kernel-fxtec-pro1x/arch/arm/kernel
Arun K S 3780f7ab49 ARM: 8062/1: Modify ldrt fixup handler to re-execute the userspace instruction
We will reach fixup handler when one thread(say cpu0) caused an undefined exception, while another thread(say cpu1) is unmmaping the page.

Fixup handler returns to the next userspace instruction which has caused the undef execption, rather than going to the same instruction.

ARM ARM says that after undefined exception, the PC will be pointing
to the next instruction. ie +4 offset in case of ARM and +2 in case of Thumb

And there is no correction offset passed to vector_stub in case of
undef exception.

File: arch/arm/kernel/entry-armv.S +1085
vector_stub     und, UND_MODE

During an undefined exception, in normal scenario(ie when ldrt
instruction does not cause an abort) after resorting the context in
VFP hardware, the PC is modified as show below before jumping to
ret_from_exception which is in r9.

File: arch/arm/vfp/vfphw.S +169
@ The context stored in the VFP hardware is up to date with this thread
vfp_hw_state_valid:
   tst     r1, #FPEXC_EX
   bne     process_exception     @ might as well handle the pending
                                 @ exception before retrying branch
                                 @ out before setting an FPEXC that
                                 @ stops us reading stuff
        VFPFMXR FPEXC, r1        @ Restore FPEXC last
        sub     r2, r2, #4       @ Retry current instruction - if Thumb
        str     r2, [sp, #S_PC]  @ mode it's two 16-bit instructions,
                                 @ else it's one 32-bit instruction, so
                                 @ always subtract 4 from the following
                                 @ instruction address.

But if ldrt results in an abort, we reach the fixup handler and return
to ret_from_execption without correcting the pc.

This patch modifes the fixup handler to re-execute the same instruction which caused undefined execption.

