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SubjectRe: [PATCH] kprobes: Enable tracing for mololithic kernel images
Hello Jarkko,

On Wed, 8 Jun 2022 at 02:02, Jarkko Sakkinen <jarkko@profian.com> wrote:
>
> Tracing with kprobes while running a monolithic kernel is currently
> impossible because CONFIG_KPROBES is dependent of CONFIG_MODULES. This
> dependency is a result of kprobes code using the module allocator for the
> trampoline code.
>
> Detaching kprobes from modules helps to squeeze down the user space,
> e.g. when developing new core kernel features, while still having all
> the nice tracing capabilities.
>
> For kernel/ and arch/*, move module_alloc() and module_memfree() to
> module_alloc.c, and compile as part of vmlinux when either CONFIG_MODULES
> or CONFIG_KPROBES is enabled. In addition, flag kernel module specific
> code with CONFIG_MODULES.
>
> As the result, kprobes can be used with a monolithic kernel.

I think I may have mentioned this the previous time as well, but I
don't think this is the right approach.

Kprobes uses alloc_insn_page() to allocate executable memory, but the
requirements for this memory are radically different compared to
loadable modules, which need to be within an arch-specific distance of
the core kernel, need KASAN backing etc etc.

This is why arm64, for instance, does not implement alloc_insn_page()
in terms of module_alloc() [and likely does not belong in this patch
for that reason]

Is there any reason kprobes cannot simply use vmalloc()?


>
> Signed-off-by: Jarkko Sakkinen <jarkko@profian.com>
> ---
> Tested with the help of BuildRoot and QEMU:
> - arm (function tracer)
> - arm64 (function tracer)
> - mips (function tracer)
> - powerpc (function tracer)
> - riscv (function tracer)
> - s390 (function tracer)
> - sparc (function tracer)
> - x86 (function tracer)
> - sh (function tracer, for the "pure" kernel/modules_alloc.c path)
> ---
> arch/Kconfig | 1 -
> arch/arm/kernel/Makefile | 5 +++
> arch/arm/kernel/module.c | 32 ----------------
> arch/arm/kernel/module_alloc.c | 42 ++++++++++++++++++++
> arch/arm64/kernel/Makefile | 5 +++
> arch/arm64/kernel/module.c | 47 -----------------------
> arch/arm64/kernel/module_alloc.c | 57 ++++++++++++++++++++++++++++
> arch/mips/kernel/Makefile | 5 +++
> arch/mips/kernel/module.c | 9 -----
> arch/mips/kernel/module_alloc.c | 18 +++++++++
> arch/parisc/kernel/Makefile | 5 +++
> arch/parisc/kernel/module.c | 11 ------
> arch/parisc/kernel/module_alloc.c | 23 +++++++++++
> arch/powerpc/kernel/Makefile | 5 +++
> arch/powerpc/kernel/module.c | 37 ------------------
> arch/powerpc/kernel/module_alloc.c | 47 +++++++++++++++++++++++
> arch/riscv/kernel/Makefile | 5 +++
> arch/riscv/kernel/module.c | 10 -----
> arch/riscv/kernel/module_alloc.c | 19 ++++++++++
> arch/s390/kernel/Makefile | 5 +++
> arch/s390/kernel/module.c | 17 ---------
> arch/s390/kernel/module_alloc.c | 33 ++++++++++++++++
> arch/sparc/kernel/Makefile | 5 +++
> arch/sparc/kernel/module.c | 30 ---------------
> arch/sparc/kernel/module_alloc.c | 39 +++++++++++++++++++
> arch/x86/kernel/Makefile | 5 +++
> arch/x86/kernel/module.c | 50 ------------------------
> arch/x86/kernel/module_alloc.c | 61 ++++++++++++++++++++++++++++++
> kernel/Makefile | 5 +++
> kernel/kprobes.c | 10 +++++
> kernel/module/main.c | 17 ---------
> kernel/module_alloc.c | 26 +++++++++++++
> kernel/trace/trace_kprobe.c | 10 ++++-
> 33 files changed, 434 insertions(+), 262 deletions(-)
> create mode 100644 arch/arm/kernel/module_alloc.c
> create mode 100644 arch/arm64/kernel/module_alloc.c
> create mode 100644 arch/mips/kernel/module_alloc.c
> create mode 100644 arch/parisc/kernel/module_alloc.c
> create mode 100644 arch/powerpc/kernel/module_alloc.c
> create mode 100644 arch/riscv/kernel/module_alloc.c
> create mode 100644 arch/s390/kernel/module_alloc.c
> create mode 100644 arch/sparc/kernel/module_alloc.c
> create mode 100644 arch/x86/kernel/module_alloc.c
> create mode 100644 kernel/module_alloc.c
>
> diff --git a/arch/Kconfig b/arch/Kconfig
> index fcf9a41a4ef5..e8e3e7998a2e 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -39,7 +39,6 @@ config GENERIC_ENTRY
>
> config KPROBES
> bool "Kprobes"
> - depends on MODULES
> depends on HAVE_KPROBES
> select KALLSYMS
> select TASKS_RCU if PREEMPTION
> diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
> index 553866751e1a..d2bb954cd54f 100644
> --- a/arch/arm/kernel/Makefile
> +++ b/arch/arm/kernel/Makefile
> @@ -44,6 +44,11 @@ obj-$(CONFIG_CPU_IDLE) += cpuidle.o
> obj-$(CONFIG_ISA_DMA_API) += dma.o
> obj-$(CONFIG_FIQ) += fiq.o fiqasm.o
> obj-$(CONFIG_MODULES) += armksyms.o module.o
> +ifeq ($(CONFIG_MODULES),y)
> +obj-y += module_alloc.o
> +else
> +obj-$(CONFIG_KPROBES) += module_alloc.o
> +endif
> obj-$(CONFIG_ARM_MODULE_PLTS) += module-plts.o
> obj-$(CONFIG_ISA_DMA) += dma-isa.o
> obj-$(CONFIG_PCI) += bios32.o isa.o
> diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
> index d59c36dc0494..054e799e7091 100644
> --- a/arch/arm/kernel/module.c
> +++ b/arch/arm/kernel/module.c
> @@ -22,38 +22,6 @@
> #include <asm/unwind.h>
> #include <asm/opcodes.h>
>
> -#ifdef CONFIG_XIP_KERNEL
> -/*
> - * The XIP kernel text is mapped in the module area for modules and
> - * some other stuff to work without any indirect relocations.
