| Message ID | 20200918132439.1475479-3-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | syscalls: remove compat_alloc_user_space callers | expand |
On Fri, Sep 18, 2020 at 03:24:37PM +0200, Arnd Bergmann wrote: > The compat version of sys_kexec_load() uses compat_alloc_user_space to > convert the user-provided arguments into the native format. > > Move the conversion into the regular implementation with > an in_compat_syscall() check to simplify it and avoid the > compat_alloc_user_space() call. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > arch/arm64/include/asm/unistd32.h | 2 +- > arch/mips/kernel/syscalls/syscall_n32.tbl | 2 +- > arch/mips/kernel/syscalls/syscall_o32.tbl | 2 +- > arch/parisc/kernel/syscalls/syscall.tbl | 2 +- > arch/powerpc/kernel/syscalls/syscall.tbl | 2 +- > arch/s390/kernel/syscalls/syscall.tbl | 2 +- > arch/sparc/kernel/syscalls/syscall.tbl | 2 +- > arch/x86/entry/syscalls/syscall_32.tbl | 2 +- > arch/x86/entry/syscalls/syscall_64.tbl | 2 +- > include/linux/compat.h | 6 -- > include/uapi/asm-generic/unistd.h | 2 +- > kernel/kexec.c | 75 ++++++----------------- > 12 files changed, 29 insertions(+), 72 deletions(-) > > diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h > index 734860ac7cf9..b6517df74037 100644 > --- a/arch/arm64/include/asm/unistd32.h > +++ b/arch/arm64/include/asm/unistd32.h > @@ -705,7 +705,7 @@ __SYSCALL(__NR_getcpu, sys_getcpu) > #define __NR_epoll_pwait 346 > __SYSCALL(__NR_epoll_pwait, compat_sys_epoll_pwait) > #define __NR_kexec_load 347 > -__SYSCALL(__NR_kexec_load, compat_sys_kexec_load) > +__SYSCALL(__NR_kexec_load, sys_kexec_load) > #define __NR_utimensat 348 > __SYSCALL(__NR_utimensat, sys_utimensat_time32) > #define __NR_signalfd 349 > diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl > index f9df9edb67a4..ad157aab4c09 100644 > --- a/arch/mips/kernel/syscalls/syscall_n32.tbl > +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl > @@ -282,7 +282,7 @@ > 271 n32 move_pages compat_sys_move_pages > 272 n32 set_robust_list compat_sys_set_robust_list > 273 n32 get_robust_list compat_sys_get_robust_list > -274 n32 kexec_load compat_sys_kexec_load > +274 n32 kexec_load sys_kexec_load > 275 n32 getcpu sys_getcpu > 276 n32 epoll_pwait compat_sys_epoll_pwait > 277 n32 ioprio_set sys_ioprio_set > diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl > index 195b43cf27c8..57baf6c8008f 100644 > --- a/arch/mips/kernel/syscalls/syscall_o32.tbl > +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl > @@ -322,7 +322,7 @@ > 308 o32 move_pages sys_move_pages compat_sys_move_pages > 309 o32 set_robust_list sys_set_robust_list compat_sys_set_robust_list > 310 o32 get_robust_list sys_get_robust_list compat_sys_get_robust_list > -311 o32 kexec_load sys_kexec_load compat_sys_kexec_load > +311 o32 kexec_load sys_kexec_load > 312 o32 getcpu sys_getcpu > 313 o32 epoll_pwait sys_epoll_pwait compat_sys_epoll_pwait > 314 o32 ioprio_set sys_ioprio_set > diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl > index def64d221cd4..778bf166d7bd 100644 > --- a/arch/parisc/kernel/syscalls/syscall.tbl > +++ b/arch/parisc/kernel/syscalls/syscall.tbl > @@ -336,7 +336,7 @@ > 297 common epoll_pwait sys_epoll_pwait compat_sys_epoll_pwait > 298 common statfs64 sys_statfs64 compat_sys_statfs64 > 299 common fstatfs64 sys_fstatfs64 compat_sys_fstatfs64 > -300 common kexec_load sys_kexec_load compat_sys_kexec_load > +300 common kexec_load sys_kexec_load > 301 32 utimensat sys_utimensat_time32 > 301 64 utimensat sys_utimensat > 302 common signalfd sys_signalfd compat_sys_signalfd > diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl > index c2d737ff2e7b..f128ba8b9a71 100644 > --- a/arch/powerpc/kernel/syscalls/syscall.tbl > +++ b/arch/powerpc/kernel/syscalls/syscall.tbl > @@ -350,7 +350,7 @@ > 265 64 mq_timedreceive sys_mq_timedreceive > 266 nospu mq_notify sys_mq_notify compat_sys_mq_notify > 267 