From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- arch/mips/power/Makefile | 2 ++ arch/mips/power/cpu.c | 43 +++++++++++++++++++++++++++++ arch/mips/power/hibernate.c | 12 +++++++++ arch/mips/power/hibernate_asm.S | 60 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 117 insertions(+) create mode 100644 arch/mips/power/Makefile create mode 100644 arch/mips/power/cpu.c create mode 100644 arch/mips/power/hibernate.c create mode 100644 arch/mips/power/hibernate_asm.S (limited to 'arch/mips/power') diff --git a/arch/mips/power/Makefile b/arch/mips/power/Makefile new file mode 100644 index 000000000..14b7d9ee6 --- /dev/null +++ b/arch/mips/power/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_HIBERNATION) += cpu.o hibernate.o hibernate_asm.o diff --git a/arch/mips/power/cpu.c b/arch/mips/power/cpu.c new file mode 100644 index 000000000..d8ef7778e --- /dev/null +++ b/arch/mips/power/cpu.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Suspend support specific for mips. + * + * Copyright (C) 2009 Lemote Inc. + * Author: Hu Hongbing + * Wu Zhangjin + */ +#include +#include +#include +#include + +static u32 saved_status; +struct pt_regs saved_regs; + +void save_processor_state(void) +{ + saved_status = read_c0_status(); + + if (is_fpu_owner()) + save_fp(current); + + save_dsp(current); +} + +void restore_processor_state(void) +{ + write_c0_status(saved_status); + + if (is_fpu_owner()) + restore_fp(current); + + restore_dsp(current); +} + +int pfn_is_nosave(unsigned long pfn) +{ + unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin)); + unsigned long nosave_end_pfn = PFN_UP(__pa(&__nosave_end)); + + return (pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn); +} diff --git a/arch/mips/power/hibernate.c b/arch/mips/power/hibernate.c new file mode 100644 index 000000000..192879e76 --- /dev/null +++ b/arch/mips/power/hibernate.c @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +extern int restore_image(void); + +int swsusp_arch_resume(void) +{ + /* Avoid TLB mismatch during and after kernel resume */ + local_flush_tlb_all(); + return restore_image(); +} diff --git a/arch/mips/power/hibernate_asm.S b/arch/mips/power/hibernate_asm.S new file mode 100644 index 000000000..e62538734 --- /dev/null +++ b/arch/mips/power/hibernate_asm.S @@ -0,0 +1,60 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Hibernation support specific for mips - temporary page tables + * + * Copyright (C) 2009 Lemote Inc. + * Author: Hu Hongbing + * Wu Zhangjin + */ +#include +#include +#include + +.text +LEAF(swsusp_arch_suspend) + PTR_LA t0, saved_regs + PTR_S ra, PT_R31(t0) + PTR_S sp, PT_R29(t0) + PTR_S fp, PT_R30(t0) + PTR_S gp, PT_R28(t0) + PTR_S s0, PT_R16(t0) + PTR_S s1, PT_R17(t0) + PTR_S s2, PT_R18(t0) + PTR_S s3, PT_R19(t0) + PTR_S s4, PT_R20(t0) + PTR_S s5, PT_R21(t0) + PTR_S s6, PT_R22(t0) + PTR_S s7, PT_R23(t0) + j swsusp_save +END(swsusp_arch_suspend) + +LEAF(restore_image) + PTR_L t0, restore_pblist +0: + PTR_L t1, PBE_ADDRESS(t0) /* source */ + PTR_L t2, PBE_ORIG_ADDRESS(t0) /* destination */ + PTR_ADDU t3, t1, _PAGE_SIZE +1: + REG_L t8, (t1) + REG_S t8, (t2) + PTR_ADDIU t1, t1, SZREG + PTR_ADDIU t2, t2, SZREG + bne t1, t3, 1b + PTR_L t0, PBE_NEXT(t0) + bnez t0, 0b + PTR_LA t0, saved_regs + PTR_L ra, PT_R31(t0) + PTR_L sp, PT_R29(t0) + PTR_L fp, PT_R30(t0) + PTR_L gp, PT_R28(t0) + PTR_L s0, PT_R16(t0) + PTR_L s1, PT_R17(t0) + PTR_L s2, PT_R18(t0) + PTR_L s3, PT_R19(t0) + PTR_L s4, PT_R20(t0) + PTR_L s5, PT_R21(t0) + PTR_L s6, PT_R22(t0) + PTR_L s7, PT_R23(t0) + PTR_LI v0, 0x0 + jr ra +END(restore_image) -- cgit v1.3.1