Re: [PATCH bpf-next v3 3/5] error-injection: Separate error-injection from kprobe
On Wed, 10 Jan 2018 10:36:15 -0500
Josef Bacik wrote:
> On Wed, Jan 10, 2018 at 07:18:05PM +0900, Masami Hiramatsu wrote:
> > Since error-injection framework is not limited to be used
> > by kprobes, nor bpf. Other kernel subsystems can use it
> > freely for checking safeness of error-injection, e.g.
> > livepatch, ftrace etc.
> > So this separate error-injection framework from kprobes.
> >
> > Some differences has been made:
> >
> > - "kprobe" word is removed from any APIs/structures.
> > - BPF_ALLOW_ERROR_INJECTION() is renamed to
> > ALLOW_ERROR_INJECTION() since it is not limited for BPF too.
> > - CONFIG_FUNCTION_ERROR_INJECTION is the config item of this
> > feature. It is automatically enabled if the arch supports
> > error injection feature for kprobe or ftrace etc.
> >
> > Signed-off-by: Masami Hiramatsu
> > ---
> > Changes in v3:
> >- Fix a build error for asmlinkage on i386 by including compiler.h
> >- Fix "CONFIG_FUNCTION_ERROR_INJECT" typo.
> >- Separate CONFIG_MODULES dependent code
> >- Add CONFIG_KPROBES dependency for arch_deref_entry_point()
> >- Call error-injection init function in late_initcall stage.
> >- Fix read-side mutex lock
> >- Some cosmetic cleanups
> > ---
> > arch/Kconfig |2
> > arch/x86/Kconfig |2
> > arch/x86/include/asm/error-injection.h | 13 ++
> > arch/x86/kernel/kprobes/core.c | 14 --
> > arch/x86/lib/Makefile |1
> > arch/x86/lib/error-inject.c| 19 +++
> > fs/btrfs/disk-io.c |2
> > fs/btrfs/free-space-cache.c|2
> > include/asm-generic/error-injection.h | 20 +++
> > include/asm-generic/vmlinux.lds.h | 14 +-
> > include/linux/bpf.h| 12 --
> > include/linux/error-injection.h| 21 +++
> > include/linux/kprobes.h|1
> > include/linux/module.h |6 -
> > kernel/kprobes.c | 163
> > kernel/module.c|8 +
> > kernel/trace/Kconfig |2
> > kernel/trace/bpf_trace.c |2
> > kernel/trace/trace_kprobe.c|3
> > lib/Kconfig.debug |4 +
> > lib/Makefile |1
> > lib/error-inject.c | 213
> >
> > 22 files changed, 315 insertions(+), 210 deletions(-)
> > create mode 100644 arch/x86/include/asm/error-injection.h
> > create mode 100644 arch/x86/lib/error-inject.c
> > create mode 100644 include/asm-generic/error-injection.h
> > create mode 100644 include/linux/error-injection.h
> > create mode 100644 lib/error-inject.c
> >
> > diff --git a/arch/Kconfig b/arch/Kconfig
> > index d3f4aaf9cb7a..97376accfb14 100644
> > --- a/arch/Kconfig
> > +++ b/arch/Kconfig
> > @@ -196,7 +196,7 @@ config HAVE_OPTPROBES
> > config HAVE_KPROBES_ON_FTRACE
> > bool
> >
> > -config HAVE_KPROBE_OVERRIDE
> > +config HAVE_FUNCTION_ERROR_INJECTION
> > bool
> >
> > config HAVE_NMI
> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> > index 45dc6233f2b9..366b19cb79b7 100644
> > --- a/arch/x86/Kconfig
> > +++ b/arch/x86/Kconfig
> > @@ -154,7 +154,7 @@ config X86
> > select HAVE_KERNEL_XZ
> > select HAVE_KPROBES
> > select HAVE_KPROBES_ON_FTRACE
> > - select HAVE_KPROBE_OVERRIDE
> > + select HAVE_FUNCTION_ERROR_INJECTION
> > select HAVE_KRETPROBES
> > select HAVE_KVM
> > select HAVE_LIVEPATCH if X86_64
> > diff --git a/arch/x86/include/asm/error-injection.h
> > b/arch/x86/include/asm/error-injection.h
> > new file mode 100644
> > index ..47b7a1296245
> > --- /dev/null
> > +++ b/arch/x86/include/asm/error-injection.h
> > @@ -0,0 +1,13 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef _ASM_ERROR_INJECTION_H
> > +#define _ASM_ERROR_INJECTION_H
> > +
> > +#include
> > +#include
> > +#include
> > +#include
> > +
> > +asmlinkage void just_return_func(void);
> > +void override_function_with_return(struct pt_regs *regs);
> > +
> > +#endif /* _ASM_ERROR_INJECTION_H */
> > diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
> > index b02a377d5905..bd36f3c33cd0 100644
> > --- a/arch/x86/kernel/kprobes/core.c
> > +++ b/arch/x86/kernel/kprobes/core.c
> > @@ -1183,17 +1183,3 @@ int arch_trampoline_kprobe(struct kprobe *p)
> > {
> > return 0;
> > }
> > -
> > -asmlinkage void override_func(void);
> > -asm(
> > - ".type override_func, @function\n"
> > - "override_func:\n"
> > - " ret\n"
> > - ".size override_func, .-override_func\n"
> > -);
> > -
> > -void arch_kprobe_override_function(struct pt_regs *regs)
> > -{
> > - regs->ip = (unsigned long)&override_func;
> > -}
> > -NOKPROBE_SYMBOL(arch_kprobe_override_function);
> > diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefil
Re: [PATCH bpf-next v3 3/5] error-injection: Separate error-injection from kprobe
On Wed, Jan 10, 2018 at 07:18:05PM +0900, Masami Hiramatsu wrote:
> Since error-injection framework is not limited to be used
> by kprobes, nor bpf. Other kernel subsystems can use it
> freely for checking safeness of error-injection, e.g.
> livepatch, ftrace etc.
> So this separate error-injection framework from kprobes.
>
> Some differences has been made:
>
> - "kprobe" word is removed from any APIs/structures.
> - BPF_ALLOW_ERROR_INJECTION() is renamed to
> ALLOW_ERROR_INJECTION() since it is not limited for BPF too.
> - CONFIG_FUNCTION_ERROR_INJECTION is the config item of this
> feature. It is automatically enabled if the arch supports
> error injection feature for kprobe or ftrace etc.
>
> Signed-off-by: Masami Hiramatsu
> ---
> Changes in v3:
>- Fix a build error for asmlinkage on i386 by including compiler.h
>- Fix "CONFIG_FUNCTION_ERROR_INJECT" typo.
>- Separate CONFIG_MODULES dependent code
>- Add CONFIG_KPROBES dependency for arch_deref_entry_point()
>- Call error-injection init function in late_initcall stage.
>- Fix read-side mutex lock
>- Some cosmetic cleanups
> ---
> arch/Kconfig |2
> arch/x86/Kconfig |2
> arch/x86/include/asm/error-injection.h | 13 ++
> arch/x86/kernel/kprobes/core.c | 14 --
> arch/x86/lib/Makefile |1
> arch/x86/lib/error-inject.c| 19 +++
> fs/btrfs/disk-io.c |2
> fs/btrfs/free-space-cache.c|2
> include/asm-generic/error-injection.h | 20 +++
> include/asm-generic/vmlinux.lds.h | 14 +-
> include/linux/bpf.h| 12 --
> include/linux/error-injection.h| 21 +++
> include/linux/kprobes.h|1
> include/linux/module.h |6 -
> kernel/kprobes.c | 163
> kernel/module.c|8 +
> kernel/trace/Kconfig |2
> kernel/trace/bpf_trace.c |2
> kernel/trace/trace_kprobe.c|3
> lib/Kconfig.debug |4 +
> lib/Makefile |1
> lib/error-inject.c | 213
>
> 22 files changed, 315 insertions(+), 210 deletions(-)
> create mode 100644 arch/x86/include/asm/error-injection.h
> create mode 100644 arch/x86/lib/error-inject.c
> create mode 100644 include/asm-generic/error-injection.h
> create mode 100644 include/linux/error-injection.h
> create mode 100644 lib/error-inject.c
>
> diff --git a/arch/Kconfig b/arch/Kconfig
> index d3f4aaf9cb7a..97376accfb14 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -196,7 +196,7 @@ config HAVE_OPTPROBES
> config HAVE_KPROBES_ON_FTRACE
> bool
>
> -config HAVE_KPROBE_OVERRIDE
> +config HAVE_FUNCTION_ERROR_INJECTION
> bool
>
> config HAVE_NMI
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 45dc6233f2b9..366b19cb79b7 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -154,7 +154,7 @@ config X86
> select HAVE_KERNEL_XZ
> select HAVE_KPROBES
> select HAVE_KPROBES_ON_FTRACE
> - select HAVE_KPROBE_OVERRIDE
> + select HAVE_FUNCTION_ERROR_INJECTION
> select HAVE_KRETPROBES
> select HAVE_KVM
> select HAVE_LIVEPATCH if X86_64
> diff --git a/arch/x86/include/asm/error-injection.h
> b/arch/x86/include/asm/error-injection.h
> new file mode 100644
> index ..47b7a1296245
> --- /dev/null
> +++ b/arch/x86/include/asm/error-injection.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_ERROR_INJECTION_H
> +#define _ASM_ERROR_INJECTION_H
> +
> +#include
> +#include
> +#include
> +#include
> +
> +asmlinkage void just_return_func(void);
> +void override_function_with_return(struct pt_regs *regs);
> +
> +#endif /* _ASM_ERROR_INJECTION_H */
> diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
> index b02a377d5905..bd36f3c33cd0 100644
> --- a/arch/x86/kernel/kprobes/core.c
> +++ b/arch/x86/kernel/kprobes/core.c
> @@ -1183,17 +1183,3 @@ int arch_trampoline_kprobe(struct kprobe *p)
> {
> return 0;
> }
> -
> -asmlinkage void override_func(void);
> -asm(
> - ".type override_func, @function\n"
> - "override_func:\n"
> - " ret\n"
> - ".size override_func, .-override_func\n"
> -);
> -
> -void arch_kprobe_override_function(struct pt_regs *regs)
> -{
> - regs->ip = (unsigned long)&override_func;
> -}
> -NOKPROBE_SYMBOL(arch_kprobe_override_function);
> diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
> index 7b181b61170e..171377b83be1 100644
> --- a/arch/x86/lib/Makefile
> +++ b/arch/x86/lib/Makefile
> @@ -26,6 +26,7 @@ lib-y += memcpy_$(BITS).o
> lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
> lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o
> lib-$
