2019-05-31 01:09:38 -07:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:31 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:32 +08:00
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2012-04-24 11:23:14 -07:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:32 +08:00
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2012-04-19 14:59:55 -07:00
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2025-02-18 14:59:19 -05:00
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2012-04-19 14:59:55 -07:00
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2021-12-12 19:33:58 +08:00
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2012-04-19 14:59:55 -07:00
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2012-04-24 11:23:14 -07:00
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2013-11-15 12:08:05 +05:30
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2014-02-18 15:29:11 +04:00
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2013-05-08 17:29:24 +01:00
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2014-01-23 15:52:46 -08:00
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2013-11-22 13:05:58 +05:30
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2021-09-24 15:43:38 -07:00
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2022-05-31 18:04:10 +08:00
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2025-01-05 11:22:17 -05:00
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2025-01-05 11:22:18 -05:00
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2025-01-05 11:22:19 -05:00
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2025-02-18 14:59:19 -05:00
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2019-12-04 08:46:28 +08:00
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2025-02-18 14:59:19 -05:00
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2019-12-04 08:46:28 +08:00
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2025-01-10 07:54:59 -05:00
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2025-02-18 14:59:19 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:20 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:20 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:20 -05:00
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2025-01-05 11:22:21 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:21 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:21 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:21 -05:00
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2025-01-05 11:22:22 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:22 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:22 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:22 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:22 -05:00
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2025-02-18 14:59:19 -05:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2012-04-24 11:23:14 -07:00
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2012-04-19 14:59:55 -07:00
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2012-04-24 11:23:14 -07:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2012-04-24 11:23:14 -07:00
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2012-04-19 14:59:55 -07:00
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2012-04-24 11:23:14 -07:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2012-04-24 11:23:14 -07:00
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2019-12-04 08:46:28 +08:00
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2012-04-24 11:23:14 -07:00
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2012-04-19 14:59:55 -07:00
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2012-04-24 11:23:14 -07:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2012-04-24 11:23:14 -07:00
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2019-12-04 08:46:28 +08:00
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2012-04-24 11:23:14 -07:00
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2019-12-04 08:46:28 +08:00
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2012-04-24 11:23:14 -07:00
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2019-12-04 08:46:28 +08:00
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2012-04-24 11:23:14 -07:00
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2019-12-04 08:46:28 +08:00
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2025-02-18 14:59:19 -05:00
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2013-11-12 15:06:51 -08:00
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2025-01-05 11:22:16 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:18 -05:00
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2025-01-07 22:32:17 -05:00
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2025-02-18 14:59:19 -05:00
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2025-01-07 22:32:17 -05:00
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2025-02-18 14:59:19 -05:00
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2025-02-18 14:59:20 -05:00
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2025-02-18 14:59:19 -05:00
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scripts/sorttable: Zero out weak functions in mcount_loc table
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit b39181f7c6907 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid
adding weak function") was a workaround to this by checking the function
address before printing its name. If the address was too far from the
function given by the name then instead of printing the name it would
print: __ftrace_invalid_address___<invalid-offset>
The real issue is that these invalid addresses are listed in the ftrace
table look up which available_filter_functions is derived from. A place
holder must be listed in that file because set_ftrace_filter may take a
series of indexes into that file instead of names to be able to do O(1)
lookups to enable filtering (many tools use this method).
Even if kallsyms saved the size of the function, it does not remove the
need of having these place holders. The real solution is to not add a weak
function into the ftrace table in the first place.
To solve this, the sorttable.c code that sorts the mcount regions during
the build is modified to take a "nm -S vmlinux" input, sort it, and any
function listed in the mcount_loc section that is not within a boundary of
the function list given by nm is considered a weak function and is zeroed
out.
Note, this does not mean they will remain zero when booting as KASLR
will still shift those addresses. To handle this, the entries in the
mcount_loc section will be ignored if they are zero or match the
kaslr_offset() value.
Before:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
551
After:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
0
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200022.883095980@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-18 14:59:22 -05:00
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2025-02-25 13:20:08 -05:00
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scripts/sorttable: Zero out weak functions in mcount_loc table
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit b39181f7c6907 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid
adding weak function") was a workaround to this by checking the function
address before printing its name. If the address was too far from the
function given by the name then instead of printing the name it would
print: __ftrace_invalid_address___<invalid-offset>
The real issue is that these invalid addresses are listed in the ftrace
table look up which available_filter_functions is derived from. A place
holder must be listed in that file because set_ftrace_filter may take a
series of indexes into that file instead of names to be able to do O(1)
lookups to enable filtering (many tools use this method).
