From: Arnd Bergmann <arnd@kernel•org>
To: Andrew Morton <akpm@linux-foundation•org>
Cc: Feng Tang <feng.tang@intel•com>,
linux-mips@vger•kernel.org,
"James E.J. Bottomley" <James.Bottomley@HansenPartnership•com>,
linux-mm@kvack•org, Paul Mackerras <paulus@samba•org>,
"H. Peter Anvin" <hpa@zytor•com>,
sparclinux@vger•kernel.org, Will Deacon <will@kernel•org>,
linux-arch@vger•kernel.org, linux-s390@vger•kernel.org,
Arnd Bergmann <arnd@arndb•de>, Helge Deller <deller@gmx•de>,
x86@kernel•org, Christoph Hellwig <hch@infradead•org>,
Christian Borntraeger <borntraeger@de•ibm.com>,
Ingo Molnar <mingo@redhat•com>,
Catalin Marinas <catalin.marinas@arm•com>,
Vasily Gorbik <gor@linux•ibm.com>,
Heiko Carstens <hca@linux•ibm.com>,
Borislav Petkov <bp@alien8•de>, Al Viro <viro@zeniv•linux.org.uk>,
Thomas Gleixner <tglx@linutronix•de>,
linux-arm-kernel@lists•infradead.org,
Thomas Bogendoerfer <tsbogend@alpha•franken.de>,
linux-parisc@vger•kernel.org, linux-api@vger•kernel.org,
linux-kernel@vger•kernel.org,
"Eric W. Biederman" <ebiederm@xmission•com>,
linuxppc-dev@lists•ozlabs.org,
"David S. Miller" <davem@davemloft•net>
Subject: [PATCH v5 1/6] kexec: move locking into do_kexec_load
Date: Tue, 27 Jul 2021 16:48:54 +0200 [thread overview]
Message-ID: <20210727144859.4150043-2-arnd@kernel.org> (raw)
In-Reply-To: <20210727144859.4150043-1-arnd@kernel.org>
From: Arnd Bergmann <arnd@arndb•de>
The locking is the same between the native and compat version of
sys_kexec_load(), so it can be done in the common implementation
to reduce duplication.
Co-developed-by: Eric Biederman <ebiederm@xmission•com>
Co-developed-by: Christoph Hellwig <hch@infradead•org>
Signed-off-by: Arnd Bergmann <arnd@arndb•de>
---
kernel/kexec.c | 44 ++++++++++++++++----------------------------
1 file changed, 16 insertions(+), 28 deletions(-)
diff --git a/kernel/kexec.c b/kernel/kexec.c
index c82c6c06f051..9c7aef8f4bb6 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -110,6 +110,17 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
unsigned long i;
int ret;
+ /*
+ * Because we write directly to the reserved memory region when loading
+ * crash kernels we need a mutex here to prevent multiple crash kernels
+ * from attempting to load simultaneously, and to prevent a crash kernel
+ * from loading over the top of a in use crash kernel.
+ *
+ * KISS: always take the mutex.
+ */
+ if (!mutex_trylock(&kexec_mutex))
+ return -EBUSY;
+
if (flags & KEXEC_ON_CRASH) {
dest_image = &kexec_crash_image;
if (kexec_crash_image)
@@ -121,7 +132,8 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
if (nr_segments == 0) {
/* Uninstall image */
kimage_free(xchg(dest_image, NULL));
- return 0;
+ ret = 0;
+ goto out_unlock;
}
if (flags & KEXEC_ON_CRASH) {
/*
@@ -134,7 +146,7 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
ret = kimage_alloc_init(&image, entry, nr_segments, segments, flags);
if (ret)
- return ret;
+ goto out_unlock;
if (flags & KEXEC_PRESERVE_CONTEXT)
image->preserve_context = 1;
@@ -171,6 +183,8 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
arch_kexec_protect_crashkres();
kimage_free(image);
+out_unlock:
+ mutex_unlock(&kexec_mutex);
return ret;
}
@@ -247,21 +261,8 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
return -EINVAL;
- /* Because we write directly to the reserved memory
- * region when loading crash kernels we need a mutex here to
- * prevent multiple crash kernels from attempting to load
- * simultaneously, and to prevent a crash kernel from loading
- * over the top of a in use crash kernel.
- *
- * KISS: always take the mutex.
- */
- if (!mutex_trylock(&kexec_mutex))
- return -EBUSY;
-
result = do_kexec_load(entry, nr_segments, segments, flags);
- mutex_unlock(&kexec_mutex);
-
return result;
}
@@ -301,21 +302,8 @@ COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
return -EFAULT;
}
- /* Because we write directly to the reserved memory
- * region when loading crash kernels we need a mutex here to
- * prevent multiple crash kernels from attempting to load
- * simultaneously, and to prevent a crash kernel from loading
- * over the top of a in use crash kernel.
- *
- * KISS: always take the mutex.
- */
- if (!mutex_trylock(&kexec_mutex))
- return -EBUSY;
-
result = do_kexec_load(entry, nr_segments, ksegments, flags);
- mutex_unlock(&kexec_mutex);
-
return result;
}
#endif
--
2.29.2
next prev parent reply other threads:[~2021-07-27 14:50 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-27 14:48 [PATCH v5 0/6] compat: remove compat_alloc_user_space Arnd Bergmann
2021-07-27 14:48 ` Arnd Bergmann [this message]
2021-07-28 16:09 ` [PATCH v5 1/6] kexec: move locking into do_kexec_load Eric W. Biederman
2021-07-27 14:48 ` [PATCH v5 2/6] kexec: avoid compat_alloc_user_space Arnd Bergmann
2021-07-28 16:10 ` Eric W. Biederman
2021-07-27 14:48 ` [PATCH v5 3/6] mm: simplify compat_sys_move_pages Arnd Bergmann
2021-07-27 14:48 ` [PATCH v5 4/6] mm: simplify compat numa syscalls Arnd Bergmann
2021-07-27 17:27 ` Heiko Carstens
2021-07-27 17:40 ` Arnd Bergmann
2021-07-27 18:38 ` Heiko Carstens
2021-07-27 18:49 ` Arnd Bergmann
2021-07-27 19:15 ` Heiko Carstens
2021-07-27 14:48 ` [PATCH v5 5/6] compat: remove some compat entry points Arnd Bergmann
2021-07-27 14:48 ` [PATCH v5 6/6] arch: remove compat_alloc_user_space Arnd Bergmann
2021-07-27 15:09 ` Christoph Hellwig
2021-07-27 14:59 ` [PATCH v5 0/6] compat: " Christoph Hellwig
2021-07-27 20:10 ` Andrew Morton
2021-07-27 20:42 ` Arnd Bergmann
2021-07-30 9:49 ` Heiko Carstens
2021-07-30 13:35 ` Arnd Bergmann
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