linux/arch/arm/kernel
Arnd Bergmann b8fd230ae0 ARM: 9081/1: fix gcc-10 thumb2-kernel regression
commit dad7b9896a 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: <stable@vger.kernel.org> # v3.18+
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Reported-by: Marek Vasut <marek.vasut@gmail.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Fixes: c0e7f7ee71 ("ARM: 8150/3: fiq: Replace default FIQ handler")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-30 08:47:16 -04:00
..
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
arch_timer.c ARM: 8913/1: arch_timer: include <asm/arch_timer.h> 2019-10-27 21:14:43 +00:00
armksyms.c crypto: lib/sha1 - remove unnecessary includes of linux/cryptohash.h 2020-05-08 15:32:17 +10:00
asm-offsets.c ARM: 9075/1: kernel: Fix interrupted SMC calls 2021-05-22 11:40:53 +02:00
atags_compat.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
atags_parse.c ARM: 9011/1: centralize phys-to-virt conversion of DT/ATAGS address 2021-05-19 10:13:18 +02:00
atags_proc.c ARM: 8973/1: Add missing newline terminator to kernel message 2020-05-07 20:53:10 +01:00
atags.h ARM: 9011/1: centralize phys-to-virt conversion of DT/ATAGS address 2021-05-19 10:13:18 +02:00
bios32.c ARM/PCI: Remove unused fields from struct hw_pci 2020-09-18 22:39:09 +01:00
bugs.c treewide: fix typos of SPDX-License-Identifier 2019-06-01 18:29:58 +02:00
cpuidle.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
crash_dump.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
debug.S ARM: 9005/1: debug: Select flow control for all debug UARTs 2020-09-15 14:35:28 +01:00
devtree.c ARM: 9011/1: centralize phys-to-virt conversion of DT/ATAGS address 2021-05-19 10:13:18 +02:00
dma-isa.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
dma.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
early_printk.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
efi.c mm/pgtable: drop pgtable_t variable from pte_fn_t functions 2019-07-12 11:05:46 -07:00
elf.c arm32/64/elf: Split READ_IMPLIES_EXEC from executable PT_GNU_STACK 2020-04-20 19:42:19 +02:00
entry-armv.S ARM: 9030/1: entry: omit FP emulation for UND exceptions taken in kernel mode 2020-12-30 11:53:43 +01:00
entry-common.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
entry-ftrace.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
entry-header.S ARM: uaccess: consolidate uaccess asm to asm/uaccess-asm.h 2020-05-03 17:30:24 +01:00
entry-v7m.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
fiq.c arm: fix the flush_icache_range arguments in set_fiq_handler 2020-06-08 11:05:57 -07:00
fiqasm.S
ftrace.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
head-common.S ARM: 8914/1: NOMMU: Fix exc_ret for XIP 2019-10-10 22:23:20 +01:00
head-inflate-data.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
head-nommu.S ARM: 8914/1: NOMMU: Fix exc_ret for XIP 2019-10-10 22:23:20 +01:00
head.S ARM: 9027/1: head.S: explicitly map DT even if it lives in the first physical section 2021-05-19 10:13:18 +02:00
hibernate.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194 2019-05-30 11:29:22 -07:00
hw_breakpoint.c ARM: 9064/1: hw_breakpoint: Do not directly check the event's overflow_handler hook 2021-05-19 10:13:01 +02:00
hyp-stub.S arm: Remove the ability to set HYP vectors outside of the decompressor 2020-03-24 10:56:05 +00:00
insn.c
io.c
irq.c ARM: Remove custom IRQ stat accounting 2020-09-17 16:37:28 +01:00
isa.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
iwmmxt.h ARM: 9029/1: Make iwmmxt.S support Clang's integrated assembler 2021-03-17 17:06:26 +01:00
iwmmxt.S ARM: 9029/1: Make iwmmxt.S support Clang's integrated assembler 2021-03-17 17:06:26 +01:00
jump_label.c jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
kgdb.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
machine_kexec.c ARM: kexec: fix oops after TLB are invalidated 2021-02-17 11:02:24 +01:00
Makefile Linux 5.5-rc1 2019-12-10 10:11:00 +01:00
module-plts.c ARM: 8910/1: fix missing declartion of module_frob_arch_sections 2019-10-27 21:14:38 +00:00
module.c mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
opcodes.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
paravirt.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
patch.c arm/patch: Fix !MMU compile 2020-02-11 12:56:27 +01:00
perf_callchain.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
perf_event_v6.c arm_pmu: Tidy up clear_event_idx call backs 2018-07-10 18:19:02 +01:00
perf_event_v7.c ARM: 8873/1: perf: cleanup cppcheck shifting warning 2019-08-23 11:38:46 +01:00
perf_event_xscale.c arm_pmu: Tidy up clear_event_idx call backs 2018-07-10 18:19:02 +01:00
perf_regs.c perf/arch: Remove perf_sample_data::regs_user_copy 2020-11-09 18:12:34 +01:00
pj4-cp0.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
process.c sched/idle: Fix arch_cpu_idle() vs tracing 2020-11-24 16:47:35 +01:00
psci_smp.c ARM: 8919/1: make unexported functions static 2019-10-31 16:58:52 +00:00
ptrace.c arm: switch to ->regset_get() 2020-07-27 14:31:09 -04:00
reboot.c ARM: Use reboot_cpu instead of hardcoding it to 0 2020-03-25 12:59:33 +01:00
reboot.h
relocate_kernel.S ARM: kexec: fix oops after TLB are invalidated 2021-02-17 11:02:24 +01:00
return_address.c ARM: 8918/2: only build return_address() if needed 2019-11-15 22:21:07 +00:00
setup.c ARM: 9081/1: fix gcc-10 thumb2-kernel regression 2021-06-30 08:47:16 -04:00
signal.c ARM: ensure the signal page contains defined contents 2021-02-17 11:02:24 +01:00
signal.h ARM: 8920/1: share get_signal_page from signal.c to process.c 2019-10-31 16:58:53 +00:00
sigreturn_codes.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
sleep.S ARM: 8847/1: pm: fix HYP/SVC mode mismatch when MCPM is used 2019-02-26 11:32:54 +00:00
smccc-call.S ARM: 9075/1: kernel: Fix interrupted SMC calls 2021-05-22 11:40:53 +02:00
smp_scu.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
smp_tlb.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
smp_twd.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
smp.c ARM: Handle no IPI being registered in show_ipi_list() 2020-09-28 11:32:04 +01:00
stacktrace.c ARM: 8992/1: Fix unwind_frame for clang-built kernels 2020-07-21 16:33:40 +01:00
suspend.c ARM: 9066/1: ftrace: pause/unpause function graph tracer in cpu_suspend() 2021-05-22 11:40:52 +02:00
swp_emulate.c mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
sys_arm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sys_oabi-compat.c ARM: 9065/1: OABI compat: fix build when EPOLL is not enabled 2021-03-04 11:38:10 +01:00
tcm.c ARM: 8925/1: tcm: include <asm/tcm.h> for missing declarations 2019-10-31 16:58:56 +00:00
thumbee.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
time.c ARM/time: Replace <linux/clk-provider.h> by <linux/of_clk.h> 2020-05-15 22:54:57 +02:00
topology.c ARM, sched/topology: Revert back to default scheduler topology 2020-08-19 10:49:47 +02:00
traps.c maccess: make get_kernel_nofault() check for minimal type compatibility 2020-06-18 12:10:37 -07:00
unwind.c arm: add loglvl to unwind_backtrace() 2020-06-09 09:39:10 -07:00
v7m.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
vdso.c ARM: 8987/1: VDSO: Fix incorrect clock_gettime64 2020-07-21 16:32:55 +01:00
vmlinux-xip.lds.S arm/build: Assert for unwanted sections 2020-09-01 10:03:18 +02:00
vmlinux.lds.S arm/build: Always handle .ARM.exidx and .ARM.extab sections 2020-10-27 11:32:21 -07:00
xscale-cp0.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00