linux-stable.git/arch/arm/kernel, branch v5.4.151

ARM: 9098/1: ftrace: MODULE_PLT: Fix build problem without DYNAMIC_FTRACE

2021-09-26T12:07:07+00:00

commit 6fa630bf473827aee48cbf0efbbdf6f03134e890 upstream

FTRACE_ADDR is only defined when CONFIG_DYNAMIC_FTRACE is defined, the
latter is even stronger requirement than CONFIG_FUNCTION_TRACER (which is
enough for MCOUNT_ADDR).

Link: https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org/thread/ZUVCQBHDMFVR7CCB7JPESLJEWERZDJ3T/

Fixes: 1f12fb25c5c5d22f ("ARM: 9079/1: ftrace: Add MODULE_PLTS support")
Reported-by: kernel test robot 
Signed-off-by: Alexander Sverdlin 
Signed-off-by: Russell King 
Signed-off-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman

ARM: 9079/1: ftrace: Add MODULE_PLTS support

2021-09-26T12:07:07+00:00

commit 79f32b221b18c15a98507b101ef4beb52444cc6f upstream

Teach ftrace_make_call() and ftrace_make_nop() about PLTs.
Teach PLT code about FTRACE and all its callbacks.
Otherwise the following might happen:

------------[ cut here ]------------
WARNING: CPU: 14 PID: 2265 at .../arch/arm/kernel/insn.c:14 __arm_gen_branch+0x83/0x8c()
...
Hardware name: LSI Axxia AXM55XX
[] (unwind_backtrace) from [] (show_stack+0x11/0x14)
[] (show_stack) from [] (dump_stack+0x81/0xa8)
[] (dump_stack) from [] (warn_slowpath_common+0x69/0x90)
[] (warn_slowpath_common) from [] (warn_slowpath_null+0x17/0x1c)
[] (warn_slowpath_null) from [] (__arm_gen_branch+0x83/0x8c)
[] (__arm_gen_branch) from [] (ftrace_make_nop+0xf/0x24)
[] (ftrace_make_nop) from [] (ftrace_process_locs+0x27b/0x3e8)
[] (ftrace_process_locs) from [] (load_module+0x11e9/0x1a44)
[] (load_module) from [] (SyS_finit_module+0x59/0x84)
[] (SyS_finit_module) from [] (ret_fast_syscall+0x1/0x18)
---[ end trace e1b64ced7a89adcc ]---
------------[ cut here ]------------
WARNING: CPU: 14 PID: 2265 at .../kernel/trace/ftrace.c:1979 ftrace_bug+0x1b1/0x234()
...
Hardware name: LSI Axxia AXM55XX
[] (unwind_backtrace) from [] (show_stack+0x11/0x14)
[] (show_stack) from [] (dump_stack+0x81/0xa8)
[] (dump_stack) from [] (warn_slowpath_common+0x69/0x90)
[] (warn_slowpath_common) from [] (warn_slowpath_null+0x17/0x1c)
[] (warn_slowpath_null) from [] (ftrace_bug+0x1b1/0x234)
[] (ftrace_bug) from [] (ftrace_process_locs+0x285/0x3e8)
[] (ftrace_process_locs) from [] (load_module+0x11e9/0x1a44)
[] (load_module) from [] (SyS_finit_module+0x59/0x84)
[] (SyS_finit_module) from [] (ret_fast_syscall+0x1/0x18)
---[ end trace e1b64ced7a89adcd ]---
ftrace failed to modify [] 0xe9ef7006
actual: 02:f0:3b:fa
ftrace record flags: 0
(0) expected tramp: c0314265

Signed-off-by: Alexander Sverdlin 
Signed-off-by: Russell King 
Signed-off-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman

ARM: 9078/1: Add warn suppress parameter to arm_gen_branch_link()

2021-09-26T12:07:06+00:00

commit 890cb057a46d323fd8c77ebecb6485476614cd21 upstream

Will be used in the following patch. No functional change.

