We'll OOPS in ramoops_get_next_prz() if the platform didn't ask for any ftrace zones (i.e., cxt->fprzs will be NULL). Let's just skip this entire FTRACE section if there's no 'fprzs'.
Regression seen on a coreboot/depthcharge-based Chromebook. Fixes: 2fbea82bbb89 ("pstore: Merge per-CPU ftrace records into one") Cc: Joel Fernandes <joe...@google.com> Cc: Kees Cook <keesc...@chromium.org> Signed-off-by: Brian Norris <briannor...@chromium.org> --- Sorry for the late notice, but I just booted 4.10 on a Chromebook. This also may not be the "perfect" fix, but it's what I scrounged up in 5 minutes today. fs/pstore/ram.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 27c059e1760a..1d887efaaf71 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -280,7 +280,7 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, 1, id, type, PSTORE_TYPE_PMSG, 0); /* ftrace is last since it may want to dynamically allocate memory. */ - if (!prz_ok(prz)) { + if (!prz_ok(prz) && cxt->fprzs) { if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)) { prz = ramoops_get_next_prz(cxt->fprzs, &cxt->ftrace_read_cnt, 1, id, type, -- 2.11.0.483.g087da7b7c-goog