Even if kallsyms saved the size of the function, it does not remove the
need of having these place holders. The real solution is to not add a weak
function into the ftrace table in the first place.
To solve this, the sorttable.c code that sorts the mcount regions during
the build is modified to take a "nm -S vmlinux" input, sort it, and any
function listed in the mcount_loc section that is not within a boundary of
the function list given by nm is considered a weak function and is zeroed
out.
Note, this does not mean they will remain zero when booting as KASLR
will still shift those addresses. To handle this, the entries in the
mcount_loc section will be ignored if they are zero or match the
kaslr_offset() value.
Before:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
551
After:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
0
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200022.883095980@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-18 14:59:22 -05:00
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2025-02-25 13:20:08 -05:00
|
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|
|
scripts/sorttable: Zero out weak functions in mcount_loc table
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit b39181f7c6907 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid
adding weak function") was a workaround to this by checking the function
address before printing its name. If the address was too far from the
function given by the name then instead of printing the name it would
print: __ftrace_invalid_address___<invalid-offset>
The real issue is that these invalid addresses are listed in the ftrace
table look up which available_filter_functions is derived from. A place
holder must be listed in that file because set_ftrace_filter may take a
series of indexes into that file instead of names to be able to do O(1)
lookups to enable filtering (many tools use this method).
Even if kallsyms saved the size of the function, it does not remove the
need of having these place holders. The real solution is to not add a weak
function into the ftrace table in the first place.
To solve this, the sorttable.c code that sorts the mcount regions during
the build is modified to take a "nm -S vmlinux" input, sort it, and any
function listed in the mcount_loc section that is not within a boundary of
the function list given by nm is considered a weak function and is zeroed
out.
Note, this does not mean they will remain zero when booting as KASLR
will still shift those addresses. To handle this, the entries in the
mcount_loc section will be ignored if they are zero or match the
kaslr_offset() value.
Before:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
551
After:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
0
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200022.883095980@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-18 14:59:22 -05:00
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2025-01-07 22:32:17 -05:00
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2025-02-18 14:59:19 -05:00
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2025-01-07 22:32:17 -05:00
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2025-02-18 14:59:21 -05:00
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2025-02-18 14:59:19 -05:00
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2025-02-18 14:59:21 -05:00
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2025-02-18 14:59:19 -05:00
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2025-02-18 14:59:21 -05:00
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2025-02-18 14:59:20 -05:00
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2025-02-18 14:59:19 -05:00
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2025-02-18 14:59:21 -05:00
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2025-02-18 14:59:19 -05:00
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2025-02-18 14:59:21 -05:00
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2025-02-18 14:59:19 -05:00
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2025-02-18 14:59:21 -05:00
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2025-02-18 14:59:19 -05:00
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2025-02-18 14:59:21 -05:00
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2025-02-18 14:59:19 -05:00
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2025-01-07 22:32:17 -05:00
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2025-02-18 14:59:21 -05:00
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2025-01-07 22:32:17 -05:00
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2025-02-18 14:59:21 -05:00
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2025-01-07 22:32:17 -05:00
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2025-02-25 13:20:07 -05:00
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2025-02-18 14:59:21 -05:00
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2025-02-25 13:20:07 -05:00
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2025-02-18 14:59:21 -05:00
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scripts/sorttable: Zero out weak functions in mcount_loc table
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit b39181f7c6907 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid
adding weak function") was a workaround to this by checking the function
address before printing its name. If the address was too far from the
function given by the name then instead of printing the name it would
print: __ftrace_invalid_address___<invalid-offset>
The real issue is that these invalid addresses are listed in the ftrace
table look up which available_filter_functions is derived from. A place
holder must be listed in that file because set_ftrace_filter may take a
series of indexes into that file instead of names to be able to do O(1)
lookups to enable filtering (many tools use this method).
Even if kallsyms saved the size of the function, it does not remove the
need of having these place holders. The real solution is to not add a weak
function into the ftrace table in the first place.
To solve this, the sorttable.c code that sorts the mcount regions during
the build is modified to take a "nm -S vmlinux" input, sort it, and any
function listed in the mcount_loc section that is not within a boundary of
the function list given by nm is considered a weak function and is zeroed
out.
