[PATCH] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again

[Petr Mladek]

The commit 0ebeea8ca8a4d1d453a ("bpf: Restrict bpf_probe_read{, str}() only
to archs where they work") caused that bpf_probe_read{, str}() functions
were not longer available on architectures where the same logical address
might have different content in kernel and user memory mapping. These
architectures should use probe_read_{user,kernel}_str helpers.

For backward compatibility, the problematic functions are still available
on architectures where the user and kernel address spaces are not
overlapping. This is defined CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE.

At the moment, these backward compatible functions are enabled only
on x86_64, arm, and arm64. Let's do it also on powerpc that has
the non overlapping address space as well.

Signed-off-by: Petr Mladek <pmladek at suse.com>
To: Michael Ellerman <mpe at ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Paul Mackerras <paulus at samba.org>
Cc: linuxppc-dev at lists.ozlabs.org
Cc: linux-kernel at vger.kernel.org
Cc: Daniel Borkmann <daniel at iogearbox.net>
Cc: Alexei Starovoitov <ast at kernel.org>
Cc: Masami Hiramatsu <mhiramat at kernel.org>
Cc: Brendan Gregg <brendan.d.gregg at gmail.com>
Cc: Christoph Hellwig <hch at lst.de>
---
 arch/powerpc/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index d13b5328ca10..b29d7cb38368 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -126,6 +126,7 @@ config PPC
 	select ARCH_HAS_MMIOWB			if PPC64
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_PMEM_API
+	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_PTE_DEVMAP		if PPC_BOOK3S_64
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_MEMBARRIER_CALLBACKS
-- 
2.26.2