> - * MODULES_VADDR is redefined here and not in asm/memory.h to avoid
> - * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
> - */
> -#undef MODULES_VADDR
> -#define MODULES_VADDR (((unsigned long)_exiprom + ~PMD_MASK) & PMD_MASK)
> -#endif
> -
> -#ifdef CONFIG_MMU
> -void *module_alloc(unsigned long size)
> -{
> - gfp_t gfp_mask = GFP_KERNEL;
> - void *p;
> -
> - /* Silence the initial allocation */
> - if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS))
> - gfp_mask |= __GFP_NOWARN;
> -
> - p = __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
> - gfp_mask, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
> - __builtin_return_address(0));
> - if (!IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || p)
> - return p;
> - return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
> - GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
> - __builtin_return_address(0));
> -}
> -#endif
> -
> bool module_init_section(const char *name)
> {
> return strstarts(name, ".init") ||
> diff --git a/arch/arm/kernel/module_alloc.c b/arch/arm/kernel/module_alloc.c
> new file mode 100644
> index 000000000000..c3cfb2b60575
> --- /dev/null
> +++ b/arch/arm/kernel/module_alloc.c
> @@ -0,0 +1,42 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2002 Russell King.
> + * Modified for nommu by Hyok S. Choi
> + *
> + * Module allocation method suggested by Andi Kleen.
> + */
> +
> +#include <linux/mm.h>
> +#include <linux/vmalloc.h>
> +
> +#ifdef CONFIG_XIP_KERNEL
> +/*
> + * The XIP kernel text is mapped in the module area for modules and
> + * some other stuff to work without any indirect relocations.
> + * MODULES_VADDR is redefined here and not in asm/memory.h to avoid
> + * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
> + */
> +#undef MODULES_VADDR
> +#define MODULES_VADDR (((unsigned long)_exiprom + ~PMD_MASK) & PMD_MASK)
> +#endif
> +
> +#ifdef CONFIG_MMU
> +void *module_alloc(unsigned long size)
> +{
> + gfp_t gfp_mask = GFP_KERNEL;
> + void *p;
> +
> + /* Silence the initial allocation */
> + if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS))
> + gfp_mask |= __GFP_NOWARN;
> +
> + p = __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
> + gfp_mask, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
> + __builtin_return_address(0));
> + if (!IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || p)
> + return p;
> + return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
> + GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
> + __builtin_return_address(0));
> +}
> +#endif
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index fa7981d0d917..d61c02da857e 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -43,6 +43,11 @@ obj-$(CONFIG_COMPAT) += sigreturn32.o
> obj-$(CONFIG_KUSER_HELPERS) += kuser32.o
> obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o
> obj-$(CONFIG_MODULES) += module.o
> +ifeq ($(CONFIG_MODULES),y)
> +obj-y += module_alloc.o
> +else
> +obj-$(CONFIG_KPROBES) += module_alloc.o
> +endif
> obj-$(CONFIG_ARM64_MODULE_PLTS) += module-plts.o
> obj-$(CONFIG_PERF_EVENTS) += perf_regs.o perf_callchain.o
> obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o
> diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
> index f2d4bb14bfab..d2a979746da0 100644
> --- a/arch/arm64/kernel/module.c
> +++ b/arch/arm64/kernel/module.c
> @@ -20,53 +20,6 @@
> #include <asm/insn.h>
> #include <asm/sections.h>
>
> -void *module_alloc(unsigned long size)
> -{
> - u64 module_alloc_end = module_alloc_base + MODULES_VSIZE;
> - gfp_t gfp_mask = GFP_KERNEL;
> - void *p;
> -
> - /* Silence the initial allocation */
> - if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS))
> - gfp_mask |= __GFP_NOWARN;
> -
> - if (IS_ENABLED(CONFIG_KASAN_GENERIC) ||
> - IS_ENABLED(CONFIG_KASAN_SW_TAGS))
> - /* don't exceed the static module region - see below */
> - module_alloc_end = MODULES_END;
> -
> - p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
> - module_alloc_end, gfp_mask, PAGE_KERNEL, VM_DEFER_KMEMLEAK,
> - NUMA_NO_NODE, __builtin_return_address(0));
> -
> - if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&
> - (IS_ENABLED(CONFIG_KASAN_VMALLOC) ||
> - (!IS_ENABLED(CONFIG_KASAN_GENERIC) &&
> - !IS_ENABLED(CONFIG_KASAN_SW_TAGS))))
> - /*
> - * KASAN without KASAN_VMALLOC can only deal with module
> - * allocations being served from the reserved module region,
> - * since the remainder of the vmalloc region is already
> - * backed by zero shadow pages, and punching holes into it
> - * is non-trivial. Since the module region is not randomized
> - * when KASAN is enabled without KASAN_VMALLOC, it is even
> - * less likely that the module region gets exhausted, so we
> - * can simply omit this fallback in that case.