Note, this does not mean they will remain zero when booting as KASLR
will still shift those addresses. To handle this, the entries in the
mcount_loc section will be ignored if they are zero or match the
kaslr_offset() value.
Before:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
551
After:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
0
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200022.883095980@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-18 14:59:22 -05:00
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2025-04-02 03:15:35 +02:00
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|
scripts/sorttable: Zero out weak functions in mcount_loc table
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit b39181f7c6907 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid
adding weak function") was a workaround to this by checking the function
address before printing its name. If the address was too far from the
function given by the name then instead of printing the name it would
print: __ftrace_invalid_address___<invalid-offset>
The real issue is that these invalid addresses are listed in the ftrace
table look up which available_filter_functions is derived from. A place
holder must be listed in that file because set_ftrace_filter may take a
series of indexes into that file instead of names to be able to do O(1)
lookups to enable filtering (many tools use this method).
Even if kallsyms saved the size of the function, it does not remove the
need of having these place holders. The real solution is to not add a weak
function into the ftrace table in the first place.
To solve this, the sorttable.c code that sorts the mcount regions during
the build is modified to take a "nm -S vmlinux" input, sort it, and any
function listed in the mcount_loc section that is not within a boundary of
the function list given by nm is considered a weak function and is zeroed
out.
Note, this does not mean they will remain zero when booting as KASLR
will still shift those addresses. To handle this, the entries in the
mcount_loc section will be ignored if they are zero or match the
kaslr_offset() value.
Before:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
551
After:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
0
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200022.883095980@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-18 14:59:22 -05:00
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2025-02-18 14:59:21 -05:00
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2025-02-18 14:59:19 -05:00
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2025-02-18 14:59:21 -05:00
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2025-01-07 22:32:17 -05:00
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2025-01-05 11:22:25 -05:00
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2025-01-07 22:32:17 -05:00
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2025-01-05 11:22:25 -05:00
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2025-01-07 22:32:17 -05:00
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2025-01-05 11:22:25 -05:00
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2025-01-07 22:32:17 -05:00
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2025-01-05 11:22:25 -05:00
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2025-01-07 22:32:17 -05:00
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scripts/sorttable: Zero out weak functions in mcount_loc table
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit b39181f7c6907 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid
adding weak function") was a workaround to this by checking the function
address before printing its name. If the address was too far from the
function given by the name then instead of printing the name it would
print: __ftrace_invalid_address___<invalid-offset>
The real issue is that these invalid addresses are listed in the ftrace
table look up which available_filter_functions is derived from. A place
holder must be listed in that file because set_ftrace_filter may take a
series of indexes into that file instead of names to be able to do O(1)
lookups to enable filtering (many tools use this method).
Even if kallsyms saved the size of the function, it does not remove the
need of having these place holders. The real solution is to not add a weak
function into the ftrace table in the first place.
To solve this, the sorttable.c code that sorts the mcount regions during
the build is modified to take a "nm -S vmlinux" input, sort it, and any
function listed in the mcount_loc section that is not within a boundary of
the function list given by nm is considered a weak function and is zeroed
out.
Note, this does not mean they will remain zero when booting as KASLR
will still shift those addresses. To handle this, the entries in the
mcount_loc section will be ignored if they are zero or match the
kaslr_offset() value.
Before:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
551
After:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
0
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200022.883095980@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-18 14:59:22 -05:00
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2025-01-07 22:32:17 -05:00
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2025-01-05 11:22:25 -05:00
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2025-01-07 22:32:17 -05:00
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2025-01-05 11:22:25 -05:00
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2025-01-07 22:32:17 -05:00
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2025-01-05 11:22:25 -05:00
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2025-01-07 22:32:17 -05:00
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2012-04-19 14:59:55 -07:00
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2012-09-05 13:26:11 +02:00
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2012-04-24 11:23:14 -07:00
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2019-12-04 08:46:28 +08:00
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2016-02-17 10:20:12 -08:00
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2019-12-04 08:46:28 +08:00
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2016-02-17 10:20:12 -08:00
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2019-12-04 08:46:28 +08:00
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2016-02-17 10:20:12 -08:00
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2019-12-04 08:46:28 +08:00
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2016-02-17 10:20:12 -08:00
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2019-12-04 08:46:28 +08:00
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2016-02-17 10:20:12 -08:00
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2019-12-04 08:46:28 +08:00
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2016-02-17 10:20:12 -08:00
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2019-12-04 08:46:28 +08:00
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2016-02-17 10:20:12 -08:00
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2021-11-08 11:42:20 +00:00
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arm64: extable: add `type` and `data` fields
Subsequent patches will add specialized handlers for fixups, in addition
to the simple PC fixup and BPF handlers we have today. In preparation,
this patch adds a new `type` field to struct exception_table_entry, and
uses this to distinguish the fixup and BPF cases. A `data` field is also
added so that subsequent patches can associate data specific to each
exception site (e.g. register numbers).
