| Message ID | 20190528101012.11402-1-chrubis@suse.cz (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [RFC] Remove bdflush syscall stub | expand |
On Mai 28 2019, Cyril Hrubis <chrubis@suse.cz> wrote: > I've tested the patch on i386. Before the patch calling bdflush() with > attempt to tune a variable returned 0 and after the patch the syscall > fails with EINVAL. Should be ENOSYS, doesn't it? Andreas.
Hi! > > I've tested the patch on i386. Before the patch calling bdflush() with > > attempt to tune a variable returned 0 and after the patch the syscall > > fails with EINVAL. > > Should be ENOSYS, doesn't it? My bad, the LTP syscall wrapper handles ENOSYS and produces skipped results based on that. EINVAL is what you get for not yet implemented syscalls, i.e. new syscall on old kernel.
* Cyril Hrubis: > Hi! >> > I've tested the patch on i386. Before the patch calling bdflush() with >> > attempt to tune a variable returned 0 and after the patch the syscall >> > fails with EINVAL. >> >> Should be ENOSYS, doesn't it? > > My bad, the LTP syscall wrapper handles ENOSYS and produces skipped > results based on that. > > EINVAL is what you get for not yet implemented syscalls, i.e. new > syscall on old kernel. EINVAL? Is that a bdflush-specific thing, test-specific, or is itmore general? glibc has fallback paths that test for ENOSYS only. EINVAL will be passed to the application, skipping fallback. For missing system calls, this is not what we want. Thanks, Florian
Hi! > >> > I've tested the patch on i386. Before the patch calling bdflush() with > >> > attempt to tune a variable returned 0 and after the patch the syscall > >> > fails with EINVAL. > >> > >> Should be ENOSYS, doesn't it? > > > > My bad, the LTP syscall wrapper handles ENOSYS and produces skipped > > results based on that. > > > > EINVAL is what you get for not yet implemented syscalls, i.e. new > > syscall on old kernel. > > EINVAL? Is that a bdflush-specific thing, test-specific, or is itmore > general? > > glibc has fallback paths that test for ENOSYS only. EINVAL will be > passed to the application, skipping fallback. For missing system calls, > this is not what we want. The syscall returns ENOSYS after this change, sorry for the confusion.
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl index 9e7704e44f6d..3a08a2708a8a 100644 --- a/arch/alpha/kernel/syscalls/syscall.tbl +++ b/arch/alpha/kernel/syscalls/syscall.tbl @@ -230,7 +230,7 @@ 259 common osf_swapctl sys_ni_syscall 260 common osf_memcntl sys_ni_syscall 261 common osf_fdatasync sys_ni_syscall -300 common bdflush sys_bdflush +# 300 was sys_bdflush 301 common sethae sys_sethae 302 common mount sys_mount 303 common old_adjtimex sys_old_adjtimex diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index aaf479a9e92d..3f247c627b5f 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -147,7 +147,7 @@ 131 common quotactl sys_quotactl 132 common getpgid sys_getpgid 133 common fchdir sys_fchdir -134 common bdflush sys_bdflush +# 134 was sys_bdflush 135 common sysfs sys_sysfs 136 common personality sys_personality # 137 was sys_afs_syscall diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h index c39e90600bb3..fd23e4db9d76 100644 --- a/arch/arm64/include/asm/unistd32.h +++ b/arch/arm64/include/asm/unistd32.h @@ -289,8 +289,7 @@ __SYSCALL(__NR_quotactl, sys_quotactl) __SYSCALL(__NR_getpgid, sys_getpgid) #define __NR_fchdir 133 __SYSCALL(__NR_fchdir, sys_fchdir) -#define __NR_bdflush 134 -__SYSCALL(__NR_bdflush, sys_bdflush) + /* 134 was sys_bdflush */ #define __NR_sysfs 135 __SYSCALL(__NR_sysfs, sys_sysfs) #define __NR_personality 136 diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl index e01df3f2f80d..9cd63d82de53 100644 --- a/arch/ia64/kernel/syscalls/syscall.tbl +++ b/arch/ia64/kernel/syscalls/syscall.tbl @@ -123,7 +123,7 @@ # 1135 was get_kernel_syms # 1136 was query_module 113 common quotactl sys_quotactl -114 common bdflush sys_bdflush +# 114 was bdflush 115 common sysfs sys_sysfs 116 common personality sys_personality 117 common afs_syscall sys_ni_syscall diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index 7e3d0734b2f3..0c44ee777964 100644 --- a/arch/m68k/kernel/syscalls/syscall.tbl +++ b/arch/m68k/kernel/syscalls/syscall.tbl @@ -141,7 +141,7 @@ 131 common quotactl sys_quotactl 132 common getpgid sys_getpgid 133 common fchdir sys_fchdir -134 common bdflush sys_bdflush +# 134 was bdflush 135 common sysfs sys_sysfs 136 common personality sys_personality # 137 was afs_syscall diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl index 26339e417695..1f1288d6212d 100644 --- a/arch/microblaze/kernel/syscalls/syscall.tbl +++ b/arch/microblaze/kernel/syscalls/syscall.tbl @@ -141,7 +141,7 @@ 131 common quotactl sys_quotactl 132 common getpgid sys_getpgid 133 common fchdir sys_fchdir -134 common bdflush sys_bdflush +# 134 was bdflush 135 common sysfs sys_sysfs 136 common personality sys_personality 137 common afs_syscall sys_ni_syscall diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl index 3cc1374e02d0..537a3828b9a0 100644 --- a/arch/mips/kernel/syscalls/syscall_o32.tbl +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl @@ -145,7 +145,7 @@ 131 o32 quotactl sys_quotactl 132 o32 getpgid sys_getpgid 133 o32 fchdir sys_fchdir -134 o32 bdflush sys_bdflush +# 134 was sys_bdflush 135 o32 sysfs sys_sysfs 136 o32 personality sys_personality sys_32_personality 137 o32 afs_syscall sys_ni_syscall diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index c9e377d59232..3ab53f3ed358 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -147,7 +147,7 @@ 131 common quotactl sys_quotactl 132 common getpgid sys_getpgid 133 common fchdir sys_fchdir -134 common bdflush sys_bdflush +# 134 was sys_bdflush 135 common sysfs sys_sysfs 136 32 personality parisc_personality 136 64 personality sys_personality diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index 103655d84b4b..5ce016e6122c 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -176,7 +176,7 @@ 131 nospu quotactl sys_quotactl 132 common getpgid sys_getpgid 133 common fchdir sys_fchdir -134 common bdflush sys_bdflush +# 134 was bdflush 135 common sysfs sys_sysfs 136 32 personality sys_personality ppc64_personality 136 64 personality ppc64_personality diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index e822b2964a83..3364da213530 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -122,7 +122,7 @@ 131 common quotactl sys_quotactl sys_quotactl 132 common getpgid sys_getpgid sys_getpgid 133 common fchdir sys_fchdir sys_fchdir -134 common bdflush sys_bdflush sys_bdflush +# 134 was bdflush 135 common sysfs sys_sysfs sys_sysfs 136 common personality sys_s390_personality sys_s390_personality 137 common afs_syscall - - diff --git a/arch/sh/include/uapi/asm/unistd_64.h b/arch/sh/include/uapi/asm/unistd_64.h index 75da54851f02..5bd0f0c29a95 100644 --- a/arch/sh/include/uapi/asm/unistd_64.h +++ b/arch/sh/include/uapi/asm/unistd_64.h @@ -149,7 +149,7 @@ #define __NR_quotactl 131 #define __NR_getpgid 132 #define __NR_fchdir 133 -#define __NR_bdflush 134 + /* 134 was sys_bdflush */ #define __NR_sysfs 135 #define __NR_personality 136 /* 137 was sys_afs_syscall */ diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl index 016a727d4357..328edef02905 100644 --- a/arch/sh/kernel/syscalls/syscall.tbl +++ b/arch/sh/kernel/syscalls/syscall.tbl @@ -141,7 +141,7 @@ 131 common quotactl sys_quotactl 132 common getpgid sys_getpgid 133 common fchdir sys_fchdir -134 common bdflush sys_bdflush +# 134 was bdflush 135 common sysfs sys_sysfs 136 common personality sys_personality # 137 was afs_syscall diff --git a/arch/sh/kernel/syscalls_64.S b/arch/sh/kernel/syscalls_64.S index 1bcb86f0b728..1b7ad08f5d2f 100644 --- a/arch/sh/kernel/syscalls_64.S +++ b/arch/sh/kernel/syscalls_64.S @@ -151,7 +151,7 @@ sys_call_table: .long sys_quotactl .long sys_getpgid .long sys_fchdir - .long sys_bdflush + .long sys_ni_syscall /* 134 old bdflush */ .long sys_sysfs /* 135 */ .long sys_personality .long sys_ni_syscall /* for afs_syscall */ diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index e047480b1605..e199062c38c7 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -270,7 +270,7 @@ 222 common delete_module sys_delete_module 223 common get_kernel_syms sys_ni_syscall 224 common getpgid sys_getpgid -225 common bdflush sys_bdflush +225 common bdflush sys_ni_syscall 226 common sysfs sys_sysfs 227 common afs_syscall sys_nis_syscall 228 common setfsuid sys_setfsuid16 diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index ad968b7bac72..b699144d52fc 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -145,7 +145,7 @@ 131 i386 quotactl sys_quotactl __ia32_compat_sys_quotactl32 132 i386 getpgid sys_getpgid __ia32_sys_getpgid 133 i386 fchdir sys_fchdir __ia32_sys_fchdir -134 i386 bdflush sys_bdflush __ia32_sys_bdflush +134 i386 bdflush sys_ni_syscall sys_ni_syscall 135 i386 sysfs sys_sysfs __ia32_sys_sysfs 136 i386 personality sys_personality __ia32_sys_personality 137 i386 afs_syscall diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl index 5fa0ee1c8e00..6b9fdddd7994 100644 --- a/arch/xtensa/kernel/syscalls/syscall.tbl +++ b/arch/xtensa/kernel/syscalls/syscall.tbl @@ -223,7 +223,7 @@ # 205 was old nfsservctl 205 common nfsservctl sys_ni_syscall 206 common _sysctl sys_sysctl -207 common bdflush sys_bdflush +207 common bdflush sys_ni_syscall 208 common uname sys_newuname 209 common sysinfo sys_sysinfo 210 common init_module sys_init_module diff --git a/fs/buffer.c b/fs/buffer.c index e450c55f6434..6f052ada051c 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -3307,33 +3307,6 @@ int try_to_free_buffers(struct page *page) } EXPORT_SYMBOL(try_to_free_buffers); -/* - * There are no bdflush tunables left. But distributions are - * still running obsolete flush daemons, so we terminate them here. - * - * Use of bdflush() is deprecated and will be removed in a future kernel. - * The `flush-X' kernel threads fully replace bdflush daemons and this call. - */ -SYSCALL_DEFINE2(bdflush, int, func, long, data) -{ - static int msg_count; - - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - if (msg_count < 5) { - msg_count++; - printk(KERN_INFO - "warning: process `%s' used the obsolete bdflush" - " system call\n", current->comm); - printk(KERN_INFO "Fix your initscripts?