linux_dsm_epyc7002/arch
Rick Lindsley f39356261c powerpc/book3s/64: check for NULL pointer in pgd_alloc()
When the memset code was added to pgd_alloc(), it failed to consider
that kmem_cache_alloc() can return NULL. It's uncommon, but not
impossible under heavy memory contention. Example oops:

  Unable to handle kernel paging request for data at address 0x00000000
  Faulting instruction address: 0xc0000000000a4000
  Oops: Kernel access of bad area, sig: 11 []
  LE SMP NR_CPUS=2048 NUMA pSeries
  CPU: 70 PID: 48471 Comm: entrypoint.sh Kdump: loaded Not tainted 4.14.0-115.6.1.el7a.ppc64le 
  task: c000000334a00000 task.stack: c000000331c00000
  NIP:  c0000000000a4000 LR: c00000000012f43c CTR: 0000000000000020
  REGS: c000000331c039c0 TRAP: 0300   Not tainted  (4.14.0-115.6.1.el7a.ppc64le)
  MSR:  800000010280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]>  CR: 44022840  XER: 20040000
  CFAR: c000000000008874 DAR: 0000000000000000 DSISR: 42000000 SOFTE: 1
  ...
  NIP [c0000000000a4000] memset+0x68/0x104
  LR [c00000000012f43c] mm_init+0x27c/0x2f0
  Call Trace:
    mm_init+0x260/0x2f0 (unreliable)
    copy_mm+0x11c/0x638
    copy_process.isra.28.part.29+0x6fc/0x1080
    _do_fork+0xdc/0x4c0
    ppc_clone+0x8/0xc
  Instruction dump:
  409e000c b0860000 38c60002 409d000c 90860000 38c60004 78a0d183 78a506a0
  7c0903a6 41820034 60000000 60420000 <f8860000> f8860008 f8860010 f8860018

Fixes: fc5c2f4a55 ("powerpc/mm/hash64: Zero PGD pages on allocation")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Rick Lindsley <ricklind@vnet.linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-07 13:24:31 +10:00
..
alpha KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
arc KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
arm A collection of x86 and ARM bugfixes, and some improvements to documentation. 2019-03-31 08:55:59 -07:00
arm64 A collection of x86 and ARM bugfixes, and some improvements to documentation. 2019-03-31 08:55:59 -07:00
c6x KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
csky kbuild: force all architectures except um to include mandatory-y 2019-03-17 12:56:32 +09:00
h8300 KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
hexagon KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
ia64 KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
m68k KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
microblaze KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
mips A small batch of MIPS fixes for 5.1: 2019-03-19 10:50:15 -07:00
nds32 kbuild: force all architectures except um to include mandatory-y 2019-03-17 12:56:32 +09:00
nios2 KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
openrisc KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
parisc KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
powerpc powerpc/book3s/64: check for NULL pointer in pgd_alloc() 2019-05-07 13:24:31 +10:00
riscv kbuild: force all architectures except um to include mandatory-y 2019-03-17 12:56:32 +09:00
s390 s390 update with improvements and bug fixes for 5.1-rc2 2019-03-28 08:35:32 -07:00
sh KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
sparc KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
um Merge branch 'for-linus-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2019-03-15 15:07:32 -07:00
unicore32 KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
x86 A collection of x86 and ARM bugfixes, and some improvements to documentation. 2019-03-31 08:55:59 -07:00
xtensa KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
.gitignore
Kconfig Char/Misc driver patches for 5.1-rc1 2019-03-06 14:18:59 -08:00