Handlers are named ex_handler_*() for consistency, following the exmaple
of x86. At the same time, get_ex_fixup() is split out into a helper so
that it can be used by other ex_handler_*() functions ins subsequent
patches.
This patch will increase the size of the exception tables, which will be
remedied by subsequent patches removing redundant fixup code. There
should be no functional change as a result of this patch.
Since each entry is now 12 bytes in size, we must reduce the alignment
of each entry from `.align 3` (i.e. 8 bytes) to `.align 2` (i.e. 4
bytes), which is the natrual alignment of the `insn` and `fixup` fields.
The current 8-byte alignment is a holdover from when the `insn` and
`fixup` fields was 8 bytes, and while not harmful has not been necessary
since commit:
6c94f27ac847ff8e ("arm64: switch to relative exception tables")
Similarly, RO_EXCEPTION_TABLE_ALIGN is dropped to 4 bytes.
Concurrently with this patch, x86's exception table entry format is
being updated (similarly to a 12-byte format, with 32-bytes of absolute
data). Once both have been merged it should be possible to unify the
sorttable logic for the two.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: James Morse <james.morse@arm.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211019160219.5202-11-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-10-19 17:02:16 +01:00
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2019-12-04 08:46:28 +08:00
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2012-04-19 14:59:55 -07:00
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2025-01-05 11:22:17 -05:00
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2019-12-04 08:46:28 +08:00
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2012-04-19 14:59:55 -07:00
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2025-01-05 11:22:17 -05:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2025-02-18 14:59:19 -05:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2025-02-18 14:59:19 -05:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2025-01-05 11:22:17 -05:00
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2019-12-04 08:46:28 +08:00
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2025-01-05 11:22:17 -05:00
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2016-01-10 11:42:28 +01:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2025-01-05 11:22:17 -05:00
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2021-11-08 11:42:20 +00:00
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2025-02-18 14:59:19 -05:00
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2025-02-25 13:20:08 -05:00
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2025-02-18 14:59:19 -05:00
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2022-12-10 22:39:59 +08:00
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2021-11-18 19:26:05 +08:00
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2022-02-28 14:52:42 +01:00
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2012-04-19 14:59:55 -07:00
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2021-11-08 11:42:20 +00:00
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2016-02-17 10:20:12 -08:00
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2016-03-23 16:00:46 +01:00
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2016-10-13 16:42:55 +11:00
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2012-09-05 13:26:11 +02:00
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2013-11-15 12:08:05 +05:30
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2013-11-22 13:05:58 +05:30
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2012-10-29 19:19:34 +01:00
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2014-01-23 15:52:46 -08:00
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2012-04-24 11:23:14 -07:00
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2014-02-18 15:29:11 +04:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2025-01-05 11:22:17 -05:00
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2019-12-04 08:46:28 +08:00
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2012-04-19 14:59:55 -07:00
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2025-01-05 11:22:17 -05:00
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2025-01-10 07:54:59 -05:00
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2025-02-18 14:59:19 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:17 -05:00
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2012-04-19 14:59:55 -07:00
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2016-01-10 11:42:28 +01:00
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2025-01-07 22:32:17 -05:00
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2012-04-19 14:59:55 -07:00
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2025-01-07 22:32:17 -05:00
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2025-01-10 07:54:59 -05:00
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2012-04-19 14:59:55 -07:00
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2025-01-10 07:54:59 -05:00
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2025-02-18 14:59:19 -05:00
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2025-01-10 07:54:59 -05:00
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2025-01-05 11:22:17 -05:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2025-01-07 22:32:17 -05:00
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2019-12-04 08:46:28 +08:00
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2025-01-07 22:32:17 -05:00
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2025-01-10 07:54:59 -05:00
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2019-12-04 08:46:28 +08:00
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2025-01-05 11:22:17 -05:00
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2025-01-07 22:32:17 -05:00
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2012-04-19 14:59:55 -07:00
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2025-01-07 22:32:17 -05:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:27 +08:00
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scripts/sorttable: Zero out weak functions in mcount_loc table
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit b39181f7c6907 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid
adding weak function") was a workaround to this by checking the function
address before printing its name. If the address was too far from the
function given by the name then instead of printing the name it would
print: __ftrace_invalid_address___<invalid-offset>
The real issue is that these invalid addresses are listed in the ftrace
table look up which available_filter_functions is derived from. A place
holder must be listed in that file because set_ftrace_filter may take a
series of indexes into that file instead of names to be able to do O(1)
lookups to enable filtering (many tools use this method).
