3d9042f8b9
Check that size is not zero, preventing the following warning: WARNING: CPU: 0 PID: 9692 at mm/vmalloc.c:3059 __vmalloc_node_range+0x528/0x648 Modules linked in: CPU: 0 PID: 9692 Comm: memop Not tainted 5.17.0-rc3-e4+ #80 Hardware name: IBM 8561 T01 701 (LPAR) Krnl PSW : 0704c00180000000 0000000082dc584c (__vmalloc_node_range+0x52c/0x648) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000083 ffffffffffffffff 0000000000000000 0000000000000001 0000038000000000 000003ff80000000 0000000000000cc0 000000008ebb8000 0000000087a8a700 000000004040aeb1 000003ffd9f7dec8 000000008ebb8000 000000009d9b8000 000000000102a1b4 00000380035afb68 00000380035afaa8 Krnl Code: 0000000082dc583e: d028a7f4ff80 trtr 2036(41,%r10),3968(%r15) 0000000082dc5844: af000000 mc 0,0 #0000000082dc5848: af000000 mc 0,0 >0000000082dc584c: a7d90000 lghi %r13,0 0000000082dc5850: b904002d lgr %r2,%r13 0000000082dc5854: eb6ff1080004 lmg %r6,%r15,264(%r15) 0000000082dc585a: 07fe bcr 15,%r14 0000000082dc585c: 47000700 bc 0,1792 Call Trace: [<0000000082dc584c>] __vmalloc_node_range+0x52c/0x648 [<0000000082dc5b62>] vmalloc+0x5a/0x68 [<000003ff8067f4ca>] kvm_arch_vm_ioctl+0x2da/0x2a30 [kvm] [<000003ff806705bc>] kvm_vm_ioctl+0x4ec/0x978 [kvm] [<0000000082e562fe>] __s390x_sys_ioctl+0xbe/0x100 [<000000008360a9bc>] __do_syscall+0x1d4/0x200 [<0000000083618bd2>] system_call+0x82/0xb0 Last Breaking-Event-Address: [<0000000082dc5348>] __vmalloc_node_range+0x28/0x648 Other than the warning, there is no ill effect from the missing check, the condition is detected by subsequent code and causes a return with ENOMEM. Fixes: ef11c9463ae0 (KVM: s390: Add vm IOCTL for key checked guest absolute memory access) Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Link: https://lore.kernel.org/r/20220221163237.4122868-1-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.