recordmcount: Correct st_shndx handling

One should only use st_shndx when >SHN_UNDEF and <SHN_LORESERVE. When
SHN_XINDEX, then use .symtab_shndx. Otherwise use 0.

This handles the case: st_shndx >=

recordmcount: Correct st_shndx handling

One should only use st_shndx when >SHN_UNDEF and <SHN_LORESERVE. When
SHN_XINDEX, then use .symtab_shndx. Otherwise use 0.

This handles the case: st_shndx >= SHN_LORESERVE && st_shndx != SHN_XINDEX.

Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]

Reported-by: Mark-PK Tsai <[email protected]>
Tested-by: Mark-PK Tsai <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
[handle endianness of sym->st_shndx]
Signed-off-by: Mark-PK Tsai <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

show more ...

recordmcount: support >64k sections

When compiling a kernel with Clang and LTO, we need to run
recordmcount on vmlinux.o with a large number of sections, which
currently fails as the program doesn't

recordmcount: support >64k sections

When compiling a kernel with Clang and LTO, we need to run
recordmcount on vmlinux.o with a large number of sections, which
currently fails as the program doesn't understand extended
section indexes. This change adds support for processing binaries
with >64k sections.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/lkml/CAK7LNARbZhoaA=Nnuw0=gBrkuKbr_4Ng_Ei57uafujZf7Xazgw@mail.gmail.com/

Cc: Kees Cook <[email protected]>
Reviewed-by: Matt Helsley <[email protected]>
Signed-off-by: Sami Tolvanen <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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recordmcount: Fix nop_mcount() function

The removal of the longjmp code in recordmcount.c mistakenly made the return
of make_nop() being negative an exit of nop_mcount(). It should not exit the
rout

recordmcount: Fix nop_mcount() function

The removal of the longjmp code in recordmcount.c mistakenly made the return
of make_nop() being negative an exit of nop_mcount(). It should not exit the
routine, but instead just not process that part of the code. By exiting with
an error code, it would cause the update of recordmcount to fail some files
which would fail the build if ftrace function tracing was enabled.

Link: http://lkml.kernel.org/r/[email protected]

Reported-by: Uwe Kleine-König <[email protected]>
Tested-by: Uwe Kleine-König <[email protected]>
Fixes: 3f1df12019f3 ("recordmcount: Rewrite error/success handling")
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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recordmcount: Remove redundant cleanup() calls

Redundant cleanup calls were introduced when transitioning from
the old error/success handling via setjmp/longjmp -- the longjmp
ensured the cleanup()

recordmcount: Remove redundant cleanup() calls

Redundant cleanup calls were introduced when transitioning from
the old error/success handling via setjmp/longjmp -- the longjmp
ensured the cleanup() call only happened once but replacing
the success_file()/fail_file() calls with cleanup() meant that
multiple cleanup() calls can happen as we return from function
calls.

In do_file(), looking just before and after the "goto out" jumps we
can see that multiple cleanups() are being performed. We remove
cleanup() calls from the nested functions because it makes the code
easier to review -- the resources being cleaned up are generally
allocated and initialized in the callers so freeing them there
makes more sense.

Other redundant cleanup() calls:

mmap_file() is only called from do_file() and, if mmap_file() fails,
then we goto out and do cleanup() there too.

write_file() is only called from do_file() and do_file()
calls cleanup() unconditionally after returning from write_file()
therefore the cleanup() calls in write_file() are not necessary.

find_secsym_ndx(), called from do_func()'s for-loop, when we are
cleaning up here it's obvious that we break out of the loop and
do another cleanup().

__has_rel_mcount() is called from two parts of do_func()
and calls cleanup(). In theory we move them into do_func(), however
these in turn prove redundant so another simplification step
removes them as well.

Link: http://lkml.kernel.org/r/de197e17fc5426623a847ea7cf3a1560a7402a4b.1564596289.git.mhelsley@vmware.com

Signed-off-by: Matt Helsley <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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recordmcount: Kernel style function signature formatting

The uwrite() and ulseek() functions are formatted inconsistently
with the rest of the file and the kernel overall. While we're
making other c

recordmcount: Kernel style function signature formatting

The uwrite() and ulseek() functions are formatted inconsistently
with the rest of the file and the kernel overall. While we're
making other changes here let's fix this.

