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| author | Joe Lawrence <joe.lawrence@redhat.com> | 2019-05-17 20:51:17 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-05-19 11:43:22 +0200 |
| commit | 7eaf51a2e094229b75cc0c315f1cbbe2f3960058 (patch) | |
| tree | b62c0d6dc023c4b01b58070c4a511fecc80dd4f7 /kernel | |
| parent | objtool: Allow AR to be overridden with HOSTAR (diff) | |
| download | linux-7eaf51a2e094229b75cc0c315f1cbbe2f3960058.tar.xz linux-7eaf51a2e094229b75cc0c315f1cbbe2f3960058.zip | |
stacktrace: Unbreak stack_trace_save_tsk_reliable()
Miroslav reported that the livepatch self-tests were failing, specifically
a case in which the consistency model ensures that a current executing
function is not allowed to be patched, "TEST: busy target module".
Recent renovations of stack_trace_save_tsk_reliable() left it returning
only an -ERRNO success indication in some configuration combinations:
klp_check_stack()
ret = stack_trace_save_tsk_reliable()
#ifdef CONFIG_ARCH_STACKWALK && CONFIG_HAVE_RELIABLE_STACKTRACE
stack_trace_save_tsk_reliable()
ret = arch_stack_walk_reliable()
return 0
return -EINVAL
...
return ret;
...
if (ret < 0)
/* stack_trace_save_tsk_reliable error */
nr_entries = ret; << 0
Previously (and currently for !CONFIG_ARCH_STACKWALK &&
CONFIG_HAVE_RELIABLE_STACKTRACE) stack_trace_save_tsk_reliable() returned
the number of entries that it consumed in the passed storage array.
In the case of the above config and trace, be sure to return the
stacktrace_cookie.len on stack_trace_save_tsk_reliable() success.
Fixes: 25e39e32b0a3f ("livepatch: Simplify stack trace retrieval")
Reported-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: live-patching@vger.kernel.org
Cc: jikos@kernel.org
Cc: pmladek@suse.com
Link: https://lkml.kernel.org/r/20190517185117.24642-1-joe.lawrence@redhat.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/stacktrace.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c index 27bafc1e271e..90d3e0bf0302 100644 --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -206,7 +206,7 @@ int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store, ret = arch_stack_walk_reliable(consume_entry, &c, tsk); put_task_stack(tsk); - return ret; + return ret ? ret : c.len; } #endif |