Re: [RFC PATCH] linux: Remove user-space probe support

[Michael Tremer <michael.tremer@ipfire.org>]

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Hello,

I would say, that we do not use this feature - or at least I don’t.

Did you check whether some other options depend on this?

-Michael

> On 2 Oct 2022, at 15:47, Peter Müller <peter.mueller(a)ipfire.org> wrote:
> 
> From the kernels' documentation:
> 
>> Uprobes is the user-space counterpart to kprobes: they
>> enable instrumentation applications (such as 'perf probe')
>> to establish unintrusive probes in user-space binaries and
>> libraries, by executing handler functions when the probes
>> are hit by user-space applications.
>> 
>> ( These probes come in the form of single-byte breakpoints,
>> managed by the kernel and kept transparent to the probed
>> application. )
> 
> To the best of the authors' understanding, no application on IPFire
> needs this functionality, and given its abuse potential, we should
> probably not enable it.
> 
> As expected, strace functionality is not impaired by this.
> 
> Signed-off-by: Peter Müller <peter.mueller(a)ipfire.org>
> ---
> config/kernel/kernel.config.aarch64-ipfire | 5 +----
> config/kernel/kernel.config.armv6l-ipfire  | 5 +----
> config/kernel/kernel.config.x86_64-ipfire  | 5 +----
> 3 files changed, 3 insertions(+), 12 deletions(-)
> 
> diff --git a/config/kernel/kernel.config.aarch64-ipfire b/config/kernel/kernel.config.aarch64-ipfire
> index 836e2b15f..76dbafc5f 100644
> --- a/config/kernel/kernel.config.aarch64-ipfire
> +++ b/config/kernel/kernel.config.aarch64-ipfire
> @@ -645,7 +645,6 @@ CONFIG_CRYPTO_AES_ARM64_BS=m
> # CONFIG_KPROBES is not set
> CONFIG_JUMP_LABEL=y
> CONFIG_STATIC_KEYS_SELFTEST=y
> -CONFIG_UPROBES=y
> CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y
> CONFIG_HAVE_KPROBES=y
> CONFIG_HAVE_KRETPROBES=y
> @@ -8154,9 +8153,7 @@ CONFIG_TRACER_SNAPSHOT=y
> CONFIG_BRANCH_PROFILE_NONE=y
> # CONFIG_PROFILE_ANNOTATED_BRANCHES is not set
> # CONFIG_BLK_DEV_IO_TRACE is not set
> -CONFIG_UPROBE_EVENTS=y
> -CONFIG_DYNAMIC_EVENTS=y
> -CONFIG_PROBE_EVENTS=y
> +# CONFIG_UPROBE_EVENTS is not set
> CONFIG_FTRACE_MCOUNT_RECORD=y
> CONFIG_FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY=y
> # CONFIG_SYNTH_EVENTS is not set
> diff --git a/config/kernel/kernel.config.armv6l-ipfire b/config/kernel/kernel.config.armv6l-ipfire
> index ae611fc6f..28f4ef3aa 100644
> --- a/config/kernel/kernel.config.armv6l-ipfire
> +++ b/config/kernel/kernel.config.armv6l-ipfire
> @@ -738,7 +738,6 @@ CONFIG_AS_VFP_VMRS_FPINST=y
> # CONFIG_KPROBES is not set
> CONFIG_JUMP_LABEL=y
> CONFIG_STATIC_KEYS_SELFTEST=y
> -CONFIG_UPROBES=y
> CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y
> CONFIG_ARCH_USE_BUILTIN_BSWAP=y
> CONFIG_HAVE_KPROBES=y
> @@ -8129,9 +8128,7 @@ CONFIG_BRANCH_PROFILE_NONE=y
> # CONFIG_PROFILE_ANNOTATED_BRANCHES is not set
> # CONFIG_PROFILE_ALL_BRANCHES is not set
> # CONFIG_BLK_DEV_IO_TRACE is not set
> -CONFIG_UPROBE_EVENTS=y
> -CONFIG_DYNAMIC_EVENTS=y
> -CONFIG_PROBE_EVENTS=y
> +# CONFIG_UPROBE_EVENTS is not set
> CONFIG_FTRACE_MCOUNT_RECORD=y
> CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT=y
> # CONFIG_SYNTH_EVENTS is not set
> diff --git a/config/kernel/kernel.config.x86_64-ipfire b/config/kernel/kernel.config.x86_64-ipfire
> index d005f98d4..bb4655a99 100644
> --- a/config/kernel/kernel.config.x86_64-ipfire
> +++ b/config/kernel/kernel.config.x86_64-ipfire
> @@ -671,7 +671,6 @@ CONFIG_GENERIC_ENTRY=y
> CONFIG_JUMP_LABEL=y
> CONFIG_STATIC_KEYS_SELFTEST=y
> # CONFIG_STATIC_CALL_SELFTEST is not set
> -CONFIG_UPROBES=y
> CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y
> CONFIG_ARCH_USE_BUILTIN_BSWAP=y
> CONFIG_USER_RETURN_NOTIFIER=y
> @@ -7594,9 +7593,7 @@ CONFIG_TRACER_SNAPSHOT=y
> CONFIG_BRANCH_PROFILE_NONE=y
> # CONFIG_PROFILE_ANNOTATED_BRANCHES is not set
> # CONFIG_BLK_DEV_IO_TRACE is not set
> -CONFIG_UPROBE_EVENTS=y
> -CONFIG_DYNAMIC_EVENTS=y
> -CONFIG_PROBE_EVENTS=y
> +# CONFIG_UPROBE_EVENTS is not set
> CONFIG_FTRACE_MCOUNT_RECORD=y
> CONFIG_FTRACE_MCOUNT_USE_CC=y
> # CONFIG_SYNTH_EVENTS is not set
> -- 
> 2.35.3