Link: http://lkml.kernel.org/r/4c67698f734be9867a2aba7035fe0ce59e1e4423.1564596289.git.mhelsley@vmware.com

Signed-off-by: Matt Helsley <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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recordmcount: Rewrite error/success handling

Recordmcount uses setjmp/longjmp to manage control flow as
it reads and then writes the ELF file. This unusual control
flow is hard to follow and check i

recordmcount: Rewrite error/success handling

Recordmcount uses setjmp/longjmp to manage control flow as
it reads and then writes the ELF file. This unusual control
flow is hard to follow and check in addition to being unlike
kernel coding style.

So we rewrite these paths to use regular return values to
indicate error/success. When an error or previously-completed object
file is found we return an error code following kernel
coding conventions -- negative error values and 0 for success when
we're not returning a pointer. We return NULL for those that fail
and return non-NULL pointers otherwise.

One oddity is already_has_rel_mcount -- there we use pointer comparison
rather than string comparison to differentiate between
previously-processed object files and returning the name of a text
section.

Link: http://lkml.kernel.org/r/8ba8633d4afe444931f363c8d924bf9565b89a86.1564596289.git.mhelsley@vmware.com

Signed-off-by: Matt Helsley <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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recordmcount: Remove unused fd from uwrite() and ulseek()

uwrite() works within the pseudo-mapping and extends it as necessary
without needing the file descriptor (fd) parameter passed to it.
Simila

recordmcount: Remove unused fd from uwrite() and ulseek()

uwrite() works within the pseudo-mapping and extends it as necessary
without needing the file descriptor (fd) parameter passed to it.
Similarly, ulseek() doesn't need its fd parameter. These parameters
were only added because the functions bear a conceptual resemblance
to write() and lseek(). Worse, they obscure the fact that at the time
uwrite() and ulseek() are called fd_map is not a valid file descriptor.

Remove the unused file descriptor parameters that make it look like
fd_map is still valid.

Link: http://lkml.kernel.org/r/2a136e820ee208469d375265c7b8eb28570749a0.1563992889.git.mhelsley@vmware.com

Signed-off-by: Matt Helsley <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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recordmcount: Fix spurious mcount entries on powerpc

An impending change to enable HAVE_C_RECORDMCOUNT on powerpc leads to
warnings such as the following:

# modprobe kprobe_example
ftrace-power

recordmcount: Fix spurious mcount entries on powerpc

An impending change to enable HAVE_C_RECORDMCOUNT on powerpc leads to
warnings such as the following:

# modprobe kprobe_example
ftrace-powerpc: Not expected bl: opcode is 3c4c0001
WARNING: CPU: 0 PID: 227 at kernel/trace/ftrace.c:2001 ftrace_bug+0x90/0x318
Modules linked in:
CPU: 0 PID: 227 Comm: modprobe Not tainted 5.2.0-rc6-00678-g1c329100b942 #2
NIP: c000000000264318 LR: c00000000025d694 CTR: c000000000f5cd30
REGS: c000000001f2b7b0 TRAP: 0700 Not tainted (5.2.0-rc6-00678-g1c329100b942)
MSR: 900000010282b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 28228222 XER: 00000000
CFAR: c0000000002642fc IRQMASK: 0
<snip>
NIP [c000000000264318] ftrace_bug+0x90/0x318
LR [c00000000025d694] ftrace_process_locs+0x4f4/0x5e0
Call Trace:
[c000000001f2ba40] [0000000000000004] 0x4 (unreliable)
[c000000001f2bad0] [c00000000025d694] ftrace_process_locs+0x4f4/0x5e0
[c000000001f2bb90] [c00000000020ff10] load_module+0x25b0/0x30c0
[c000000001f2bd00] [c000000000210cb0] sys_finit_module+0xc0/0x130
[c000000001f2be20] [c00000000000bda4] system_call+0x5c/0x70
Instruction dump:
419e0018 2f83ffff 419e00bc 2f83ffea 409e00cc 4800001c 0fe00000 3c62ff96
39000001 39400000 386386d0 480000c4 <0fe00000> 3ce20003 39000001 3c62ff96
---[ end trace 4c438d5cebf78381 ]---
ftrace failed to modify
[<c0080000012a0008>] 0xc0080000012a0008
actual: 01:00:4c:3c
Initializing ftrace call sites
ftrace record flags: 2000000
(0)
expected tramp: c00000000006af4c

Looking at the relocation records in __mcount_loc shows a few spurious
entries:

