2013-05-07 18:11:23

by David Daney

[permalink] [raw]
Subject: [PATCH v2] MIPS: Make virt_to_phys() work for all unmapped addresses.

From: David Daney <[email protected]>

As reported:
This problem was discovered when doing BGP traffic with the TCP MD5 option
activated, where the following call chain caused a crash:

* tcp_v4_rcv
* tcp_v4_timewait_ack
* tcp_v4_send_ack -> follow stack variable rep.th
* tcp_v4_md5_hash_hdr
* tcp_md5_hash_header
* sg_init_one
* sg_set_buf
* virt_to_page

I noticed that tcp_v4_send_reset uses a similar stack variable and
also calls tcp_v4_md5_hash_hdr, so it has the same problem.

The networking core can indirectly call virt_to_phys() on stack
addresses, if this is done from PID 0, the stack will usually be in
CKSEG0, so virt_to_phys() needs to work there as well

Signed-off-by: David Daney <[email protected]>
---

This one appears to build against Linus' tree.

This could also fix problems noted by Eunbong Song with the
free_initmem_default() call.

arch/mips/include/asm/io.h | 2 +-
arch/mips/include/asm/page.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 1be1372..b7e5985 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -118,7 +118,7 @@ static inline void set_io_port_base(unsigned long base)
*/
static inline unsigned long virt_to_phys(volatile const void *address)
{
- return (unsigned long)address - PAGE_OFFSET + PHYS_OFFSET;
+ return __pa(address);
}

/*
diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h
index eab99e5..ec1ca53 100644
--- a/arch/mips/include/asm/page.h
+++ b/arch/mips/include/asm/page.h
@@ -46,7 +46,6 @@
#endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */

#include <linux/pfn.h>
-#include <asm/io.h>

extern void build_clear_page(void);
extern void build_copy_page(void);
@@ -151,6 +150,7 @@ typedef struct { unsigned long pgprot; } pgprot_t;
((unsigned long)(x) - PAGE_OFFSET + PHYS_OFFSET)
#endif
#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - PHYS_OFFSET))
+#include <asm/io.h>

/*
* RELOC_HIDE was originally added by 6007b903dfe5f1d13e0c711ac2894bdd4a61b1ad
--
1.7.11.7