diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl index 8ebacf37a8cf4a..c9d25f85d86d5e 100644 --- a/arch/alpha/kernel/syscalls/syscall.tbl +++ b/arch/alpha/kernel/syscalls/syscall.tbl @@ -490,3 +490,4 @@ 558 common process_mrelease sys_process_mrelease 559 common futex_waitv sys_futex_waitv 560 common set_mempolicy_home_node sys_ni_syscall +561 common pmadv_ksm sys_pmadv_ksm diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index ac964612d8b078..90933eabe11564 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -464,3 +464,4 @@ 448 common process_mrelease sys_process_mrelease 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node +451 common pmadv_ksm sys_pmadv_ksm diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h index 037feba03a51d8..64a514f90131b8 100644 --- a/arch/arm64/include/asm/unistd.h +++ b/arch/arm64/include/asm/unistd.h @@ -39,7 +39,7 @@ #define __ARM_NR_compat_set_tls (__ARM_NR_COMPAT_BASE + 5) #define __ARM_NR_COMPAT_END (__ARM_NR_COMPAT_BASE + 0x800) -#define __NR_compat_syscalls 451 +#define __NR_compat_syscalls 452 #endif #define __ARCH_WANT_SYS_CLONE diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h index 604a2053d00670..91f2bb7199af95 100644 --- a/arch/arm64/include/asm/unistd32.h +++ b/arch/arm64/include/asm/unistd32.h @@ -907,6 +907,8 @@ __SYSCALL(__NR_process_mrelease, sys_process_mrelease) __SYSCALL(__NR_futex_waitv, sys_futex_waitv) #define __NR_set_mempolicy_home_node 450 __SYSCALL(__NR_set_mempolicy_home_node, sys_set_mempolicy_home_node) +#define __NR_pmadv_ksm 451 +__SYSCALL(__NR_pmadv_ksm, sys_pmadv_ksm) /* * Please add new compat syscalls above this comment and update diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl index 72c929d9902b99..0d5b1d14b2b53b 100644 --- a/arch/ia64/kernel/syscalls/syscall.tbl +++ b/arch/ia64/kernel/syscalls/syscall.tbl @@ -371,3 +371,4 @@ 448 common process_mrelease sys_process_mrelease 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node +451 common pmadv_ksm sys_pmadv_ksm diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index b1f3940bc29816..5ccf925567da00 100644 --- a/arch/m68k/kernel/syscalls/syscall.tbl +++ b/arch/m68k/kernel/syscalls/syscall.tbl @@ -450,3 +450,4 @@ 448 common process_mrelease sys_process_mrelease 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node +451 common pmadv_ksm sys_pmadv_ksm diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl index 820145e473501e..6b76208597f3c4 100644 --- a/arch/microblaze/kernel/syscalls/syscall.tbl +++ b/arch/microblaze/kernel/syscalls/syscall.tbl @@ -456,3 +456,4 @@ 448 common process_mrelease sys_process_mrelease 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node +451 common pmadv_ksm sys_pmadv_ksm diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl index 253ff994ed2ece..e4aeedb17c3835 100644 --- a/arch/mips/kernel/syscalls/syscall_n32.tbl +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl @@ -389,3 +389,4 @@ 448 n32 process_mrelease sys_process_mrelease 449 n32 futex_waitv sys_futex_waitv 450 n32 set_mempolicy_home_node sys_set_mempolicy_home_node +451 n32 pmadv_ksm sys_pmadv_ksm diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl index 3f1886ad9d8060..fe88db51efa003 100644 --- a/arch/mips/kernel/syscalls/syscall_n64.tbl +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl @@ -365,3 +365,4 @@ 448 n64 process_mrelease sys_process_mrelease 449 n64 futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node +451 n64 pmadv_ksm sys_pmadv_ksm diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl index 8f243e35a7b209..674cb940bd1536 100644 --- a/arch/mips/kernel/syscalls/syscall_o32.tbl +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl @@ -438,3 +438,4 @@ 448 o32 process_mrelease sys_process_mrelease 449 o32 futex_waitv sys_futex_waitv 450 o32 set_mempolicy_home_node sys_set_mempolicy_home_node +451 o32 pmadv_ksm sys_pmadv_ksm diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index 8a99c998da9bb7..429b129d5d464b 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -448,3 +448,4 @@ 448 common process_mrelease sys_process_mrelease 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node +451 common pmadv_ksm sys_pmadv_ksm diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index a0be127475b1f7..347894da4eb6c4 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -537,3 +537,4 @@ 448 common process_mrelease sys_process_mrelease 449 common futex_waitv sys_futex_waitv 450 nospu set_mempolicy_home_node sys_set_mempolicy_home_node +451 common pmadv_ksm sys_pmadv_ksm diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index 