From f46e49a9cc3814f3564477f0fffc00e0a2bc9e80 Mon Sep 17 00:00:00 2001 From: Petr Mladek Date: Thu, 16 Jan 2020 16:31:45 +0100 Subject: [PATCH] livepatch: Handle allocation failure in the sample of shadow variable API klp_shadow_alloc() is not handled in the sample of shadow variable API. It is not strictly necessary because livepatch_fix1_dummy_free() is able to handle the potential failure. But it is an example and it should use the API a clean way. Signed-off-by: Petr Mladek Reviewed-by: Joe Lawrence Acked-by: Miroslav Benes Reviewed-by: Kamalesh Babulal Signed-off-by: Jiri Kosina --- samples/livepatch/livepatch-shadow-fix1.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/samples/livepatch/livepatch-shadow-fix1.c b/samples/livepatch/livepatch-shadow-fix1.c index de0363b..918ce17 100644 --- a/samples/livepatch/livepatch-shadow-fix1.c +++ b/samples/livepatch/livepatch-shadow-fix1.c @@ -66,6 +66,7 @@ static struct dummy *livepatch_fix1_dummy_alloc(void) { struct dummy *d; int *leak; + int **shadow_leak; d = kzalloc(sizeof(*d), GFP_KERNEL); if (!d) @@ -80,18 +81,27 @@ static struct dummy *livepatch_fix1_dummy_alloc(void) * pointer to handle resource release. */ leak = kzalloc(sizeof(*leak), GFP_KERNEL); - if (!leak) { - kfree(d); - return NULL; + if (!leak) + goto err_leak; + + shadow_leak = klp_shadow_alloc(d, SV_LEAK, sizeof(leak), GFP_KERNEL, + shadow_leak_ctor, &leak); + if (!shadow_leak) { + pr_err("%s: failed to allocate shadow variable for the leaking pointer: dummy @ %p, leak @ %p\n", + __func__, d, leak); + goto err_shadow; } - klp_shadow_alloc(d, SV_LEAK, sizeof(leak), GFP_KERNEL, - shadow_leak_ctor, &leak); - pr_info("%s: dummy @ %p, expires @ %lx\n", __func__, d, d->jiffies_expire); return d; + +err_shadow: + kfree(leak); +err_leak: + kfree(d); + return NULL; } static void livepatch_fix1_dummy_leak_dtor(void *obj, void *shadow_data) -- 2.7.4