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From: Ravi Bangoria <ravi.bangoria@amd.com>
To: acme@kernel.org
Cc: jolsa@kernel.org, namhyung@kernel.org, irogers@google.com,
	kan.liang@linux.intel.com, peterz@infradead.org,
	mark.rutland@arm.com, mingo@redhat.com,
	alexander.shishkin@linux.intel.com, james.clark@arm.com,
	german.gomez@arm.com, leo.yan@linaro.org,
	adrian.hunter@intel.com, alexey.v.bayduraev@linux.intel.com,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	sandipan.das@amd.com, ananth.narayan@amd.com,
	santosh.shukla@amd.com, Ravi Bangoria <ravi.bangoria@amd.com>
Subject: Re: [RFC 0/4] perf tool: Fix non-".text" symbol resolution for kernel modules
Date: Mon, 16 Jan 2023 09:51:27 +0530	[thread overview]
Message-ID: <98570bf8-dd78-3d9c-61da-9ac6b3502fd5@amd.com> (raw)
In-Reply-To: <20230110055859.685-1-ravi.bangoria@amd.com>

Hi all,

On 10-Jan-23 11:28 AM, Ravi Bangoria wrote:
> Kernel module elf contains executable code in non-".text" sections as
> well, for ex: ".noinstr.text". Plus, kernel module's memory layout
> differs from it's binary layout because .ko elf does not contain
> program header table.
> 
> Perf tries to solve it by creating special maps for allocated (SHF_ALLOC)
> elf sections, but perf uses elf addresses for map address range and thus
> these special maps remains unused because no real ip falls into their
> address range.
> 
> Solve this by preparing section specific special maps using addresses
> provided by sysfs /sys/module/.../sections/. Also save these details in
> PERF_RECORD_KMOD_SEC_MAP format in perf.data which can be consumed at
> perf-report time.

Do you guys feel this is worth to fix and I shall continue? Or --kcore /
--kallsyms workarounds are sufficient?

Thanks,
Ravi

      parent reply	other threads:[~2023-01-16  4:21 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-10  5:58 [RFC 0/4] perf tool: Fix non-".text" symbol resolution for kernel modules Ravi Bangoria
2023-01-10  5:58 ` [RFC 1/4] perf tool: Simplify machine__create_modules() a bit Ravi Bangoria
2023-01-10  5:58 ` [RFC 2/4] perf tool: Refactor perf_event__synthesize_modules() Ravi Bangoria
2023-01-10  5:58 ` [RFC 3/4] perf tool: Introduce PERF_RECORD_KMOD_SEC_MAP Ravi Bangoria
2023-01-16  6:14   ` Adrian Hunter
2023-01-16 13:34     ` Ravi Bangoria
2023-01-10  5:58 ` [RFC 4/4] perf tool: Fix non-".text" symbol resolution for kernel modules Ravi Bangoria
2023-01-10  6:35 ` [RFC 0/4] " Adrian Hunter
2023-01-10  8:43   ` Ravi Bangoria
2023-01-10  8:58     ` Ravi Bangoria
2023-01-16  4:21 ` Ravi Bangoria [this message]

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