Mailing List Archive

# HG changeset patch
# User Ian Jackson <Ian.Jackson@eu.citrix.com>
# Date 1296243469 0
# Node ID 52e928af363726b96698ee2ecc9c3d6c0b08678d
# Parent 88cf07fed7d21202d4b26e5161d10e92e771ea18
libxc: Do not use dom0 physmem as parameter to lzma decoder

It's not clear why a userspace lzma decode would want to use that
particular value, what bearing it has on anything or why it would
assume it could use 1/3 of the total RAM in the system (potentially
quite a large amount of RAM) as opposed to any other limit number.

Instead, hardcode 32Mby.

This reverts 22830:c80960244942, removes the xc_get_physmem/physmem
function entirely, and replaces the expression at the call site with a
fixed constant.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Cc: Christoph Egger <Christoph.Egger@amd.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
---
tools/libxc/xc_dom_bzimageloader.c | 2 +-
tools/libxc/xc_linux.c | 21 ---------------------
tools/libxc/xc_netbsd.c | 21 ---------------------
tools/libxc/xc_private.h | 3 ---
4 files changed, 1 insertion(+), 46 deletions(-)

diff -r 88cf07fed7d2 -r 52e928af3637 tools/libxc/xc_dom_bzimageloader.c
--- a/tools/libxc/xc_dom_bzimageloader.c Fri Jan 28 18:39:09 2011 +0000
+++ b/tools/libxc/xc_dom_bzimageloader.c Fri Jan 28 19:37:49 2011 +0000
@@ -152,7 +152,7 @@ static int xc_try_lzma_decode(
int outsize;
const char *msg;

- ret = lzma_alone_decoder(&stream, xc_get_physmem() / 3);
+ ret = lzma_alone_decoder(&stream, 32*1024*1024);
if ( ret != LZMA_OK )
{
DOMPRINTF("LZMA: Failed to init stream decoder");
diff -r 88cf07fed7d2 -r 52e928af3637 tools/libxc/xc_linux.c
--- a/tools/libxc/xc_linux.c Fri Jan 28 18:39:09 2011 +0000
+++ b/tools/libxc/xc_linux.c Fri Jan 28 19:37:49 2011 +0000
@@ -55,27 +55,6 @@ void discard_file_cache(xc_interface *xc
errno = saved_errno;
}

-uint64_t xc_get_physmem(void)
-{
- uint64_t ret = 0;
- const long pagesize = sysconf(_SC_PAGESIZE);
- const long pages = sysconf(_SC_PHYS_PAGES);
-
- if ( (pagesize != -1) || (pages != -1) )
- {
- /*
- * According to docs, pagesize * pages can overflow.
- * Simple case is 32-bit box with 4 GiB or more RAM,
- * which may report exactly 4 GiB of RAM, and "long"
- * being 32-bit will overflow. Casting to uint64_t
- * hopefully avoids overflows in the near future.
- */
- ret = (uint64_t)(pagesize) * (uint64_t)(pages);
- }
-
- return ret;
-}
-
/*
* Local variables:
* mode: C
diff -r 88cf07fed7d2 -r 52e928af3637 tools/libxc/xc_netbsd.c
--- a/tools/libxc/xc_netbsd.c Fri Jan 28 18:39:09 2011 +0000
+++ b/tools/libxc/xc_netbsd.c Fri Jan 28 19:37:49 2011 +0000
@@ -23,9 +23,6 @@
#include <xen/sys/evtchn.h>
#include <unistd.h>
#include <fcntl.h>
-#include <stdio.h>
-#include <errno.h>
-#include <sys/sysctl.h>

static xc_osdep_handle netbsd_privcmd_open(xc_interface *xch)
{
@@ -354,24 +351,6 @@ void discard_file_cache(xc_interface *xc
errno = saved_errno;
}

-uint64_t xc_get_physmem(void)
-{
- int mib[2], rc;
- size_t len;
- uint64_t physmem;
-
- mib[0] = CTL_HW;
- mib[1] = HW_PHYSMEM64;
- rc = sysctl(mib, 2, &physmem, &len, NULL, 0);
-
- if (rc == -1) {
- /* PERROR("%s: Failed to get hw.physmem64: %s\n", strerror(errno)); */
- return 0;
- }
-
- return physmem;
-}
-
static struct xc_osdep_ops *netbsd_osdep_init(xc_interface *xch, enum xc_osdep_type type)
{
switch ( type )
diff -r 88cf07fed7d2 -r 52e928af3637 tools/libxc/xc_private.h
--- a/tools/libxc/xc_private.h Fri Jan 28 18:39:09 2011 +0000
+++ b/tools/libxc/xc_private.h Fri Jan 28 19:37:49 2011 +0000
@@ -275,9 +275,6 @@ void bitmap_byte_to_64(uint64_t *lp, con
/* Optionally flush file to disk and discard page cache */
void discard_file_cache(xc_interface *xch, int fd, int flush);

-/* How much physical RAM is available? */
-uint64_t xc_get_physmem(void);
-
#define MAX_MMU_UPDATES 1024
struct xc_mmu {
mmu_update_t updates[MAX_MMU_UPDATES];

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