Subject [PATCH kexec-tools 3/5] ppc64: segments may be reordered
Date: Fri, 02 Jan 2009 14:44:13 -0600
Subject: (No subject header)
X-Originating-IP: 205.232.218.102
Instead of fetching data from the segment array, remember the address
when added and find the kernel text from the parsed elf header.
While add_segment (and hence add_buffer) always adds to the end of
the list of segments, it sorts the previous segments before each
allocation. In some layouts, the device tree or initrd will fit
in a hole below the the kernel. When that happens, the previus
code mis-patches purgatory and the kexec fails.
Signed-off-by: Milton Miller <miltonm at bga.com>
---
The only safe reference is to info->segments[info->nr_segments]
kexec/arch/ppc64/kexec-elf-ppc64.c | 14 +++++++-------
1 files changed, 7 insertions(+), 7 deletions(-)
Index: kexec-tools/kexec/arch/ppc64/kexec-elf-ppc64.c
===================================================================
--- kexec-tools.orig/kexec/arch/ppc64/kexec-elf-ppc64.c 2009-01-01 21:46:24.000000000 -0600
+++ kexec-tools/kexec/arch/ppc64/kexec-elf-ppc64.c 2009-01-02 01:48:28.000000000 -0600
@@ -86,7 +86,7 @@ int elf_ppc64_load(int argc, char **argv
size_t size;
uint64_t *rsvmap_ptr;
struct bootblock *bb_ptr;
- unsigned int nr_segments, i;
+ unsigned int i;
int result, opt;
uint64_t my_kernel, my_dt_offset;
unsigned int my_panic_kernel;
@@ -187,7 +187,7 @@ int elf_ppc64_load(int argc, char **argv
if (size > phdr->p_memsz)
size = phdr->p_memsz;
- hole_addr = (uint64_t)locate_hole(info, size, 0, 0,
+ my_kernel = hole_addr = (uint64_t)locate_hole(info, size, 0, 0,
max_addr, 1);
ehdr.e_phdr[0].p_paddr = hole_addr;
result = elf_exec_load(&ehdr, info);
@@ -233,12 +233,10 @@ int elf_ppc64_load(int argc, char **argv
return -1;
}
seg_buf = (unsigned char *)slurp_file(ramdisk, &seg_size);
- add_buffer(info, seg_buf, seg_size, seg_size, 0, 0, max_addr, 1);
- hole_addr = (uintptr_t)
- info->segment[info->nr_segments-1].mem;
+ hole_addr = add_buffer(info, seg_buf, seg_size, seg_size,
+ 0, 0, max_addr, 1);
initrd_base = hole_addr;
- initrd_size = (uint64_t)
- info->segment[info->nr_segments-1].memsz;
+ initrd_size = seg_size;
} /* ramdisk */
if (devicetreeblob) {
@@ -248,44 +246,37 @@ int elf_ppc64_load(int argc, char **argv
/* Grab device tree from buffer */
blob_buf =
(unsigned char *)slurp_file(devicetreeblob, &blob_size);
- add_buffer(info, blob_buf, blob_size, blob_size, 0, 0,
- max_addr, -1);
+ seg_buf = blob_buf;
+ seg_size = blob_size;
} else {
/* create from fs2dt */
seg_buf = NULL;
seg_size = 0;
create_flatten_tree(info, (unsigned char **)&seg_buf,
(unsigned long *)&seg_size,cmdline);
- add_buffer(info, seg_buf, seg_size, seg_size,
- 0, 0, max_addr, -1);
}
+ my_dt_offset = add_buffer(info, seg_buf, seg_size, seg_size,
+ 0, 0, max_addr, -1);
/* patch reserve map address for flattened device-tree
* find last entry (both 0) in the reserve mem list. Assume DT
* entry is before this one
*/
- bb_ptr = (struct bootblock *)(
- (unsigned char *)info->segment[(info->nr_segments)-1].buf);
- rsvmap_ptr = (uint64_t *)(
- (unsigned char *)info->segment[(info->nr_segments)-1].buf +
- bb_ptr->off_mem_rsvmap);
+ bb_ptr = (struct bootblock *)(seg_buf);
+ rsvmap_ptr = (uint64_t *)
+ (((char *)seg_buf) + bb_ptr->off_mem_rsvmap);
while (*rsvmap_ptr || *(rsvmap_ptr+1))
rsvmap_ptr += 2;
rsvmap_ptr -= 2;
- *rsvmap_ptr = (uintptr_t)(
- info->segment[(info->nr_segments)-1].mem);
+ *rsvmap_ptr = my_dt_offset;
rsvmap_ptr++;
*rsvmap_ptr = (uint64_t)bb_ptr->totalsize;
- nr_segments = info->nr_segments;
-
/* Set kernel */
- my_kernel = (uintptr_t)info->segment[0].mem;
elf_rel_set_symbol(&info->rhdr, "kernel", &my_kernel, sizeof(my_kernel));
/* Set dt_offset */
- my_dt_offset = (uintptr_t)info->segment[nr_segments-1].mem;
elf_rel_set_symbol(&info->rhdr, "dt_offset", &my_dt_offset,
sizeof(my_dt_offset));
@@ -293,7 +284,7 @@ int elf_ppc64_load(int argc, char **argv
elf_rel_get_symbol(&info->rhdr, "purgatory_start", slave_code,
sizeof(slave_code));
master_entry = slave_code[0];
- memcpy(slave_code, info->segment[0].buf, sizeof(slave_code));
+ memcpy(slave_code, phdr->p_data, sizeof(slave_code));
slave_code[0] = master_entry;
elf_rel_set_symbol(&info->rhdr, "purgatory_start", slave_code,
sizeof(slave_code));
@@ -366,7 +357,7 @@ int elf_ppc64_load(int argc, char **argv
fprintf(stderr, "purgatory size is %zu\n", purgatory_size);
#endif
- for (i = 0; i < nr_segments; i++)
+ for (i = 0; i < info->nr_segments; i++)
fprintf(stderr, "segment[%d].mem:%p memsz:%zu\n", i,
info->segment[i].mem, info->segment[i].memsz);
