From: "Christopher M. Riedl" <cmr@bluescreens.de>
To: linuxppc-dev@lists.ozlabs.org
Cc: linux-hardening@vger.kernel.org
Subject: [PATCH v6 3/4] powerpc: Use WARN_ON and fix check in poking_init
Date: Fri, 10 Sep 2021 21:29:03 -0500 [thread overview]
Message-ID: <20210911022904.30962-4-cmr@bluescreens.de> (raw)
In-Reply-To: <20210911022904.30962-1-cmr@bluescreens.de>
The latest kernel docs list BUG_ON() as 'deprecated' and that they
should be replaced with WARN_ON() (or pr_warn()) when possible. The
BUG_ON() in poking_init() warrants a WARN_ON() rather than a pr_warn()
since the error condition is deemed "unreachable".
Also take this opportunity to fix the failure check in the WARN_ON():
cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, ...) returns a positive integer
on success and a negative integer on failure.
Signed-off-by: Christopher M. Riedl <cmr@bluescreens.de>
---
v6: * New to series - based on Christophe's relentless feedback in the
crusade against BUG_ON()s :)
---
arch/powerpc/lib/code-patching.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 8d0bb86125d5..e802e42c2789 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -126,16 +126,11 @@ static int text_area_cpu_down(unsigned int cpu)
return 0;
}
-/*
- * Although BUG_ON() is rude, in this case it should only happen if ENOMEM, and
- * we judge it as being preferable to a kernel that will crash later when
- * someone tries to use patch_instruction().
- */
void __init poking_init(void)
{
- BUG_ON(!cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+ WARN_ON(cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
"powerpc/text_poke:online", text_area_cpu_up,
- text_area_cpu_down));
+ text_area_cpu_down) < 0);
}
/*
--
2.32.0
next prev parent reply other threads:[~2021-09-11 2:29 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-11 2:29 [PATCH v6 0/4] Use per-CPU temporary mappings for patching on Radix MMU Christopher M. Riedl
2021-09-11 2:29 ` [PATCH v6 1/4] powerpc/64s: Introduce temporary mm for " Christopher M. Riedl
2021-09-11 8:26 ` Jordan Niethe
2021-09-16 0:24 ` Christopher M. Riedl
2021-09-11 2:29 ` [PATCH v6 2/4] powerpc: Rework and improve STRICT_KERNEL_RWX patching Christopher M. Riedl
2021-09-11 2:29 ` Christopher M. Riedl [this message]
2021-09-11 2:29 ` [PATCH v6 4/4] powerpc/64s: Initialize and use a temporary mm for patching on Radix Christopher M. Riedl
2021-09-11 9:14 ` Jordan Niethe
2021-09-16 0:29 ` Christopher M. Riedl
2021-09-16 1:52 ` Jordan Niethe
2021-09-15 4:24 ` Jordan Niethe
2021-09-16 0:45 ` Christopher M. Riedl
2021-09-16 2:04 ` Jordan Niethe
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