From fe557319aa06c23cffc9346000f119547e0f289a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 17 Jun 2020 09:37:53 +0200 Subject: maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault Better describe what these functions do. Suggested-by: Linus Torvalds Signed-off-by: Christoph Hellwig Signed-off-by: Linus Torvalds --- kernel/debug/debug_core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/debug/debug_core.c') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index ccc0f98abdd4..bc8d25f2ac8a 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -169,18 +169,18 @@ int __weak kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) { int err; - err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr, + err = copy_from_kernel_nofault(bpt->saved_instr, (char *)bpt->bpt_addr, BREAK_INSTR_SIZE); if (err) return err; - err = probe_kernel_write((char *)bpt->bpt_addr, + err = copy_to_kernel_nofault((char *)bpt->bpt_addr, arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE); return err; } int __weak kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) { - return probe_kernel_write((char *)bpt->bpt_addr, + return copy_to_kernel_nofault((char *)bpt->bpt_addr, (char *)bpt->saved_instr, BREAK_INSTR_SIZE); } -- cgit v1.3-14-g43fede From 440ab9e10e2e6e5fd677473ee6f9e3af0f6904d6 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Tue, 2 Jun 2020 15:47:39 -0700 Subject: kgdb: Avoid suspicious RCU usage warning At times when I'm using kgdb I see a splat on my console about suspicious RCU usage. I managed to come up with a case that could reproduce this that looked like this: WARNING: suspicious RCU usage 5.7.0-rc4+ #609 Not tainted ----------------------------- kernel/pid.c:395 find_task_by_pid_ns() needs rcu_read_lock() protection! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by swapper/0/1: #0: ffffff81b6b8e988 (&dev->mutex){....}-{3:3}, at: __device_attach+0x40/0x13c #1: ffffffd01109e9e8 (dbg_master_lock){....}-{2:2}, at: kgdb_cpu_enter+0x20c/0x7ac #2: ffffffd01109ea90 (dbg_slave_lock){....}-{2:2}, at: kgdb_cpu_enter+0x3ec/0x7ac stack backtrace: CPU: 7 PID: 1 Comm: swapper/0 Not tainted 5.7.0-rc4+ #609 Hardware name: Google Cheza (rev3+) (DT) Call trace: dump_backtrace+0x0/0x1b8 show_stack+0x1c/0x24 dump_stack+0xd4/0x134 lockdep_rcu_suspicious+0xf0/0x100 find_task_by_pid_ns+0x5c/0x80 getthread+0x8c/0xb0 gdb_serial_stub+0x9d4/0xd04 kgdb_cpu_enter+0x284/0x7ac kgdb_handle_exception+0x174/0x20c kgdb_brk_fn+0x24/0x30 call_break_hook+0x6c/0x7c brk_handler+0x20/0x5c do_debug_exception+0x1c8/0x22c el1_sync_handler+0x3c/0xe4 el1_sync+0x7c/0x100 rpmh_rsc_probe+0x38/0x420 platform_drv_probe+0x94/0xb4 really_probe+0x134/0x300 driver_probe_device+0x68/0x100 __device_attach_driver+0x90/0xa8 bus_for_each_drv+0x84/0xcc __device_attach+0xb4/0x13c device_initial_probe+0x18/0x20 bus_probe_device+0x38/0x98 device_add+0x38c/0x420 If I understand properly we should just be able to blanket kgdb under one big RCU read lock and the problem should go away. We'll add it to the beast-of-a-function known as kgdb_cpu_enter(). With this I no longer get any splats and things seem to work fine. Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20200602154729.v2.1.I70e0d4fd46d5ed2aaf0c98a355e8e1b7a5bb7e4e@changeid Signed-off-by: Daniel Thompson --- kernel/debug/debug_core.