> - */
> - p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
> - module_alloc_base + SZ_2G, GFP_KERNEL,
> - PAGE_KERNEL, 0, NUMA_NO_NODE,
> - __builtin_return_address(0));
> -
> - if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
> - vfree(p);
> - return NULL;
> - }
> -
> - /* Memory is intended to be executable, reset the pointer tag. */
> - return kasan_reset_tag(p);
> -}
> -
> enum aarch64_reloc_op {
> RELOC_OP_NONE,
> RELOC_OP_ABS,
> diff --git a/arch/arm64/kernel/module_alloc.c b/arch/arm64/kernel/module_alloc.c
> new file mode 100644
> index 000000000000..0340c8c0b782
> --- /dev/null
> +++ b/arch/arm64/kernel/module_alloc.c
> @@ -0,0 +1,57 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2012 ARM Limited
> + *
> + * Author: Will Deacon <will.deacon@arm.com>
> + */
> +
> +#include <linux/mm.h>
> +#include <linux/moduleloader.h>
> +#include <linux/vmalloc.h>
> +
> +void *module_alloc(unsigned long size)
> +{
> + u64 module_alloc_end = module_alloc_base + MODULES_VSIZE;
> + gfp_t gfp_mask = GFP_KERNEL;
> + void *p;
> +
> + /* Silence the initial allocation */
> + if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS))
> + gfp_mask |= __GFP_NOWARN;
> +
> + if (IS_ENABLED(CONFIG_KASAN_GENERIC) ||
> + IS_ENABLED(CONFIG_KASAN_SW_TAGS))
> + /* don't exceed the static module region - see below */
> + module_alloc_end = MODULES_END;
> +
> + p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
> + module_alloc_end, gfp_mask, PAGE_KERNEL, VM_DEFER_KMEMLEAK,
> + NUMA_NO_NODE, __builtin_return_address(0));
> +
> + if (!p && IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) &&
> + (IS_ENABLED(CONFIG_KASAN_VMALLOC) ||
> + (!IS_ENABLED(CONFIG_KASAN_GENERIC) &&
> + !IS_ENABLED(CONFIG_KASAN_SW_TAGS))))
> + /*
> + * KASAN without KASAN_VMALLOC can only deal with module
> + * allocations being served from the reserved module region,
> + * since the remainder of the vmalloc region is already
> + * backed by zero shadow pages, and punching holes into it
> + * is non-trivial. Since the module region is not randomized
> + * when KASAN is enabled without KASAN_VMALLOC, it is even
> + * less likely that the module region gets exhausted, so we
> + * can simply omit this fallback in that case.
> + */
> + p = __vmalloc_node_range(size, MODULE_ALIGN, module_alloc_base,
> + module_alloc_base + SZ_2G, GFP_KERNEL,
> + PAGE_KERNEL, 0, NUMA_NO_NODE,
> + __builtin_return_address(0));
> +
> + if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
> + vfree(p);
> + return NULL;
> + }
> +
> + /* Memory is intended to be executable, reset the pointer tag. */
> + return kasan_reset_tag(p);
> +}
> diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
> index 7c96282bff2e..cb9297b613a1 100644
> --- a/arch/mips/kernel/Makefile
> +++ b/arch/mips/kernel/Makefile
> @@ -38,6 +38,11 @@ obj-$(CONFIG_SYNC_R4K) += sync-r4k.o
> obj-$(CONFIG_DEBUG_FS) += segment.o
> obj-$(CONFIG_STACKTRACE) += stacktrace.o
> obj-$(CONFIG_MODULES) += module.o
> +ifeq ($(CONFIG_MODULES),y)
> +obj-y += module_alloc.o
> +else
> +obj-$(CONFIG_KPROBES) += module_alloc.o
> +endif
>
> obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o
> obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o
> diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
> index 14f46d17500a..214b2d1868a5 100644
> --- a/arch/mips/kernel/module.c
> +++ b/arch/mips/kernel/module.c
> @@ -31,15 +31,6 @@ struct mips_hi16 {
> static LIST_HEAD(dbe_list);
> static DEFINE_SPINLOCK(dbe_lock);
>
> -#ifdef MODULE_START
> -void *module_alloc(unsigned long size)
> -{
> - return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
> - GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
> - __builtin_return_address(0));
> -}
> -#endif
> -
> static void apply_r_mips_32(u32 *location, u32 base, Elf_Addr v)
> {
> *location = base + v;
> diff --git a/arch/mips/kernel/module_alloc.c b/arch/mips/kernel/module_alloc.c
> new file mode 100644
> index 000000000000..582ab5ed8916
> --- /dev/null
> +++ b/arch/mips/kernel/module_alloc.c
> @@ -0,0 +1,18 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2001 Rusty Russell.
> + * Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org)
> + * Copyright (C) 2005 Thiemo Seufer
> + */
> +
> +#include <linux/mm.h>
> +#include <linux/vmalloc.h>
> +
> +#ifdef MODULE_START
> +void *module_alloc(unsigned long size)
> +{
> + return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
> + GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
> + __builtin_return_address(0));
> +}
> +#endif
> diff --git a/arch/parisc/kernel/Makefile b/arch/parisc/kernel/Makefile
> index d0bfac89a842..cd38083ae077 100644
> --- a/arch/parisc/kernel/Makefile
> +++ b/arch/parisc/kernel/Makefile
> @@ -25,6 +25,11 @@ obj-$(CONFIG_SMP) += smp.o
> obj-$(CONFIG_PA11) += pci-dma.o
> obj-$(CONFIG_PCI) += pci.o
> obj-$(CONFIG_MODULES) += module.o
> +ifeq ($(CONFIG_MODULES),y)
> +obj-y += module_alloc.o
> +else
> +obj-$(CONFIG_KPROBES) += module_alloc.o
> +endif
> obj-$(CONFIG_64BIT) += sys_parisc32.o signal32.o
> obj-$(CONFIG_STACKTRACE)+= stacktrace.o
> obj-$(CONFIG_AUDIT) += audit.o
> diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
> index 7df140545b22..c81e63e2549b 100644
> --- a/arch/parisc/kernel/module.c
> +++ b/arch/parisc/kernel/module.c
> @@ -192,17 +192,6 @@ static inline int reassemble_22(int as22)
> ((as22 & 0x0003ff) << 3));
> }
>
> -void *module_alloc(unsigned long size)
> -{
> - /* using RWX means less protection for modules, but it's
> - * easier than trying to map the text, data, init_text and
> - * init_data correctly */
> - return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
> - GFP_KERNEL,
> - PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
> - __builtin_return_address(0));
> -}
> -
> #ifndef CONFIG_64BIT
> static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
> {
> diff --git a/arch/parisc/kernel/module_alloc.c b/arch/parisc/kernel/module_alloc.c
> new file mode 100644
> index 000000000000..4e4e4ce1132e
> --- /dev/null
> +++ b/arch/parisc/kernel/module_alloc.c
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Linux/PA-RISC Project
> + * Copyright (C) 2003 Randolph Chung <tausq at debian . org>
> + * Copyright (C) 2008 Helge Deller <deller@gmx.de>
> + */
> +
> +#include <linux/mm.h>
> +#include <linux/moduleloader.h>
> +#include <linux/vmalloc.h>
> +
> +void *module_alloc(unsigned long size)
> +{
> + /*
> + * Using RWX means less protection for modules, but it's
> + * easier than trying to map the text, data, init_text and
> + * init_data correctly.
> + */
> + return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
> + GFP_KERNEL,
> + PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
> + __builtin_return_address(0));
> +}
> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
> index 2e2a2a9bcf43..5a811cdf230b 100644
> --- a/arch/powerpc/kernel/Makefile
> +++ b/arch/powerpc/kernel/Makefile
> @@ -103,6 +103,11 @@ obj-$(CONFIG_HIBERNATION) += swsusp_$(BITS).o
> endif
> obj64-$(CONFIG_HIBERNATION) += swsusp_asm64.o
> obj-$(CONFIG_MODULES) += module.o module_$(BITS).o
> +ifeq ($(CONFIG_MODULES),y)
> +obj-y += module_alloc.o
> +else
> +obj-$(CONFIG_KPROBES) += module_alloc.o
> +endif
> obj-$(CONFIG_44x) += cpu_setup_44x.o
> obj-$(CONFIG_PPC_FSL_BOOK3E) += cpu_setup_fsl_booke.o
> obj-$(CONFIG_PPC_DOORBELL) += dbell.o
> diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
> index f6d6ae0a1692..b30e00964a60 100644
> --- a/arch/powerpc/kernel/module.c
> +++ b/arch/powerpc/kernel/module.c
> @@ -88,40 +88,3 @@ int module_finalize(const Elf_Ehdr *hdr,
>
> return 0;
> }
> -
> -static __always_inline void *
> -__module_alloc(unsigned long size, unsigned long start, unsigned long end, bool nowarn)
> -{
> - pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;
> - gfp_t gfp = GFP_KERNEL | (nowarn ? __GFP_NOWARN : 0);
> -
> - /*
> - * Don't do huge page allocations for modules yet until more testing
> - * is done. STRICT_MODULE_RWX may require extra work to support this
> - * too.
> - */
> - return __vmalloc_node_range(size, 1, start, end, gfp, prot,
> - VM_FLUSH_RESET_PERMS,
> - NUMA_NO_NODE, __builtin_return_address(0));
> -}
> -
> -void *module_alloc(unsigned long size)
> -{
> -#ifdef MODULES_VADDR
> - unsigned long limit = (unsigned long)_etext - SZ_32M;
> - void *ptr = NULL;
> -
> - BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
> -
> - /* First try within 32M limit from _etext to avoid branch trampolines */
> - if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit)
> - ptr = __module_alloc(size, limit, MODULES_END, true);
> -
> - if (!ptr)
> - ptr = __module_alloc(size, MODULES_VADDR, MODULES_END, false);
> -
> - return ptr;
> -#else
> - return __module_alloc(size, VMALLOC_START, VMALLOC_END, false);
> -#endif
> -}
> diff --git a/arch/powerpc/kernel/module_alloc.c b/arch/powerpc/kernel/module_alloc.c
> new file mode 100644
> index 000000000000..48541c27ce46
> --- /dev/null
> +++ b/arch/powerpc/kernel/module_alloc.c
> @@ -0,0 +1,47 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Kernel module help for powerpc.
