Re: [Crash-utility] [PATCH 0/1] Add --kaslr support for s390x
Hello Mikhail, Philipp and Gerald,
For the first time today I'm testing a 5.2.0-0.rc1 kernel that has
been configured with CONFIG_RANDOMIZE_BASE=y, and I have verified
that it runs live using the KERNELOFFSET value from the /proc/kcore
VMCOREINFO as the --kalsr argument.
For live system analysis, it seems that the existing kaslr
code in symbols.c should be able to calculate the offset
by comparing the _stext values from /proc/kallsyms and the
the vmlinux file. But obviously it doesn't, although I
haven't investigate why not.
Also, I can't create a kdump dumpfile, so I can't test that,
so it's not clear whether the initial patchset also requires
the -kaslr argument for vmcores?
Anyway, are you guys planning to post a follow-on patch to make
things work automagically both live and with kdumps?
Thanks,
Dave
----- Original Message -----
Add --kaslr support for s390x kernels configured with
CONFIG_RANDOMIZE_BASE. Only kdumps or ELF dumps with
vmcoreinfo are supported.
Suggested-by: Gerald Schaefer <gerald schaefer de ibm com>
Signed-off-by: Mikhail Zaslonko <zaslonko linux ibm com>
---
help.c | 2 +-
main.c | 3 ++-
symbols.c | 9 +++++----
3 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/help.c b/help.c
index ba15dec..47058ed 100644
--- a/help.c
+++ b/help.c
@@ -335,7 +335,7 @@ char *program_usage_info[] = {
" and verification. The default count is 32768.",
"",
" --kaslr offset | auto",
- " If an x86 or x86_64 kernel was configured with
CONFIG_RANDOMIZE_BASE,",
+ " If x86, x86_64 or s390x kernel was configured with
CONFIG_RANDOMIZE_BASE,",
" the offset value is equal to the difference between the symbol values
",
" compiled into the vmlinux file and their relocated KASLR value. If",
" set to auto, the KASLR offset value will be automatically
calculated.",
diff --git a/main.c b/main.c
index cd282cd..83ccd31 100644
--- a/main.c
+++ b/main.c
@@ -227,7 +227,8 @@ main(int argc, char **argv)
}
} else if (STREQ(long_options[option_index].name, "kaslr")) {
if (!machine_type("X86_64") &&
- !machine_type("ARM64") && !machine_type("X86"))
+ !machine_type("ARM64") && !machine_type("X86")
&&
+ !machine_type("S390X"))
error(INFO, "--kaslr not valid "
"with this machine type.\n");
else if (STREQ(optarg, "auto"))
diff --git a/symbols.c b/symbols.c
index 77f45f9..1ed75fe 100644
--- a/symbols.c
+++ b/symbols.c
@@ -593,8 +593,8 @@ kaslr_init(void)
{
char *string;
- if ((!machine_type("X86_64") && !machine_type("ARM64")
&& !machine_type("X86")) ||
- (kt->flags & RELOC_SET))
+ if ((!machine_type("X86_64") && !machine_type("ARM64")
&& !machine_type("X86") &&
+ !machine_type("S390X")) || (kt->flags & RELOC_SET))
return;
/*
@@ -751,7 +751,8 @@ store_symbols(bfd *abfd, int dynamic, void *minisyms, long symcount,
fromend, size, store);
} else if (!(kt->flags & RELOC_SET))
kt->flags |= RELOC_FORCE;
- } else if (machine_type("X86_64") || machine_type("ARM64")) {
+ } else if (machine_type("X86_64") || machine_type("ARM64") ||
+ machine_type("S390X")) {
if ((kt->flags2 & RELOC_AUTO) && !(kt->flags & RELOC_SET))
derive_kaslr_offset(abfd, dynamic, from,
fromend, size, store);
@@ -823,7 +824,7 @@ store_sysmap_symbols(void)
strerror(errno));
if (!machine_type("X86") && !machine_type("X86_64")
&&
- !machine_type("ARM64"))
+ !machine_type("ARM64") && !machine_type("S390X"))
kt->flags &= ~RELOC_SET;
first = 0;
--
2.16.4