diff mbox series

netpoll: don't require irqs disabled in rt kernels

Message ID 20210531152325.36671-1-wander@redhat.com (mailing list archive)
State Accepted
Commit b0f6c9ac8088a01cd9b6bfba8ede22f1bd0ff72f
Delegated to: Netdev Maintainers
Headers show
Series netpoll: don't require irqs disabled in rt kernels | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Guessed tree name to be net-next
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/header_inline success Link

Commit Message

Wander Lairson Costa May 31, 2021, 3:23 p.m. UTC 
From: Wander Lairson Costa <wander@redhat.com>

write_msg(netconsole.c:836) calls netpoll_send_udp after a call to
spin_lock_irqsave, which normally disables interrupts; but in PREEMPT_RT
this call just locks an rt_mutex without disabling irqs. In this case,
netpoll_send_udp is called with interrupts enabled.

Signed-off-by: Wander Lairson Costa <wander@redhat.com>
---
 net/core/netpoll.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

patchwork-bot+netdevbpf@kernel.org June 1, 2021, 10:20 p.m. UTC | #1 
Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Mon, 31 May 2021 12:23:23 -0300 you wrote:
> From: Wander Lairson Costa <wander@redhat.com>
> 
> write_msg(netconsole.c:836) calls netpoll_send_udp after a call to
> spin_lock_irqsave, which normally disables interrupts; but in PREEMPT_RT
> this call just locks an rt_mutex without disabling irqs. In this case,
> netpoll_send_udp is called with interrupts enabled.
> 
> [...]

Here is the summary with links:
  - netpoll: don't require irqs disabled in rt kernels
    https://git.kernel.org/netdev/net-next/c/b0f6c9ac8088

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index c310c7c1cef7..0a6b04714558 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -36,6 +36,7 @@ 
 #include <net/ip6_checksum.h>
 #include <asm/unaligned.h>
 #include <trace/events/napi.h>
+#include <linux/kconfig.h>
 
 /*
  * We maintain a small pool of fully-sized skbs, to make sure the
@@ -389,7 +390,8 @@  void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 	static atomic_t ip_ident;
 	struct ipv6hdr *ip6h;
 
-	WARN_ON_ONCE(!irqs_disabled());
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		WARN_ON_ONCE(!irqs_disabled());
 
 	udp_len = len + sizeof(*udph);
 	if (np->ipv6)