm/i915: Disable compression tricks on JSL") Cc: <stable(a)vger.kernel.org> # v6.13+ --- v1 -> v2: - clarify commit message --- drivers/gpu/drm/i915/gt/intel_workarounds.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c index b37e400f74e5..5a95f06900b5 100644 --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c @@ -634,6 +634,8 @@ static void cfl_ctx_workarounds_init(struct intel_engine_cs *engine, static void icl_ctx_workarounds_init(struct intel_engine_cs *engine, struct i915_wa_list *wal) { + struct drm_i915_private *i915 = engine->i915; + /* Wa_1406697149 (WaDisableBankHangMode:icl) */ wa_write(wal, GEN8_L3CNTLREG, GEN8_ERRDETBCTRL); @@ -669,6 +671,15 @@ static void icl_ctx_workarounds_init(struct intel_engine_cs *engine, /* Wa_1406306137:icl,ehl */ wa_mcr_masked_en(wal, GEN9_ROW_CHICKEN4, GEN11_DIS_PICK_2ND_EU); + + if (IS_JASPERLAKE(i915) || IS_ELKHARTLAKE(i915)) { + /* + * Disable Repacking for Compression (masked R/W access) + * before rendering compressed surfaces for display. + */ + wa_masked_en(wal, CACHE_MODE_0_GEN7, + DISABLE_REPACKING_FOR_COMPRESSION); + } } /* @@ -2306,15 +2317,6 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal) GEN8_RC_SEMA_IDLE_MSG_DISABLE); } - if (IS_JASPERLAKE(i915) || IS_ELKHARTLAKE(i915)) { - /* - * "Disable Repacking for Compression (masked R/W access) - * before rendering compressed surfaces for display." - */ - wa_masked_en(wal, CACHE_MODE_0_GEN7, - DISABLE_REPACKING_FOR_COMPRESSION); - } - if (GRAPHICS_VER(i915) == 11) { /* This is not an Wa. Enable for better image quality */ wa_masked_en(wal, -- 2.34.1

3 months, 3 weeks

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[PATCH] kcov, usb: Fix invalid context sleep in softirq path on PREEMPT_RT

by Yunseong Kim

When fuzzing USB with syzkaller on a PREEMPT_RT enabled kernel, following bug is triggered in the ksoftirqd context. | BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 | in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 30, name: ksoftirqd/1 | preempt_count: 0, expected: 0 | RCU nest depth: 2, expected: 2 | CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Tainted: G W 6.16.0-rc1-rt1 #11 PREEMPT_RT | Tainted: [W]=WARN | Hardware name: QEMU KVM Virtual Machine, BIOS 2025.02-8 05/13/2025 | Call trace: | show_stack+0x2c/0x3c (C) | __dump_stack+0x30/0x40 | dump_stack_lvl+0x148/0x1d8 | dump_stack+0x1c/0x3c | __might_resched+0x2e4/0x52c | rt_spin_lock+0xa8/0x1bc | kcov_remote_start+0xb0/0x490 | __usb_hcd_giveback_urb+0x2d0/0x5e8 | usb_giveback_urb_bh+0x234/0x3c4 | process_scheduled_works+0x678/0xd18 | bh_worker+0x2f0/0x59c | workqueue_softirq_action+0x104/0x14c | tasklet_action+0x18/0x8c | handle_softirqs+0x208/0x63c | run_ksoftirqd+0x64/0x264 | smpboot_thread_fn+0x4ac/0x908 | kthread+0x5e8/0x734 | ret_from_fork+0x10/0x20 To reproduce on PREEMPT_RT kernel: $ git remote add rt-devel git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git $ git fetch rt-devel $ git checkout -b v6.16-rc1-rt1 v6.16-rc1-rt1 I have attached the syzlang and the C source code converted by syz-prog2c: Link: https://gist.github.com/kzall0c/9455aaa246f4aa1135353a51753adbbe Then, run with a PREEMPT_RT config. This issue was introduced by commit f85d39dd7ed8 ("kcov, usb: disable interrupts in kcov_remote_start_usb_softirq"). However, this creates a conflict on PREEMPT_RT kernels. The local_irq_save() call establishes an atomic context where sleeping is forbidden. Inside this context, kcov_remote_start() is called, which on PREEMPT_RT uses sleeping locks (spinlock_t and local_lock_t are mapped to rt_mutex). This results in a sleeping function called from invalid context. On PREEMPT_RT, interrupt handlers are threaded, so the re-entrancy scenario is already safely handled by the existing local_lock_t and the global kcov_remote_lock within kcov_remote_start(). Therefore, the outer local_irq_save() is not necessary. This preserves the intended re-entrancy protection for non-RT kernels while resolving the locking violation on PREEMPT_RT kernels. After making this modification and testing it, syzkaller fuzzing the PREEMPT_RT kernel is now running without stopping on latest announced Real-time Linux. Link: https://lore.kernel.org/linux-rt-devel/20250610080307.LMm1hleC@linutronix.d… Fixes: f85d39dd7ed8 ("kcov, usb: disable interrupts in kcov_remote_start_usb_softirq") Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Tetsuo Handa <penguin-kernel(a)i-love.sakura.ne.jp> Cc: Alan Stern <stern(a)rowland.harvard.edu> Cc: Dmitry Vyukov <dvyukov(a)google.com> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de> Cc: Byungchul Park <byungchul(a)sk.com> Cc: stable(a)vger.kernel.org Cc: kasan-dev(a)googlegroups.com Cc: syzkaller(a)googlegroups.com Cc: linux-usb(a)vger.kernel.org Cc: linux-rt-devel(a)lists.linux.dev Signed-off-by: Yunseong Kim <ysk(a)kzalloc.com> --- include/linux/kcov.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/linux/kcov.h b/include/linux/kcov.h index 75a2fb8b16c3..c5e1b2dd0bb7 100644 --- a/include/linux/kcov.h +++ b/include/linux/kcov.h @@ -85,7 +85,9 @@ static inline unsigned long kcov_remote_start_usb_softirq(u64 id) unsigned long flags = 0; if (in_serving_softirq()) { +#ifndef CONFIG_PREEMPT_RT local_irq_save(flags); +#endif kcov_remote_start_usb(id); } @@ -96,7 +98,9 @@ static inline void kcov_remote_stop_softirq(unsigned long flags) { if (in_serving_softirq()) { kcov_remote_stop(); +#ifndef CONFIG_PREEMPT_RT local_irq_restore(flags); +#endif } } -- 2.50.0

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