linux-stable/arch/powerpc/kernel
Linus Torvalds f70efe54b9 work around gcc bugs with 'asm goto' with outputs
commit 68fb3ca0e4 upstream.

We've had issues with gcc and 'asm goto' before, and we created a
'asm_volatile_goto()' macro for that in the past: see commits
3f0116c323 ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f180345f ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").

Then, much later, we ended up removing the workaround in commit
43c249ea0b ("compiler-gcc.h: remove ancient workaround for gcc PR
58670") because we no longer supported building the kernel with the
affected gcc versions, but we left the macro uses around.

Now, Sean Christopherson reports a new version of a very similar
problem, which is fixed by re-applying that ancient workaround.  But the
problem in question is limited to only the 'asm goto with outputs'
cases, so instead of re-introducing the old workaround as-is, let's
rename and limit the workaround to just that much less common case.

It looks like there are at least two separate issues that all hit in
this area:

 (a) some versions of gcc don't mark the asm goto as 'volatile' when it
     has outputs:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619
        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420

     which is easy to work around by just adding the 'volatile' by hand.

 (b) Internal compiler errors:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422

     which are worked around by adding the extra empty 'asm' as a
     barrier, as in the original workaround.

but the problem Sean sees may be a third thing since it involves bad
code generation (not an ICE) even with the manually added 'volatile'.

The same old workaround works for this case, even if this feels a
bit like voodoo programming and may only be hiding the issue.