> + * Copyright (C) 2001, 2003 Rusty Russell IBM Corporation.
> + * Copyright (C) 2008 Freescale Semiconductor, Inc.
> + */
> +
> +#include <linux/mm.h>
> +#include <linux/moduleloader.h>
> +#include <linux/vmalloc.h>
> +
> +static __always_inline void *
> +__module_alloc(unsigned long size, unsigned long start, unsigned long end, bool nowarn)
> +{
> + pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;
> + gfp_t gfp = GFP_KERNEL | (nowarn ? __GFP_NOWARN : 0);
> +
> + /*
> + * Don't do huge page allocations for modules yet until more testing
> + * is done. STRICT_MODULE_RWX may require extra work to support this
> + * too.
> + */
> + return __vmalloc_node_range(size, 1, start, end, gfp, prot,
> + VM_FLUSH_RESET_PERMS,
> + NUMA_NO_NODE, __builtin_return_address(0));
> +}
> +
> +void *module_alloc(unsigned long size)
> +{
> +#ifdef MODULES_VADDR
> + unsigned long limit = (unsigned long)_etext - SZ_32M;
> + void *ptr = NULL;
> +
> + BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
> +
> + /* First try within 32M limit from _etext to avoid branch trampolines */
> + if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit)
> + ptr = __module_alloc(size, limit, MODULES_END, true);
> +
> + if (!ptr)
> + ptr = __module_alloc(size, MODULES_VADDR, MODULES_END, false);
> +
> + return ptr;
> +#else
> + return __module_alloc(size, VMALLOC_START, VMALLOC_END, false);
> +#endif
> +}
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index c71d6591d539..7af346ae575e 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -61,6 +61,11 @@ obj-$(CONFIG_SMP) += cpu_ops.o
>
> obj-$(CONFIG_RISCV_BOOT_SPINWAIT) += cpu_ops_spinwait.o
> obj-$(CONFIG_MODULES) += module.o
> +ifeq ($(CONFIG_MODULES),y)
> +obj-y += module_alloc.o
> +else
> +obj-$(CONFIG_KPROBES) += module_alloc.o
> +endif
> obj-$(CONFIG_MODULE_SECTIONS) += module-sections.o
>
> obj-$(CONFIG_CPU_PM) += suspend_entry.o suspend.o
> diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
> index 91fe16bfaa07..1621d5e458f7 100644
> --- a/arch/riscv/kernel/module.c
> +++ b/arch/riscv/kernel/module.c
> @@ -419,16 +419,6 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
> return 0;
> }
>
> -#if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
> -void *module_alloc(unsigned long size)
> -{
> - return __vmalloc_node_range(size, 1, MODULES_VADDR,
> - MODULES_END, GFP_KERNEL,
> - PAGE_KERNEL, 0, NUMA_NO_NODE,
> - __builtin_return_address(0));
> -}
> -#endif
> -
> static const Elf_Shdr *find_section(const Elf_Ehdr *hdr,
> const Elf_Shdr *sechdrs,
> const char *name)
> diff --git a/arch/riscv/kernel/module_alloc.c b/arch/riscv/kernel/module_alloc.c
> new file mode 100644
> index 000000000000..ed87ed048713
> --- /dev/null
> +++ b/arch/riscv/kernel/module_alloc.c
> @@ -0,0 +1,19 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2017 Zihao Yu
> + */
> +
> +#include <linux/mm.h>
> +#include <linux/moduleloader.h>
> +#include <linux/vmalloc.h>
> +#include <asm/sections.h>
> +
> +#if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
> +void *module_alloc(unsigned long size)
> +{
> + return __vmalloc_node_range(size, 1, MODULES_VADDR,
> + MODULES_END, GFP_KERNEL,
> + PAGE_KERNEL, 0, NUMA_NO_NODE,
> + __builtin_return_address(0));
> +}
> +#endif
> diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
> index 27d6b3c7aa06..71e73e34b441 100644
> --- a/arch/s390/kernel/Makefile
> +++ b/arch/s390/kernel/Makefile
> @@ -48,6 +48,11 @@ obj-$(CONFIG_SYSFS) += nospec-sysfs.o
> CFLAGS_REMOVE_nospec-branch.o += $(CC_FLAGS_EXPOLINE)
>
> obj-$(CONFIG_MODULES) += module.o
> +ifeq ($(CONFIG_MODULES),y)
> +obj-y += module_alloc.o
> +else
> +obj-$(CONFIG_KPROBES) += module_alloc.o
> +endif
> obj-$(CONFIG_SCHED_TOPOLOGY) += topology.o
> obj-$(CONFIG_NUMA) += numa.o
> obj-$(CONFIG_AUDIT) += audit.o
> diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
> index 26125a9c436d..e15f09fa50e2 100644
> --- a/arch/s390/kernel/module.c
> +++ b/arch/s390/kernel/module.c
> @@ -35,23 +35,6 @@
>
> #define PLT_ENTRY_SIZE 22
>
> -void *module_alloc(unsigned long size)
> -{
> - gfp_t gfp_mask = GFP_KERNEL;
> - void *p;
> -
> - if (PAGE_ALIGN(size) > MODULES_LEN)
> - return NULL;
> - p = __vmalloc_node_range(size, MODULE_ALIGN, MODULES_VADDR, MODULES_END,
> - gfp_mask, PAGE_KERNEL_EXEC, VM_DEFER_KMEMLEAK, NUMA_NO_NODE,
> - __builtin_return_address(0));
> - if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
> - vfree(p);
> - return NULL;
> - }
> - return p;
> -}
> -
> #ifdef CONFIG_FUNCTION_TRACER
> void module_arch_cleanup(struct module *mod)
> {
> diff --git a/arch/s390/kernel/module_alloc.c b/arch/s390/kernel/module_alloc.c
> new file mode 100644
> index 000000000000..e4c4175fb759
> --- /dev/null
> +++ b/arch/s390/kernel/module_alloc.c
> @@ -0,0 +1,33 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Kernel module help for s390.
