[RFC PATCH 09/11] mm/mempolicy: add get_mempolicy2 syscall
From: Gregory Price <hidden>
Date: 2023-12-07 00:28:29
Also in:
linux-arch, linux-doc, linux-fsdevel, lkml
Subsystem:
abi/api, alpha port, arm port, documentation, generic include/asm header files, linux for powerpc (32-bit and 64-bit), m68k architecture, memory management, memory management - memory policy and migration, memory management - misc, microblaze architecture, mips, parisc architecture, s390 architecture, sparc + ultrasparc (sparc/sparc64), superh, tensilica xtensa port (xtensa), the rest, x86 architecture (32-bit and 64-bit), x86 entry code · Maintainers:
Richard Henderson, Matt Turner, Magnus Lindholm, Russell King, Jonathan Corbet, Arnd Bergmann, Madhavan Srinivasan, Michael Ellerman, Geert Uytterhoeven, Andrew Morton, David Hildenbrand, Michal Simek, Thomas Bogendoerfer, "James E.J. Bottomley", Helge Deller, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, "David S. Miller", Andreas Larsson, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Chris Zankel, Max Filippov, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski
get_mempolicy2 is an extensible get_mempolicy interface which allows
a user to retrieve the memory policy for a task or address.
Defined as:
get_mempolicy2(struct mpol_args *args, size_t size, unsigned long flags)
Input values include the following fields of mpol_args:
pol_nodes: if set, the nodemask of the policy returned here
pol_maxnodes: if pol_nodes is set, must describe max number of nodes
to be copied to pol_nodes
addr: if MPOL_F_ADDR is passed in `flags`, this address will be
used to return the mempolicy details of the vma the
address belongs to
flags: if MPOL_F_MEMS_ALLOWED, returns mems_allowed in pol_nodes
if MPOL_F_ADDR, return mempolicy info vma containing addr
else, returns per-task mempolicy information
Output values include the following fields of mpol_args:
mode: mempolicy mode
mode_flags: mempolicy mode flags
pol_nodes: if set, the nodemask for the mempolicy
policy_node: if the policy has extended node information, it will
be placed here. For example MPOL_INTERLEAVE will
return the next node which will be used for allocation
addr_node: If MPOL_F_ADDR is set, the numa node that the address
is located on will be returned.
home_node: policy home node will be returned here, or -1 if not.
MPOL_F_NODE has been dropped from get_mempolicy2 (it is ignored) in
favor or returning explicit values in `policy_node` and `addr_node`.
Suggested-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Gregory Price <redacted>
---
.../admin-guide/mm/numa_memory_policy.rst | 8 +++-
arch/alpha/kernel/syscalls/syscall.tbl | 1 +
arch/arm/tools/syscall.tbl | 1 +
arch/m68k/kernel/syscalls/syscall.tbl | 1 +
arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 1 +
arch/mips/kernel/syscalls/syscall_o32.tbl | 1 +
arch/parisc/kernel/syscalls/syscall.tbl | 1 +
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
arch/s390/kernel/syscalls/syscall.tbl | 1 +
arch/sh/kernel/syscalls/syscall.tbl | 1 +
arch/sparc/kernel/syscalls/syscall.tbl | 1 +
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/xtensa/kernel/syscalls/syscall.tbl | 1 +
include/linux/syscalls.h | 2 +
include/uapi/asm-generic/unistd.h | 4 +-
mm/mempolicy.c | 43 +++++++++++++++++++
18 files changed, 69 insertions(+), 2 deletions(-)
diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst
index 7195edaeaad9..82cdb765dd58 100644
--- a/Documentation/admin-guide/mm/numa_memory_policy.rst
+++ b/Documentation/admin-guide/mm/numa_memory_policy.rst@@ -462,11 +462,17 @@ Get [Task] Memory Policy or Related Information:: long get_mempolicy(int *mode, const unsigned long *nmask, unsigned long maxnode, void *addr, int flags); + long get_mempolicy2(struct mpol_args args, size_t size, + unsigned long flags); Queries the "task/process memory policy" of the calling task, or the policy or location of a specified virtual address, depending on the 'flags' argument. +get_mempolicy2() is an extended version of get_mempolicy() capable of +acquiring extended information about a mempolicy, including those +that can only be set via set_mempolicy2() or mbind2().. + See the get_mempolicy(2) man page for more details
@@ -523,7 +529,7 @@ Extended Mempolicy Arguments:: The extended mempolicy argument structure is defined to allow the mempolicy interfaces future extensibility without the need for additional system calls. -Extended interfaces (set_mempolicy2) use this argument structure. +Extended interfaces (set_mempolicy2 and get_mempolicy2) use this structure. The core arguments (mode, mode_flags, pol_nodes, and pol_maxnodes) apply to all interfaces relative to their non-extended counterparts. Each additional
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 0dc288a1118a..0301a8b0a262 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl@@ -497,3 +497,4 @@ 565 common futex_wait sys_futex_wait 566 common futex_requeue sys_futex_requeue 567 common set_mempolicy2 sys_set_mempolicy2 +568 common get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 50172ec0e1f5..771a33446e8e 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl@@ -471,3 +471,4 @@ 455 common futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue 457 common set_mempolicy2 sys_set_mempolicy2 +458 common get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 839d90c535f2..048a409e684c 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl@@ -457,3 +457,4 @@ 455 common futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue 457 common set_mempolicy2 sys_set_mempolicy2 +458 common get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index 567c8b883735..327b01bd6793 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl@@ -463,3 +463,4 @@ 455 common futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue 457 common set_mempolicy2 sys_set_mempolicy2 +458 common get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index cc0640e16f2f..921d58e1da23 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl@@ -396,3 +396,4 @@ 455 n32 futex_wait sys_futex_wait 456 n32 futex_requeue sys_futex_requeue 457 n32 set_mempolicy2 sys_set_mempolicy2 +458 n32 get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index f7262fde98d9..9271c83c9993 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl@@ -445,3 +445,4 @@ 455 o32 futex_wait sys_futex_wait 456 o32 futex_requeue sys_futex_requeue 457 o32 set_mempolicy2 sys_set_mempolicy2 +458 o32 get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index e10f0e8bd064..0654f3f89fc7 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl@@ -456,3 +456,4 @@ 455 common futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue 457 common set_mempolicy2 sys_set_mempolicy2 +458 common get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 4f03f5f42b78..ac11d2064e7a 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl@@ -544,3 +544,4 @@ 455 common futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue 457 common set_mempolicy2 sys_set_mempolicy2 +458 common get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index f98dadc2e9df..1cdcafe1ccca 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl@@ -460,3 +460,4 @@ 455 common futex_wait sys_futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue sys_futex_requeue 457 common set_mempolicy2 sys_set_mempolicy2 sys_set_mempolicy2 +458 common get_mempolicy2 sys_get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index f47ba9f2d05d..f71742024c29 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl@@ -460,3 +460,4 @@ 455 common futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue 457 common set_mempolicy2 sys_set_mempolicy2 +458 common get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index 53fb16616728..2fbf5dbe0620 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl@@ -503,3 +503,4 @@ 455 common futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue 457 common set_mempolicy2 sys_set_mempolicy2 +458 common get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 4b4dc41b24ee..0af813b9a118 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl@@ -462,3 +462,4 @@ 455 i386 futex_wait sys_futex_wait 456 i386 futex_requeue sys_futex_requeue 457 i386 set_mempolicy2 sys_set_mempolicy2 +458 i386 get_mempolicy2 sys_get_mempolicy2
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 1bc2190bec27..0b777876fc15 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl@@ -379,6 +379,7 @@ 455 common futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue 457 common set_mempolicy2 sys_set_mempolicy2 +458 common get_mempolicy2 sys_get_mempolicy2 # # 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 e26dc89399eb..4536c9a4227d 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl@@ -428,3 +428,4 @@ 455 common futex_wait sys_futex_wait 456 common futex_requeue sys_futex_requeue 457 common set_mempolicy2 sys_set_mempolicy2 +458 common get_mempolicy2 sys_get_mempolicy2
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 3244cd990858..774512b7934e 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h@@ -820,6 +820,8 @@ asmlinkage long sys_get_mempolicy(int __user *policy, unsigned long __user *nmask, unsigned long maxnode, unsigned long addr, unsigned long flags); +asmlinkage long sys_get_mempolicy2(struct mpol_args *args, size_t size, + unsigned long flags); asmlinkage long sys_set_mempolicy(int mode, const unsigned long __user *nmask, unsigned long maxnode); asmlinkage long sys_set_mempolicy2(struct mpol_args *args, size_t size,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 55486aba099f..719accc731db 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h@@ -830,9 +830,11 @@ __SYSCALL(__NR_futex_wait, sys_futex_wait) __SYSCALL(__NR_futex_requeue, sys_futex_requeue) #define __NR_set_mempolicy2 457 __SYSCALL(__NR_set_mempolicy2, sys_set_mempolicy2) +#define __NR_get_mempolicy2 458 +__SYSCALL(__NR_get_mempolicy2, sys_get_mempolicy2) #undef __NR_syscalls -#define __NR_syscalls 458 +#define __NR_syscalls 459 /* * 32 bit systems traditionally used different
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index fdc56798226b..d1d10b2746e3 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c@@ -1860,6 +1860,49 @@ SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, return kernel_get_mempolicy(policy, nmask, maxnode, addr, flags); } +SYSCALL_DEFINE3(get_mempolicy2, struct mpol_args __user *, uargs, size_t, usize, + unsigned long, flags) +{ + struct mpol_args kargs; + struct mempolicy_args margs; + int err; + nodemask_t policy_nodemask; + + err = copy_struct_from_user(&kargs, sizeof(kargs), uargs, usize); + if (err) + return -EINVAL; + + if (flags & MPOL_F_MEMS_ALLOWED) { + if (!margs.policy_nodes) + return -EINVAL; + err = do_get_mems_allowed(&policy_nodemask); + if (err) + return err; + return copy_nodes_to_user(kargs.pol_nodes, kargs.pol_maxnodes, + &policy_nodemask); + } + + margs.policy_nodes = kargs.pol_nodes ? &policy_nodemask : NULL; + if (flags & MPOL_F_ADDR) { + margs.addr = kargs.addr; + err = do_get_vma_mempolicy(&margs); + } else + err = do_get_task_mempolicy(&margs); + + if (err) + return err; + + kargs.mode = margs.mode; + kargs.mode_flags = margs.mode_flags; + kargs.policy_node = margs.policy_node; + kargs.addr_node = (flags & MPOL_F_ADDR) ? margs.addr_node : -1; + if (kargs.pol_nodes) + err = copy_nodes_to_user(kargs.pol_nodes, kargs.pol_maxnodes, + margs.policy_nodes); + + return copy_to_user(uargs, &kargs, usize) ? -EFAULT : 0; +} + bool vma_migratable(struct vm_area_struct *vma) { if (vma->vm_flags & (VM_IO | VM_PFNMAP))
--
2.39.1