\n"); - } - - if (func == 1) - do_exit(0); - return 0; -} - /* * Buffer-head allocation */ diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index e2870fe1be5b..3ede2f17a044 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1104,7 +1104,6 @@ asmlinkage long sys_ustat(unsigned dev, struct ustat __user *ubuf); asmlinkage long sys_vfork(void); asmlinkage long sys_recv(int, void __user *, size_t, unsigned); asmlinkage long sys_send(int, void __user *, size_t, unsigned); -asmlinkage long sys_bdflush(int func, long data); asmlinkage long sys_oldumount(char __user *name); asmlinkage long sys_uselib(const char __user *library); asmlinkage long sys_sysctl(struct __sysctl_args __user *args); diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 4d9ae5ea6caf..5bab44795a17 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -405,7 +405,6 @@ COND_SYSCALL(epoll_wait); COND_SYSCALL(recv); COND_SYSCALL_COMPAT(recv); COND_SYSCALL(send); -COND_SYSCALL(bdflush); COND_SYSCALL(uselib); diff --git a/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl b/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl index db3bbb8744af..56b5567de7ff 100644 --- a/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl +++ b/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl @@ -169,7 +169,7 @@ 131 nospu quotactl sys_quotactl 132 common getpgid sys_getpgid 133 common fchdir sys_fchdir -134 common bdflush sys_bdflush +134 common bdflush sys_ni_syscall 135 common sysfs sys_sysfs 136 32 personality sys_personality ppc64_personality 136 64 personality ppc64_personality diff --git a/tools/perf/arch/s390/entry/syscalls/syscall.tbl b/tools/perf/arch/s390/entry/syscalls/syscall.tbl index b38d48464368..a83eba11c877 100644 --- a/tools/perf/arch/s390/entry/syscalls/syscall.tbl +++ b/tools/perf/arch/s390/entry/syscalls/syscall.tbl @@ -122,7 +122,7 @@ 131 common quotactl sys_quotactl compat_sys_quotactl 132 common getpgid sys_getpgid sys_getpgid 133 common fchdir sys_fchdir sys_fchdir -134 common bdflush sys_bdflush compat_sys_bdflush +134 common bdflush - - 135 common sysfs sys_sysfs compat_sys_sysfs 136 common personality sys_s390_personality sys_s390_personality 137 common afs_syscall - -
While reviewing LTP testcases I've found that we still carry workaround for 17 years old distributions that attempted to start bdflush from userspace. I guess it's about the time to remove it. I've tested the patch on i386. Before the patch calling bdflush() with attempt to tune a variable returned 0 and after the patch the syscall fails with EINVAL. You can use the now deleted LTP bdflush testcase for testing: https://github.com/linux-test-project/ltp/commit/53ede74305ff7f6498d7456b6e3ea3053ed4b7dd Also I'm not 100% sure that I patched all the syscall tables correctly, so this needs a proper review from arch maintainers. CC: linux-alpha@vger.kernel.org CC: linux-arm-kernel@lists.infradead.org CC: linux-ia64@vger.kernel.org CC: linux-m68k@lists.linux-m68k.org CC: Michal Simek <monstr@monstr.eu> CC: linux-mips@vger.kernel.org CC: linux-parisc@vger.kernel.org CC: linuxppc-dev@lists.ozlabs.org CC: linux-s390@vger.kernel.org CC: linux-sh@vger.kernel.org CC: sparclinux@vger.kernel.org CC: linux-xtensa@linux-xtensa.org CC: linux-fsdevel@vger.kernel.org CC: linux-api@vger.kernel.org Signed-off-by: Cyril Hrubis <chrubis@suse.cz> --- arch/alpha/kernel/syscalls/syscall.tbl | 2 +- arch/arm/tools/syscall.tbl | 2 +- arch/arm64/include/asm/unistd32.h | 3 +-- arch/ia64/kernel/syscalls/syscall.tbl | 2 +- arch/m68k/kernel/syscalls/syscall.tbl | 2 +- arch/microblaze/kernel/syscalls/syscall.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/sh/include/uapi/asm/unistd_64.h | 2 +- arch/sh/kernel/syscalls/syscall.tbl | 2 +- arch/sh/kernel/syscalls_64.S | 2 +- arch/sparc/kernel/syscalls/syscall.tbl | 2 +- arch/x86/entry/syscalls/syscall_32.tbl | 2 +- arch/xtensa/kernel/syscalls/syscall.tbl | 2 +- fs/buffer.c | 27 ------------------- include/linux/syscalls.h | 1 - kernel/sys_ni.c | 1 - .../arch/powerpc/entry/syscalls/syscall.tbl | 2 +- .../perf/arch/s390/entry/syscalls/syscall.tbl | 2 +- 21 files changed, 18 insertions(+), 48 deletions(-)