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel/debug/debug_core.c') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index bc8d25f2ac8a..9e5934780f41 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -587,6 +587,7 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs, arch_kgdb_ops.disable_hw_break(regs); acquirelock: + rcu_read_lock(); /* * Interrupts will be restored by the 'trap return' code, except when * single stepping. @@ -646,6 +647,7 @@ return_normal: atomic_dec(&slaves_in_kgdb); dbg_touch_watchdogs(); local_irq_restore(flags); + rcu_read_unlock(); return 0; } cpu_relax(); @@ -664,6 +666,7 @@ return_normal: raw_spin_unlock(&dbg_master_lock); dbg_touch_watchdogs(); local_irq_restore(flags); + rcu_read_unlock(); goto acquirelock; } @@ -787,6 +790,7 @@ kgdb_restore: raw_spin_unlock(&dbg_master_lock); dbg_touch_watchdogs(); local_irq_restore(flags); + rcu_read_unlock(); return kgdb_info[cpu].ret_state; } -- cgit v1.3-14-g43fede From b13fecb1c3a603c4b8e99b306fecf4f668c11b32 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 13 Jul 2020 15:01:26 -0700 Subject: treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD() This converts all the existing DECLARE_TASKLET() (and ...DISABLED) macros with DECLARE_TASKLET_OLD() in preparation for refactoring the tasklet callback type. All existing DECLARE_TASKLET() users had a "0" data argument, it has been removed here as well. Reviewed-by: Greg Kroah-Hartman Acked-by: Thomas Gleixner Signed-off-by: Kees Cook --- drivers/input/keyboard/omap-keypad.c | 2 +- drivers/input/serio/hil_mlc.c | 2 +- drivers/net/wan/farsync.c | 4 ++-- drivers/s390/crypto/ap_bus.c | 2 +- drivers/staging/most/dim2/dim2.c | 2 +- drivers/staging/octeon/ethernet-tx.c | 2 +- drivers/tty/vt/keyboard.c | 2 +- drivers/usb/gadget/udc/snps_udc_core.c | 2 +- drivers/usb/host/fhci-sched.c | 2 +- include/linux/interrupt.h | 15 ++++++++++----- kernel/backtracetest.c | 2 +- kernel/debug/debug_core.c | 2 +- kernel/irq/resend.c | 2 +- net/atm/pppoatm.c | 2 +- net/iucv/iucv.c | 2 +- sound/drivers/pcsp/pcsp_lib.c | 2 +- 16 files changed, 26 insertions(+), 21 deletions(-) (limited to 'kernel/debug/debug_core.c') diff --git a/drivers/input/keyboard/omap-keypad.c b/drivers/input/keyboard/omap-keypad.c index 5fe7a5633e33..dbe836c7ff47 100644 --- a/drivers/input/keyboard/omap-keypad.c +++ b/drivers/input/keyboard/omap-keypad.c @@ -46,7 +46,7 @@ struct omap_kp { unsigned short keymap[]; }; -static DECLARE_TASKLET_DISABLED(kp_tasklet, omap_kp_tasklet, 0); +static DECLARE_TASKLET_DISABLED_OLD(kp_tasklet, omap_kp_tasklet); static unsigned int *row_gpios; static unsigned int *col_gpios; diff --git a/drivers/input/serio/hil_mlc.c b/drivers/input/serio/hil_mlc.c index e1423f7648d6..65f4e9d62a67 100644 --- a/drivers/input/serio/hil_mlc.c +++ b/drivers/input/serio/hil_mlc.c @@ -77,7 +77,7 @@ static struct timer_list hil_mlcs_kicker; static int hil_mlcs_probe; static void hil_mlcs_process(unsigned long unused); -static DECLARE_TASKLET_DISABLED(hil_mlcs_tasklet, hil_mlcs_process, 0); +static DECLARE_TASKLET_DISABLED_OLD(hil_mlcs_tasklet, hil_mlcs_process); /* #define HIL_MLC_DEBUG */ diff --git a/drivers/net/wan/farsync.c b/drivers/net/wan/farsync.c index 7916efce7188..f5198a391417 100644 --- a/drivers/net/wan/farsync.c +++ b/drivers/net/wan/farsync.c @@ -569,8 +569,8 @@ static void do_bottom_half_rx(struct fst_card_info *card); static void fst_process_tx_work_q(unsigned long work_q); static void fst_process_int_work_q(unsigned long work_q); -static DECLARE_TASKLET(fst_tx_task, fst_process_tx_work_q, 0); -static DECLARE_TASKLET(fst_int_task, fst_process_int_work_q, 0); +static DECLARE_TASKLET_OLD(fst_tx_task, fst_process_tx_work_q); +static