From: Petr Mladek <pmladek@suse.com> To: Jiri Kosina <jikos@kernel.org>, Josh Poimboeuf <jpoimboe@redhat.com>, Miroslav Benes <mbenes@suse.cz> Cc: Joe Lawrence <joe.lawrence@redhat.com>, Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>, Nicolai Stange <nstange@suse.de>, Dan Carpenter <dan.carpenter@oracle.com>, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org, Petr Mladek <pmladek@suse.com> Subject: [PATCH 4/4] livepatch: Handle allocation failure in the sample of shadow variable API Date: Thu, 16 Jan 2020 16:31:45 +0100 Message-ID: <20200116153145.2392-5-pmladek@suse.com> (raw) In-Reply-To: <20200116153145.2392-1-pmladek@suse.com> 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 <pmladek@suse.com> --- 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 de0363b288a7..918ce17b43fd 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) -- 2.16.4
next prev parent reply index Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-16 15:31 [PATCH 0/4] livepatch/samples/selftest: Clean up show variables handling Petr Mladek 2020-01-16 15:31 ` [PATCH 1/4] livepatch/sample: Use the right type for the leaking data pointer Petr Mladek 2020-01-16 15:31 ` [PATCH 2/4] livepatch/selftest: Clean up shadow variable names and type Petr Mladek 2020-01-16 15:31 ` [PATCH 3/4] livepatch/samples/selftest: Use klp_shadow_alloc() API correctly Petr Mladek 2020-01-16 15:31 ` Petr Mladek [this message] 2020-01-16 19:29 ` [PATCH 0/4] livepatch/samples/selftest: Clean up show variables handling Joe Lawrence 2020-01-17 8:26 ` Miroslav Benes 2020-01-17 9:41 ` Kamalesh Babulal 2020-01-17 10:13 ` Jiri Kosina
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