linux-kernel - [PATCH 5.6 173/177] powerpc/bpf: Enable bpf_probe

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200601174102.468155104@linuxfoundation.org>
Date:   Mon,  1 Jun 2020 19:55:11 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Petr Mladek <pmladek@...e.com>,
        Daniel Borkmann <daniel@...earbox.net>,
        Michael Ellerman <mpe@...erman.id.au>
Subject: [PATCH 5.6 173/177] powerpc/bpf: Enable bpf_probe_read{, str}() on powerpc again

From: Petr Mladek <pmladek@...e.com>

commit d195b1d1d1196681ac4775e0361e9cca70f740c2 upstream.

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.

Fixes: 0ebeea8ca8a4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work")
Signed-off-by: Petr Mladek <pmladek@...e.com>
Signed-off-by: Daniel Borkmann <daniel@...earbox.net>
Acked-by: Michael Ellerman <mpe@...erman.id.au>
Link: https://lore.kernel.org/lkml/20200527122844.19524-1-pmladek@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/powerpc/Kconfig |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -125,6 +125,7 @@ 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