RELOCATION RECORDS FOR [__mcount_loc]:
OFFSET TYPE VALUE
0000000000000000 R_PPC64_ADDR64 .text.unlikely+0x0000000000000008
0000000000000008 R_PPC64_ADDR64 .text.unlikely+0x0000000000000014
0000000000000010 R_PPC64_ADDR64 .text.unlikely+0x0000000000000060
0000000000000018 R_PPC64_ADDR64 .text.unlikely+0x00000000000000b4
0000000000000020 R_PPC64_ADDR64 .init.text+0x0000000000000008
0000000000000028 R_PPC64_ADDR64 .init.text+0x0000000000000014

The first entry in each section is incorrect. Looking at the
relocation records, the spurious entries correspond to the
R_PPC64_ENTRY records:

RELOCATION RECORDS FOR [.text.unlikely]:
OFFSET TYPE VALUE
0000000000000000 R_PPC64_REL64 .TOC.-0x0000000000000008
0000000000000008 R_PPC64_ENTRY *ABS*
0000000000000014 R_PPC64_REL24 _mcount
<snip>

The problem is that we are not validating the return value from
get_mcountsym() in sift_rel_mcount(). With this entry, mcountsym is 0,
but Elf_r_sym(relp) also ends up being 0. Fix this by ensuring
mcountsym is valid before processing the entry.

Signed-off-by: Naveen N. Rao <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Tested-by: Satheesh Rajendran <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 378

Based on 1 normalized pattern(s):

licensed under the gnu general public license version 2 gplv2

extracted by the scancode licen

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 378

Based on 1 normalized pattern(s):

licensed under the gnu general public license version 2 gplv2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 5 file(s).

Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Kate Stewart <[email protected]>
Reviewed-by: Armijn Hemel <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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scripts: Fixed printf format mismatch

scripts/kallsyms.c: function write_src:
"printf", the #1 format specifier "d" need arg type "int",
but the according arg "table_cnt" has type "unsigned int"

sc

scripts: Fixed printf format mismatch

scripts/kallsyms.c: function write_src:
"printf", the #1 format specifier "d" need arg type "int",
but the according arg "table_cnt" has type "unsigned int"

scripts/recordmcount.c: function do_file:
"fprintf", the #1 format specifier "d" need arg type "int",
but the according arg "(*w2)(ehdr->e_machine)" has type "unsigned int"

scripts/recordmcount.h: function find_secsym_ndx:
"fprintf", the #1 format specifier "d" need arg type "int",
but the according arg "txtndx" has type "unsigned int"

Signed-off-by: nixiaoming <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

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recordmcount: Fix endianness handling bug for nop_mcount

In nop_mcount, shdr->sh_offset and welp->r_offset should handle
endianness properly, otherwise it will trigger Segmentation fault
if the reco

recordmcount: Fix endianness handling bug for nop_mcount

In nop_mcount, shdr->sh_offset and welp->r_offset should handle
endianness properly, otherwise it will trigger Segmentation fault
if the recordmcount main and file.o have different endianness.

Link: http://lkml.kernel.org/r/[email protected]

Cc: <[email protected]> # 3.0+
Signed-off-by: Li Bin <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

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recordmcount/MIPS: Fix possible incorrect mcount_loc table entries in modules

On MIPS calls to _mcount in modules generate 2 instructions to load
the _mcount address (and therefore 2 relocations). T

recordmcount/MIPS: Fix possible incorrect mcount_loc table entries in modules

On MIPS calls to _mcount in modules generate 2 instructions to load
the _mcount address (and therefore 2 relocations). The mcount_loc
table should only reference the first of these, so the second is
filtered out by checking the relocation offset and ignoring ones that
immediately follow the previous one seen.

However if a module has an _mcount call at offset 0, the second
relocation would not be filtered out due to old_r_offset == 0
being taken to mean that the current relocation is the first one
seen, and both would end up in the mcount_loc table.

This results in ftrace_make_nop() patching both (adjacent)
instructions to branches over the _mcount call sequence like so:

0xffffffffc08a8000: 04 00 00 10 b 0xffffffffc08a8014
0xffffffffc08a8004: 04 00 00 10 b 0xffffffffc08a8018
0xffffffffc08a8008: 2d 08 e0 03 move at,ra
...

The second branch is in the delay slot of the first, which is
defined to be unpredictable - on the platform on which this bug was
encountered, it triggers a reserved instruction exception.