Even if kallsyms saved the size of the function, it does not remove the
need of having these place holders. The real solution is to not add a weak
function into the ftrace table in the first place.
To solve this, the sorttable.c code that sorts the mcount regions during
the build is modified to take a "nm -S vmlinux" input, sort it, and any
function listed in the mcount_loc section that is not within a boundary of
the function list given by nm is considered a weak function and is zeroed
out.
Note, this does not mean they will remain zero when booting as KASLR
will still shift those addresses. To handle this, the entries in the
mcount_loc section will be ignored if they are zero or match the
kaslr_offset() value.
Before:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
551
After:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
0
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200022.883095980@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-18 14:59:22 -05:00
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2012-04-19 14:59:55 -07:00
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scripts/sorttable: Zero out weak functions in mcount_loc table
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit b39181f7c6907 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid
adding weak function") was a workaround to this by checking the function
address before printing its name. If the address was too far from the
function given by the name then instead of printing the name it would
print: __ftrace_invalid_address___<invalid-offset>
The real issue is that these invalid addresses are listed in the ftrace
table look up which available_filter_functions is derived from. A place
holder must be listed in that file because set_ftrace_filter may take a
series of indexes into that file instead of names to be able to do O(1)
lookups to enable filtering (many tools use this method).
Even if kallsyms saved the size of the function, it does not remove the
need of having these place holders. The real solution is to not add a weak
function into the ftrace table in the first place.
To solve this, the sorttable.c code that sorts the mcount regions during
the build is modified to take a "nm -S vmlinux" input, sort it, and any
function listed in the mcount_loc section that is not within a boundary of
the function list given by nm is considered a weak function and is zeroed
out.
Note, this does not mean they will remain zero when booting as KASLR
will still shift those addresses. To handle this, the entries in the
mcount_loc section will be ignored if they are zero or match the
kaslr_offset() value.
Before:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
551
After:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
0
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200022.883095980@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-18 14:59:22 -05:00
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2019-12-04 08:46:31 +08:00
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2012-04-19 14:59:55 -07:00
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|
scripts/sorttable: Zero out weak functions in mcount_loc table
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit b39181f7c6907 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid
adding weak function") was a workaround to this by checking the function
address before printing its name. If the address was too far from the
function given by the name then instead of printing the name it would
print: __ftrace_invalid_address___<invalid-offset>
The real issue is that these invalid addresses are listed in the ftrace
table look up which available_filter_functions is derived from. A place
holder must be listed in that file because set_ftrace_filter may take a
series of indexes into that file instead of names to be able to do O(1)
lookups to enable filtering (many tools use this method).
Even if kallsyms saved the size of the function, it does not remove the
need of having these place holders. The real solution is to not add a weak
function into the ftrace table in the first place.
To solve this, the sorttable.c code that sorts the mcount regions during
the build is modified to take a "nm -S vmlinux" input, sort it, and any
function listed in the mcount_loc section that is not within a boundary of
the function list given by nm is considered a weak function and is zeroed
out.
Note, this does not mean they will remain zero when booting as KASLR
will still shift those addresses. To handle this, the entries in the
mcount_loc section will be ignored if they are zero or match the
kaslr_offset() value.
Before:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
551
After:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
0
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200022.883095980@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-18 14:59:22 -05:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:27 +08:00
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2012-04-19 14:59:55 -07:00
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2019-12-04 08:46:28 +08:00
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2012-04-19 14:59:55 -07:00
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