linux-kernel - [PATCH] proc/kcore: Use __pa_symbol() for KCORE

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Date:   Wed, 11 Jul 2018 14:19:44 +0100
From:   James Morse <james.morse@....com>
To:     linux-fsdevel@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org,
        Alexey Dobriyan <adobriyan@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>, james.morse@....com,
        Omar Sandoval <osandov@...com>
Subject: [PATCH] proc/kcore: Use __pa_symbol() for KCORE_TEXT list entries

elf_kcore_store_hdr() uses __pa() to find the physical address
of KCORE_RAM or KCORE_TEXT entries exported as program headers.

This trips CONFIG_DEBUG_VIRTUAL's checks, as the KCORE_TEXT
entries are not in the linear map.

Handle these two cases separately, using __pa_symbol() for the
KCORE_TEXT entries.

Signed-off-by: James Morse <james.morse@....com>
---
This will clash with a series from Omar:
https://lkml.org/lkml/2018/7/6/868

 fs/proc/kcore.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index e64ecb9f2720..66c373230e60 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -384,8 +384,10 @@ static void elf_kcore_store_hdr(char *bufp, int nphdr, int dataoff)
 		phdr->p_flags	= PF_R|PF_W|PF_X;
 		phdr->p_offset	= kc_vaddr_to_offset(m->addr) + dataoff;
 		phdr->p_vaddr	= (size_t)m->addr;
-		if (m->type == KCORE_RAM || m->type == KCORE_TEXT)
+		if (m->type == KCORE_RAM)
 			phdr->p_paddr	= __pa(m->addr);
+		else if (m->type == KCORE_TEXT)
+			phdr->p_paddr	= __pa_symbol(m->addr);
 		else
 			phdr->p_paddr	= (elf_addr_t)-1;
 		phdr->p_filesz	= phdr->p_memsz	= m->size;
-- 
2.18.0