[v5,0/6] arch/x86: kprobes: Remove MODULES dependency

Message

Jarkko Sakkinen July 24, 2020, 5:05 a.m. UTC

Remove MODULES dependency by migrating from module_alloc() to the new
text_alloc() API. Essentially these changes provide preliminaries for
allowing to compile a static kernel with a proper tracing support.

The same API can be used later on in other sites that allocate space for
trampolines, and trivially scaled to other arch's. An arch can inform
with CONFIG_ARCH_HAS_TEXT_ALLOC that it's providing implementation for
text_alloc().

Cc: [e-mail]
Cc: Andi Kleen <[e-mail]>
Cc: Masami Hiramatsu <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>

v4:
* Squash lock_modules() patches into one.
* Remove fallback versions of text_alloc() and text_free(). Instead, use
  ARCH_HAS_TEXT_ALLOC at site when required.
* Use lockdep_assert_irqs_enabled() in text_free() instead of
  WARN_ON(in_interrupt()).

v3:
* Make text_alloc() API disjoint.
* Remove all the possible extra clutter not absolutely required and
  split into more logical pieces.

Jarkko Sakkinen (6):
  kprobes: Remove dependency to the module_mutex
  vmalloc: Add text_alloc() and text_free()
  arch/x86: Implement text_alloc() and text_free()
  arch/x86: kprobes: Use text_alloc() and text_free()
  kprobes: Use text_alloc() and text_free()
  kprobes: Remove CONFIG_MODULES dependency

 arch/Kconfig                   |  2 +-
 arch/x86/Kconfig               |  3 ++
 arch/x86/kernel/Makefile       |  1 +
 arch/x86/kernel/kprobes/core.c |  4 +--
 arch/x86/kernel/text_alloc.c   | 41 +++++++++++++++++++++++
 include/linux/module.h         | 32 ++++++++++++++----
 include/linux/vmalloc.h        | 17 ++++++++++
 kernel/kprobes.c               | 61 +++++++++++++++++++++++-----------
 kernel/trace/trace_kprobe.c    | 20 ++++++++---
 9 files changed, 147 insertions(+), 34 deletions(-)
 create mode 100644 arch/x86/kernel/text_alloc.c

Comments

Jarkko Sakkinen July 24, 2020, 7:01 a.m. UTC | #1

On Fri, Jul 24, 2020 at 08:05:47AM +0300, Jarkko Sakkinen wrote:
> Remove MODULES dependency by migrating from module_alloc() to the new
> text_alloc() API. Essentially these changes provide preliminaries for
> allowing to compile a static kernel with a proper tracing support.
> 
> The same API can be used later on in other sites that allocate space for
> trampolines, and trivially scaled to other arch's. An arch can inform
> with CONFIG_ARCH_HAS_TEXT_ALLOC that it's providing implementation for
> text_alloc().
> 
> Cc: [e-mail]
> Cc: Andi Kleen <[e-mail]>
> Cc: Masami Hiramatsu <[e-mail]>
> Cc: Peter Zijlstra <[e-mail]>
> 
> v4:
> * Squash lock_modules() patches into one.
> * Remove fallback versions of text_alloc() and text_free(). Instead, use
>   ARCH_HAS_TEXT_ALLOC at site when required.
> * Use lockdep_assert_irqs_enabled() in text_free() instead of
>   WARN_ON(in_interrupt()).
> 
> v3:
> * Make text_alloc() API disjoint.
> * Remove all the possible extra clutter not absolutely required and
>   split into more logical pieces.
> 
> Jarkko Sakkinen (6):
>   kprobes: Remove dependency to the module_mutex
>   vmalloc: Add text_alloc() and text_free()
>   arch/x86: Implement text_alloc() and text_free()
>   arch/x86: kprobes: Use text_alloc() and text_free()
>   kprobes: Use text_alloc() and text_free()
>   kprobes: Remove CONFIG_MODULES dependency
> 
>  arch/Kconfig                   |  2 +-
>  arch/x86/Kconfig               |  3 ++
>  arch/x86/kernel/Makefile       |  1 +
>  arch/x86/kernel/kprobes/core.c |  4 +--
>  arch/x86/kernel/text_alloc.c   | 41 +++++++++++++++++++++++
>  include/linux/module.h         | 32 ++++++++++++++----
>  include/linux/vmalloc.h        | 17 ++++++++++
>  kernel/kprobes.c               | 61 +++++++++++++++++++++++-----------
>  kernel/trace/trace_kprobe.c    | 20 ++++++++---
>  9 files changed, 147 insertions(+), 34 deletions(-)
>  create mode 100644 arch/x86/kernel/text_alloc.c
> 
> -- 
> 2.25.1
> 

Duplicates were caused by Internet connection breaking up in the
middle. Apologies.

/Jarkko

Mike Rapoport July 24, 2020, 10:26 a.m. UTC | #2

(cc people whi particpaged in v2 disuccsion)

On Fri, Jul 24, 2020 at 08:05:47AM +0300, Jarkko Sakkinen wrote:
> Remove MODULES dependency by migrating from module_alloc() to the new
> text_alloc() API. Essentially these changes provide preliminaries for
> allowing to compile a static kernel with a proper tracing support.
> 
> The same API can be used later on in other sites that allocate space for
> trampolines, and trivially scaled to other arch's. An arch can inform
> with CONFIG_ARCH_HAS_TEXT_ALLOC that it's providing implementation for
> text_alloc().
> 
> Cc: [e-mail]
> Cc: Andi Kleen <[e-mail]>
> Cc: Masami Hiramatsu <[e-mail]>
> Cc: Peter Zijlstra <[e-mail]>
> 
> v4:
> * Squash lock_modules() patches into one.
> * Remove fallback versions of text_alloc() and text_free(). Instead, use
>   ARCH_HAS_TEXT_ALLOC at site when required.
> * Use lockdep_assert_irqs_enabled() in text_free() instead of
>   WARN_ON(in_interrupt()).
> 
> v3:
> * Make text_alloc() API disjoint.
> * Remove all the possible extra clutter not absolutely required and
>   split into more logical pieces.
> 
> Jarkko Sakkinen (6):
>   kprobes: Remove dependency to the module_mutex
>   vmalloc: Add text_alloc() and text_free()
>   arch/x86: Implement text_alloc() and text_free()
>   arch/x86: kprobes: Use text_alloc() and text_free()
>   kprobes: Use text_alloc() and text_free()
>   kprobes: Remove CONFIG_MODULES dependency
> 
>  arch/Kconfig                   |  2 +-
>  arch/x86/Kconfig               |  3 ++
>  arch/x86/kernel/Makefile       |  1 +
>  arch/x86/kernel/kprobes/core.c |  4 +--
>  arch/x86/kernel/text_alloc.c   | 41 +++++++++++++++++++++++
>  include/linux/module.h         | 32 ++++++++++++++----
>  include/linux/vmalloc.h        | 17 ++++++++++
>  kernel/kprobes.c               | 61 +++++++++++++++++++++++-----------
>  kernel/trace/trace_kprobe.c    | 20 ++++++++---
>  9 files changed, 147 insertions(+), 34 deletions(-)
>  create mode 100644 arch/x86/kernel/text_alloc.c
> 
> -- 
> 2.25.1
>