On Fri, Sep 22, 2023 at 12:37:07PM +0200, Alexandre Ghiti wrote:
> Hi Mike,
>
> On 18/09/2023 09:29, Mike Rapoport wrote:
> > From: "Mike Rapoport (IBM)" <rppt@xxxxxxxxxx>
> >
> > The memory allocations for kprobes and BPF on RISC-V are not placed in
> > the modules area and these custom allocations are implemented with
> > overrides of alloc_insn_page() and bpf_jit_alloc_exec().
> >
> > Slightly reorder execmem_params initialization to support both 32 and 64
> > bit variants, define EXECMEM_KPROBES and EXECMEM_BPF ranges in
> > riscv::execmem_params and drop overrides of alloc_insn_page() and
> > bpf_jit_alloc_exec().
> >
> > Signed-off-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
> > ---
> > arch/riscv/kernel/module.c | 21 ++++++++++++++++++++-
> > arch/riscv/kernel/probes/kprobes.c | 10 ----------
> > arch/riscv/net/bpf_jit_core.c | 13 -------------
> > 3 files changed, 20 insertions(+), 24 deletions(-)
> >
> > diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
> > index 343a0edfb6dd..31505ecb5c72 100644
> > --- a/arch/riscv/kernel/module.c
> > +++ b/arch/riscv/kernel/module.c
> > @@ -436,20 +436,39 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
> > return 0;
> > }
> > -#if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
> > +#ifdef CONFIG_MMU
> > static struct execmem_params execmem_params __ro_after_init = {
> > .ranges = {
> > [EXECMEM_DEFAULT] = {
> > .pgprot = PAGE_KERNEL,
> > .alignment = 1,
> > },
> > + [EXECMEM_KPROBES] = {
> > + .pgprot = PAGE_KERNEL_READ_EXEC,
> > + .alignment = 1,
> > + },
> > + [EXECMEM_BPF] = {
> > + .pgprot = PAGE_KERNEL,
> > + .alignment = 1,
>
>
> Not entirely sure it is the same alignment (sorry did not go through the
> entire series), but if it is, the alignment above ^ is not the same that is
> requested by our current bpf_jit_alloc_exec() implementation which is
> PAGE_SIZE.
This literally translates vmalloc() in alloc_insn_page() to a set of
parameters, so "1" comes from there. And using alignment of 1 with
vmalloc() implicitly sets it to PAGE_SIZE.
> > + },
> > },
> > };
> > struct execmem_params __init *execmem_arch_params(void)
> > {
> > +#ifdef CONFIG_64BIT
> > execmem_params.ranges[EXECMEM_DEFAULT].start = MODULES_VADDR;
> > execmem_params.ranges[EXECMEM_DEFAULT].end = MODULES_END;
> > +#else
> > + execmem_params.ranges[EXECMEM_DEFAULT].start = VMALLOC_START;
> > + execmem_params.ranges[EXECMEM_DEFAULT].end = VMALLOC_END;
> > +#endif
> > +
> > + execmem_params.ranges[EXECMEM_KPROBES].start = VMALLOC_START;
> > + execmem_params.ranges[EXECMEM_KPROBES].end = VMALLOC_END;
> > +
> > + execmem_params.ranges[EXECMEM_BPF].start = BPF_JIT_REGION_START;
> > + execmem_params.ranges[EXECMEM_BPF].end = BPF_JIT_REGION_END;
> > return &execmem_params;
> > }
> > diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
> > index 2f08c14a933d..e64f2f3064eb 100644
> > --- a/arch/riscv/kernel/probes/kprobes.c
> > +++ b/arch/riscv/kernel/probes/kprobes.c
> > @@ -104,16 +104,6 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
> > return 0;
> > }
> > -#ifdef CONFIG_MMU
> > -void *alloc_insn_page(void)
> > -{
> > - return __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, VMALLOC_END,
> > - GFP_KERNEL, PAGE_KERNEL_READ_EXEC,
> > - VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
> > - __builtin_return_address(0));
> > -}
> > -#endif
> > -
> > /* install breakpoint in text */
> > void __kprobes arch_arm_kprobe(struct kprobe *p)
> > {
> > diff --git a/arch/riscv/net/bpf_jit_core.c b/arch/riscv/net/bpf_jit_core.c
> > index 7b70ccb7fec3..c8a758f0882b 100644
> > --- a/arch/riscv/net/bpf_jit_core.c
> > +++ b/arch/riscv/net/bpf_jit_core.c
> > @@ -218,19 +218,6 @@ u64 bpf_jit_alloc_exec_limit(void)
> > return BPF_JIT_REGION_SIZE;
> > }
> > -void *bpf_jit_alloc_exec(unsigned long size)
> > -{
> > - return __vmalloc_node_range(size, PAGE_SIZE, BPF_JIT_REGION_START,
> > - BPF_JIT_REGION_END, GFP_KERNEL,
> > - PAGE_KERNEL, 0, NUMA_NO_NODE,
> > - __builtin_return_address(0));
> > -}
> > -
> > -void bpf_jit_free_exec(void *addr)
> > -{
> > - return vfree(addr);
> > -}
> > -
> > void *bpf_arch_text_copy(void *dst, void *src, size_t len)
> > {
> > int ret;
>
>
> Otherwise, you can add:
>
> Reviewed-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
>
> Thanks,
>
> Alex
>
>
--
Sincerely yours,
Mike.
