Daniel Axtens b0f8599196 powerpc/nohash: fix undefined behaviour when testing page size support ... [ Upstream commit f5e284803a ] When enumerating page size definitions to check hardware support, we construct a constant which is (1U << (def->shift - 10)). However, the array of page size definitions is only initalised for various MMU_PAGE_* constants, so it contains a number of 0-initialised elements with def->shift == 0. This means we end up shifting by a very large number, which gives the following UBSan splat: ================================================================================ UBSAN: Undefined behaviour in /home/dja/dev/linux/linux/arch/powerpc/mm/tlb_nohash.c:506:21 shift exponent 4294967286 is too large for 32-bit type 'unsigned int' CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-00045-ga604f927b012-dirty #6 Call Trace: [c00000000101bc20] [c000000000a13d54] .dump_stack+0xa8/0xec (unreliable) [c00000000101bcb0] [c0000000004f20a8] .ubsan_epilogue+0x18/0x64 [c00000000101bd30] [c0000000004f2b10] .__ubsan_handle_shift_out_of_bounds+0x110/0x1a4 [c00000000101be20] [c000000000d21760] .early_init_mmu+0x1b4/0x5a0 [c00000000101bf10] [c000000000d1ba28] .early_setup+0x100/0x130 [c00000000101bf90] [c000000000000528] start_here_multiplatform+0x68/0x80 ================================================================================ Fix this by first checking if the element exists (shift != 0) before constructing the constant. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2018-11-21 09:19:09 +01:00
..
alpha
arc	ARC: clone syscall to setp r25 as thread pointer	2018-10-05 14:33:29 -07:00
arm	ARM: imx_v6_v7_defconfig: Select CONFIG_TMPFS_POSIX_ACL	2018-11-21 09:19:09 +01:00
arm64	arm64: dts: stratix10: Correct System Manager register size	2018-11-13 11:08:55 -08:00
c6x
h8300
hexagon	hexagon: modify ffs() and fls() to return int	2018-09-10 19:42:15 -05:00
ia64
m68k	crypto: speck - remove Speck	2018-11-13 11:08:46 -08:00
microblaze
mips	MIPS: OCTEON: fix out of bounds array access on CN68XX	2018-11-13 11:08:50 -08:00
nds32	nds32: linker script: GCOV kernel may refers data in __exit	2018-09-05 10:16:26 +08:00
nios2
openrisc
parisc	parisc: Fix exported address of os_hpmc handler	2018-11-13 11:08:18 -08:00
powerpc	powerpc/nohash: fix undefined behaviour when testing page size support	2018-11-21 09:19:09 +01:00
riscv	RISCV: Fix end PFN for low memory	2018-10-02 12:50:01 -07:00
s390	crypto: speck - remove Speck	2018-11-13 11:08:46 -08:00
sh
sparc	sparc64: Wire up compat getpeername and getsockname.	2018-11-04 14:50:54 +01:00
um
unicore32
x86	xen: fix xen_qlock_wait()	2018-11-13 11:08:52 -08:00
xtensa	xtensa: enable SG chaining in Kconfig	2018-09-11 22:12:59 -07:00
.gitignore
Kconfig