Reported-and-tested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 09:12:28 +01:00
..
ptrace powerpc: Don't try to copy PPR for task with NULL pt_regs 2023-04-06 12:10:53 +02:00
syscalls powerpc/32: fix syscall wrappers with 64-bit arguments 2022-11-01 10:24:09 +11:00
trace powerpc/ftrace: Fix stack teardown in ftrace_no_trace 2023-12-20 17:00:14 +01:00
vdso powerpc: Drops STABS_DEBUG from linker scripts 2022-09-30 18:35:52 +10:00
.gitignore
85xx_entry_mapping.S powerpc: Remove CONFIG_FSL_BOOKE 2022-09-26 22:47:37 +10:00
align.c powerpc/inst: Define ppc_inst_t 2021-12-09 22:41:21 +11:00
asm-offsets.c powerpc: Remove CONFIG_PPC_FSL_BOOK3E 2022-09-26 23:00:13 +10:00
audit.c Revert "powerpc/audit: Convert powerpc to AUDIT_ARCH_COMPAT_GENERIC" 2021-10-27 22:30:32 +11:00
btext.c powerpc: Fix all occurences of duplicate words 2022-07-25 12:05:15 +10:00
cacheinfo.c powerpc: Remove asm/prom.h from all files that don't need it 2022-05-08 22:15:04 +10:00
cacheinfo.h
compat_audit.c Revert "powerpc/audit: Convert powerpc to AUDIT_ARCH_COMPAT_GENERIC" 2021-10-27 22:30:32 +11:00
cpu_setup_6xx.S
cpu_setup_44x.S
cpu_setup_e500.S powerpc: Remove CONFIG_PPC_BOOK3E_MMU 2022-09-26 23:00:14 +10:00
cpu_setup_pa6t.S
cpu_setup_power.c powerpc/cputable: Move __cpu_setup() prototypes out of cputable.h 2022-09-26 22:26:49 +10:00
cpu_setup_ppc970.S
cpu_specs.h powerpc/cputable: Split cpu_specs[] for mpc85xx and e500mc 2022-09-26 23:00:05 +10:00
cpu_specs_8xx.h powerpc/cputable: Split cpu_specs[] out of cputable.h 2022-09-26 22:47:13 +10:00
cpu_specs_40x.h powerpc/cputable: Split cpu_specs[] out of cputable.h 2022-09-26 22:47:13 +10:00
cpu_specs_44x.h powerpc/cputable: Split cpu_specs[] out of cputable.h 2022-09-26 22:47:13 +10:00
cpu_specs_47x.h powerpc/cputable: Split cpu_specs[] out of cputable.h 2022-09-26 22:47:13 +10:00
cpu_specs_85xx.h powerpc/cputable: Split cpu_specs[] for mpc85xx and e500mc 2022-09-26 23:00:05 +10:00
cpu_specs_book3s_32.h powerpc/cputable: Split cpu_specs[] out of cputable.h 2022-09-26 22:47:13 +10:00
cpu_specs_book3s_64.h powerpc/cputable: Split cpu_specs[] out of cputable.h 2022-09-26 22:47:13 +10:00
cpu_specs_e500mc.h powerpc/cputable: Split cpu_specs[] for mpc85xx and e500mc 2022-09-26 23:00:05 +10:00
cputable.c powerpc/cputable: Split cpu_specs[] out of cputable.h 2022-09-26 22:47:13 +10:00
crash_dump.c powerpc updates for 5.19 2022-05-28 11:27:17 -07:00
dawr.c powerpc: Include asm/firmware.h in all users of firmware_has_feature() 2022-06-29 16:45:05 +10:00
dbell.c powerpc/64: Fix perf profiling asynchronous interrupt handlers 2023-02-22 12:59:43 +01:00
dma-iommu.c powerpc/iommu: Incorrect DDW Table is referenced for SR-IOV device 2023-05-24 17:32:52 +01:00
dma-mask.c
dma-swiotlb.c swiotlb: add a SWIOTLB_ANY flag to lift the low memory restriction 2022-04-18 07:21:12 +02:00
dt_cpu_ftrs.c powerpc: move from strlcpy with unused retval to strscpy 2022-08-26 11:02:20 +10:00
early_32.c powerpc: Move C prototypes out of asm-prototypes.h 2022-03-08 22:06:25 +11:00
eeh.c powerpc: fix typos in comments 2022-05-05 22:12:44 +10:00
eeh_cache.c powerpc/kernel: Add __init attribute to eligible functions 2021-12-23 22:33:10 +11:00
eeh_driver.c powerpc: Fix all occurences of duplicate words 2022-07-25 12:05:15 +10:00
eeh_event.c powerpc: fix typos in comments 2022-05-05 22:12:44 +10:00
