linux-stable.git/include/asm-generic/vmlinux.lds.h, branch v4.14.78

earlycon: Use a pointer table to fix __earlycon_table stride

2018-05-01T19:58:24+00:00

commit dd709e72cb934eefd44de8d9969097173fbf45dc upstream.

Commit 99492c39f39f ("earlycon: Fix __earlycon_table stride") tried to fix
__earlycon_table stride by forcing the earlycon_id struct alignment to 32
and asking the linker to 32-byte align the __earlycon_table symbol.  This
fix was based on commit 07fca0e57fca92 ("tracing: Properly align linker
defined symbols") which tried a similar fix for the tracing subsystem.

However, this fix doesn't quite work because there is no guarantee that
gcc will place structures packed into an array format.  In fact, gcc 4.9
chooses to 64-byte align these structs by inserting additional padding
between the entries because it has no clue that they are supposed to be in
an array.  If we are unlucky, the linker will assign symbol
"__earlycon_table" to a 32-byte aligned address which does not correspond
to the 64-byte aligned contents of section "__earlycon_table".

To address this same problem, the fix to the tracing system was
subsequently re-implemented using a more robust table of pointers approach
by commits:
 3d56e331b653 ("tracing: Replace syscall_meta_data struct array with pointer array")
 654986462939 ("tracepoints: Fix section alignment using pointer array")
 e4a9ea5ee7c8 ("tracing: Replace trace_event struct array with pointer array")

Let's use this same "array of pointers to structs" approach for
EARLYCON_TABLE.

Fixes: 99492c39f39f ("earlycon: Fix __earlycon_table stride")
Signed-off-by: Daniel Kurtz 
Suggested-by: Aaron Durbin 
Reviewed-by: Rob Herring 
Tested-by: Guenter Roeck 
Reviewed-by: Guenter Roeck 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

x86/unwind: Rename unwinder config options to 'CONFIG_UNWINDER_*'

2017-12-25T13:26:13+00:00

commit 11af847446ed0d131cf24d16a7ef3d5ea7a49554 upstream.

Rename the unwinder config options from:

  CONFIG_ORC_UNWINDER
  CONFIG_FRAME_POINTER_UNWINDER
  CONFIG_GUESS_UNWINDER

to:

  CONFIG_UNWINDER_ORC
  CONFIG_UNWINDER_FRAME_POINTER
  CONFIG_UNWINDER_GUESS

... in order to give them a more logical config namespace.

Suggested-by: Ingo Molnar 
Signed-off-by: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/73972fc7e2762e91912c6b9584582703d6f1b8cc.1507924831.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

locking/refcounts, x86/asm: Use unique .text section for refcount exceptions

2017-12-10T12:40:42+00:00

[ Upstream commit 564c9cc84e2adf8a6671c1937f0a9fe3da2a4b0e ]

Using .text.unlikely for refcount exceptions isn't safe because gcc may
move entire functions into .text.unlikely (e.g. in6_dev_dev()), which
would cause any uses of a protected refcount_t function to stay inline
with the function, triggering the protection unconditionally:

        .section        .text.unlikely,"ax",@progbits
        .type   in6_dev_get, @function
in6_dev_getx:
.LFB4673:
        .loc 2 4128 0
        .cfi_startproc
...
        lock; incl 480(%rbx)
        js 111f
        .pushsection .text.unlikely
111:    lea 480(%rbx), %rcx
112:    .byte 0x0f, 0xff
.popsection
113:

This creates a unique .text..refcount section and adds an additional
test to the exception handler to WARN in the case of having none of OF,
SF, nor ZF set so we can see things like this more easily in the future.

The double dot for the section name keeps it out of the TEXT_MAIN macro
namespace, to avoid collisions and so it can be put at the end with
text.unlikely to keep the cold code together.

See commit:

  cb87481ee89db ("kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured")

... which matches C names: [a-zA-Z0-9_] but not ".".

Reported-by: Mike Galbraith 
Signed-off-by: Kees Cook 
Cc: Ard Biesheuvel 
Cc: Elena 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-arch 
Fixes: 7a46ec0e2f48 ("locking/refcounts, x86/asm: Implement fast refcount overflow protection")
Link: http://lkml.kernel.org/r/1504382986-49301-2-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'for-linus-20170904' of git://git.infradead.org/linux-mtd

2017-09-09T21:48:21+00:00

Pull MTD updates from Boris Brezillon:
 "General updates:
   - Constify pci_device_id in various drivers
   - Constify device_type
   - Remove pad control code from the Gemini driver
   - Use %pOF to print OF node full_name
   - Various fixes in the physmap_of driver
   - Remove unused vars in mtdswap
   - Check devm_kzalloc() return value in the spear_smi driver
   - Check clk_prepare_enable() return code in the st_spi_fsm driver
   - Create per MTD device debugfs enties

  NAND updates, from Boris Brezillon:
   - Fix memory leaks in the core
   - Remove unused NAND locking support
   - Rename nand.h into rawnand.h (preparing support for spi NANDs)
   - Use NAND_MAX_ID_LEN where appropriate
   - Fix support for 20nm Hynix chips
   - Fix support for Samsung and Hynix SLC NANDs
   - Various cleanup, improvements and fixes in the qcom driver
   - Fixes for bugs detected by various static code analysis tools
   - Fix mxc ooblayout definition
   - Add a new part_parsers to tmio and sharpsl platform data in order
     to define a custom list of partition parsers
   - Request the reset line in exclusive mode in the sunxi driver
   - Fix a build error in the orion-nand driver when compiled for ARMv4
   - Allow 64-bit mvebu platforms to select the PXA3XX driver

  SPI NOR updates, from Cyrille Pitchen and Marek Vasut:
   - add support to the JEDEC JESD216B specification (SFDP tables).
   - add support to the Intel Denverton SPI flash controller.
   - fix error recovery for Spansion/Cypress SPI NOR memories.
   - fix 4-byte address management for the Aspeed SPI controller.
   - add support to some Microchip SST26 memory parts
   - remove unneeded pinctrl header Write a message for tag:"

* tag 'for-linus-20170904' of git://git.infradead.org/linux-mtd: (74 commits)
  mtd: nand: complain loudly when chip->bits_per_cell is not correctly initialized
  mtd: nand: make Samsung SLC NAND usable again
  mtd: nand: tmio: Register partitions using the parsers
  mfd: tmio: Add partition parsers platform data
  mtd: nand: sharpsl: Register partitions using the parsers
  mtd: nand: sharpsl: Add partition parsers platform data
  mtd: nand: qcom: Support for IPQ8074 QPIC NAND controller
  mtd: nand: qcom: support for IPQ4019 QPIC NAND controller
  dt-bindings: qcom_nandc: IPQ8074 QPIC NAND documentation
  dt-bindings: qcom_nandc: IPQ4019 QPIC NAND documentation
  dt-bindings: qcom_nandc: fix the ipq806x device tree example
  mtd: nand: qcom: support for different DEV_CMD register offsets
  mtd: nand: qcom: QPIC data descriptors handling
  mtd: nand: qcom: enable BAM or ADM mode
  mtd: nand: qcom: erased codeword detection configuration
  mtd: nand: qcom: support for read location registers
  mtd: nand: qcom: support for passing flags in DMA helper functions
  mtd: nand: qcom: add BAM DMA descriptor handling
  mtd: nand: qcom: allocate BAM transaction
  mtd: nand: qcom: DMA mapping support for register read buffer
  ...

Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-09-04T16:52:57+00:00

Pull x86 asm updates from Ingo Molnar:

 - Introduce the ORC unwinder, which can be enabled via
   CONFIG_ORC_UNWINDER=y.

   The ORC unwinder is a lightweight, Linux kernel specific debuginfo
   implementation, which aims to be DWARF done right for unwinding.
   Objtool is used to generate the ORC unwinder tables during build, so
   the data format is flexible and kernel internal: there's no
   dependency on debuginfo created by an external toolchain.

   The ORC unwinder is almost two orders of magnitude faster than the
   (out of tree) DWARF unwinder - which is important for perf call graph
   profiling. It is also significantly simpler and is coded defensively:
   there has not been a single ORC related kernel crash so far, even
   with early versions. (knock on wood!)

   But the main advantage is that enabling the ORC unwinder allows
   CONFIG_FRAME_POINTERS to be turned off - which speeds up the kernel
   measurably:

   With frame pointers disabled, GCC does not have to add frame pointer
   instrumentation code to every function in the kernel. The kernel's
   .text size decreases by about 3.2%, resulting in better cache
   utilization and fewer instructions executed, resulting in a broad
   kernel-wide speedup. Average speedup of system calls should be
   roughly in the 1-3% range - measurements by Mel Gorman [1] have shown
   a speedup of 5-10% for some function execution intense workloads.

   The main cost of the unwinder is that the unwinder data has to be
   stored in RAM: the memory cost is 2-4MB of RAM, depending on kernel
   config - which is a modest cost on modern x86 systems.

   Given how young the ORC unwinder code is it's not enabled by default
   - but given the performance advantages the plan is to eventually make
   it the default unwinder on x86.

   See Documentation/x86/orc-unwinder.txt for more details.

 - Remove lguest support: its intended role was that of a temporary
   proof of concept for virtualization, plus its removal will enable the
   reduction (removal) of the paravirt API as well, so Rusty agreed to
   its removal. (Juergen Gross)

 - Clean up and fix FSGS related functionality (Andy Lutomirski)

 - Clean up IO access APIs (Andy Shevchenko)

 - Enhance the symbol namespace (Jiri Slaby)

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  objtool: Handle GCC stack pointer adjustment bug
  x86/entry/64: Use ENTRY() instead of ALIGN+GLOBAL for stub32_clone()
  x86/fpu/math-emu: Add ENDPROC to functions
  x86/boot/64: Extract efi_pe_entry() from startup_64()
  x86/boot/32: Extract efi_pe_entry() from startup_32()
  x86/lguest: Remove lguest support
  x86/paravirt/xen: Remove xen_patch()
  objtool: Fix objtool fallthrough detection with function padding
  x86/xen/64: Fix the reported SS and CS in SYSCALL
  objtool: Track DRAP separately from callee-saved registers
  objtool: Fix validate_branch() return codes
  x86: Clarify/fix no-op barriers for text_poke_bp()
  x86/switch_to/64: Rewrite FS/GS switching yet again to fix AMD CPUs
  selftests/x86/fsgsbase: Test selectors 1, 2, and 3
  x86/fsgsbase/64: Report FSBASE and GSBASE correctly in core dumps
  x86/fsgsbase/64: Fully initialize FS and GS state in start_thread_common
  x86/asm: Fix UNWIND_HINT_REGS macro for older binutils
  x86/asm/32: Fix regs_get_register() on segment registers
  x86/xen/64: Rearrange the SYSCALL entries
  x86/asm/32: Remove a bunch of '& 0xffff' from pt_regs segment reads
  ...

Merge tag 'v4.13-rc7' into mtd/next

2017-08-28T16:04:15+00:00

Merge v4.13-rc7 back to resolve merge conflicts in
drivers/mtd/nand/nandsim.c and include/asm-generic/vmlinux.lds.h.

Merge branch 'perf/urgent' into perf/core, to pick up fixes

2017-08-25T09:01:05+00:00

Signed-off-by: Ingo Molnar

mtd: only use __xipram annotation when XIP_KERNEL is set

2017-08-15T12:00:44+00:00

When XIP_KERNEL is enabled, some functions are defined in the .data
ELF section because we require them to be in RAM whenever we communicate
with the flash chip. However this causes problems when FTRACE is
enabled and gcc emits calls to __gnu_mcount_nc in the function
prolog:

drivers/built-in.o: In function `cfi_chip_setup':
:(.data+0x272fc): relocation truncated to fit: R_ARM_CALL against symbol `__gnu_mcount_nc' defined in .text section in arch/arm/kernel/built-in.o
drivers/built-in.o: In function `cfi_probe_chip':
:(.data+0x27de8): relocation truncated to fit: R_ARM_CALL against symbol `__gnu_mcount_nc' defined in .text section in arch/arm/kernel/built-in.o
/tmp/ccY172rP.s: Assembler messages:
/tmp/ccY172rP.s:70: Warning: ignoring changed section attributes for .data
/tmp/ccY172rP.s: Error: 1 warning, treating warnings as errors
make[5]: *** [drivers/mtd/chips/cfi_probe.o] Error 1
/tmp/ccK4rjeO.s: Assembler messages:
/tmp/ccK4rjeO.s:421: Warning: ignoring changed section attributes for .data
/tmp/ccK4rjeO.s: Error: 1 warning, treating warnings as errors
make[5]: *** [drivers/mtd/chips/cfi_util.o] Error 1
/tmp/ccUvhCYR.s: Assembler messages:
/tmp/ccUvhCYR.s:1895: Warning: ignoring changed section attributes for .data
/tmp/ccUvhCYR.s: Error: 1 warning, treating warnings as errors

Specifically, this does not work because the .data section is not
marked executable, which leads LD to not generate trampolines for
long calls.

This moves the __xipram functions into their own .xiptext section instead.
The section is still placed next to .data and located in RAM but is marked
executable, which avoids the build errors.

Also, we only need to place the XIP functions into a separate section
if both CONFIG_XIP_KERNEL and CONFIG_MTD_XIP are set: When only MTD_XIP
is used, the whole kernel is still in RAM and we do not need to worry
about pulling out the rug under it. When only XIP_KERNEL but not MTD_XIP
is set, the kernel is in some form of ROM, but we never write to it.

Note that MTD_XIP has been broken on ARM since around 2011 or 2012. I
have sent another patch[2] to fix compilation, which I plan to merge
through arm-soc unless there are objections. The obvious alternative
to that would be to completely rip out the MTD_XIP support from the
kernel, since obviously nobody has been using it in a long while.

Link: [1] https://patchwork.kernel.org/patch/8109771/
Link: [2] https://patchwork.kernel.org/patch/9855225/
Signed-off-by: Arnd Bergmann 
Signed-off-by: Boris Brezillon

irq: Make the irqentry text section unconditional

2017-08-10T14:28:53+00:00

Generate irqentry and softirqentry text sections without
any Kconfig dependencies. This will add extra sections, but
there should be no performace impact.

Suggested-by: Ingo Molnar 
Signed-off-by: Masami Hiramatsu 
Cc: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: Chris Zankel 
Cc: David S . Miller 
Cc: Francis Deslauriers 
Cc: Jesper Nilsson 
Cc: Linus Torvalds 
Cc: Max Filippov 
Cc: Mikael Starvik 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Yoshinori Sato 
Cc: linux-arch@vger.kernel.org
Cc: linux-cris-kernel@axis.com
Cc: mathieu.desnoyers@efficios.com
Link: http://lkml.kernel.org/r/150172789110.27216.3955739126693102122.stgit@devbox
Signed-off-by: Ingo Molnar

kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured

2017-08-09T15:57:42+00:00

The .data and .bss sections were modified in the generic linker script to
pull in sections named .data., which are generated by gcc with
-ffunction-sections and -fdata-sections options.

The problem with this pattern is it can also match section names that Linux
defines explicitly, e.g., .data.unlikely. This can cause Linux sections to
get moved into the wrong place.

The way to avoid this is to use ".." separators for explicit section names
(the dot character is valid in a section name but not a C identifier).
However currently there are sections which don't follow this rule, so for
now just disable the wild card by default.

Example: http://marc.info/?l=linux-arm-kernel&m=150106824024221&w=2

Cc:  # 4.9
Fixes: b67067f1176df ("kbuild: allow archs to select link dead code/data elimination")
Signed-off-by: Nicholas Piggin 
Signed-off-by: Masahiro Yamada