The initial patch: 11ff40fa7bb5fdcc69a58d0fec49c904ffca4793
"xen/xsplice: Hypervisor implementation of XEN_XSPLICE_op" caps the
size of the binary at 2MB. We follow that in capping the size
of the .BSSes to be at maximum 2MB.
Reviewed-by: Ross Lagerwall <ross.lagerw...@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
---
Cc: Ross Lagerwall <ross.lagerw...@citrix.com>
Cc: Jan Beulich <jbeul...@suse.com>
v5: Initial submission. Came about from conversation about
"livepatch: Clear .bss when payload is reverted"
- Use only one sh_flags comparison instead of two.
- And check for the _right_ combination (WA).
v6: Remove the logging
Move the MB(2) to a #define in the header file.
Add the newline after the addition in livepatch_elf.c.
Added Reviewed-by from Ross.
---
xen/common/livepatch_elf.c | 4 ++++
xen/include/xen/livepatch.h | 2 ++
2 files changed, 6 insertions(+)
diff --git a/xen/common/livepatch_elf.c b/xen/common/livepatch_elf.c
index cda9b27..79c290e 100644
--- a/xen/common/livepatch_elf.c
+++ b/xen/common/livepatch_elf.c
@@ -86,6 +86,10 @@ static int elf_resolve_sections(struct livepatch_elf *elf,
const void *data)
delta < sizeof(Elf_Ehdr) ? "at ELF header" : "is past
end");
return -EINVAL;
}
+ else if ( (sec[i].sec->sh_flags & (SHF_WRITE | SHF_ALLOC)) &&
+ sec[i].sec->sh_type == SHT_NOBITS &&
+ sec[i].sec->sh_size > BSS_MAX_SIZE )
+ return -EINVAL;
sec[i].data = data + delta;
/* Name is populated in elf_resolve_section_names. */
diff --git a/xen/include/xen/livepatch.h b/xen/include/xen/livepatch.h
index 243e240..46b9fc2 100644
--- a/xen/include/xen/livepatch.h
+++ b/xen/include/xen/livepatch.h
@@ -30,6 +30,8 @@ struct xen_sysctl_livepatch_op;
#define ELF_LIVEPATCH_FUNC ".livepatch.funcs"
#define ELF_LIVEPATCH_DEPENDS ".livepatch.depends"
#define ELF_BUILD_ID_NOTE ".note.gnu.build-id"
+/* Arbitrary limit. */
+#define BSS_MAX_SIZE MB(2)
struct livepatch_symbol {
const char *name;
--
2.5.5
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