linux-stable.git/arch/powerpc/kernel, branch v4.4.185

powerpc/64s: Include cpu header

2019-05-16T17:45:16+00:00

commit 42e2acde1237878462b028f5a27d9cc5bea7502c upstream.

Current powerpc security.c file is defining functions, as
cpu_show_meltdown(), cpu_show_spectre_v{1,2} and others, that are being
declared at linux/cpu.h header without including the header file that
contains these declarations.

This is being reported by sparse, which thinks that these functions are
static, due to the lack of declaration:

	arch/powerpc/kernel/security.c:105:9: warning: symbol 'cpu_show_meltdown' was not declared. Should it be static?
	arch/powerpc/kernel/security.c:139:9: warning: symbol 'cpu_show_spectre_v1' was not declared. Should it be static?
	arch/powerpc/kernel/security.c:161:9: warning: symbol 'cpu_show_spectre_v2' was not declared. Should it be static?
	arch/powerpc/kernel/security.c:209:6: warning: symbol 'stf_barrier' was not declared. Should it be static?
	arch/powerpc/kernel/security.c:289:9: warning: symbol 'cpu_show_spec_store_bypass' was not declared. Should it be static?

This patch simply includes the proper header (linux/cpu.h) to match
function definition and declaration.

Signed-off-by: Breno Leitao 
Signed-off-by: Michael Ellerman 
Cc: Joel Stanley 
Cc: Nathan Chancellor 
Cc: Major Hayden 
Signed-off-by: Greg Kroah-Hartman

powerpc/fsl: Fixed warning: orphan section `__btb_flush_fixup'

2019-05-16T17:44:55+00:00

commit 039daac5526932ec731e4499613018d263af8b3e upstream.

Fixed the following build warning:
powerpc-linux-gnu-ld: warning: orphan section `__btb_flush_fixup' from
`arch/powerpc/kernel/head_44x.o' being placed in section
`__btb_flush_fixup'.

Signed-off-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/fsl: Sanitize the syscall table for NXP PowerPC 32 bit platforms

2019-05-16T17:44:55+00:00

commit c28218d4abbf4f2035495334d8bfcba64bda4787 upstream.

Used barrier_nospec to sanitize the syscall table.

Signed-off-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/fsl: Flush the branch predictor at each kernel entry (32 bit)

2019-05-16T17:44:53+00:00

commit 7fef436295bf6c05effe682c8797dfcb0deb112a upstream.

In order to protect against speculation attacks on
indirect branches, the branch predictor is flushed at
kernel entry to protect for the following situations:
- userspace process attacking another userspace process
- userspace process attacking the kernel
Basically when the privillege level change (i.e.the kernel
is entered), the branch predictor state is flushed.

Signed-off-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/fsl: Enable runtime patching if nospectre_v2 boot arg is used

2019-05-16T17:44:52+00:00

commit 3bc8ea8603ae4c1e09aca8de229ad38b8091fcb3 upstream.

If the user choses not to use the mitigations, replace
the code sequence with nops.

Signed-off-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/fsl: Fix the flush of branch predictor.

2019-05-16T17:44:51+00:00

commit 27da80719ef132cf8c80eb406d5aeb37dddf78cc upstream.

The commit identified below adds MC_BTB_FLUSH macro only when
CONFIG_PPC_FSL_BOOK3E is defined. This results in the following error
on some configs (seen several times with kisskb randconfig_defconfig)

arch/powerpc/kernel/exceptions-64e.S:576: Error: Unrecognized opcode: `mc_btb_flush'
make[3]: *** [scripts/Makefile.build:367: arch/powerpc/kernel/exceptions-64e.o] Error 1
make[2]: *** [scripts/Makefile.build:492: arch/powerpc/kernel] Error 2
make[1]: *** [Makefile:1043: arch/powerpc] Error 2
make: *** [Makefile:152: sub-make] Error 2

This patch adds a blank definition of MC_BTB_FLUSH for other cases.

Fixes: 10c5e83afd4a ("powerpc/fsl: Flush the branch predictor at each kernel entry (64bit)")
Cc: Diana Craciun 
Signed-off-by: Christophe Leroy 
Reviewed-by: Daniel Axtens 
Reviewed-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/security: Fix spectre_v2 reporting

2019-05-16T17:44:51+00:00

commit 92edf8df0ff2ae86cc632eeca0e651fd8431d40d upstream.

When I updated the spectre_v2 reporting to handle software count cache
flush I got the logic wrong when there's no software count cache
enabled at all.

The result is that on systems with the software count cache flush
disabled we print:

  Mitigation: Indirect branch cache disabled, Software count cache flush

Which correctly indicates that the count cache is disabled, but
incorrectly says the software count cache flush is enabled.

The root of the problem is that we are trying to handle all
combinations of options. But we know now that we only expect to see
the software count cache flush enabled if the other options are false.

So split the two cases, which simplifies the logic and fixes the bug.
We were also missing a space before "(hardware accelerated)".

The result is we see one of:

  Mitigation: Indirect branch serialisation (kernel only)
  Mitigation: Indirect branch cache disabled
  Mitigation: Software count cache flush
  Mitigation: Software count cache flush (hardware accelerated)

Fixes: ee13cb249fab ("powerpc/64s: Add support for software count cache flush")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Michael Ellerman 
Reviewed-by: Michael Neuling 
Reviewed-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/fsl: Update Spectre v2 reporting

2019-05-16T17:44:50+00:00

commit dfa88658fb0583abb92e062c7a9cd5a5b94f2a46 upstream.

Report branch predictor state flush as a mitigation for
Spectre variant 2.

Signed-off-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/fsl: Flush the branch predictor at each kernel entry (64bit)

2019-05-16T17:44:50+00:00

commit 10c5e83afd4a3f01712d97d3bb1ae34d5b74a185 upstream.

In order to protect against speculation attacks on
indirect branches, the branch predictor is flushed at
kernel entry to protect for the following situations:
- userspace process attacking another userspace process
- userspace process attacking the kernel
Basically when the privillege level change (i.e. the
kernel is entered), the branch predictor state is flushed.

Signed-off-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/fsl: Add nospectre_v2 command line argument

2019-05-16T17:44:50+00:00

commit f633a8ad636efb5d4bba1a047d4a0f1ef719aa06 upstream.

When the command line argument is present, the Spectre variant 2
mitigations are disabled.

Signed-off-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman