2023-09-18 07:38:38

by Mike Rapoport

Subject: [PATCH v3 08/13] riscv: extend execmem_params for generated code allocations

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

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) <[email protected]>
---
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,
+ },
},
};

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;
--
2.39.2

2023-09-22 10:45:37

by Alexandre Ghiti

Subject: Re: [PATCH v3 08/13] riscv: extend execmem_params for generated code allocations

Hi Mike,

On 18/09/2023 09:29, Mike Rapoport wrote:
> From: "Mike Rapoport (IBM)" <[email protected]>
>
> 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) <[email protected]>
> ---
> 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.


> + },
> },
> };
>
> 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 <[email protected]>

Thanks,

Alex

2023-09-23 16:25:04

by Mike Rapoport

Subject: Re: [PATCH v3 08/13] riscv: extend execmem_params for generated code allocations

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)" <[email protected]>
> >
> > 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) <[email protected]>
> > ---
> > 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 <[email protected]>
>
> Thanks,
>
> Alex
>
>

--
Sincerely yours,
Mike.