Fix by initializing old_r_offset to ~0 and using that instead of 0
to determine whether the current relocation is the first seen.

Signed-off-by: Alex Smith <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Patchwork: https://patchwork.linux-mips.org/patch/7098/
Signed-off-by: Ralf Baechle <[email protected]>

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ftrace: Make recordmcount.c handle __fentry__

With gcc 4.6.0 the -mfentry feature places the function profiling
call at the start of the function. When this is used, the call is
to __fentry__ and no

ftrace: Make recordmcount.c handle __fentry__

With gcc 4.6.0 the -mfentry feature places the function profiling
call at the start of the function. When this is used, the call is
to __fentry__ and not mcount.

Change recordmcount.c to record both callers to __fentry__ and
mcount.

Link: http://lkml.kernel.org/r/[email protected]

Acked-by: H. Peter Anvin <[email protected]>
Acked-by: John Reiser <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Cc: Andi Kleen <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

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recordmcount: Fix handling of elf64 big-endian objects.

In ELF64, the sh_flags field is 64-bits wide. recordmcount was
erroneously treating it as a 32-bit wide field. For little endian
objects thi

recordmcount: Fix handling of elf64 big-endian objects.

In ELF64, the sh_flags field is 64-bits wide. recordmcount was
erroneously treating it as a 32-bit wide field. For little endian
objects this works because the flags of interest (SHF_EXECINSTR)
reside in the lower 32 bits of the word, and you get the same result
with either a 32-bit or 64-bit read. Big endian objects on the
other hand do not work at all with this error.

The fix: Correctly treat sh_flags as 64-bits wide in elf64 objects.

The symptom I observed was that my
__start_mcount_loc..__stop_mcount_loc was empty even though ftrace
function tracing was enabled.

Link: http://lkml.kernel.org/r/[email protected]

Cc: [email protected] # 3.0+
Signed-off-by: David Daney <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

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ftrace/recordmcount: Avoid STT_FUNC symbols as base on ARM

While find_secsym_ndx often finds the unamed local STT_SECTION, if a
section has only one function in it, the ARM toolchain generates the
S

ftrace/recordmcount: Avoid STT_FUNC symbols as base on ARM

While find_secsym_ndx often finds the unamed local STT_SECTION, if a
section has only one function in it, the ARM toolchain generates the
STT_FUNC symbol before the STT_SECTION, and recordmcount finds this
instead.

This is problematic on ARM because in ARM ELFs, "if a [STT_FUNC] symbol
addresses a Thumb instruction, its value is the address of the
instruction with bit zero set (in a relocatable object, the section
offset with bit zero set)". This leads to incorrect mcount addresses
being recorded.

Fix this by not using STT_FUNC symbols as the base on ARM.

Signed-off-by: Rabin Vincent <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Steven Rostedt <[email protected]>

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ftrace/recordmcount: mcount address adjustment

Introduce mcount_adjust{,_32,_64} to the C implementation of
recordmcount analog to $mcount_adjust in the perl script.
The adjustment is added to the a

ftrace/recordmcount: mcount address adjustment

Introduce mcount_adjust{,_32,_64} to the C implementation of
recordmcount analog to $mcount_adjust in the perl script.
The adjustment is added to the address of the relocations
against the mcount symbol. If this adjustment is done by
recordmcount at compile time the ftrace_call_adjust function
can be turned into a nop.

Cc: John Reiser <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

show more ...

ftrace/recordmcount: Add helper function get_sym_str_and_relp()

The code to get the symbol, string, and relp pointers in the two functions
sift_rel_mcount() and nop_mcount() are identical and also n

ftrace/recordmcount: Add helper function get_sym_str_and_relp()

The code to get the symbol, string, and relp pointers in the two functions
sift_rel_mcount() and nop_mcount() are identical and also non-trivial.
Moving this duplicate code into a single helper function makes the code
easier to read and more maintainable.

Cc: John Reiser <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Steven Rostedt <[email protected]>

show more ...

ftrace/recordmcount: Remove duplicate code to find mcount symbol

The code in sift_rel_mcount() and nop_mcount() to get the mcount symbol
number is identical. Replace the two locations with a call to

ftrace/recordmcount: Remove duplicate code to find mcount symbol

The code in sift_rel_mcount() and nop_mcount() to get the mcount symbol
number is identical. Replace the two locations with a call to a function
that does the work.

Cc: John Reiser <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Steven Rostedt <[email protected]>

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ftrace/recordmcount: Add warning logic to warn on mcount not recorded

There's some sections that should not have mcount recorded and should not have
modifications to the that code. But currently the

ftrace/recordmcount: Add warning logic to warn on mcount not recorded

There's some sections that should not have mcount recorded and should not have
modifications to the that code. But currently they waste some time by calling
mcount anyway (which simply returns). As the real answer should be to
either whitelist the section or have gcc ignore it fully.

This change adds a option to recordmcount to warn when it finds a section
that is ignored by ftrace but still contains mcount callers. This is not on
by default as developers may not know if the section should be completely
ignored or added to the whitelist.

Cc: John Reiser <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Steven Rostedt <[email protected]>

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ftrace/recordmcount: Make ignored mcount calls into nops at compile time

There are sections that are ignored by ftrace for the function tracing because
the text is in a section that can be removed w

ftrace/recordmcount: Make ignored mcount calls into nops at compile time

There are sections that are ignored by ftrace for the function tracing because
the text is in a section that can be removed without notice. The mcount calls
in these sections are ignored and ftrace never sees them. The downside of this
is that the functions in these sections still call mcount. Although the mcount
function is defined in assembly simply as a return, this added overhead is
unnecessary.

The solution is to convert these callers into nops at compile time.
A better solution is to add 'notrace' to the section markers, but as new sections
come up all the time, it would be nice that they are delt with when they
are created.

Later patches will deal with finding these sections and doing the proper solution.

Thanks to H. Peter Anvin for giving me the right nops to use for x86.

Cc: "H. Peter Anvin" <[email protected]>
Cc: John Reiser <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Steven Rostedt <[email protected]>

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ftrace/recordmcount: Modify only executable sections

PROGBITS is not enough to determine if the section should be modified
or not. Only process sections that are marked as executable.

Cc: John Reis

ftrace/recordmcount: Modify only executable sections

PROGBITS is not enough to determine if the section should be modified
or not. Only process sections that are marked as executable.

Cc: John Reiser <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Steven Rostedt <[email protected]>

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ftrace/trivial: Clean up recordmcount.c to use Linux style comparisons

The Linux ftrace subsystem style for comparing is:

var == 1
var > 0

and not:

1 == var
0 < var

It is considered that

ftrace/trivial: Clean up recordmcount.c to use Linux style comparisons

The Linux ftrace subsystem style for comparing is:

var == 1
var > 0

and not:

1 == var
0 < var

It is considered that Linux developers are smart enough not to do the

if (var = 1)

mistake.

Cc: John Reiser <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Steven Rostedt <[email protected]>

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ftrace/recordmcount: mcount address adjustment

Introduce mcount_adjust{,_32,_64} to the C implementation of
recordmcount analog to $mcount_adjust in the perl script.
The adjustment is added to the a

ftrace/recordmcount: mcount address adjustment

Introduce mcount_adjust{,_32,_64} to the C implementation of
recordmcount analog to $mcount_adjust in the perl script.
The adjustment is added to the address of the relocations
against the mcount symbol. If this adjustment is done by
recordmcount at compile time the ftrace_call_adjust function
can be turned into a nop.

Cc: John Reiser <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>

show more ...

ftrace/recordmcount: Add helper function get_sym_str_and_relp()

The code to get the symbol, string, and relp pointers in the two functions
sift_rel_mcount() and nop_mcount() are identical and also n

ftrace/recordmcount: Add helper function get_sym_str_and_relp()

The code to get the symbol, string, and relp pointers in the two functions
sift_rel_mcount() and nop_mcount() are identical and also non-trivial.
Moving this duplicate code into a single helper function makes the code
easier to read and more maintainable.

Cc: John Reiser <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Steven Rostedt <[email protected]>

show more ...

ftrace/recordmcount: Remove duplicate code to find mcount symbol

The code in sift_rel_mcount() and nop_mcount() to get the mcount symbol
number is identical. Replace the two locations with a call to

ftrace/recordmcount: Remove duplicate code to find mcount symbol

The code in sift_rel_mcount() and nop_mcount() to get the mcount symbol
number is identical. Replace the two locations with a call to a function
that does the work.

Cc: John Reiser <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Steven Rostedt <[email protected]>

show more ...