| Message ID | 20210727144859.4150043-2-arnd@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | compat: remove compat_alloc_user_space | expand |
Arnd Bergmann <arnd@kernel.org> writes: > 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. Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> > > 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
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