eeh_pe.c powerpc: Fix all occurences of "the the" 2022-05-22 15:59:43 +10:00
eeh_sysfs.c powerpc: Add missing headers 2022-05-08 22:15:40 +10:00
entry_32.S powerpc/47x: Fix 47x syscall return crash 2023-10-19 23:08:56 +02:00
entry_64.S powerpc: Remove CONFIG_PPC_BOOK3E 2022-09-26 23:00:13 +10:00
epapr_hcalls.S
epapr_paravirt.c powerpc/inst: Define ppc_inst_t 2021-12-09 22:41:21 +11:00
exceptions-64e.S powerpc/64/interrupt: Prevent NMI PMI causing a dangerous warning 2022-10-18 22:46:19 +11:00
exceptions-64s.S powerpc/64s/interrupt: Perf NMI should not take normal exit path 2022-10-18 22:46:19 +11:00
fadump.c powerpc/fadump: reset dump area size if fadump memory reserve fails 2023-09-13 09:42:47 +02:00
firmware.c powerpc: fix unbalanced node refcount in check_kvm_guest() 2021-10-09 00:15:59 +11:00
fpu.S powerpc: Don't clobber f0/vs0 during fp|altivec register save 2023-12-08 08:51:15 +01:00
head_8xx.S powerpc/32: Remove _ENTRY() macro 2022-02-07 21:03:10 +11:00
head_32.h powerpc updates for 5.17 2022-01-14 15:17:26 +01:00
head_40x.S powerpc/32: Remove _ENTRY() macro 2022-02-07 21:03:10 +11:00
head_44x.S powerpc/32: Remove _ENTRY() macro 2022-02-07 21:03:10 +11:00
head_64.S bitmap patches for v6.1-rc1 2022-10-10 12:49:34 -07:00
head_85xx.S powerpc/85xx: Fix math emulation exception 2023-11-08 14:10:58 +01:00
head_book3s_32.S powerpc/32: Set an IBAT covering up to _einittext during init 2022-07-27 21:36:05 +10:00
head_booke.h powerpc: Remove CONFIG_PPC_BOOK3E_MMU 2022-09-26 23:00:14 +10:00
hw_breakpoint.c powerpc/watchpoints: Annotate atomic context in more places 2023-10-06 14:56:57 +02:00
hw_breakpoint_constraints.c powerpc/watchpoint: Disable pagefaults when getting user instruction 2023-10-06 14:56:57 +02:00
idle.c powerpc/idle: Fix return value of __setup() handler 2022-05-04 19:37:46 +10:00
idle_6xx.S powerpc/mm: Switch obsolete dssall to .long 2021-12-23 22:35:13 +11:00
idle_64e.S powerpc: add ISA v3.0 / v3.1 wait opcode macro 2022-09-28 19:22:10 +10:00
idle_85xx.S powerpc: Cleanup idle for e500 2022-09-26 23:00:14 +10:00
idle_book3s.S powerpc/idle: Don't corrupt back chain when going idle 2021-10-20 21:37:58 +11:00
ima_arch.c
interrupt.c powerpc/interrupt: Don't read MSR from interrupt_exit_kernel_prepare() 2023-07-19 16:21:37 +02:00
interrupt_64.S powerpc/64s/interrupt: Fix clear of PACA_IRQS_HARD_DIS when returning to soft-masked context 2022-10-27 00:38:35 +11:00
io-workarounds.c
io.c
iomap.c
iommu.c powerpc/iommu: Fix notifiers being shared by PCI and VIO buses 2023-09-13 09:42:48 +02:00
irq.c powerpc/64: Fix perf profiling asynchronous interrupt handlers 2023-02-22 12:59:43 +01:00
irq_64.c work around gcc bugs with 'asm goto' with outputs 2024-02-23 09:12:28 +01:00
isa-bridge.c powerpc: Add missing headers 2022-05-08 22:15:40 +10:00
jump_label.c
kdebugfs.c powerpc: rename powerpc_debugfs_root to arch_debugfs_dir 2021-08-13 22:04:26 +10:00
kgdb.c powerpc: Remove CONFIG_FSL_BOOKE 2022-09-26 22:47:37 +10:00
kprobes-ftrace.c ftrace: disable preemption when recursion locked 2021-10-27 11:21:49 -04:00
kprobes.c powerpc/kprobes: Fix null pointer reference in arch_prepare_kprobe() 2022-09-28 22:19:52 +10:00
kvm.c powerpc: Remove CONFIG_PPC_BOOK3E_MMU 2022-09-26 23:00:14 +10:00
kvm_emul.S
l2cr_6xx.S powerpc/mm: Switch obsolete dssall to .long 2021-12-23 22:35:13 +11:00
