[Crash-utility] [PATCH v2 2/3] xen: get stack address via stack_base array if available
Since many years now the stack address of each percpu stack is
available via the stack_base[] array (Xen commit 3cb68d2b59ab made
it visible). Use that instead of the indirect method via the percpu
variables tss_init or tss_page, especially as the layout of tss_page
has changed in Xen 4.16 (Xen commit 91d26ed304ff5), resulting in the
stack no longer to be found.
Signed-off-by: Juergen Gross <jgross(a)suse.com>
---
V2:
- add Xen commit ids to commit message (lijiang)
- avoid uninitialized init_tss (Hagio Kazuhito)
- alloc buf only if needed (lijiang)
- use FAULT_ON_ERROR in readmem() call (lijiang)
---
xen_hyper.c | 56 +++++++++++++++++++++++++++++++----------------------
1 file changed, 33 insertions(+), 23 deletions(-)
diff --git a/xen_hyper.c b/xen_hyper.c
index 1030c0a..ac257b6 100644
--- a/xen_hyper.c
+++ b/xen_hyper.c
@@ -324,7 +324,7 @@ void
xen_hyper_x86_pcpu_init(void)
{
ulong cpu_info;
- ulong init_tss_base, init_tss;
+ ulong init_tss_base, init_tss, stack_base;
ulong sp;
struct xen_hyper_pcpu_context *pcc;
char *buf, *bp;
@@ -340,34 +340,41 @@ xen_hyper_x86_pcpu_init(void)
}
/* get physical cpu context */
xen_hyper_alloc_pcpu_context_space(XEN_HYPER_MAX_CPUS());
- if (symbol_exists("per_cpu__init_tss")) {
+ if (symbol_exists("stack_base")) {
+ stack_base = symbol_value("stack_base");
+ flag = 0;
+ } else if (symbol_exists("per_cpu__init_tss")) {
init_tss_base = symbol_value("per_cpu__init_tss");
- flag = TRUE;
+ flag = 1;
} else if (symbol_exists("per_cpu__tss_page")) {
init_tss_base = symbol_value("per_cpu__tss_page");
- flag = TRUE;
+ flag = 1;
} else {
init_tss_base = symbol_value("init_tss");
- flag = FALSE;
+ flag = 2;
}
- buf = GETBUF(XEN_HYPER_SIZE(tss));
+ if (flag)
+ buf = GETBUF(XEN_HYPER_SIZE(tss));
for_cpu_indexes(i, cpuid)
{
- if (flag)
- init_tss = xen_hyper_per_cpu(init_tss_base, cpuid);
- else
- init_tss = init_tss_base +
- XEN_HYPER_SIZE(tss) * cpuid;
- if (!readmem(init_tss, KVADDR, buf,
- XEN_HYPER_SIZE(tss), "init_tss", RETURN_ON_ERROR)) {
- error(FATAL, "cannot read init_tss.\n");
- }
- if (machine_type("X86")) {
- sp = ULONG(buf + XEN_HYPER_OFFSET(tss_esp0));
- } else if (machine_type("X86_64")) {
- sp = ULONG(buf + XEN_HYPER_OFFSET(tss_rsp0));
- } else
- sp = 0;
+ if (flag) {
+ if (flag == 1)
+ init_tss = xen_hyper_per_cpu(init_tss_base, cpuid);
+ else
+ init_tss = init_tss_base +
+ XEN_HYPER_SIZE(tss) * cpuid;
+ readmem(init_tss, KVADDR, buf,
+ XEN_HYPER_SIZE(tss), "init_tss", FAULT_ON_ERROR);
+ if (machine_type("X86")) {
+ sp = ULONG(buf + XEN_HYPER_OFFSET(tss_esp0));
+ } else if (machine_type("X86_64")) {
+ sp = ULONG(buf + XEN_HYPER_OFFSET(tss_rsp0));
+ } else
+ sp = 0;
+ } else {
+ readmem(stack_base + sizeof(ulong) * cpuid, KVADDR, &sp,
+ sizeof(ulong), "stack_base", FAULT_ON_ERROR);
+ }
cpu_info = XEN_HYPER_GET_CPU_INFO(sp);
if (CRASHDEBUG(1)) {
fprintf(fp, "sp=%lx, cpu_info=%lx\n", sp, cpu_info);
@@ -377,9 +384,12 @@ xen_hyper_x86_pcpu_init(void)
}
pcc = &xhpct->context_array[cpuid];
xen_hyper_store_pcpu_context(pcc, cpu_info, bp);
- xen_hyper_store_pcpu_context_tss(pcc, init_tss, buf);
+ if (flag) {
+ xen_hyper_store_pcpu_context_tss(pcc, init_tss, buf);
+ }
}
- FREEBUF(buf);
+ if (flag)
+ FREEBUF(buf);
}
#elif defined(IA64)
--
2.35.3