Signed-off-by: Alexander Sverdlin 
Signed-off-by: Russell King 
Signed-off-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman

ARM: 9077/1: PLT: Move struct plt_entries definition to header

2021-09-26T12:07:06+00:00

commit 4e271701c17dee70c6e1351c4d7d42e70405c6a9 upstream

No functional change, later it will be re-used in several files.

Signed-off-by: Alexander Sverdlin 
Signed-off-by: Russell King 
Signed-off-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman

ARM: 8918/2: only build return_address() if needed

2021-09-12T06:56:40+00:00

commit fb033c95c94ca1ee3d16e04ebdb85d65fb55fff8 upstream.

The system currently warns if the config conditions for
building return_address in arch/arm/kernel/return_address.c
are not met, leaving just an EXPORT_SYMBOL_GPL(return_address)
of a function defined to be 'static linline'.
This is a result of aeea3592a13b ("ARM: 8158/1: LLVMLinux: use static inline in ARM ftrace.h").

Since we're not going to build anything other than an exported
symbol for something that is already being defined to be an
inline-able return of NULL, just avoid building the code to
remove the following warning:

Fixes: aeea3592a13b ("ARM: 8158/1: LLVMLinux: use static inline in ARM ftrace.h")
Signed-off-by: Ben Dooks 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

arm_pmu: Fix write counter incorrect in ARMv7 big-endian mode

2021-07-14T14:53:02+00:00

commit fdbef8c4e68ad423416aa6cc93d1616d6f8ac5b3 upstream.

Commit 3a95200d3f89 ("arm_pmu: Change API to support 64bit counter values")
changes the input "value" type from 32-bit to 64-bit, which introduces the
following problem: ARMv7 PMU counters is 32-bit width, in big-endian mode,
write counter uses high 32-bit, which writes an incorrect value.

Before:

 Performance counter stats for 'ls':

              2.22 msec task-clock                #    0.675 CPUs utilized
                 0      context-switches          #    0.000 K/sec
                 0      cpu-migrations            #    0.000 K/sec
                49      page-faults               #    0.022 M/sec
        2150476593      cycles                    #  966.663 GHz
        2148588788      instructions              #    1.00  insn per cycle
        2147745484      branches                  # 965435.074 M/sec
        2147508540      branch-misses             #   99.99% of all branches

None of the above hw event counters are correct.

Solution:

"value" forcibly converted to 32-bit type before being written to PMU register.

After:

 Performance counter stats for 'ls':

              2.09 msec task-clock                #    0.681 CPUs utilized
                 0      context-switches          #    0.000 K/sec
                 0      cpu-migrations            #    0.000 K/sec
                46      page-faults               #    0.022 M/sec
           2807301      cycles                    #    1.344 GHz
           1060159      instructions              #    0.38  insn per cycle
            250496      branches                  #  119.914 M/sec
             23192      branch-misses             #    9.26% of all branches

Fixes: 3a95200d3f89 ("arm_pmu: Change API to support 64bit counter values")
Cc: 
Signed-off-by: Yang Jihong 
Acked-by: Mark Rutland 
Link: https://lore.kernel.org/r/20210430012659.232110-1-yangjihong1@huawei.com
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

ARM: 9081/1: fix gcc-10 thumb2-kernel regression

2021-06-30T12:47:43+00:00

commit dad7b9896a5dbac5da8275d5a6147c65c81fb5f2 upstream.

When building the kernel wtih gcc-10 or higher using the
CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE=y flag, the compiler picks a slightly
different set of registers for the inline assembly in cpu_init() that
subsequently results in a corrupt kernel stack as well as remaining in
FIQ mode. If a banked register is used for the last argument, the wrong
version of that register gets loaded into CPSR_c.  When building in Arm
mode, the arguments are passed as immediate values and the bug cannot
happen.

This got introduced when Daniel reworked the FIQ handling and was
technically always broken, but happened to work with both clang and gcc
before gcc-10 as long as they picked one of the lower registers.
This is probably an indication that still very few people build the
kernel in Thumb2 mode.

