+ powerpc-extend-execmem_params-for-kprobes-allocations.patch added to mm-unstable branch

+ powerpc-extend-execmem_params-for-kprobes-allocations.patch added to mm-unstable branch

[Andrew Morton]

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The patch titled
     Subject: powerpc: extend execmem_params for kprobes allocations
has been added to the -mm mm-unstable branch.  Its filename is
     powerpc-extend-execmem_params-for-kprobes-allocations.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/powerpc-extend-execmem_params-for-kprobes-allocations.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: "Mike Rapoport (IBM)" <rppt@kernel.org>
Subject: powerpc: extend execmem_params for kprobes allocations
Date: Mon, 18 Sep 2023 10:29:51 +0300

powerpc overrides kprobes::alloc_insn_page() to remove writable
permissions when STRICT_MODULE_RWX is on.

Add definition of EXECMEM_KRPOBES to execmem_params to allow using the
generic kprobes::alloc_insn_page() with the desired permissions.

As powerpc uses breakpoint instructions to inject kprobes, it does not
need to constrain kprobe allocations to the modules area and can use the
entire vmalloc address space.

Link: https://lkml.kernel.org/r/20230918072955.2507221-10-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Björn Töpel <bjorn@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Puranjay Mohan <puranjay12@gmail.com>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Russell King (Oracle) <linux@armlinux.org.uk>
Cc: Song Liu <song@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/powerpc/kernel/kprobes.c |   14 --------------
 arch/powerpc/kernel/module.c  |   11 +++++++++++
 2 files changed, 11 insertions(+), 14 deletions(-)

--- a/arch/powerpc/kernel/kprobes.c~powerpc-extend-execmem_params-for-kprobes-allocations
+++ a/arch/powerpc/kernel/kprobes.c
@@ -126,20 +126,6 @@ kprobe_opcode_t *arch_adjust_kprobe_addr
 	return (kprobe_opcode_t *)(addr + offset);
 }
 
-void *alloc_insn_page(void)
-{
-	void *page;
-
-	page = execmem_text_alloc(EXECMEM_KPROBES, PAGE_SIZE);
-	if (!page)
-		return NULL;
-
-	if (strict_module_rwx_enabled())
-		set_memory_rox((unsigned long)page, 1);
-
-	return page;
-}
-
 int arch_prepare_kprobe(struct kprobe *p)
 {
 	int ret = 0;
--- a/arch/powerpc/kernel/module.c~powerpc-extend-execmem_params-for-kprobes-allocations
+++ a/arch/powerpc/kernel/module.c
@@ -95,6 +95,9 @@ static struct execmem_params execmem_par
 		[EXECMEM_DEFAULT] = {
 			.alignment = 1,
 		},
+		[EXECMEM_KPROBES] = {
+			.alignment = 1,
+		},
 		[EXECMEM_MODULE_DATA] = {
 			.alignment = 1,
 		},
@@ -135,5 +138,13 @@ struct execmem_params __init *execmem_ar
 
 	range->pgprot = prot;
 
+	execmem_params.ranges[EXECMEM_KPROBES].start = VMALLOC_START;
+	execmem_params.ranges[EXECMEM_KPROBES].start = VMALLOC_END;
+
+	if (strict_module_rwx_enabled())
+		execmem_params.ranges[EXECMEM_KPROBES].pgprot = PAGE_KERNEL_ROX;
+	else
+		execmem_params.ranges[EXECMEM_KPROBES].pgprot = PAGE_KERNEL_EXEC;
+
 	return &execmem_params;
 }
_

Patches currently in -mm which might be from rppt@kernel.org are

nios2-define-virtual-address-space-for-modules.patch
mm-introduce-execmem_text_alloc-and-execmem_free.patch
mm-execmem-arch-convert-simple-overrides-of-module_alloc-to-execmem.patch
mm-execmem-arch-convert-remaining-overrides-of-module_alloc-to-execmem.patch
modules-execmem-drop-module_alloc.patch
mm-execmem-introduce-execmem_data_alloc.patch
arm64-execmem-extend-execmem_params-for-generated-code-allocations.patch
riscv-extend-execmem_params-for-generated-code-allocations.patch
powerpc-extend-execmem_params-for-kprobes-allocations.patch
arch-make-execmem-setup-available-regardless-of-config_modules.patch
x86-ftrace-enable-dynamic-ftrace-without-config_modules.patch
kprobes-remove-dependency-on-config_modules.patch
bpf-remove-config_bpf_jit-dependency-on-config_modules-of.patch