> + *
> + * S390 version
> + * Copyright IBM Corp. 2002, 2003
> + * Author(s): Arnd Bergmann (arndb@de.ibm.com)
> + * Martin Schwidefsky (schwidefsky@de.ibm.com)
> + *
> + * based on i386 version
> + * Copyright (C) 2001 Rusty Russell.
> + */
> +
> +#include <linux/mm.h>
> +#include <linux/moduleloader.h>
> +#include <linux/vmalloc.h>
> +
> +void *module_alloc(unsigned long size)
> +{
> + gfp_t gfp_mask = GFP_KERNEL;
> + void *p;
> +
> + if (PAGE_ALIGN(size) > MODULES_LEN)
> + return NULL;
> + p = __vmalloc_node_range(size, MODULE_ALIGN, MODULES_VADDR, MODULES_END,
> + gfp_mask, PAGE_KERNEL_EXEC, VM_DEFER_KMEMLEAK, NUMA_NO_NODE,
> + __builtin_return_address(0));
> + if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
> + vfree(p);
> + return NULL;
> + }
> + return p;
> +}
> diff --git a/arch/sparc/kernel/Makefile b/arch/sparc/kernel/Makefile
> index d3a0e072ebe8..53905c00a094 100644
> --- a/arch/sparc/kernel/Makefile
> +++ b/arch/sparc/kernel/Makefile
> @@ -89,6 +89,11 @@ obj-$(CONFIG_SUN_PM) += apc.o pmc.o
>
> obj-$(CONFIG_MODULES) += module.o
> obj-$(CONFIG_MODULES) += sparc_ksyms.o
> +ifeq ($(CONFIG_MODULES),y)
> +obj-y += module_alloc.o
> +else
> +obj-$(CONFIG_KPROBES) += module_alloc.o
> +endif
> obj-$(CONFIG_SPARC_LED) += led.o
> obj-$(CONFIG_KGDB) += kgdb_$(BITS).o
>
> diff --git a/arch/sparc/kernel/module.c b/arch/sparc/kernel/module.c
> index df39580f398d..f2babc69f189 100644
> --- a/arch/sparc/kernel/module.c
> +++ b/arch/sparc/kernel/module.c
> @@ -21,36 +21,6 @@
>
> #include "entry.h"
>
> -#ifdef CONFIG_SPARC64
> -
> -#include <linux/jump_label.h>
> -
> -static void *module_map(unsigned long size)
> -{
> - if (PAGE_ALIGN(size) > MODULES_LEN)
> - return NULL;
> - return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
> - GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
> - __builtin_return_address(0));
> -}
> -#else
> -static void *module_map(unsigned long size)
> -{
> - return vmalloc(size);
> -}
> -#endif /* CONFIG_SPARC64 */
> -
> -void *module_alloc(unsigned long size)
> -{
> - void *ret;
> -
> - ret = module_map(size);
> - if (ret)
> - memset(ret, 0, size);
> -
> - return ret;
> -}
> -
> /* Make generic code ignore STT_REGISTER dummy undefined symbols. */
> int module_frob_arch_sections(Elf_Ehdr *hdr,
> Elf_Shdr *sechdrs,
> diff --git a/arch/sparc/kernel/module_alloc.c b/arch/sparc/kernel/module_alloc.c
> new file mode 100644
> index 000000000000..4bacf8cff012
> --- /dev/null
> +++ b/arch/sparc/kernel/module_alloc.c
> @@ -0,0 +1,39 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Kernel module help for sparc64.
> + *
> + * Copyright (C) 2001 Rusty Russell.
> + * Copyright (C) 2002 David S. Miller.