Marek pointed out the problem on IRC, Arnd narrowed it down to this
inline assembly and Russell pinpointed the exact bug.

Change the constraints to force the final mode switch to use a non-banked
register for the argument to ensure that the correct constant gets loaded.
Another alternative would be to always use registers for the constant
arguments to avoid the #ifdef that has now become more complex.

Cc:  # v3.18+
Cc: Daniel Thompson 
Reported-by: Marek Vasut 
Acked-by: Ard Biesheuvel 
Fixes: c0e7f7ee717e ("ARM: 8150/3: fiq: Replace default FIQ handler")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

ARM: 9075/1: kernel: Fix interrupted SMC calls

2021-05-22T09:38:28+00:00

[ Upstream commit 57ac51667d8cd62731223d687e5fe7b41c502f89 ]

On Qualcomm ARM32 platforms, the SMC call can return before it has
completed. If this occurs, the call can be restarted, but it requires
using the returned session ID value from the interrupted SMC call.

The ARM32 SMCC code already has the provision to add platform specific
quirks for things like this. So let's make use of it and add the
Qualcomm specific quirk (ARM_SMCCC_QUIRK_QCOM_A6) used by the QCOM_SCM
driver.

This change is similar to the below one added for ARM64 a while ago:
commit 82bcd087029f ("firmware: qcom: scm: Fix interrupted SCM calls")

Without this change, the Qualcomm ARM32 platforms like SDX55 will return
-EINVAL for SMC calls used for modem firmware loading and validation.

Signed-off-by: Manivannan Sadhasivam 
Reviewed-by: Bjorn Andersson 
Signed-off-by: Russell King 
Signed-off-by: Sasha Levin

ARM: 9066/1: ftrace: pause/unpause function graph tracer in cpu_suspend()

2021-05-22T09:38:28+00:00

[ Upstream commit 8252ca87c7a2111502ee13994956f8c309faad7f ]

Enabling function_graph tracer on ARM causes kernel panic, because the
function graph tracer updates the "return address" of a function in order
to insert a trace callback on function exit, it saves the function's
original return address in a return trace stack, but cpu_suspend() may not
return through the normal return path.

cpu_suspend() will resume directly via the cpu_resume path, but the return
trace stack has been set-up by the subfunctions of cpu_suspend(), which
makes the "return address" inconsistent with cpu_suspend().

This patch refers to Commit de818bd4522c40ea02a81b387d2fa86f989c9623
("arm64: kernel: pause/unpause function graph tracer in cpu_suspend()"),

fixes the issue by pausing/resuming the function graph tracer on the thread
executing cpu_suspend(), so that the function graph tracer state is kept
consistent across functions that enter power down states and never return
by effectively disabling graph tracer while they are executing.

Signed-off-by: louis.wang 
Signed-off-by: Russell King 
Signed-off-by: Sasha Levin

ARM: 9027/1: head.S: explicitly map DT even if it lives in the first physical section

2021-05-19T08:08:32+00:00

commit 10fce53c0ef8f6e79115c3d9e0d7ea1338c3fa37 upstream

The early ATAGS/DT mapping code uses SECTION_SHIFT to mask low order
bits of R2, and decides that no ATAGS/DTB were provided if the resulting
value is 0x0.

This means that on systems where DRAM starts at 0x0 (such as Raspberry
Pi), no explicit mapping of the DT will be created if R2 points into the
first 1 MB section of memory. This was not a problem before, because the
decompressed kernel is loaded at the base of DRAM and mapped using
sections as well, and so as long as the DT is referenced via a virtual
address that uses the same translation (the linear map, in this case),
things work fine.

However, commit 7a1be318f579 ("9012/1: move device tree mapping out of
linear region") changes this, and now the DT is referenced via a virtual
address that is disjoint from the linear mapping of DRAM, and so we need
the early code to create the DT mapping unconditionally.

So let's create the early DT mapping for any value of R2 != 0x0.

Reported-by: "kernelci.org bot" 
Reviewed-by: Linus Walleij 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Russell King 
Signed-off-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman