From 9c28765934eafaff8d73a642512b2b6118aea976 Mon Sep 17 00:00:00 2001 From: Peter Jung Date: Fri, 7 Mar 2025 19:32:25 +0100 Subject: [PATCH 10/12] pksm Signed-off-by: Peter Jung --- arch/alpha/kernel/syscalls/syscall.tbl | 3 + arch/arm/tools/syscall.tbl | 3 + arch/m68k/kernel/syscalls/syscall.tbl | 3 + arch/microblaze/kernel/syscalls/syscall.tbl | 3 + arch/mips/kernel/syscalls/syscall_n32.tbl | 3 + arch/mips/kernel/syscalls/syscall_n64.tbl | 3 + arch/mips/kernel/syscalls/syscall_o32.tbl | 3 + arch/parisc/kernel/syscalls/syscall.tbl | 3 + arch/powerpc/kernel/syscalls/syscall.tbl | 3 + arch/s390/kernel/syscalls/syscall.tbl | 3 + arch/sh/kernel/syscalls/syscall.tbl | 3 + arch/sparc/kernel/syscalls/syscall.tbl | 3 + arch/x86/entry/syscalls/syscall_32.tbl | 3 + arch/x86/entry/syscalls/syscall_64.tbl | 3 + arch/xtensa/kernel/syscalls/syscall.tbl | 3 + include/linux/syscalls.h | 3 + include/uapi/asm-generic/unistd.h | 9 +- kernel/sys.c | 138 ++++++++++++++++++ kernel/sys_ni.c | 3 + scripts/syscall.tbl | 3 + .../arch/powerpc/entry/syscalls/syscall.tbl | 3 + .../perf/arch/s390/entry/syscalls/syscall.tbl | 3 + 22 files changed, 206 insertions(+), 1 deletion(-) diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl index c59d53d6d3f3..121696f903e8 100644 --- a/arch/alpha/kernel/syscalls/syscall.tbl +++ b/arch/alpha/kernel/syscalls/syscall.tbl @@ -506,3 +506,6 @@ 574 common getxattrat sys_getxattrat 575 common listxattrat sys_listxattrat 576 common removexattrat sys_removexattrat +577 common process_ksm_enable sys_process_ksm_enable +578 common process_ksm_disable sys_process_ksm_disable +579 common process_ksm_status sys_process_ksm_status diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl index 49eeb2ad8dbd..1ce4d983b5b2 100644 --- a/arch/arm/tools/syscall.tbl +++ b/arch/arm/tools/syscall.tbl @@ -481,3 +481,6 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl index f5ed71f1910d..17e865370d37 100644 --- a/arch/m68k/kernel/syscalls/syscall.tbl +++ b/arch/m68k/kernel/syscalls/syscall.tbl @@ -466,3 +466,6 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl index 680f568b77f2..64740e895587 100644 --- a/arch/microblaze/kernel/syscalls/syscall.tbl +++ b/arch/microblaze/kernel/syscalls/syscall.tbl @@ -472,3 +472,6 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl index 0b9b7e25b69a..bfafb91a2eda 100644 --- a/arch/mips/kernel/syscalls/syscall_n32.tbl +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl @@ -405,3 +405,6 @@ 464 n32 getxattrat sys_getxattrat 465 n32 listxattrat sys_listxattrat 466 n32 removexattrat sys_removexattrat +467 n32 process_ksm_enable sys_process_ksm_enable +468 n32 process_ksm_disable sys_process_ksm_disable +469 n32 process_ksm_status sys_process_ksm_status diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl index c844cd5cda62..39d446aeac64 100644 --- a/arch/mips/kernel/syscalls/syscall_n64.tbl +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl @@ -381,3 +381,6 @@ 464 n64 getxattrat sys_getxattrat 465 n64 listxattrat sys_listxattrat 466 n64 removexattrat sys_removexattrat +467 n64 process_ksm_enable sys_process_ksm_enable +468 n64 process_ksm_disable sys_process_ksm_disable +469 n64 process_ksm_status sys_process_ksm_status diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl index 349b8aad1159..61536c55715a 100644 --- a/arch/mips/kernel/syscalls/syscall_o32.tbl +++ b/arch/mips/kernel/syscalls/syscall_o32.tbl @@ -454,3 +454,6 @@ 464 o32 getxattrat sys_getxattrat 465 o32 listxattrat sys_listxattrat 466 o32 removexattrat sys_removexattrat +467 o32 process_ksm_enable sys_process_ksm_enable +468 o32 process_ksm_disable sys_process_ksm_disable +469 o32 process_ksm_status sys_process_ksm_status diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl index d9fc94c86965..85dca5afcf06 100644 --- a/arch/parisc/kernel/syscalls/syscall.tbl +++ b/arch/parisc/kernel/syscalls/syscall.tbl @@ -465,3 +465,6 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl index d8b4ab78bef0..57aa958c1b97 100644 --- a/arch/powerpc/kernel/syscalls/syscall.tbl +++ b/arch/powerpc/kernel/syscalls/syscall.tbl @@ -557,3 +557,6 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl index e9115b4d8b63..2afc778f2d17 100644 --- a/arch/s390/kernel/syscalls/syscall.tbl +++ b/arch/s390/kernel/syscalls/syscall.tbl @@ -469,3 +469,6 @@ 464 common getxattrat sys_getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status sys_process_ksm_status diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl index c8cad33bf250..dfe06a84d902 100644 --- a/arch/sh/kernel/syscalls/syscall.tbl +++ b/arch/sh/kernel/syscalls/syscall.tbl @@ -470,3 +470,6 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl index 727f99d333b3..4c43b0d2d09f 100644 --- a/arch/sparc/kernel/syscalls/syscall.tbl +++ b/arch/sparc/kernel/syscalls/syscall.tbl @@ -512,3 +512,6 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl index 4d0fb2fba7e2..a63252b84261 100644 --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -472,3 +472,6 @@ 464 i386 getxattrat sys_getxattrat 465 i386 listxattrat sys_listxattrat 466 i386 removexattrat sys_removexattrat +467 i386 process_ksm_enable sys_process_ksm_enable +468 i386 process_ksm_disable sys_process_ksm_disable +469 i386 process_ksm_status sys_process_ksm_status diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl index 5eb708bff1c7..b5fe77405938 100644 --- a/arch/x86/entry/syscalls/syscall_64.tbl +++ b/arch/x86/entry/syscalls/syscall_64.tbl @@ -390,6 +390,9 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status # # 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 37effc1b134e..5c944f0dcc20 100644 --- a/arch/xtensa/kernel/syscalls/syscall.tbl +++ b/arch/xtensa/kernel/syscalls/syscall.tbl @@ -437,3 +437,6 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index c6333204d451..00400d99eef3 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -831,6 +831,9 @@ 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_process_ksm_enable(int pidfd, unsigned int flags); +asmlinkage long sys_process_ksm_disable(int pidfd, unsigned int flags); +asmlinkage long sys_process_ksm_status(int pidfd, 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 88dc393c2bca..34d73f16b478 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -850,8 +850,15 @@ __SYSCALL(__NR_listxattrat, sys_listxattrat) #define __NR_removexattrat 466 __SYSCALL(__NR_removexattrat, sys_removexattrat) +#define __NR_process_ksm_enable 467 +__SYSCALL(__NR_process_ksm_enable, sys_process_ksm_enable) +#define __NR_process_ksm_disable 468 +__SYSCALL(__NR_process_ksm_disable, sys_process_ksm_disable) +#define __NR_process_ksm_status 469 +__SYSCALL(__NR_process_ksm_status, sys_process_ksm_status) + #undef __NR_syscalls -#define __NR_syscalls 467 +#define __NR_syscalls 470 /* * 32 bit systems traditionally used different diff --git a/kernel/sys.c b/kernel/sys.c index c4c701c6f0b4..8806d113f5db 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2816,6 +2816,144 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, return error; } +#ifdef CONFIG_KSM +enum pkc_action { + PKSM_ENABLE = 0, + PKSM_DISABLE, + PKSM_STATUS, +}; + +static long do_process_ksm_control(int pidfd, enum pkc_action action) +{ + long ret; + struct task_struct *task; + struct mm_struct *mm; + unsigned int f_flags; + + task = pidfd_get_task(pidfd, &f_flags); + if (IS_ERR(task)) { + ret = PTR_ERR(task); + goto out; + } + + /* 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; + } + + switch (action) { + case PKSM_ENABLE: + ret = ksm_enable_merge_any(mm); + break; + case PKSM_DISABLE: + ret = ksm_disable_merge_any(mm); + break; + case PKSM_STATUS: + ret = !!test_bit(MMF_VM_MERGE_ANY, &mm->flags); + break; + } + + mmap_write_unlock(mm); + +release_mm: + mmput(mm); +release_task: + put_task_struct(task); +out: + return ret; +} +#endif /* CONFIG_KSM */ + +SYSCALL_DEFINE2(process_ksm_enable, int, pidfd, unsigned int, flags) +{ +#ifdef CONFIG_KSM + if (flags != 0) + return -EINVAL; + + return do_process_ksm_control(pidfd, PKSM_ENABLE); +#else /* CONFIG_KSM */ + return -ENOSYS; +#endif /* CONFIG_KSM */ +} + +SYSCALL_DEFINE2(process_ksm_disable, int, pidfd, unsigned int, flags) +{ +#ifdef CONFIG_KSM + if (flags != 0) + return -EINVAL; + + return do_process_ksm_control(pidfd, PKSM_DISABLE); +#else /* CONFIG_KSM */ + return -ENOSYS; +#endif /* CONFIG_KSM */ +} + +SYSCALL_DEFINE2(process_ksm_status, int, pidfd, unsigned int, flags) +{ +#ifdef CONFIG_KSM + if (flags != 0) + return -EINVAL; + + return do_process_ksm_control(pidfd, PKSM_STATUS); +#else /* CONFIG_KSM */ + return -ENOSYS; +#endif /* CONFIG_KSM */ +} + +#ifdef CONFIG_KSM +static ssize_t process_ksm_enable_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%u\n", __NR_process_ksm_enable); +} +static struct kobj_attribute process_ksm_enable_attr = __ATTR_RO(process_ksm_enable); + +static ssize_t process_ksm_disable_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%u\n", __NR_process_ksm_disable); +} +static struct kobj_attribute process_ksm_disable_attr = __ATTR_RO(process_ksm_disable); + +static ssize_t process_ksm_status_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%u\n", __NR_process_ksm_status); +} +static struct kobj_attribute process_ksm_status_attr = __ATTR_RO(process_ksm_status); + +static struct attribute *process_ksm_sysfs_attrs[] = { + &process_ksm_enable_attr.attr, + &process_ksm_disable_attr.attr, + &process_ksm_status_attr.attr, + NULL, +}; + +static const struct attribute_group process_ksm_sysfs_attr_group = { + .attrs = process_ksm_sysfs_attrs, + .name = "process_ksm", +}; + +static int __init process_ksm_sysfs_init(void) +{ + return sysfs_create_group(kernel_kobj, &process_ksm_sysfs_attr_group); +} +subsys_initcall(process_ksm_sysfs_init); +#endif /* CONFIG_KSM */ + SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, struct getcpu_cache __user *, unused) { diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index c00a86931f8c..d82213d68522 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -186,6 +186,9 @@ COND_SYSCALL(mincore); COND_SYSCALL(madvise); COND_SYSCALL(process_madvise); COND_SYSCALL(process_mrelease); +COND_SYSCALL(process_ksm_enable); +COND_SYSCALL(process_ksm_disable); +COND_SYSCALL(process_ksm_status); COND_SYSCALL(remap_file_pages); COND_SYSCALL(mbind); COND_SYSCALL(get_mempolicy); diff --git a/scripts/syscall.tbl b/scripts/syscall.tbl index ebbdb3c42e9f..b19b6bfe5cd4 100644 --- a/scripts/syscall.tbl +++ b/scripts/syscall.tbl @@ -407,3 +407,6 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status diff --git a/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl b/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl index d8b4ab78bef0..57aa958c1b97 100644 --- a/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl +++ b/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl @@ -557,3 +557,6 @@ 464 common getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status diff --git a/tools/perf/arch/s390/entry/syscalls/syscall.tbl b/tools/perf/arch/s390/entry/syscalls/syscall.tbl index e9115b4d8b63..2afc778f2d17 100644 --- a/tools/perf/arch/s390/entry/syscalls/syscall.tbl +++ b/tools/perf/arch/s390/entry/syscalls/syscall.tbl @@ -469,3 +469,6 @@ 464 common getxattrat sys_getxattrat sys_getxattrat 465 common listxattrat sys_listxattrat sys_listxattrat 466 common removexattrat sys_removexattrat sys_removexattrat +467 common process_ksm_enable sys_process_ksm_enable sys_process_ksm_enable +468 common process_ksm_disable sys_process_ksm_disable sys_process_ksm_disable +469 common process_ksm_status sys_process_ksm_status sys_process_ksm_status -- 2.48.0.rc1