DECLARE_TASKLET_OLD(fst_int_task, fst_process_int_work_q); static struct fst_card_info *fst_card_array[FST_MAX_CARDS]; static spinlock_t fst_work_q_lock; diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c index e71ca4a719a5..2589ccd257e3 100644 --- a/drivers/s390/crypto/ap_bus.c +++ b/drivers/s390/crypto/ap_bus.c @@ -93,7 +93,7 @@ static DECLARE_WORK(ap_scan_work, ap_scan_bus); * Tasklet & timer for AP request polling and interrupts */ static void ap_tasklet_fn(unsigned long); -static DECLARE_TASKLET(ap_tasklet, ap_tasklet_fn, 0); +static DECLARE_TASKLET_OLD(ap_tasklet, ap_tasklet_fn); static DECLARE_WAIT_QUEUE_HEAD(ap_poll_wait); static struct task_struct *ap_poll_kthread; static DEFINE_MUTEX(ap_poll_thread_mutex); diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/dim2.c index 8e0f27e61652..509c8012d20b 100644 --- a/drivers/staging/most/dim2/dim2.c +++ b/drivers/staging/most/dim2/dim2.c @@ -46,7 +46,7 @@ MODULE_PARM_DESC(fcnt, "Num of frames per sub-buffer for sync channels as a powe static DEFINE_SPINLOCK(dim_lock); static void dim2_tasklet_fn(unsigned long data); -static DECLARE_TASKLET(dim2_tasklet, dim2_tasklet_fn, 0); +static DECLARE_TASKLET_OLD(dim2_tasklet, dim2_tasklet_fn); /** * struct hdm_channel - private structure to keep channel specific data diff --git a/drivers/staging/octeon/ethernet-tx.c b/drivers/staging/octeon/ethernet-tx.c index ab7dd8216006..9c71ad5af7b9 100644 --- a/drivers/staging/octeon/ethernet-tx.c +++ b/drivers/staging/octeon/ethernet-tx.c @@ -41,7 +41,7 @@ #endif static void cvm_oct_tx_do_cleanup(unsigned long arg); -static DECLARE_TASKLET(cvm_oct_tx_cleanup_tasklet, cvm_oct_tx_do_cleanup, 0); +static DECLARE_TASKLET_OLD(cvm_oct_tx_cleanup_tasklet, cvm_oct_tx_do_cleanup); /* Maximum number of SKBs to try to free per xmit packet. */ #define MAX_SKB_TO_FREE (MAX_OUT_QUEUE_DEPTH * 2) diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c index 568b2171f335..f80199984ee0 100644 --- a/drivers/tty/vt/keyboard.c +++ b/drivers/tty/vt/keyboard.c @@ -1236,7 +1236,7 @@ static void kbd_bh(unsigned long dummy) } } -DECLARE_TASKLET_DISABLED(keyboard_tasklet, kbd_bh, 0); +DECLARE_TASKLET_DISABLED_OLD(keyboard_tasklet, kbd_bh); #if defined(CONFIG_X86) || defined(CONFIG_IA64) || defined(CONFIG_ALPHA) ||\ defined(CONFIG_MIPS) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) ||\ diff --git a/drivers/usb/gadget/udc/snps_udc_core.c b/drivers/usb/gadget/udc/snps_udc_core.c index afdd28f332ce..e76f1a50b0fc 100644 --- a/drivers/usb/gadget/udc/snps_udc_core.c +++ b/drivers/usb/gadget/udc/snps_udc_core.c @@ -96,7 +96,7 @@ static int stop_pollstall_timer; static DECLARE_COMPLETION(on_pollstall_exit); /* tasklet for usb disconnect */ -static DECLARE_TASKLET(disconnect_tasklet, udc_tasklet_disconnect, 0); +static DECLARE_TASKLET_OLD(disconnect_tasklet, udc_tasklet_disconnect); /* endpoint names used for print */ static const char ep0_string[] = "ep0in"; diff --git a/drivers/usb/host/fhci-sched.c b/drivers/usb/host/fhci-sched.c index 3235d5307403..5c423f240a1f 100644 --- a/drivers/usb/host/fhci-sched.c +++ b/drivers/usb/host/fhci-sched.c @@ -677,7 +677,7 @@ static void process_done_list(unsigned long data) enable_irq(fhci_to_hcd(fhci)->irq); } -DECLARE_TASKLET(fhci_tasklet, process_done_list, 0); +DECLARE_TASKLET_OLD(fhci_tasklet, process_done_list); /* transfer complted callback */ u32 fhci_transfer_confirm_callback(struct fhci_hcd *fhci) diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 5db970b6615a..b911196f03eb 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -612,12 +612,17 @@ struct tasklet_struct unsigned long data; }; -#define DECLARE_TASKLET(name, func, data) \ -struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data } - -#define DECLARE_TASKLET_DISABLED(name, func, data) \ -struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data } +#define DECLARE_TASKLET_OLD(name, _func) \ +struct tasklet_struct name = { \ + .count = ATOMIC_INIT(0), \ + .func = _func, \ +} +#define DECLARE_TASKLET_DISABLED_OLD(name, _func) \ +struct tasklet_struct name = { \ + .count = ATOMIC_INIT(1), \ + .func = _func, \ +} enum { diff --git a/kernel/backtracetest.c b/kernel/backtracetest.c index a2a97fa3071b..370217dd7e39 100644 --- a/kernel/backtracetest.c +++ b/kernel/backtracetest.c @@ -29,7 +29,7 @@ static void backtrace_test_irq_callback(unsigned long data) complete(&backtrace_work); } -static DECLARE_TASKLET(backtrace_tasklet, &backtrace_test_irq_callback, 0); +static DECLARE_TASKLET_OLD(backtrace_tasklet, &backtrace_test_irq_callback); static void backtrace_test_irq(void) { diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 9e5934780f41..b16dbc1bf056 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -1068,7 +1068,7 @@ static void kgdb_tasklet_bpt(unsigned long ing) atomic_set(&kgdb_break_tasklet_var, 0); } -static DECLARE_TASKLET(kgdb_tasklet_breakpoint, kgdb_tasklet_bpt, 0); +static DECLARE_TASKLET_OLD(kgdb_tasklet_breakpoint, kgdb_tasklet_bpt); void kgdb_schedule_breakpoint(void) { diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c index 27634f4022d0..c48ce19a257f 100644 --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -45,7 +45,7 @@ static void resend_irqs(unsigned long arg) } /* Tasklet to handle resend: */ -static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0); +static DECLARE_TASKLET_OLD(resend_tasklet, resend_irqs); static int irq_sw_resend(struct irq_desc *desc) { diff --git a/net/atm/pppoatm.c b/net/atm/pppoatm.c index 45d8e1d5d033..579b66da1d95 100644 --- a/net/atm/pppoatm.c +++ b/net/atm/pppoatm.c @@ -393,7 +393,7 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg) * Each PPPoATM instance has its own tasklet - this is just a * prototypical one used to initialize them */ - static const DECLARE_TASKLET(tasklet_proto, pppoatm_wakeup_sender, 0); + static const DECLARE_TASKLET_OLD(tasklet_proto, pppoatm_wakeup_sender); if (copy_from_user(&be, arg, sizeof be)) return -EFAULT; if (be.encaps != PPPOATM_ENCAPS_AUTODETECT && diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c index 19250a0c85d3..cd2e468852e7 100644 --- a/net/iucv/iucv.c +++ b/net/iucv/iucv.c @@ -105,7 +105,7 @@ static LIST_HEAD(iucv_task_queue); * The tasklet for fast delivery of iucv interrupts. */ static void iucv_tasklet_fn(unsigned long); -static DECLARE_TASKLET(iucv_tasklet, iucv_tasklet_fn,0); +static DECLARE_TASKLET_OLD(iucv_tasklet, iucv_tasklet_fn); /* * Queue of interrupt buffers for delivery via a work queue diff --git a/sound/drivers/pcsp/pcsp_lib.c b/sound/drivers/pcsp/pcsp_lib.c index 05244b11ed5e..4e79293d7f11 100644 --- a/sound/drivers/pcsp/pcsp_lib.c +++ b/sound/drivers/pcsp/pcsp_lib.c @@ -36,7 +36,7 @@ static void pcsp_call_pcm_elapsed(unsigned long priv) } } -static DECLARE_TASKLET(pcsp_pcm_tasklet, pcsp_call_pcm_elapsed, 0); +static DECLARE_TASKLET_OLD(pcsp_pcm_tasklet, pcsp_call_pcm_elapsed); /* write the port and returns the next expire time in ns; * called at the trigger-start and in hrtimer callback -- cgit v1.3-14-g43fede