[PATCH RESEND v8 10/16] arm64: extend execmem_info for generated code allocations

Mike Rapoport
2024-05-05T16:08:46Z

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) <rppt@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
---
arch/arm64/kernel/module.c | 12 ++++++++++++
arch/arm64/kernel/probes/kprobes.c | 7 -------
arch/arm64/net/bpf_jit_comp.c | 11 -----------
3 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index b7a7a23f9f8f..a52240ea084b 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -146,6 +146,18 @@ struct execmem_info __init *execmem_arch_setup(void)
.fallback_start = fallback_start,
.fallback_end = fallback_end,
},
+ [EXECMEM_KPROBES] = {
+ .start = VMALLOC_START,
+ .end = VMALLOC_END,
+ .pgprot = PAGE_KERNEL_ROX,
+ .alignment = 1,
+ },
+ [EXECMEM_BPF] = {
+ .start = VMALLOC_START,
+ .end = VMALLOC_END,
+ .pgprot = PAGE_KERNEL,
+ .alignment = 1,
+ },
},
};

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