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56d20861c0
linux/arch/powerpc/kernel
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Alan Modra 56d20861c0 powerpc/vdso: Correct call frame information 
Call Frame Information is used by gdb for back-traces and inserting
breakpoints on function return for the "finish" command.  This failed
when inside __kernel_clock_gettime.  More concerning than difficulty
debugging is that CFI is also used by stack frame unwinding code to
implement exceptions.  If you have an app that needs to handle
asynchronous exceptions for some reason, and you are unlucky enough to
get one inside the VDSO time functions, your app will crash.

What's wrong:  There is control flow in __kernel_clock_gettime that
reaches label 99 without saving lr in r12.  CFI info however is
interpreted by the unwinder without reference to control flow: It's a
simple matter of "Execute all the CFI opcodes up to the current
address".  That means the unwinder thinks r12 contains the return
address at label 99.  Disabuse it of that notion by resetting CFI for
the return address at label 99.

Note that the ".cfi_restore lr" could have gone anywhere from the
"mtlr r12" a few instructions earlier to the instruction at label 99.
I put the CFI as late as possible, because in general that's best
practice (and if possible grouped with other CFI in order to reduce
the number of CFI opcodes executed when unwinding).  Using r12 as the
return address is perfectly fine after the "mtlr r12" since r12 on
that code path still contains the return address.

__get_datapage also has a CFI error.  That function temporarily saves
lr in r0, and reflects that fact with ".cfi_register lr,r0".  A later
use of r0 means the CFI at that point isn't correct, as r0 no longer
contains the return address.  Fix that too.

Signed-off-by: Alan Modra <amodra@gmail.com>
Tested-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-09-14 13:47:31 +10:00
..
trace powerpc/kprobes: Remove jprobe powerpc implementation 2018-06-21 12:33:08 +02:00
vdso32 powerpc/vdso: Correct call frame information 2018-09-14 13:47:31 +10:00
vdso64 powerpc/vdso: Correct call frame information 2018-09-14 13:47:31 +10:00
.gitignore
align.c powerpc/sstep: Introduce GETTYPE macro 2018-06-03 21:19:40 +10:00
asm-offsets.c powerpc/64s: Remove POWER9 DD1 support 2018-07-16 11:37:21 +10:00
audit.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
btext.c powerpc: Make function btext_initialize static 2018-05-25 12:04:44 +10:00
cacheinfo.c powerpc: Convert to using %pOF instead of full_name 2017-08-23 22:27:04 +10:00
cacheinfo.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat_audit.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cpu_setup_6xx.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
cpu_setup_44x.S
cpu_setup_fsl_booke.S powerpc: Free up CPU feature bits on 64-bit machines 2018-03-24 00:38:51 +11:00
cpu_setup_pa6t.S
cpu_setup_power.S powerpc/64s: Clear PCR on boot 2018-05-18 16:05:15 +10:00
cpu_setup_ppc970.S
cputable.c Merge branch 'topic/ppc-kvm' into next 2018-07-19 14:37:57 +10:00
crash_dump.c
crash.c powerpc: remove kdump.h from page.h 2018-07-30 22:47:53 +10:00
dbell.c
dma-iommu.c powerpc: rename dma_direct_ to dma_nommu_ 2018-01-10 16:41:14 +01:00
dma-swiotlb.c swiotlb: rename swiotlb_free to swiotlb_exit 2018-01-15 09:35:39 +01:00
dma.c PCI: Call dma_debug_add_bus() for pci_bus_type from PCI core 2018-07-30 15:58:01 -05:00
dt_cpu_ftrs.c Merge branch 'topic/ppc-kvm' into next 2018-07-19 14:37:57 +10:00
eeh_cache.c powerpc/eeh: Fix misleading comment in __eeh_addr_cache_get_device() 2018-03-27 23:44:58 +11:00
eeh_dev.c powerpc/eeh: Create PHB PEs after EEH is initialized 2017-09-21 14:56:00 +10:00
eeh_driver.c powerpc/eeh: Refactor report functions 2018-06-03 20:43:41 +10:00
eeh_event.c powerpc/eeh: Manage EEH_PE_RECOVERING inside eeh_handle_normal_event() 2018-03-27 23:44:58 +11:00
eeh_pe.c powerpc/eeh: Introduce eeh_for_each_pe() 2018-06-03 20:43:39 +10:00
eeh_sysfs.c powerpc/eeh: Add EEH notify resume sysfs 2018-01-27 20:02:52 +11:00
eeh.c powerpc/eeh: Avoid misleading message "EEH: no capable adapters found" 2018-07-02 23:54:26 +10:00
entry_32.S powerpc/fsl: Sanitize the syscall table for NXP PowerPC 32 bit platforms 2018-08-08 00:32:24 +10:00
entry_64.S powerpc/64s: Add support for software count cache flush 2018-08-08 00:32:26 +10:00
epapr_hcalls.S
epapr_paravirt.c
exceptions-64e.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
exceptions-64s.S powerpc/64s: Make rfi_flush_fallback a little more robust 2018-08-08 00:32:27 +10:00
fadump.c powerpc/fadump: cleanup crash memory ranges support 2018-08-20 20:19:54 +10:00
firmware.c
fpu.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
fsl_booke_entry_mapping.S License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
head_8xx.S powerpc: remove superflous inclusions of asm/fixmap.h 2018-07-30 22:48:18 +10:00
head_32.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
head_40x.S powerpc/405: move PPC405_ERR77 in asm-405.h 2018-07-30 22:48:13 +10:00
head_44x.S
head_64.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
head_booke.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
head_fsl_booke.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
hw_breakpoint.c perf/arch/powerpc: Implement hw_breakpoint_arch_parse() 2018-06-26 09:07:55 +02:00
idle_6xx.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
idle_book3e.S powerpc/64s: make PACA_IRQ_HARD_DIS track MSR[EE] closely 2018-07-24 22:03:14 +10:00
idle_book3s.S Merge branch 'fixes' into next 2018-08-13 15:59:06 +10:00
idle_e500.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
idle_power4.S powerpc/64s: Fix PACA_IRQ_HARD_DIS accounting in idle_power4() 2018-08-14 15:36:02 +10:00
idle.c
ima_kexec.c
io-workarounds.c powerpc: Convert to using %pOF instead of full_name 2017-08-23 22:27:04 +10:00
io.c
iomap.c powerpc: iomap.c: introduce io{read|write}64_{lo_hi|hi_lo} 2018-04-05 14:59:26 +10:00
iommu.c powerpc/iommu: Use permission-specific DEVICE_ATTR variants 2017-09-01 16:42:54 +10:00
irq.c powerpc/64: Disable irq restore warning for now 2018-08-07 21:49:24 +10:00
isa-bridge.c powerpc: Convert to using %pOF instead of full_name 2017-08-23 22:27:04 +10:00
jump_label.c
kexec_elf_64.c kernel/kexec_file.c: allow archs to set purgatory load address 2018-04-13 17:10:28 -07:00
kgdb.c powerpc/8xx: Getting rid of remaining use of CONFIG_8xx 2017-08-10 23:32:12 +10:00
kprobes-ftrace.c bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe 2018-06-21 12:33:19 +02:00
kprobes.c bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe 2018-06-21 12:33:19 +02:00
kvm_emul.S powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30 22:48:16 +10:00
kvm.c powerpc/kvm: Prefer fault_in_pages_readable function 2018-05-17 14:12:40 +10:00
l2cr_6xx.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
legacy_serial.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
machine_kexec_32.c
machine_kexec_64.c powerpc/64/kexec: fix race in kexec when XIVE is shutdown 2018-05-10 23:25:08 +10:00
machine_kexec_file_64.c powerpc/kexec: Use common error handling code in setup_new_fdt() 2018-08-10 22:12:36 +10:00
machine_kexec.c powerpc: remove kdump.h from page.h 2018-07-30 22:47:53 +10:00
Makefile powerpc/Makefiles: Convert ifeq to ifdef where possible 2018-08-08 00:32:36 +10:00
mce_power.c powerpc/64s: move machine check SLB flushing to mm/slb.c 2018-08-10 22:12:39 +10:00
mce.c powerpc updates for 4.16 2018-02-02 10:01:04 -08:00
misc_32.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
misc_64.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
misc.S powerpc/misc: merge reloc_offset() and add_reloc_offset() 2018-06-04 00:39:17 +10:00
module_32.c powerpc/sparse: Fix plain integer as NULL pointer warning 2018-05-25 12:04:38 +10:00
module_64.c powerpc/kbuild: move -mprofile-kernel check to Kconfig 2018-06-11 09:16:29 +09:00
module.c powerpc/64: Add CONFIG_PPC_BARRIER_NOSPEC 2018-08-08 00:32:23 +10:00
module.lds powerpc/modules: Fix alignment of .toc section in kernel modules 2017-12-11 13:03:35 +11:00
msi.c
nvram_64.c powerpc/64: Fix strncpy() related build failures with GCC 8.1 2018-06-03 20:40:24 +10:00
of_platform.c powerpc: Convert to using %pOF instead of full_name 2017-08-23 22:27:04 +10:00
optprobes_head.S powerpc/64: Rename soft_enabled to irq_soft_mask 2018-01-19 22:37:01 +11:00
optprobes.c powerpc/kprobes: Do not disable interrupts for optprobes and kprobes_on_ftrace 2017-11-12 23:51:41 +11:00
paca.c Merge branch 'topic/paca' into next 2018-03-31 09:09:36 +11:00
pci_32.c powerpc: Remove -Wattribute-alias pragmas 2018-06-25 23:21:13 +09:00
pci_64.c powerpc: Remove -Wattribute-alias pragmas 2018-06-25 23:21:13 +09:00
pci_dn.c powerpc/pci: Separate SR-IOV Calls 2017-12-11 13:03:35 +11:00
pci_of_scan.c pci-v4.16-changes 2018-02-06 09:59:40 -08:00
pci-common.c powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
pci-hotplug.c powerpc/pci: Unroll two pass loop when scanning bridges 2017-12-18 23:05:52 -06:00
pmc.c
ppc32.h
ppc_save_regs.S powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30 22:48:16 +10:00
proc_powerpc.c powerpc: Use octal numbers for file permissions 2018-01-22 05:48:33 +11:00
process.c powerpc: Add show_user_instructions() 2018-08-08 00:32:30 +10:00
prom_init_check.sh powerpc/mm/radix: Update command line parsing for disable_radix 2018-04-04 16:59:50 +10:00
prom_init.c powerpc: Move path variable inside DEBUG_PROM 2018-08-10 22:12:38 +10:00
prom_parse.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
prom.c powerpc: clean the inclusion of stringify.h 2018-07-30 22:48:17 +10:00
ptrace32.c
ptrace.c powerpc/ptrace: Use copy_{from, to}_user() rather than open-coding 2018-06-03 20:43:41 +10:00
reloc_32.S
reloc_64.S powerpc/asm: Convert .llong directives to .8byte 2017-08-31 14:26:47 +10:00
rtas_flash.c powerpc: Use octal numbers for file permissions 2018-01-22 05:48:33 +11:00
rtas_pci.c powerpc/kernel: Change retrieval of pci_dn 2017-08-31 14:26:40 +10:00
rtas-proc.c powerpc updates for 4.18 2018-06-07 10:23:33 -07:00
rtas-rtc.c powerpc: use time64_t in read_persistent_clock 2018-06-03 20:43:33 +10:00
rtas.c powerpc: Remove -Wattribute-alias pragmas 2018-06-25 23:21:13 +09:00
rtasd.c treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
security.c powerpc/64s: Add support for software count cache flush 2018-08-08 00:32:26 +10:00
setup_32.c powerpc/32: Include setup.h header file to fix warnings 2018-08-10 22:12:38 +10:00
setup_64.c powerpc/tm: Fix HFSCR bit for no suspend case 2018-09-14 13:47:31 +10:00
setup-common.c powerpc/64: Call setup_barrier_nospec() from setup_arch() 2018-08-08 00:32:23 +10:00
setup.h powerpc/tau: Synchronize function prototypes and body 2018-05-25 12:04:43 +10:00
signal_32.c powerpc: Remove -Wattribute-alias pragmas 2018-06-25 23:21:13 +09:00
signal_64.c powerpc: Remove -Wattribute-alias pragmas 2018-06-25 23:21:13 +09:00
signal.c rseq: Avoid infinite recursion when delivering SIGSEGV 2018-06-22 19:04:22 +02:00
signal.h powerpc/syscalls: signal_{32, 64} - switch to SYSCALL_DEFINE 2018-05-10 23:25:13 +10:00
smp-tbsync.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smp.c powerpc/topology: Get topology for shared processors at boot 2018-08-21 16:01:59 +10:00
stacktrace.c powerpc/64s: Fix build failures with CONFIG_NMI_IPI=n 2018-06-19 23:03:50 +10:00
suspend.c
swsusp_32.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
swsusp_64.c
swsusp_asm64.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
swsusp_booke.S License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swsusp.c
sys_ppc32.c powerpc/syscalls: kill ppc32_select() 2018-05-10 23:25:15 +10:00
syscalls.c powerpc: Remove -Wattribute-alias pragmas 2018-06-25 23:21:13 +09:00
sysfs.c Merge branch 'topic/paca' into next 2018-03-31 09:09:36 +11:00
systbl_chk.c powerpc/syscalls: Add COMPAT_SPU_NEW() macro 2018-05-10 23:25:14 +10:00
systbl_chk.sh powerpc: Make it clearer that systbl check errors are errors 2018-05-10 23:25:16 +10:00
systbl.S powerpc/syscalls: Add COMPAT_SPU_NEW() macro 2018-05-10 23:25:14 +10:00
tau_6xx.c powerpc/tau: Make some function static 2018-05-25 12:04:44 +10:00
time.c powerpc/time: inline arch_vtime_task_switch() 2018-06-04 00:39:20 +10:00
tm.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
traps.c powerpc/traps: Avoid rate limit messages from show unhandled signals 2018-08-20 20:19:46 +10:00
udbg_16550.c
udbg.c
uprobes.c powerpc/uprobes: Implement arch_uretprobe_is_alive() 2017-08-24 16:19:21 +10:00
vdso.c powerpc: remove unneeded inclusions of cpu_has_feature.h 2018-07-30 22:47:54 +10:00
vecemu.c powerpc: Add a missing include header 2018-05-25 12:04:46 +10:00
vector.S powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30 22:48:16 +10:00
vmlinux.lds.S powerpc/64: Add CONFIG_PPC_BARRIER_NOSPEC 2018-08-08 00:32:23 +10:00
watchdog.c powerpc: NMI IPI make NMI IPIs fully sychronous 2018-07-24 22:03:14 +10:00