> + */
> +
> +#include <linux/mm.h>
> +#include <linux/moduleloader.h>
> +#include <linux/vmalloc.h>
> +
> +#ifdef CONFIG_SPARC64
> +#include <linux/jump_label.h>
> +
> +static void *module_map(unsigned long size)
> +{
> + if (PAGE_ALIGN(size) > MODULES_LEN)
> + return NULL;
> + return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
> + GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
> + __builtin_return_address(0));
> +}
> +#else
> +static void *module_map(unsigned long size)
> +{
> + return vmalloc(size);
> +}
> +#endif /* CONFIG_SPARC64 */
> +
> +void *module_alloc(unsigned long size)
> +{
> + void *ret;
> +
> + ret = module_map(size);
> + if (ret)
> + memset(ret, 0, size);
> +
> + return ret;
> +}
> diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
> index 03364dc40d8d..1f0304140f44 100644
> --- a/arch/x86/kernel/Makefile
> +++ b/arch/x86/kernel/Makefile
> @@ -108,6 +108,11 @@ obj-$(CONFIG_KEXEC_FILE) += kexec-bzimage64.o
> obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o
> obj-y += kprobes/
> obj-$(CONFIG_MODULES) += module.o
> +ifeq ($(CONFIG_MODULES),y)
> +obj-y += module_alloc.o
> +else
> +obj-$(CONFIG_KPROBES) += module_alloc.o
> +endif
> obj-$(CONFIG_X86_32) += doublefault_32.o
> obj-$(CONFIG_KGDB) += kgdb.o
> obj-$(CONFIG_VM86) += vm86_32.o
> diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
> index b98ffcf4d250..40bb10b5a68d 100644
> --- a/arch/x86/kernel/module.c
> +++ b/arch/x86/kernel/module.c
> @@ -36,56 +36,6 @@ do { \
> } while (0)
> #endif
>
> -#ifdef CONFIG_RANDOMIZE_BASE
> -static unsigned long module_load_offset;
> -
> -/* Mutex protects the module_load_offset. */
> -static DEFINE_MUTEX(module_kaslr_mutex);
> -
> -static unsigned long int get_module_load_offset(void)
> -{
> - if (kaslr_enabled()) {
> - mutex_lock(&module_kaslr_mutex);
> - /*
> - * Calculate the module_load_offset the first time this
> - * code is called. Once calculated it stays the same until
> - * reboot.
> - */
> - if (module_load_offset == 0)
> - module_load_offset =
> - (get_random_int() % 1024 + 1) * PAGE_SIZE;
> - mutex_unlock(&module_kaslr_mutex);
> - }
> - return module_load_offset;
> -}
> -#else
> -static unsigned long int get_module_load_offset(void)
> -{
> - return 0;
> -}
> -#endif
> -
> -void *module_alloc(unsigned long size)
> -{
> - gfp_t gfp_mask = GFP_KERNEL;
> - void *p;
> -
> - if (PAGE_ALIGN(size) > MODULES_LEN)
> - return NULL;
> -
> - p = __vmalloc_node_range(size, MODULE_ALIGN,
> - MODULES_VADDR + get_module_load_offset(),
> - MODULES_END, gfp_mask,
> - PAGE_KERNEL, VM_DEFER_KMEMLEAK, NUMA_NO_NODE,
> - __builtin_return_address(0));
> - if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
> - vfree(p);
> - return NULL;
> - }
> -
> - return p;
> -}
> -
> #ifdef CONFIG_X86_32
> int apply_relocate(Elf32_Shdr *sechdrs,
> const char *strtab,
> diff --git a/arch/x86/kernel/module_alloc.c b/arch/x86/kernel/module_alloc.c
> new file mode 100644
> index 000000000000..a7df2af1467a
> --- /dev/null
> +++ b/arch/x86/kernel/module_alloc.c
> @@ -0,0 +1,61 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Kernel module help for x86.
> + * Copyright (C) 2001 Rusty Russell.
> + */
> +
> +#include <linux/mm.h>
> +#include <linux/moduleloader.h>
> +#include <linux/random.h>
> +#include <linux/vmalloc.h>
> +#include <asm/setup.h>
> +
> +#ifdef CONFIG_RANDOMIZE_BASE
> +static unsigned long module_load_offset;
> +
> +/* Mutex protects the module_load_offset. */
> +static DEFINE_MUTEX(module_kaslr_mutex);
> +
> +static unsigned long get_module_load_offset(void)
> +{
> + if (kaslr_enabled()) {
> + mutex_lock(&module_kaslr_mutex);
> + /*
> + * Calculate the module_load_offset the first time this
> + * code is called. Once calculated it stays the same until
> + * reboot.
> + */
> + if (module_load_offset == 0)
> + module_load_offset =
> + (get_random_int() % 1024 + 1) * PAGE_SIZE;
> + mutex_unlock(&module_kaslr_mutex);
> + }
> + return module_load_offset;
> +}
> +#else
> +static unsigned long get_module_load_offset(void)
> +{
> + return 0;
> +}
> +#endif
> +
> +void *module_alloc(unsigned long size)
> +{
> + gfp_t gfp_mask = GFP_KERNEL;
> + void *p;
> +
> + if (PAGE_ALIGN(size) > MODULES_LEN)
> + return NULL;
> +
> + p = __vmalloc_node_range(size, MODULE_ALIGN,
> + MODULES_VADDR + get_module_load_offset(),
> + MODULES_END, gfp_mask,
> + PAGE_KERNEL, VM_DEFER_KMEMLEAK, NUMA_NO_NODE,
> + __builtin_return_address(0));
> + if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
> + vfree(p);
> + return NULL;
> + }
> +
> + return p;
> +}
> diff --git a/kernel/Makefile b/kernel/Makefile
> index 318789c728d3..2981fe42060d 100644
> --- a/kernel/Makefile
> +++ b/kernel/Makefile
> @@ -53,6 +53,11 @@ obj-y += livepatch/
> obj-y += dma/
> obj-y += entry/
> obj-$(CONFIG_MODULES) += module/
> +ifeq ($(CONFIG_MODULES),y)
> +obj-y += module_alloc.o
> +else
> +obj-$(CONFIG_KPROBES) += module_alloc.o
> +endif
>
> obj-$(CONFIG_KCMP) += kcmp.o
> obj-$(CONFIG_FREEZER) += freezer.o
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index f214f8c088ed..3f9876374cd3 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -1569,6 +1569,7 @@ static int check_kprobe_address_safe(struct kprobe *p,
> goto out;
> }
>
> +#ifdef CONFIG_MODULES
> /* Check if 'p' is probing a module. */
> *probed_mod = __module_text_address((unsigned long) p->addr);
> if (*probed_mod) {
> @@ -1592,6 +1593,8 @@ static int check_kprobe_address_safe(struct kprobe *p,
> ret = -ENOENT;
> }
> }
> +#endif
> +
> out:
> preempt_enable();
> jump_label_unlock();
> @@ -2475,6 +2478,7 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end)
> return 0;
> }
>
> +#ifdef CONFIG_MODULES
> /* Remove all symbols in given area from kprobe blacklist */
> static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end)
> {
> @@ -2492,6 +2496,7 @@ static void kprobe_remove_ksym_blacklist(unsigned long entry)
> {
> kprobe_remove_area_blacklist(entry, entry + 1);
> }
> +#endif /* CONFIG_MODULES */
>
> int __weak arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value,
> char *type, char *sym)
> @@ -2557,6 +2562,7 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
> return ret ? : arch_populate_kprobe_blacklist();
> }
>
> +#ifdef CONFIG_MODULES
> static void add_module_kprobe_blacklist(struct module *mod)
> {
> unsigned long start, end;
> @@ -2658,6 +2664,7 @@ static struct notifier_block kprobe_module_nb = {
> .notifier_call = kprobes_module_callback,
> .priority = 0
> };
> +#endif /* CONFIG_MODULES */
>
> void kprobe_free_init_mem(void)
> {
> @@ -2717,8 +2724,11 @@ static int __init init_kprobes(void)
> err = arch_init_kprobes();
> if (!err)
> err = register_die_notifier(&kprobe_exceptions_nb);
> +
> +#ifdef CONFIG_MODULES
> if (!err)
> err = register_module_notifier(&kprobe_module_nb);
> +#endif
>
> kprobes_initialized = (err == 0);
> kprobe_sysctls_init();
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index fed58d30725d..7fa182b78550 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -1121,16 +1121,6 @@ resolve_symbol_wait(struct module *mod,
> return ksym;
> }
>
> -void __weak module_memfree(void *module_region)
> -{
> - /*
> - * This memory may be RO, and freeing RO memory in an interrupt is not
> - * supported by vmalloc.
> - */
> - WARN_ON(in_interrupt());
> - vfree(module_region);
> -}
> -
> void __weak module_arch_cleanup(struct module *mod)
> {
> }
> @@ -1606,13 +1596,6 @@ static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
> ddebug_remove_module(mod->name);
> }
>
> -void * __weak module_alloc(unsigned long size)
> -{
> - return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
> - GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
> - NUMA_NO_NODE, __builtin_return_address(0));
> -}
> -
> bool __weak module_init_section(const char *name)
> {
> return strstarts(name, ".init");
> diff --git a/kernel/module_alloc.c b/kernel/module_alloc.c
> new file mode 100644
> index 000000000000..26a4c60998ad
> --- /dev/null
> +++ b/kernel/module_alloc.c
> @@ -0,0 +1,26 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2002 Richard Henderson
> + * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
> + */
> +
> +#include <linux/mm.h>
> +#include <linux/moduleloader.h>
> +#include <linux/vmalloc.h>
> +
> +void * __weak module_alloc(unsigned long size)
> +{
> + return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
> + GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
> + NUMA_NO_NODE, __builtin_return_address(0));
> +}
> +
> +void __weak module_memfree(void *module_region)
> +{
> + /*
> + * This memory may be RO, and freeing RO memory in an interrupt is not
> + * supported by vmalloc.
> + */
> + WARN_ON(in_interrupt());
> + vfree(module_region);
> +}
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 93507330462c..050b2975332e 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -101,6 +101,7 @@ static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
> return kprobe_gone(&tk->rp.kp);
> }
>
> +#ifdef CONFIG_MODULES
> static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
> struct module *mod)
> {
> @@ -109,11 +110,13 @@ static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
>
> return strncmp(module_name(mod), name, len) == 0 && name[len] == ':';
> }
> +#endif /* CONFIG_MODULES */
>
> static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
> {
> + bool ret = false;
> +#ifdef CONFIG_MODULES
> char *p;
> - bool ret;
>
> if (!tk->symbol)
> return false;
> @@ -125,6 +128,7 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
> ret = !!find_module(tk->symbol);
> rcu_read_unlock_sched();
> *p = ':';
> +#endif /* CONFIG_MODULES */
>
> return ret;
> }
> @@ -668,6 +672,7 @@ static int register_trace_kprobe(struct trace_kprobe *tk)
> return ret;
> }
>
> +#ifdef CONFIG_MODULES
> /* Module notifier call back, checking event on the module */
> static int trace_kprobe_module_callback(struct notifier_block *nb,
> unsigned long val, void *data)
> @@ -702,6 +707,7 @@ static struct notifier_block trace_kprobe_module_nb = {
> .notifier_call = trace_kprobe_module_callback,
> .priority = 1 /* Invoked after kprobe module callback */
> };
> +#endif /* CONFIG_MODULES */
>
> static int __trace_kprobe_create(int argc, const char *argv[])
> {
> @@ -1896,8 +1902,10 @@ static __init int init_kprobe_trace_early(void)
> if (ret)
> return ret;
>
> +#ifdef CONFIG_MODULES
> if (register_module_notifier(&trace_kprobe_module_nb))
> return -EINVAL;
> +#endif /* CONFIG_MODULES */
>
> return 0;
> }
> --
> 2.36.1
>

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