legacy_serial.c powerpc/kernel: Add missing of_node_put() in legacy_serial.c 2022-09-05 17:28:26 +10:00
Makefile powerpc/32: fix syscall wrappers with 64-bit arguments of unaligned register-pairs 2022-10-13 00:49:58 +11:00
mce.c powerpc/mce: use early_cpu_to_node() in mce_init() 2022-07-27 21:36:04 +10:00
mce_power.c powerpc/inst: Define ppc_inst_t 2021-12-09 22:41:21 +11:00
misc.S powerpc: Avoid link stack corruption in misc asm functions 2021-08-25 13:35:47 +10:00
misc_32.S powerpc: Avoid link stack corruption in misc asm functions 2021-08-25 13:35:47 +10:00
misc_64.S powerpc: Remove CONFIG_PPC_BOOK3E 2022-09-26 23:00:13 +10:00
module.c powerpc: Replace PPC64_ELF_ABI_v{1/2} by CONFIG_PPC64_ELF_ABI_V{1/2} 2022-05-19 23:11:29 +10:00
module_32.c powerpc/modules: Use PPC_LI macros instead of opencoding 2022-05-22 15:58:27 +10:00
module_64.c powerpc/modules: Use PPC_LI macros instead of opencoding 2022-05-22 15:58:27 +10:00
msi.c
note.S
nvram_64.c powerpc: Add missing headers 2022-05-08 22:15:40 +10:00
of_platform.c
optprobes.c powerpc/inst: Define ppc_inst_t as u32 on PPC32 2021-12-09 22:41:21 +11:00
optprobes_head.S powerpc/64: provide a helper macro to load r2 with the kernel TOC 2022-09-28 19:22:12 +10:00
paca.c powerpc: Remove CONFIG_PPC_BOOK3E 2022-09-26 23:00:13 +10:00
pci-common.c powerpc/pci-common: Fix refcount bug for 'phb->dn' 2022-09-05 17:30:29 +10:00
pci-hotplug.c powerpc: Add missing headers 2022-05-08 22:15:40 +10:00
pci_32.c powerpc/pci: Enable PCI domains in /proc when PCI bus numbers are not unique 2022-08-25 17:47:08 +10:00
pci_64.c powerpc/pci: Hide pci_device_from_OF_node() for non-powermac code 2022-07-27 21:36:03 +10:00
pci_dn.c powerpc/pci_dn: Add missing of_node_put() 2022-09-05 17:30:25 +10:00
pci_of_scan.c powerpc: Add missing headers 2022-05-08 22:15:40 +10:00
pmc.c
ppc_save_regs.S powerpc: update ppc_save_regs to save current r1 in pt_regs 2023-07-19 16:21:39 +02:00
proc_powerpc.c powerpc: Add missing headers 2022-05-08 22:15:40 +10:00
process.c KVM: PPC: Book3S HV: Fix KVM_RUN clobbering FP/VEC user registers 2023-12-08 08:51:15 +01:00
prom.c powerpc/64: Move paca allocation to early_setup() 2023-03-17 08:50:31 +01:00
prom_init.c powerpc/prom_init: drop PROM_BUG() 2022-09-26 20:58:18 +10:00
prom_init_check.sh powerpc/64: Remove unused prom_init_toc symbols 2022-09-26 20:58:16 +10:00
prom_parse.c
reloc_32.S powerpc: Avoid link stack corruption in misc asm functions 2021-08-25 13:35:47 +10:00
reloc_64.S powerpc/64: avoid using r13 in relocate 2022-09-28 19:22:13 +10:00
rtas-proc.c powerpc: Add missing headers 2022-05-08 22:15:40 +10:00
rtas-rtc.c powerpc: Remove asm/prom.h from all files that don't need it 2022-05-08 22:15:04 +10:00
rtas.c powerpc/rtas: use memmove for potentially overlapping buffer copy 2023-05-11 23:03:31 +09:00
rtas_entry.S powerpc/rtas: Fix RTAS MSR[HV] handling for Cell 2022-08-26 08:41:54 +10:00
rtas_flash.c powerpc/rtas_flash: allow user copy to flash block cache objects 2023-08-23 17:52:30 +02:00
rtas_pci.c powerpc: Add missing headers 2022-05-08 22:15:40 +10:00
rtasd.c powerpc: Remove asm/prom.h from all files that don't need it 2022-05-08 22:15:04 +10:00
secure_boot.c
security.c powerpc/security: Fix Speculation_Store_Bypass reporting on Power10 2023-07-23 13:49:32 +02:00