Signed-off-by: Vinayak Menon <vinayakm.list@gmail.com>
Signed-off-by: Arun KS <getarunks@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-05-30 01:12:28 +01:00
..
.gitignore
arch_timer.c arch_timer: Move to generic sched_clock framework 2013-10-09 16:54:10 -07:00
armksyms.c ARM: Better virt_to_page() handling 2014-04-03 22:46:34 +01:00
arthur.c
asm-offsets.c ARM: KVM: introduce per-vcpu HYP Configuration Register 2014-03-03 01:15:23 +00:00
atags.h ARM: constify machine_desc structure uses 2013-07-26 14:55:59 +01:00
atags_compat.c ARM: 7505/1: split out ATAGS parsing 2012-09-03 22:55:56 +01:00
atags_parse.c ARM: constify machine_desc structure uses 2013-07-26 14:55:59 +01:00
atags_proc.c procfs: new helper - PDE_DATA(inode) 2013-04-09 14:13:32 -04:00
bios32.c Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2014-04-05 13:20:43 -07:00
calls.S sched: Add new scheduler syscalls to support an extended scheduling parameters ABI 2014-01-13 13:41:04 +01:00
cpuidle.c cpuidle: Add common time keeping and irq enabling 2012-03-21 01:59:40 -04:00
crash_dump.c ARM: 8012/1: kdump: Avoid overflow when converting pfn to physaddr 2014-04-07 12:10:00 +01:00
debug.S ARM: compile fix for DEBUG_LL=y && MMU=n 2013-01-16 14:30:06 -08:00
devtree.c ARM: Introduce CPU_METHOD_OF_DECLARE() for cpu hotplug/smp 2014-02-11 15:00:37 -06:00
dma-isa.c
dma.c locking, ARM: Annotate low level hw locks as raw 2011-09-13 11:12:14 +02:00
early_printk.c early_printk: consolidate random copies of identical code 2013-04-29 18:28:13 -07:00
elf.c Disintegrate asm/system.h for ARM 2012-03-28 18:30:01 +01:00
entry-armv.S ARM: 8062/1: Modify ldrt fixup handler to re-execute the userspace instruction 2014-05-30 01:12:28 +01:00
entry-common.S ARM: asm: Add ARM_BE8() assembly helper 2013-10-19 20:46:33 +01:00
entry-header.S ARM: 8017/1: Move asm macro get_thread_info to asm/assembler.h 2014-04-09 13:08:07 +01:00
entry-v7m.S ARM: 7890/1: v7-M: drop using mach/entry-macro.S 2013-12-29 12:32:32 +00:00
etm.c ARM: 7905/1: etm: Remove unnecessary amba_set_drvdata() 2013-12-29 12:32:34 +00:00
fiq.c ARM: 7819/1: fiq: Cast the first argument of flush_icache_range() 2013-08-20 00:11:50 +01:00
fiqasm.S ARM: 6938/1: fiq: Refactor {get,set}_fiq_regs() for Thumb-2 2011-05-26 10:31:06 +01:00
ftrace.c ARM: 8022/1: ftrace: work with CONFIG_DEBUG_SET_MODULE_RONX 2014-04-23 01:24:31 +01:00
head-common.S ARM: 7980/1: kernel: improve error message when LPAE config doesn't match CPU 2014-02-21 11:56:32 +00:00
head-nommu.S ARM: fix asm/memory.h build error 2013-12-13 20:25:30 +00:00
head.S ARM: 8028/1: move __fixup_smp out of init section 2014-05-25 23:46:51 +01:00
hibernate.c ARM: 8011/1: ARM hibernation / suspend-to-disk 2014-04-23 01:24:14 +01:00
hw_breakpoint.c CPU hotplug notifiers registration fixes for 3.15-rc1 2014-04-07 14:55:46 -07:00
hyp-stub.S ARM: 7786/1: hyp: fix macro parameterisation 2013-07-22 14:30:34 +01:00
insn.c ARM: fix missing bug.h include in arch/arm/kernel/insn.c 2012-03-30 11:51:46 +01:00
insn.h ARM: 7334/1: add jump label support 2012-03-24 09:38:56 +00:00
io.c ARM: 7930/1: Introduce atomic MMIO modify 2014-01-28 14:06:25 +00:00
irq.c ARM: irq: Call irqchip_init if no init_irq function is specified 2013-04-02 11:05:40 -07:00
isa.c
iwmmxt.S ARM: 8036/1: Enable IRQs before attempting to read user space in __und_usr 2014-04-25 12:06:38 +01:00
jump_label.c ARM: 7334/1: add jump label support 2012-03-24 09:38:56 +00:00
kgdb.c kgdb,arm: fix register dump 2010-10-29 13:14:40 -05:00
kprobes-arm.c ARM: Make arch_specific_insn a define for new arch_probes_insn structure 2014-03-18 16:39:40 -04:00
kprobes-common.c ARM: probes: fix instruction fetch order with <asm/opcodes.h> 2014-04-01 16:45:19 +03:00
kprobes-test-arm.c ARM: kprobes-test: use <asm/opcodes.h> for ARM instruction building 2014-04-01 16:48:24 +03:00
kprobes-test-thumb.c ARM: kprobes-test: use <asm/opcodes.h> for Thumb instruction building 2014-04-01 16:48:26 +03:00
kprobes-test.c ARM: kprobes-test: Workaround GAS .align bug 2014-04-01 16:48:27 +03:00
kprobes-test.h ARM: kprobes-test: Workaround GAS .align bug 2014-04-01 16:48:27 +03:00
kprobes-thumb.c ARM: probes: fix instruction fetch order with <asm/opcodes.h> 2014-04-01 16:45:19 +03:00
kprobes.c ARM: probes: fix instruction fetch order with <asm/opcodes.h> 2014-04-01 16:45:19 +03:00
kprobes.h ARM: Make arch_specific_insn a define for new arch_probes_insn structure 2014-03-18 16:39:40 -04:00
machine_kexec.c ARM: 7897/1: kexec: Use the right ISA for relocate_new_kernel 2013-11-30 22:21:02 +00:00
Makefile ARM: 8011/1: ARM hibernation / suspend-to-disk 2014-04-23 01:24:14 +01:00
