Subject: [PATCH v4 08/15] arm64: extend execmem_info for generated code allocations

From: Mike Rapoport <[email-masked]>
Date: Thu, 11 Apr 2024 19:00:44 +0300

From: "Mike Rapoport (IBM)" <[email-masked]>

The memory allocations for kprobes and BPF on arm64 can be placed
anywhere in vmalloc address space and currently this is implemented with
overrides of alloc_insn_page() and bpf_jit_alloc_exec() in arm64.

Define EXECMEM_KPROBES and EXECMEM_BPF ranges in arm64::execmem_info and
drop overrides of alloc_insn_page() and bpf_jit_alloc_exec().

Signed-off-by: Mike Rapoport (IBM) <[email-masked]>
Acked-by: Will Deacon <[email-masked]>
---
 arch/arm64/kernel/module.c         | 14 ++++++++++++++
 arch/arm64/kernel/probes/kprobes.c |  7 -------
 arch/arm64/net/bpf_jit_comp.c      | 11 -----------
 3 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index a377a3217cf2..aa9e2b3d7459 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -115,6 +115,12 @@ static struct execmem_info execmem_info __ro_after_init = {
 		[EXECMEM_DEFAULT] = {
 			.alignment = MODULE_ALIGN,
 		},
+		[EXECMEM_KPROBES] = {
+			.alignment = 1,
+		},
+		[EXECMEM_BPF] = {
+			.alignment = 1,
+		},
 	},
 };
 
@@ -143,6 +149,14 @@ struct execmem_info __init *execmem_arch_setup(void)
 		r->end = module_plt_base + SZ_2G;
 	}
 
+	execmem_info.ranges[EXECMEM_KPROBES].pgprot = PAGE_KERNEL_ROX;
+	execmem_info.ranges[EXECMEM_KPROBES].start = VMALLOC_START;
+	execmem_info.ranges[EXECMEM_KPROBES].end = VMALLOC_END;
+
+	execmem_info.ranges[EXECMEM_BPF].pgprot = PAGE_KERNEL;
+	execmem_info.ranges[EXECMEM_BPF].start = VMALLOC_START;
+	execmem_info.ranges[EXECMEM_BPF].end = VMALLOC_END;
+
 	return &execmem_info;
 }
 
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index 327855a11df2..4268678d0e86 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -129,13 +129,6 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
 	return 0;
 }
 
-void *alloc_insn_page(void)
-{
-	return __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, VMALLOC_END,
-			GFP_KERNEL, PAGE_KERNEL_ROX, VM_FLUSH_RESET_PERMS,
-			NUMA_NO_NODE, __builtin_return_address(0));
-}
-
 /* arm kprobe: install breakpoint in text */
 void __kprobes arch_arm_kprobe(struct kprobe *p)
 {
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 122021f9bdfc..456f5af239fc 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -1793,17 +1793,6 @@ u64 bpf_jit_alloc_exec_limit(void)
 	return VMALLOC_END - VMALLOC_START;
 }
 
-void *bpf_jit_alloc_exec(unsigned long size)
-{
-	/* Memory is intended to be executable, reset the pointer tag. */
-	return kasan_reset_tag(vmalloc(size));
-}
-
-void bpf_jit_free_exec(void *addr)
-{
-	return vfree(addr);
-}
-
 /* Indicate the JIT backend supports mixing bpf2bpf and tailcalls. */
 bool bpf_jit_supports_subprog_tailcalls(void)
 {
-- 
2.43.0