linux/arch/powerpc/kernel
Michael Ellerman f0eee815ba powerpc/47x: Fix 47x syscall return crash
Eddie reported that newer kernels were crashing during boot on his 476
FSP2 system:

  kernel tried to execute user page (b7ee2000) - exploit attempt? (uid: 0)
  BUG: Unable to handle kernel instruction fetch
  Faulting instruction address: 0xb7ee2000
  Oops: Kernel access of bad area, sig: 11 [#1]
  BE PAGE_SIZE=4K FSP-2
  Modules linked in:
  CPU: 0 PID: 61 Comm: mount Not tainted 6.1.55-d23900f.ppcnf-fsp2 #1
  Hardware name: ibm,fsp2 476fpe 0x7ff520c0 FSP-2
  NIP:  b7ee2000 LR: 8c008000 CTR: 00000000
  REGS: bffebd83 TRAP: 0400   Not tainted (6.1.55-d23900f.ppcnf-fs p2)
  MSR:  00000030 <IR,DR>  CR: 00001000  XER: 20000000
  GPR00: c00110ac bffebe63 bffebe7e bffebe88 8c008000 00001000 00000d12 b7ee2000
  GPR08: 00000033 00000000 00000000 c139df10 48224824 1016c314 10160000 00000000
  GPR16: 10160000 10160000 00000008 00000000 10160000 00000000 10160000 1017f5b0
  GPR24: 1017fa50 1017f4f0 1017fa50 1017f740 1017f630 00000000 00000000 1017f4f0
  NIP [b7ee2000] 0xb7ee2000
  LR [8c008000] 0x8c008000
  Call Trace:
  Instruction dump:
  XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
  XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
  ---[ end trace 0000000000000000 ]---

The problem is in ret_from_syscall where the check for
icache_44x_need_flush is done. When the flush is needed the code jumps
out-of-line to do the flush, and then intends to jump back to continue
the syscall return.

However the branch back to label 1b doesn't return to the correct
location, instead branching back just prior to the return to userspace,
causing bogus register values to be used by the rfi.

The breakage was introduced by commit 6f76a01173
("powerpc/syscall: implement system call entry/exit logic in C for PPC32") which
inadvertently removed the "1" label and reused it elsewhere.

Fix it by adding named local labels in the correct locations. Note that
the return label needs to be outside the ifdef so that CONFIG_PPC_47x=n
compiles.

Fixes: 6f76a01173 ("powerpc/syscall: implement system call entry/exit logic in C for PPC32")
Cc: stable@vger.kernel.org # v5.12+
Reported-by: Eddie James <eajames@linux.ibm.com>
Tested-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/linuxppc-dev/fdaadc46-7476-9237-e104-1d2168526e72@linux.ibm.com/
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://msgid.link/20231010114750.847794-1-mpe@ellerman.id.au
2023-10-11 09:31:26 +11:00
..
ptrace powerpc/ptrace: Split gpr32_set_common 2023-08-16 23:54:50 +10:00
syscalls arch: Register fchmodat2, usually as syscall 452 2023-07-27 12:25:35 +02:00
trace powerpc updates for 6.6 2023-08-31 12:43:10 -07:00
vdso Kbuild updates for v6.5 2023-07-01 09:24:31 -07:00
.gitignore
85xx_entry_mapping.S powerpc: Remove CONFIG_FSL_BOOKE 2022-09-26 22:47:37 +10:00
Makefile powerpc/64: Rename entry_64.S to prom_entry_64.S 2023-06-15 14:04:19 +10:00
align.c powerpc/inst: Define ppc_inst_t 2021-12-09 22:41:21 +11:00
asm-offsets.c powerpc/64: vmlinux support building with PCREL addresing 2023-04-20 12:59:21 +10:00
audit.c powerpc: address missing-prototypes warnings 2023-08-02 22:22:19 +10:00
audit_32.h powerpc: address missing-prototypes warnings 2023-08-02 22:22:19 +10:00
btext.c powerpc: Use of_property_read_bool() for boolean properties 2023-03-30 23:36:35 +11:00
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 powerpc: address missing-prototypes warnings 2023-08-02 22:22:19 +10:00
cpu_setup_6xx.S powerpc/32: Fix objtool unannotated intra-function call warnings 2022-11-18 19:00:06 +11:00
cpu_setup_44x.S
cpu_setup_e500.S powerpc/32: Fix objtool unannotated intra-function call warnings 2022-11-18 19:00:06 +11:00
cpu_setup_pa6t.S
cpu_setup_power.c powerpc/dexcr: Add initial Dynamic Execution Control Register (DEXCR) support 2023-06-19 17:36:25 +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/kuap: Use MMU_FTR_KUAP on all and refactor disabling kuap 2023-08-02 22:22:18 +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 2023-01-30 20:07:42 +11:00
dma-iommu.c powerpc/iommu: Incorrect DDW Table is referenced for SR-IOV device 2023-05-17 00:54:55 +10:00
dma-mask.c dma-mapping: move arch_dma_set_mask() declaration to header 2023-07-31 17:54:28 +02:00
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/eeh: Set channel state after notifying the drivers 2023-02-15 22:41:11 +11:00
eeh_event.c powerpc: fix typos in comments 2022-05-05 22:12:44 +10:00
eeh_pe.c powerpc/eeh: Rely on dev->link_active_reporting 2023-06-14 17:58:12 -05:00
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 2023-10-11 09:31:26 +11:00
epapr_hcalls.S powerpc: replace #include <asm/export.h> with #include <linux/export.h> 2023-08-16 23:54:48 +10:00
epapr_paravirt.c powerpc/inst: Define ppc_inst_t 2021-12-09 22:41:21 +11:00
exceptions-64e.S powerpc/64e: Fix obtool warnings in exceptions-64e.S 2023-07-10 09:47:47 +10:00
exceptions-64s.S powerpc: add CFUNC assembly label annotation 2023-04-20 12:54:24 +10:00
fadump.c powerpc/fadump: reset dump area size if fadump memory reserve fails 2023-08-18 17:03:15 +10:00
firmware.c powerpc: fix unbalanced node refcount in check_kvm_guest() 2021-10-09 00:15:59 +11:00
fpu.S powerpc: replace #include <asm/export.h> with #include <linux/export.h> 2023-08-16 23:54:48 +10:00
head_8xx.S powerpc: remove unneeded #include <asm/export.h> 2023-08-16 23:54:48 +10:00
head_32.h powerpc: add a definition for the marker offset within the interrupt frame 2022-12-02 17:54:08 +11:00
head_40x.S powerpc: remove unneeded #include <asm/export.h> 2023-08-16 23:54:48 +10:00
head_44x.S powerpc: remove unneeded #include <asm/export.h> 2023-08-16 23:54:48 +10:00
head_64.S powerpc updates for 6.6 2023-08-31 12:43:10 -07:00
head_85xx.S powerpc/85xx: Fix math emulation exception 2023-10-10 21:32:40 +11:00
head_book3s_32.S powerpc: remove unneeded #include <asm/export.h> 2023-08-16 23:54:48 +10:00
head_booke.h powerpc/32: Include thread_info.h in head_booke.h 2023-04-11 23:13:33 +10:00
hw_breakpoint.c powerpc/watchpoints: Annotate atomic context in more places 2023-09-18 12:23:47 +10:00
hw_breakpoint_constraints.c powerpc/watchpoint: Disable pagefaults when getting user instruction 2023-09-18 12:23:47 +10:00
idle.c powerpc: Simplify sysctl registration for powersave_nap_ctl_table 2023-03-16 15:18:12 +11:00
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 integrity: Always reference the blacklist keyring with appraisal 2023-08-01 08:17:25 -04:00
interrupt.c powerpc: Mark [h]ssr_valid accesses in check_return_regs_valid 2023-06-21 15:13:57 +10:00
interrupt_64.S powerpc: Fix merge conflict between pcrel and copy_thread changes 2023-04-26 16:20:16 +10:00
io-workarounds.c powerpc: Fix reverse map real-mode address lookup with huge vmalloc 2021-05-28 22:54:27 +10:00
io.c
iomap.c powerpc: inline iomap accessors 2020-12-04 01:01:09 +11:00
iommu.c powerpc/iommu: Fix notifiers being shared by PCI and VIO buses 2023-08-25 23:44:35 +10:00
irq.c powerpc/64: vmlinux support building with PCREL addresing 2023-04-20 12:59:21 +10:00
irq_64.c powerpc/64: Don't call trace_hardirqs_on() in prep_irq_for_idle() 2023-04-20 13:21:49 +10:00
isa-bridge.c powerpc/isa-bridge: Fix ISA mapping when "ranges" is not present 2023-05-08 22:57:10 +10:00
jump_label.c powerpc: Don't use 'struct ppc_inst' to reference instruction location 2021-06-17 00:09:00 +10:00
kdebugfs.c powerpc: rename powerpc_debugfs_root to arch_debugfs_dir 2021-08-13 22:04:26 +10:00
kgdb.c powerpc: add definition for pt_regs offset within an interrupt frame 2022-12-02 17:54:08 +11:00
kprobes-ftrace.c ftrace: disable preemption when recursion locked 2021-10-27 11:21:49 -04:00
kprobes.c powerpc updates for 6.2 2022-12-19 07:13:33 -06:00
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: Explicitly include correct DT includes 2023-08-02 22:22:19 +10:00
mce.c powerpc/mce: log the error for all unrecoverable errors 2023-02-10 22:17:34 +11:00
mce_power.c powerpc/inst: Define ppc_inst_t 2021-12-09 22:41:21 +11:00
misc.S powerpc: replace #include <asm/export.h> with #include <linux/export.h> 2023-08-16 23:54:48 +10:00
misc_32.S powerpc: replace #include <asm/export.h> with #include <linux/export.h> 2023-08-16 23:54:48 +10:00
misc_64.S powerpc: replace #include <asm/export.h> with #include <linux/export.h> 2023-08-16 23:54:48 +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 module: replace module_layout with module_memory 2023-03-09 12:55:15 -08:00
module_64.c powerpc/ftrace: Add support for -fpatchable-function-entry 2023-08-22 00:09:06 +10:00
msi.c
note.S
nvram_64.c powerpc: Add missing headers 2022-05-08 22:15:40 +10:00
of_platform.c powerpc: Explicitly include correct DT includes 2023-08-02 22:22:19 +10:00
optprobes.c powerpc/kprobes: Have optimized_callback() use preempt_enable() 2022-11-24 23:31:49 +11:00
optprobes_head.S powerpc: add definition for pt_regs offset within an interrupt frame 2022-12-02 17:54:08 +11:00
paca.c powerpc/64: vmlinux support building with PCREL addresing 2023-04-20 12:59:21 +10:00
pci-common.c powerpc: Drop zalloc_maybe_bootmem() 2023-08-24 22:33:16 +10:00
pci-hotplug.c powerpc: Add missing headers 2022-05-08 22:15:40 +10:00
pci_32.c powerpc/pci: Add option for using pci_to_OF_bus_map 2023-02-07 20:15:23 +11:00
pci_64.c powerpc/pci_64: Init pcibios subsys a bit later 2023-03-14 23:36:27 +11:00
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 powerpc/85xx: Mark some functions static and add missing includes to fix no previous prototype error 2023-08-23 15:55:21 +10:00
ppc_save_regs.S powerpc: update ppc_save_regs to save current r1 in pt_regs 2023-06-19 17:37:14 +10:00
proc_powerpc.c powerpc: Add missing headers 2022-05-08 22:15:40 +10:00
process.c powerpc/dexcr: Support userspace ROP protection 2023-06-19 17:36:26 +10:00
prom.c powerpc/dexcr: Add initial Dynamic Execution Control Register (DEXCR) support 2023-06-19 17:36:25 +10:00
prom_entry_64.S powerpc/64: Rename entry_64.S to prom_entry_64.S 2023-06-15 14:04:19 +10:00
prom_init.c powerpc/prom_init: drop PROM_BUG() 2022-09-26 20:58:18 +10:00
prom_init_check.sh kasan, powerpc: don't rename memintrinsics if compiler adds prefixes 2023-03-23 17:18:33 -07:00
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/rtas: arch-wide function token lookup conversions 2023-02-13 22:35:03 +11:00
rtas-rtc.c powerpc/rtas: arch-wide function token lookup conversions 2023-02-13 22:35:03 +11:00
rtas.c powerpc/rtas: export rtas_error_rc() for reuse. 2023-08-18 23:28:57 +10:00
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 2023-08-17 09:46:14 +10:00
rtas_pci.c powerpc/rtas: arch-wide function token lookup conversions 2023-02-13 22:35:03 +11:00
rtasd.c powerpc/rtas: arch-wide function token lookup conversions 2023-02-13 22:35:03 +11:00
secure_boot.c
security.c powerpc/security: Fix Speculation_Store_Bypass reporting on Power10 2023-07-10 09:47:47 +10:00
secvar-ops.c powerpc/secvar: Warn and error if multiple secvar ops are set 2023-02-12 22:12:36 +11:00
secvar-sysfs.c powerpc/secvar: Don't print error on ENOENT when reading variables 2023-02-12 22:12:37 +11:00
setup-common.c powerpc: Explicitly include correct DT includes 2023-08-02 22:22:19 +10:00
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 cpu: Mark panic_smp_self_stop() __noreturn 2023-04-14 17:31:25 +02:00
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() 2023-06-09 23:29:51 +10:00
signal_64.c powerpc/signal: Update comment for clarity 2022-07-28 16:22:14 +10:00
smp-tbsync.c
smp.c Merge branch 'topic/cpu-smt' into next 2023-08-14 21:46:03 +10:00
stacktrace.c powerpc/stacktrace: Fix arch_stack_walk_reliable() 2023-09-22 20:29:27 +10:00
static_call.c powerpc/32: Add support for out-of-line static calls 2021-10-22 15:22:05 +11:00
suspend.c
switch.S powerpc: merge 32-bit and 64-bit _switch implementation 2023-06-15 14:03:55 +10:00
swsusp.c
swsusp_32.S powerpc/32: Fix objtool unannotated intra-function call warnings 2022-11-18 19:00:06 +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/kuap: MMU_FTR_BOOK3S_KUAP becomes MMU_FTR_KUAP 2023-08-02 22:22:18 +10:00
syscalls.c powerpc: Adopt SYSCALL_DEFINE for arch-specific syscall handlers 2022-09-28 19:22:08 +10:00
sysfs.c powerpc/sysfs: move to use bus_get_dev_root() 2023-03-17 15:29:34 +01:00
systbl.c powerpc: Don't add __powerpc_ prefix to syscall entry points 2022-10-07 00:59:54 +11:00
tau_6xx.c powerpc, workqueue: Use alloc_ordered_workqueue() to create ordered workqueues 2023-05-08 13:52:27 -10:00
time.c powerpc: Make generic_calibrate_decr() the default 2023-03-16 08:56:48 +11:00
tm.S powerpc: replace #include <asm/export.h> with #include <linux/export.h> 2023-08-16 23:54:48 +10:00
traps.c powerpc/dexcr: Move HASHCHK trap handler 2023-09-18 12:23:48 +10:00
ucall.S powerpc: replace #include <asm/export.h> with #include <linux/export.h> 2023-08-16 23:54:48 +10:00
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 mm: remove zap_page_range and create zap_vma_pages 2023-01-18 17:12:55 -08:00
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: replace #include <asm/export.h> with #include <linux/export.h> 2023-08-16 23:54:48 +10:00
vmlinux.lds.S powerpc/ftrace: Extend ftrace support for large kernels to ppc32 2023-08-22 00:09:05 +10:00
watchdog.c nmi_backtrace: allow excluding an arbitrary CPU 2023-08-18 10:19:00 -07:00