module.c Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2013-11-14 08:51:29 +09:00
opcodes.c ARM: 7206/1: Add generic ARM instruction set condition code checks. 2011-12-13 08:52:02 +00:00
patch.c ARM: 7332/1: extract out code patch function from kprobes 2012-03-24 09:38:55 +00:00
patch.h ARM: 7332/1: extract out code patch function from kprobes 2012-03-24 09:38:55 +00:00
perf_event.c ARM: perf: hook up perf_sample_event_took around pmu irq handling 2014-02-21 11:11:21 +00:00
perf_event_cpu.c ARM: 8054/1: perf: add support for the Cortex-A17 PMU 2014-05-25 23:49:43 +01:00
perf_event_v6.c ARM: perf: don't pretend to support counting of L1I writes 2013-01-16 12:01:59 +00:00
perf_event_v7.c ARM: 8054/1: perf: add support for the Cortex-A17 PMU 2014-05-25 23:49:43 +01:00
perf_event_xscale.c ARM: perf: don't pretend to support counting of L1I writes 2013-01-16 12:01:59 +00:00
perf_regs.c ARM: perf: add support for perf registers API 2013-09-30 16:41:50 +01:00
pj4-cp0.c ARM: 8016/1: Check cpu id in pj4_cp0_init. 2014-04-08 17:55:28 +01:00
probes-arm.c ARM: Make arch_specific_insn a define for new arch_probes_insn structure 2014-03-18 16:39:40 -04:00
probes-arm.h ARM: Make arch_specific_insn a define for new arch_probes_insn structure 2014-03-18 16:39:40 -04:00
probes-thumb.c ARM: Make arch_specific_insn a define for new arch_probes_insn structure 2014-03-18 16:39:40 -04:00
probes-thumb.h ARM: Make arch_specific_insn a define for new arch_probes_insn structure 2014-03-18 16:39:40 -04:00
probes.c ARM: probes: fix instruction fetch order with <asm/opcodes.h> 2014-04-01 16:45:19 +03:00
probes.h ARM: Make arch_specific_insn a define for new arch_probes_insn structure 2014-03-18 16:39:40 -04:00
process.c Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2014-04-11 11:56:40 -07:00
psci.c arm: introduce psci_smp_ops 2013-05-21 14:24:11 +00:00
psci_smp.c ARM: PSCI: remove unnecessary include of arm-gic.h 2013-10-01 16:34:10 -05:00
ptrace.c ptrace/arm: revert "hw_breakpoints: Fix racy access to ptrace breakpoints" 2013-07-09 10:33:25 -07:00
relocate_kernel.S ARM: 7897/1: kexec: Use the right ISA for relocate_new_kernel 2013-11-30 22:21:02 +00:00
return_address.c ARM: 7676/1: fix a wrong value returned from CALLER_ADDRn 2013-03-19 11:43:46 +00:00
setup.c Merge branches 'amba', 'fixes', 'misc', 'mmci', 'unstable/omap-dma' and 'unstable/sa11x0' into for-next 2014-04-04 00:33:32 +01:00
signal.c ARM: add uprobes support 2014-03-18 16:39:40 -04:00
sigreturn_codes.S ARM: 7895/1: signal: fix armv7-m build issue in sigreturn_codes.S 2013-11-30 22:21:00 +00:00
sleep.S ARM: 8053/1: kernel: sleep: restore HYP mode configuration in cpu_resume 2014-05-25 23:49:27 +01:00
smp.c cpufreq: remove unused notifier: CPUFREQ_{SUSPENDCHANGE|RESUMECHANGE} 2014-03-19 14:10:24 +01:00
smp_scu.c ARM: smp_scu: data endian fixes 2013-10-19 20:46:33 +01:00
smp_tlb.c ARM: 7855/1: Add check for Cortex-A15 errata 798181 ECO 2013-10-29 11:06:13 +00:00
smp_twd.c cpufreq: remove unused notifier: CPUFREQ_{SUSPENDCHANGE|RESUMECHANGE} 2014-03-19 14:10:24 +01:00
stacktrace.c ARM: stacktrace: include exception PC value in stacktrace output 2014-05-22 16:33:24 +01:00
suspend.c ARM: suspend: use hash of cpu_logical_map value to index into save array 2013-07-30 09:00:43 -04:00
swp_emulate.c arm: single_open() leaks 2013-05-05 00:07:22 -04:00
sys_arm.c arm: switch to generic fork/vfork/clone 2012-11-28 22:13:54 -05:00
sys_oabi-compat.c locks: add new fcntl cmd values for handling file private locks 2014-03-31 08:24:43 -04:00
tcm.c ARM: add permission annotations to MT_MEMORY* mapping types 2013-12-11 09:53:14 +00:00
thumbee.c ARM: 7385/1: ThumbEE: Use cpuid macros to read ID_PFR0 for ThumbEE 2012-04-25 19:49:26 +01:00
time.c ARM: call of_clk_init from default time_init handler 2013-09-29 21:09:15 +02:00
topology.c ARM: 8008/1: topology: Coding style fixes 2014-04-14 23:27:19 +01:00
traps.c Dump the registers on undefined instruction userspace faults 2014-04-11 14:48:39 +01:00
unwind.c ARM: 7987/1: ARM : unwinder : Prevent data abort due to stack overflow 2014-02-25 11:48:24 +00:00
uprobes-arm.c ARM: add uprobes support 2014-03-18 16:39:40 -04:00
uprobes.c ARM: 8043/1: uprobes need icache flush after xol write 2014-05-25 23:48:45 +01:00
uprobes.h ARM: add uprobes support 2014-03-18 16:39:40 -04:00
v7m.c ARM: 7828/1: ARMv7-M: implement restart routine common to all v7-M machines 2013-09-02 13:49:29 +01:00
vmlinux.lds.S ARM: use linker magic for vectors and vector stubs 2013-07-31 21:34:24 +01:00
xscale-cp0.c arm: remove several unnecessary module.h include instances 2011-10-31 19:30:48 -04:00