secvar-ops.c
secvar-sysfs.c powerpc/secvar: fix refcount leak in format_show() 2022-03-08 22:07:41 +11:00
setup-common.c powerpc/mm: Fix boot crash with FLATMEM 2023-11-08 14:11:02 +01:00
setup.h powerpc: Remove CONFIG_PPC_BOOK3E 2022-09-26 23:00:13 +10:00
setup_32.c powerpc: Change CONFIG_E500 to CONFIG_PPC_E500 2022-09-26 23:00:13 +10:00
setup_64.c powerpc/64: Move paca allocation to early_setup() 2023-03-17 08:50:31 +01:00
signal.c powerpc/signal: Report minimum signal frame size to userspace via AT_MINSIGSTKSZ 2022-05-19 23:11:26 +10:00
signal.h powerpc: Don't add __powerpc_ prefix to syscall entry points 2022-10-07 00:59:54 +11:00
signal_32.c powerpc/signal32: Force inlining of __unsafe_save_user_regs() and save_tm_user_regs_unsafe() 2023-07-19 16:21:37 +02:00
signal_64.c powerpc/signal: Update comment for clarity 2022-07-28 16:22:14 +10:00
smp-tbsync.c
smp.c powerpc/smp: poll cpu_callin_map more aggressively in __cpu_up() 2022-09-28 19:22:14 +10:00
stacktrace.c kprobes: treewide: Make it harder to refer kretprobe_trampoline directly 2021-09-30 21:24:06 -04:00
static_call.c powerpc/32: Add support for out-of-line static calls 2021-10-22 15:22:05 +11:00
suspend.c
swsusp.c
swsusp_32.S powerpc/mm: Switch obsolete dssall to .long 2021-12-23 22:35:13 +11:00
swsusp_64.c powerpc/machdep: Remove stale functions from ppc_md structure 2021-10-22 15:22:05 +11:00
swsusp_85xx.S powerpc: Remove CONFIG_FSL_BOOKE 2022-09-26 22:47:37 +10:00
swsusp_asm64.S powerpc/64: asm use consistent global variable declaration and access 2022-09-28 19:22:12 +10:00
sys_ppc32.c powerpc/32: fix syscall wrappers with 64-bit arguments 2022-11-01 10:24:09 +11:00
syscall.c powerpc: Provide syscall wrapper 2022-09-28 19:22:09 +10:00
syscalls.c powerpc: Adopt SYSCALL_DEFINE for arch-specific syscall handlers 2022-09-28 19:22:08 +10:00
sysfs.c powerpc: Remove CONFIG_PPC_FSL_BOOK3E 2022-09-26 23:00:13 +10:00
systbl.c powerpc: Don't add __powerpc_ prefix to syscall entry points 2022-10-07 00:59:54 +11:00
tau_6xx.c powerpc: Move C prototypes out of asm-prototypes.h 2022-03-08 22:06:25 +11:00
time.c powerpc/kcsan: Exclude udelay to prevent recursive instrumentation 2023-03-17 08:50:31 +01:00
tm.S powerpc/tm: Fix more userspace r13 corruption 2022-03-16 11:59:24 +11:00
traps.c powerpc: Fix build error due to is_valid_bugaddr() 2024-02-05 20:12:46 +00:00
ucall.S
udbg.c powerpc: Add support for early debugging via Serial 16550 console 2022-09-28 19:22:09 +10:00
udbg_16550.c powerpc: Add support for early debugging via Serial 16550 console 2022-09-28 19:22:09 +10:00
uprobes.c powerpc: Reject probes on instructions that can't be single stepped 2022-05-06 00:00:20 +10:00
vdso.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
vdso32_wrapper.S powerpc/vdso: Merge vdso64 and vdso32 into a single directory 2022-02-12 22:47:43 +11:00
vdso64_wrapper.S powerpc/vdso: Merge vdso64 and vdso32 into a single directory 2022-02-12 22:47:43 +11:00
vecemu.c powerpc/inst: Define ppc_inst_t 2021-12-09 22:41:21 +11:00
vector.S powerpc: Don't clobber f0/vs0 during fp|altivec register save 2023-12-08 08:51:15 +01:00
vmlinux.lds.S powerpc/vmlinux.lds: Don't discard .rela* for relocatable builds 2023-02-25 11:25:42 +01:00
watchdog.c powerpc/watchdog: introduce a NMI watchdog's factor 2022-07-27 21:36:02 +10:00