linux/arch/x86
Kees Cook 184d47f0fd x86/mm: Avoid VLA in pgd_alloc()
Arnd Bergmann reported that turning on -Wvla found a new (unintended) VLA usage:

  arch/x86/mm/pgtable.c: In function 'pgd_alloc':
  include/linux/build_bug.h:29:45: error: ISO C90 forbids variable length array 'u_pmds' [-Werror=vla]
  arch/x86/mm/pgtable.c:190:34: note: in expansion of macro 'static_cpu_has'
   #define PREALLOCATED_USER_PMDS  (static_cpu_has(X86_FEATURE_PTI) ? \
                                    ^~~~~~~~~~~~~~
  arch/x86/mm/pgtable.c:431:16: note: in expansion of macro 'PREALLOCATED_USER_PMDS'
    pmd_t *u_pmds[PREALLOCATED_USER_PMDS];
                ^~~~~~~~~~~~~~~~~~~~~~

Use the actual size of the array that is used for X86_FEATURE_PTI,
which is known at build time, instead of the variable size.

[ mingo: Squashed original fix with followup fix to avoid bisection breakage, wrote new changelog. ]

Reported-by: Arnd Bergmann <arnd@arndb.de>
Original-written-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Fixes: 1be3f247c288 ("x86/mm: Avoid VLA in pgd_alloc()")
Link: http://lkml.kernel.org/r/20181008235434.GA35035@beast
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-09 08:55:07 +02:00
..
boot x86/boot: Fix kexec booting failure in the SEV bit detection code 2018-09-27 19:35:03 +02:00
configs
crypto crypto: x86/aegis,morus - Do not require OSXSAVE for SSE2 2018-09-14 14:08:27 +08:00
entry x86/vdso: Fix vDSO syscall fallback asm constraint regression 2018-10-04 08:17:50 +02:00
events perf/x86/amd/uncore: Set ThreadMask and SliceMask for L3 Cache perf events 2018-10-02 09:38:04 +02:00
hyperv x86/hyper-v: rename ipi_arg_{ex,non_ex} structures 2018-09-20 00:51:42 +02:00
ia32 syscalls/x86: auto-create compat_sys_*() prototypes 2018-04-02 20:16:18 +02:00
include Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-05 16:07:13 -07:00
kernel x86/intel_rdt: Fix out-of-bounds memory access in CBM tests 2018-10-09 08:02:15 +02:00
kvm kvm: nVMX: fix entry with pending interrupt if APICv is enabled 2018-10-04 17:10:40 +02:00
lib x86/nmi: Fix NMI uaccess race against CR3 switching 2018-08-31 17:08:22 +02:00
math-emu
mm x86/mm: Avoid VLA in pgd_alloc() 2018-10-09 08:55:07 +02:00
net bpf, x32: Fix regression caused by commit 24dea04767 2018-07-26 02:51:12 +02:00
oprofile x86/oprofile: Fix bogus GCC-8 warning in nmi_setup() 2018-02-21 09:54:17 +01:00
pci PCI: Make early dump functionality generic 2018-06-29 20:06:07 -05:00
platform x86/efi: Load fixmap GDT in efi_call_phys_epilog() before setting %cr3 2018-09-12 21:53:34 +02:00
power Power management updates for 4.19-rc1 2018-08-14 13:12:24 -07:00
purgatory kbuild: move bin2c back to scripts/ from scripts/basic/ 2018-07-18 01:18:05 +09:00
ras
realmode x86-64/realmode: Add instruction suffix 2018-02-20 09:33:41 +01:00
tools x86/relocs: Add __end_rodata_aligned to S_REL 2018-08-09 20:42:07 +02:00
um Consolidation of Kconfig files by Christoph Hellwig. 2018-08-15 13:05:12 -07:00
video
xen xen: fixes for 4.19-rc5 2018-09-23 13:32:19 +02:00
.gitignore x86/build: Add arch/x86/tools/insn_decoder_test to .gitignore 2018-02-13 14:10:29 +01:00
Kbuild
Kconfig x86/Kconfig: Fix trivial typo 2018-08-27 10:29:14 +02:00
Kconfig.cpu Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-03-25 07:36:02 -10:00
Kconfig.debug Kconfig: consolidate the "Kernel hacking" menu 2018-08-02 08:06:48 +09:00
Makefile x86: Allow generating user-space headers without a compiler 2018-08-31 17:08:22 +02:00
Makefile_32.cpu
Makefile.um kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00