nospu mq_getsetattr sys_mq_getsetattr compat_sys_mq_getsetattr > -268 nospu kexec_load sys_kexec_load compat_sys_kexec_load > +268 nospu kexec_load sys_kexec_load > 269 nospu add_key sys_add_key > 270 nospu request_key sys_request_key > 271 nospu keyctl sys_keyctl compat_sys_keyctl > diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl > index 10456bc936fb..d45952058be2 100644 > --- a/arch/s390/kernel/syscalls/syscall.tbl > +++ b/arch/s390/kernel/syscalls/syscall.tbl > @@ -283,7 +283,7 @@ > 274 common mq_timedreceive sys_mq_timedreceive sys_mq_timedreceive_time32 > 275 common mq_notify sys_mq_notify compat_sys_mq_notify > 276 common mq_getsetattr sys_mq_getsetattr compat_sys_mq_getsetattr > -277 common kexec_load sys_kexec_load compat_sys_kexec_load > +277 common kexec_load sys_kexec_load sys_kexec_load > 278 common add_key sys_add_key sys_add_key > 279 common request_key sys_request_key sys_request_key > 280 common keyctl sys_keyctl compat_sys_keyctl > diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl > index 4af114e84f20..a46edcdd950d 100644 > --- a/arch/sparc/kernel/syscalls/syscall.tbl > +++ b/arch/sparc/kernel/syscalls/syscall.tbl > @@ -369,7 +369,7 @@ > 303 common mbind sys_mbind compat_sys_mbind > 304 common get_mempolicy sys_get_mempolicy compat_sys_get_mempolicy > 305 common set_mempolicy sys_set_mempolicy compat_sys_set_mempolicy > -306 common kexec_load sys_kexec_load compat_sys_kexec_load > +306 common kexec_load sys_kexec_load sys_kexec_load > 307 common move_pages sys_move_pages compat_sys_move_pages > 308 common getcpu sys_getcpu > 309 common epoll_pwait sys_epoll_pwait compat_sys_epoll_pwait > diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl > index 3db3d8823dc8..7e4140b78aad 100644 > --- a/arch/x86/entry/syscalls/syscall_32.tbl > +++ b/arch/x86/entry/syscalls/syscall_32.tbl > @@ -294,7 +294,7 @@ > 280 i386 mq_timedreceive sys_mq_timedreceive_time32 > 281 i386 mq_notify sys_mq_notify compat_sys_mq_notify > 282 i386 mq_getsetattr sys_mq_getsetattr compat_sys_mq_getsetattr > -283 i386 kexec_load sys_kexec_load compat_sys_kexec_load > +283 i386 kexec_load sys_kexec_load sys_kexec_load > 284 i386 waitid sys_waitid compat_sys_waitid > # 285 sys_setaltroot > 286 i386 add_key sys_add_key > diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl > index f30d6ae9a688..9986f5f08278 100644 > --- a/arch/x86/entry/syscalls/syscall_64.tbl > +++ b/arch/x86/entry/syscalls/syscall_64.tbl > @@ -384,7 +384,7 @@ > 525 x32 sigaltstack compat_sys_sigaltstack > 526 x32 timer_create compat_sys_timer_create > 527 x32 mq_notify compat_sys_mq_notify > -528 x32 kexec_load compat_sys_kexec_load > +528 x32 kexec_load sys_kexec_load > 529 x32 waitid compat_sys_waitid > 530 x32 set_robust_list compat_sys_set_robust_list > 531 x32 get_robust_list compat_sys_get_robust_list > diff --git a/include/linux/compat.h b/include/linux/compat.h > index 3d96a841bd49..a7a5a0ff59ef 100644 > --- a/include/linux/compat.h > +++ b/include/linux/compat.h > @@ -643,12 +643,6 @@ asmlinkage long compat_sys_setitimer(int which, > struct old_itimerval32 __user *in, > struct old_itimerval32 __user *out); > > -/* kernel/kexec.c */ > -asmlinkage long compat_sys_kexec_load(compat_ulong_t entry, > - compat_ulong_t nr_segments, > - struct compat_kexec_segment __user *, > - compat_ulong_t flags); > - > /* kernel/posix-timers.c */ > asmlinkage long compat_sys_timer_create(clockid_t which_clock, > struct compat_sigevent __user *timer_event_spec, > diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h > index 995b36c2ea7d..83f1fc7fd3d7 100644 > --- a/include/uapi/asm-generic/unistd.h > +++ b/include/uapi/asm-generic/unistd.h > @@ -342,7 +342,7 @@ __SC_COMP(__NR_setitimer, sys_setitimer, compat_sys_setitimer) > > /* kernel/kexec.c */ > #define __NR_kexec_load 104 > -__SC_COMP(__NR_kexec_load, sys_kexec_load, compat_sys_kexec_load) > +__SYSCALL(__NR_kexec_load, sys_kexec_load) > > /* kernel/module.c */ > #define __NR_init_module 105 > diff --git a/kernel/kexec.c b/kernel/kexec.c > index f977786fe498..1ef7d3dc906f 100644 > --- a/kernel/kexec.c > +++ b/kernel/kexec.c > @@ -29,7 +29,25 @@ static int copy_user_segment_list(struct kimage *image, > /* Read in the segments */ > image->nr_segments = nr_segments; > segment_bytes = nr_segments * sizeof(*segments); > - ret = copy_from_user(image->segment, segments, segment_bytes); > + if (in_compat_syscall()) { > + struct compat_kexec_segment __user *cs = (void __user *)segments; > + struct compat_kexec_segment segment; > + int i; > + for (i=0; i< nr_segments; i++) { Missing empty line after the variable declarations and really strange indentation. > + copy_from_user(&segment, &cs[i], sizeof(segment)); Missing return value check. > + if (ret) > + break; > + > + image->segment[i] = (struct kexec_segment) { > + .buf = compat_ptr(segment.buf), > + .bufsz = segment.bufsz, > + .mem = segment.mem, > + .memsz = segment.memsz, > + }; > + } I'd split the whole compat handling into a helper, and I'd probably use the unsafe_get/put user to optimize it a little more. > + } else { > + ret = copy_from_user(image->segment, segments, segment_bytes); > + } > if (ret) > ret = -EFAULT; Why not just if (copy_from_user(image->segment, segments, segment_bytes)) ret = -EFAULT; ?
On Sat, Sep 19, 2020 at 7:37 AM Christoph Hellwig <hch@infradead.org> wrote: > > + struct compat_kexec_segment __user *cs = (void __user *)segments; > > + struct compat_kexec_segment segment; > > + int i; > > + for (i=0; i< nr_segments; i++) { > > Missing empty line after the variable declarations and really strange > indentation. > > > + copy_from_user(&segment, &cs[i], sizeof(segment)); > > Missing return value check. > > > + if (ret) > > + break; > > + > > + image->segment[i] = (struct kexec_segment) { > > + .buf = compat_ptr(segment.buf), > > + .bufsz = segment.bufsz, > > + .mem = segment.mem, > > + .memsz = segment.memsz, > > + }; > > + } > > I'd split the whole compat handling into a helper, and I'd probably > use the unsafe_get/put user to optimize it a little more. > > > + } else { > > + ret = copy_from_user(image->segment, segments, segment_bytes); > > + } > > if (ret) > > ret = -EFAULT; > > Why not just > > if (copy_from_user(image->segment, segments, segment_bytes)) > ret = -EFAULT; > > ? Addressed all of these now, thanks for the suggestions! I had already fixed the missing error handling after the kbuild bot pointed that out. The separate function does improve the error handling. I ended up not using unsafe_get/put since I find the copy_from_user based loop more readable and it should lead to smaller object code in most cases as well. kexec is not performance critical, so readability seems more important here. Arnd
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h index 734860ac7cf9..b6517df74037 100644 --- a/arch/arm64/include/asm/unistd32.h +++ b/arch/arm64/include/asm/unistd32.h @@ -705,7 +705,7 @@ __SYSCALL(__NR_getcpu, sys_getcpu) #define __NR_epoll_pwait 346 __SYSCALL(__NR_epoll_pwait, compat_sys_epoll_pwait) #define __NR_kexec_load 347 -__SYSCALL(__NR_kexec_load, compat_sys_kexec_load) +__SYSCALL(__NR_kexec_load, sys_kexec_load) #define __NR_utimensat 348 __SYSCALL(__NR_utimensat, sys_utimensat_time32) #define __NR_signalfd 349 diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl index f9df9edb67a4..ad157aab4c09 100644 --- a/arch/mips/kernel/syscalls/syscall_n32.tbl +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl @@ -282,7 +282,7 @@ 271 n32 move_pages compat_sys_move_pages 272 n32 set_robust_list compat_sys_set_robust_list 273 n32 get_robust_list compat_sys_get_robust_list -274 n32 kexec_load compat_sys_kexec_load +274 n32 kexec_load sys_kexec_load 275 n32 getcpu sys_getcpu 276 n32 epoll_pwait compat_sys_epoll_pwait 277 n32 ioprio_set sys_ioprio_set diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl index 195b43cf27c8..57baf6c8008f 100644 --- a/arch/mips/kernel/syscalls/syscall_o32.tbl +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl @@ -322,7 +322,7 @@ 308 o32 move_pages sys_move_pages compat_sys_move_pages 309 o32 set_robust_list sys_set_robust_list compat_sys_set_robust_list 310 o32 get_robust_list sys_get_robust_list compat_sys_get_robust_list -311 o32 kexec_load sys_kexec_load compat_sys_kexec_load +311 o32 kexec_load sys_kexec_load 312 o32 getcpu sys_getcpu 313 o32 epoll_pwait sys_epoll_pwait compat_sys_epoll_pwait 314 o32 ioprio_set sys_ioprio_set diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index def64d221cd4..778bf166d7bd 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -336,7 +336,7 @@ 297 common epoll_pwait sys_epoll_pwait compat_sys_epoll_pwait 298 common statfs64 sys_statfs64 compat_sys_statfs64 299 common fstatfs64 sys_fstatfs64 compat_sys_fstatfs64 -300 common kexec_load sys_kexec_load compat_sys_kexec_load +300 common kexec_load sys_kexec_load 301 32 utimensat sys_utimensat_time32 301 64 utimensat sys_utimensat 302 common signalfd sys_signalfd compat_sys_signalfd diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index c2d737ff2e7b..f128ba8b9a71 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -350,7 +350,7 @@ 265 64 mq_timedreceive sys_mq_timedreceive 266 nospu mq_notify sys_mq_notify compat_sys_mq_notify 267 nospu mq_getsetattr sys_mq_getsetattr compat_sys_mq_getsetattr -268 nospu kexec_load sys_kexec_load compat_sys_kexec_load +268 nospu kexec_load sys_kexec_load 269 nospu add_key sys_add_key 270 nospu request_key sys_request_key 271 nospu keyctl sys_keyctl compat_sys_keyctl diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index 10456bc936fb..d45952058be2 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -283,7 +283,7 @@ 274 common mq_timedreceive sys_mq_timedreceive sys_mq_timedreceive_time32 275 common mq_notify sys_mq_notify compat_sys_mq_notify 276 common mq_getsetattr sys_mq_getsetattr compat_sys_mq_getsetattr -277 common kexec_load sys_kexec_load compat_sys_kexec_load +277 common kexec_load sys_kexec_load sys_kexec_load 278 common add_key sys_add_key sys_add_key 279 common request_key sys_request_key sys_request_key 280 common keyctl sys_keyctl compat_sys_keyctl diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index 4af114e84f20..a46edcdd950d 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -369,7 +369,7 @@ 303 common mbind sys_mbind compat_sys_mbind 304 common get_mempolicy sys_get_mempolicy compat_sys_get_mempolicy 305 common set_mempolicy sys_set_mempolicy compat_sys_set_mempolicy -306 common kexec_load sys_kexec_load compat_sys_kexec_load +306 common kexec_load sys_kexec_load sys_kexec_load 307 common move_pages sys_move_pages compat_sys_move_pages 308 common getcpu sys_getcpu 309 common epoll_pwait sys_epoll_pwait compat_sys_epoll_pwait diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 3db3d8823dc8..7e4140b78aad 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -294,7 +294,7 @@ 280 i386 mq_timedreceive sys_mq_timedreceive_time32 281 i386 mq_notify sys_mq_notify compat_sys_mq_notify 282 i386 mq_getsetattr sys_mq_getsetattr compat_sys_mq_getsetattr -283 i386 kexec_load sys_kexec_load compat_sys_kexec_load +283 i386 kexec_load sys_kexec_load sys_kexec_load 284 i386 waitid sys_waitid compat_sys_waitid # 285 sys_setaltroot 286 i386 add_key sys_add_key diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index f30d6ae9a688..9986f5f08278 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -384,7 +384,7 @@ 525 x32 sigaltstack compat_sys_sigaltstack 526 x32 timer_create compat_sys_timer_create 527 x32 mq_notify compat_sys_mq_notify -528 x32 kexec_load compat_sys_kexec_load +528 x32 kexec_load sys_kexec_load 529 x32 waitid compat_sys_waitid 530 x32 set_robust_list compat_sys_set_robust_list 531 x32 get_robust_list compat_sys_get_robust_list diff --git a/include/linux/compat.h b/include/linux/compat.h index 3d96a841bd49..a7a5a0ff59ef 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -643,12 +643,6 @@ asmlinkage long compat_sys_setitimer(int which, struct old_itimerval32 __user *in, struct old_itimerval32 __user *out); -/* kernel/kexec.c */ -asmlinkage long compat_sys_kexec_load(compat_ulong_t entry, - compat_ulong_t nr_segments, - struct compat_kexec_segment __user *, - compat_ulong_t flags); - /* kernel/posix-timers.c */ asmlinkage long compat_sys_timer_create(clockid_t which_clock, struct compat_sigevent __user *timer_event_spec, diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 995b36c2ea7d..83f1fc7fd3d7 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -342,7 +342,7 @@ __SC_COMP(__NR_setitimer, sys_setitimer, compat_sys_setitimer) /* kernel/kexec.c */ #define __NR_kexec_load 104 -__SC_COMP(__NR_kexec_load, sys_kexec_load, compat_sys_kexec_load) +__SYSCALL(__NR_kexec_load, sys_kexec_load) /* kernel/module.c */ #define __NR_init_module 105 diff --git a/kernel/kexec.c b/kernel/kexec.c index f977786fe498..1ef7d3dc906f 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -29,7 +29,25 @@ static int copy_user_segment_list(struct kimage *image, /* Read in the segments */ image->nr_segments = nr_segments; segment_bytes = nr_segments * sizeof(*segments); - ret = copy_from_user(image->segment, segments, segment_bytes); + if (in_compat_syscall()) { + struct compat_kexec_segment __user *cs = (void __user *)segments; + struct compat_kexec_segment segment; + int i; + for (i=0; i< nr_segments; i++) { + copy_from_user(&segment, &cs[i], sizeof(segment)); + if (ret) + break; + + image->segment[i] = (struct kexec_segment) { + .buf = compat_ptr(segment.buf), + .bufsz = segment.bufsz, + .mem = segment.mem, + .memsz = segment.memsz, + }; + } + } else { + ret = copy_from_user(image->segment, segments, segment_bytes); + } if (ret) ret = -EFAULT; @@ -264,58 +282,3 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, return result; } - -#ifdef CONFIG_COMPAT -COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry, - compat_ulong_t, nr_segments, - struct compat_kexec_segment __user *, segments, - compat_ulong_t, flags) -{ - struct compat_kexec_segment in; - struct kexec_segment out, __user *ksegments; - unsigned long i, result; - - result = kexec_load_check(nr_segments, flags); - if (result) - return result; - - /* Don't allow clients that don't understand the native - * architecture to do anything. - */ - if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT) - return -EINVAL; - - ksegments = compat_alloc_user_space(nr_segments * sizeof(out)); - for (i = 0; i < nr_segments; i++) { - result = copy_from_user(&in, &segments[i], sizeof(in)); - if (result) - return -EFAULT; - - out.buf = compat_ptr(in.buf); - out.bufsz = in.bufsz; - out.mem = in.mem; - out.memsz = in.memsz; - - result = copy_to_user(&ksegments[i], &out, sizeof(out)); - if (result) - 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
The compat version of sys_kexec_load() uses compat_alloc_user_space to convert the user-provided arguments into the native format. Move the conversion into the regular implementation with an in_compat_syscall() check to simplify it and avoid the compat_alloc_user_space() call. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- arch/arm64/include/asm/unistd32.h | 2 +- arch/mips/kernel/syscalls/syscall_n32.tbl | 2 +- arch/mips/kernel/syscalls/syscall_o32.tbl | 2 +- arch/parisc/kernel/syscalls/syscall.tbl | 2 +- arch/powerpc/kernel/syscalls/syscall.tbl | 2 +- arch/s390/kernel/syscalls/syscall.tbl | 2 +- arch/sparc/kernel/syscalls/syscall.tbl | 2 +- arch/x86/entry/syscalls/syscall_32.tbl | 2 +- arch/x86/entry/syscalls/syscall_64.tbl | 2 +- include/linux/compat.h | 6 -- include/uapi/asm-generic/unistd.h | 2 +- kernel/kexec.c | 75 ++++++----------------- 12 files changed, 29 insertions(+), 72 deletions(-)