799147658dee20..1cd523748bd2ea 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -453,3 +453,4 @@ 448 common process_mrelease sys_process_mrelease sys_process_mrelease 449 common futex_waitv sys_futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node sys_set_mempolicy_home_node +451 common pmadv_ksm sys_pmadv_ksm sys_pmadv_ksm diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl index 2de85c977f54f9..cfc75fa43eae45 100644 --- a/arch/sh/kernel/syscalls/syscall.tbl +++ b/arch/sh/kernel/syscalls/syscall.tbl @@ -453,3 +453,4 @@ 448 common process_mrelease sys_process_mrelease 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node +451 common pmadv_ksm sys_pmadv_ksm diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index 4398cc6fb68dd8..d2c0a6426f6b80 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -496,3 +496,4 @@ 448 common process_mrelease sys_process_mrelease 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node +451 common pmadv_ksm sys_pmadv_ksm diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 320480a8db4f83..331aaf1a782ff7 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -455,3 +455,4 @@ 448 i386 process_mrelease sys_process_mrelease 449 i386 futex_waitv sys_futex_waitv 450 i386 set_mempolicy_home_node sys_set_mempolicy_home_node +451 i386 pmadv_ksm sys_pmadv_ksm diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index c84d12608cd2de..14902db4c01fcf 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -372,6 +372,7 @@ 448 common process_mrelease sys_process_mrelease 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node +451 common pmadv_ksm sys_pmadv_ksm # # Due to a historical design error, certain syscalls are numbered differently diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl index 52c94ab5c2058c..1518e261d882e5 100644 --- a/arch/xtensa/kernel/syscalls/syscall.tbl +++ b/arch/xtensa/kernel/syscalls/syscall.tbl @@ -421,3 +421,4 @@ 448 common process_mrelease sys_process_mrelease 449 common futex_waitv sys_futex_waitv 450 common set_mempolicy_home_node sys_set_mempolicy_home_node +451 common pmadv_ksm sys_pmadv_ksm diff --git a/include/linux/ksm.h b/include/linux/ksm.h index 7e232ba59b8656..632a1a792ebb58 100644 --- a/include/linux/ksm.h +++ b/include/linux/ksm.h @@ -16,6 +16,10 @@ #include #ifdef CONFIG_KSM +int ksm_madvise_merge(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long *vm_flags); +int ksm_madvise_unmerge(struct vm_area_struct *vma, unsigned long start, + unsigned long end, unsigned long *vm_flags); int ksm_madvise(struct vm_area_struct *vma, unsigned long start, unsigned long end, int advice, unsigned long *vm_flags); int __ksm_enter(struct mm_struct *mm); diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index a34b0f9a9972ef..82afad91de9fb6 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -917,6 +917,7 @@ asmlinkage long sys_madvise(unsigned long start, size_t len, int behavior); asmlinkage long sys_process_madvise(int pidfd, const struct iovec __user *vec, size_t vlen, int behavior, unsigned int flags); asmlinkage long sys_process_mrelease(int pidfd, unsigned int flags); +asmlinkage long sys_pmadv_ksm(int pidfd, int behavior, unsigned int flags); asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size, unsigned long prot, unsigned long pgoff, unsigned long flags); diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 45fa180cc56adf..40f7e6d04af0ce 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -886,8 +886,11 @@ __SYSCALL(__NR_futex_waitv, sys_futex_waitv) #define __NR_set_mempolicy_home_node 450 __SYSCALL(__NR_set_mempolicy_home_node, sys_set_mempolicy_home_node) +#define __NR_pmadv_ksm 451 +__SYSCALL(__NR_pmadv_ksm, sys_pmadv_ksm) + #undef __NR_syscalls -#define __NR_syscalls 451 +#define __NR_syscalls 452 /* * 32 bit systems traditionally used different diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 860b2dcf3ac465..810e1fcaff944b 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -292,6 +292,7 @@ COND_SYSCALL(mincore); COND_SYSCALL(madvise); COND_SYSCALL(process_madvise); COND_SYSCALL(process_mrelease); +COND_SYSCALL(pmadv_ksm); COND_SYSCALL(remap_file_pages); COND_SYSCALL(mbind); COND_SYSCALL(get_mempolicy); diff --git a/mm/ksm.c b/mm/ksm.c index c19fcca9bc03dc..d9c5e1655b4e9f 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -2438,54 +2438,78 @@ static int ksm_scan_thread(void *nothing) return 0; } -int ksm_madvise(struct vm_area_struct *vma, unsigned long start, - unsigned long end, int advice, unsigned long *vm_flags) +int ksm_madvise_merge(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long *vm_flags) { - struct mm_struct *mm = vma->vm_mm; int err; - switch (advice) { - case MADV_MERGEABLE: - /* - * Be somewhat over-protective for now! - */ - if (*vm_flags & (VM_MERGEABLE | VM_SHARED | VM_MAYSHARE | - VM_PFNMAP | VM_IO | VM_DONTEXPAND | - VM_HUGETLB | VM_MIXEDMAP)) - return 0; /* just ignore the advice */ + /* + * Be somewhat over-protective for now! + */ + if (*vm_flags & (VM_MERGEABLE | VM_SHARED | VM_MAYSHARE | + VM_PFNMAP | VM_IO | VM_DONTEXPAND | + VM_HUGETLB | VM_MIXEDMAP)) + return 0; /* just ignore the advice */ - if (vma_is_dax(vma)) - return 0; + if (vma_is_dax(vma)) + return 0; #ifdef VM_SAO if (*vm_flags & VM_SAO) return 0; #endif #ifdef VM_SPARC_ADI - if (*vm_flags & VM_SPARC_ADI) - return 0; + if (*vm_flags & VM_SPARC_ADI) + return 0; #endif - if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) { - err = __ksm_enter(mm); - if (err) - return err; - } + if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) { + err = __ksm_enter(mm); + if (err) + return err; + } - *vm_flags |= VM_MERGEABLE; - break; + *vm_flags |= VM_MERGEABLE; - case MADV_UNMERGEABLE: - if (!(*vm_flags & VM_MERGEABLE)) - return 0; /* just ignore the advice */ + return 0; +} - if (vma->anon_vma) { - err = unmerge_ksm_pages(vma, start, end); - if (err) - return err; - } +int ksm_madvise_unmerge(struct vm_area_struct *vma, unsigned long start, + unsigned long end, unsigned long *vm_flags) +{ + int err; + + if (!(*vm_flags & VM_MERGEABLE)) + return 0; /* just ignore the advice */ + + if (vma->anon_vma) { + err = unmerge_ksm_pages(vma, start, end); + if (err) + return err; + } - *vm_flags &= ~VM_MERGEABLE; + *vm_flags &= ~VM_MERGEABLE; + + return 0; +} + +int ksm_madvise(struct vm_area_struct *vma, unsigned long start, + unsigned long end, int advice, unsigned long *vm_flags) +{ + struct mm_struct *mm = vma->vm_mm; + int err; + + switch (advice) { + case MADV_MERGEABLE: + err = ksm_madvise_merge(mm, vma, vm_flags); + if (err) + return err; + break; + + case MADV_UNMERGEABLE: + err = ksm_madvise_unmerge(vma, start, end, vm_flags); + if (err) + return err; break; } diff --git a/mm/madvise.c b/mm/madvise.c index b913ba6efc10be..8c5a8dcd49f76f 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1512,3 +1512,116 @@ SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec, out: return ret; } + +SYSCALL_DEFINE3(pmadv_ksm, int, pidfd, int, behaviour, unsigned int, flags) +{ +#ifdef CONFIG_KSM + ssize_t ret; + struct pid *pid; + struct task_struct *task; + struct mm_struct *mm; + unsigned int f_flags; + struct vm_area_struct *vma; + struct vma_iterator vmi; + + if (flags != 0) { + ret = -EINVAL; + goto out; + } + + switch (behaviour) { + case MADV_MERGEABLE: + case MADV_UNMERGEABLE: + break; + default: + ret = -EINVAL; + goto out; + break; + } + + pid = pidfd_get_pid(pidfd, &f_flags); + if (IS_ERR(pid)) { + ret = PTR_ERR(pid); + goto out; + } + + task = get_pid_task(pid, PIDTYPE_PID); + if (!task) { + ret = -ESRCH; + goto put_pid; + } + + /* Require PTRACE_MODE_READ to avoid leaking ASLR metadata. */ + mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); + if (IS_ERR_OR_NULL(mm)) { + ret = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH; + goto release_task; + } + + /* Require CAP_SYS_NICE for influencing process performance. */ + if (!capable(CAP_SYS_NICE)) { + ret = -EPERM; + goto release_mm; + } + + if (mmap_write_lock_killable(mm)) { + ret = -EINTR; + goto release_mm; + } + + vma_iter_init(&vmi, mm, 0); + for_each_vma(vmi, vma) { + switch (behaviour) { + case MADV_MERGEABLE: + ret = ksm_madvise_merge(vma->vm_mm, vma, &vma->vm_flags); + break; + case MADV_UNMERGEABLE: + ret = ksm_madvise_unmerge(vma, vma->vm_start, vma->vm_end, &vma->vm_flags); + break; + default: + /* look, ma, no brain */ + break; + } + if (ret) + break; + } + + mmap_write_unlock(mm); + +release_mm: + mmput(mm); +release_task: + put_task_struct(task); +put_pid: + put_pid(pid); +out: + return ret; +#else /* CONFIG_KSM */ + return -ENOSYS; +#endif /* CONFIG_KSM */ +} + +#ifdef CONFIG_KSM +static ssize_t ksm_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%u\n", __NR_pmadv_ksm); +} +static struct kobj_attribute pmadv_ksm_attr = __ATTR_RO(ksm); + +static struct attribute *pmadv_sysfs_attrs[] = { + &pmadv_ksm_attr.attr, + NULL, +}; + +static const struct attribute_group pmadv_sysfs_attr_group = { + .attrs = pmadv_sysfs_attrs, + .name = "pmadv", +}; + +static int __init pmadv_sysfs_init(void) +{ + return sysfs_create_group(kernel_kobj, &pmadv_sysfs_attr_group); +} +subsys_initcall(pmadv_sysfs_init); +#endif /* CONFIG_KSM */