arm64: hibernate: Avoid sending cross-calling with interrupts disabled
authorWill Deacon <will.deacon@arm.com>
Fri, 7 Dec 2018 12:47:10 +0000 (12:47 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 13 Dec 2018 08:16:19 +0000 (09:16 +0100)
commit1d9ca56698ad6554d41057fec297b2ca7c842871
tree0e89326f13fda2b86f01c955ddf189595cf0e588
parentf9cd25b1e5e575a5f18547bdc04ea40a23ad511a
arm64: hibernate: Avoid sending cross-calling with interrupts disabled

commit b4aecf78083d8c6424657c1746c7c3de6e61669f upstream.

Since commit 3b8c9f1cdfc50 ("arm64: IPI each CPU after invalidating the
I-cache for kernel mappings"), a call to flush_icache_range() will use
an IPI to cross-call other online CPUs so that any stale instructions
are flushed from their pipelines. This triggers a WARN during the
hibernation resume path, where flush_icache_range() is called with
interrupts disabled and is therefore prone to deadlock:

  | Disabling non-boot CPUs ...
  | CPU1: shutdown
  | psci: CPU1 killed.
  | CPU2: shutdown
  | psci: CPU2 killed.
  | CPU3: shutdown
  | psci: CPU3 killed.
  | WARNING: CPU: 0 PID: 1 at ../kernel/smp.c:416 smp_call_function_many+0xd4/0x350
  | Modules linked in:
  | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.20.0-rc4 #1

Since all secondary CPUs have been taken offline prior to invalidating
the I-cache, there's actually no need for an IPI and we can simply call
__flush_icache_range() instead.

Cc: <stable@vger.kernel.org>
Fixes: 3b8c9f1cdfc50 ("arm64: IPI each CPU after invalidating the I-cache for kernel mappings")
Reported-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Tested-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Tested-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/arm64/kernel/hibernate.c