[PATCH] mm: retain consistent pidfd syscall naming
From: Christian Brauner
Date: Tue May 19 2020 - 02:26:07 EST
I think there's value in consistent api naming. So far we have
pidfd_open(), pidfd_send_signal(), pidfd_getfd(), likely there's going
to be a pidfd_addfd() in the near future. process_madvise() would
currently be the only syscall not fitting in that set. It probably
doesn't matter much whether we call it process_madvise() or
pidfd_madvise() and as long as noone has serious problems with renaming
this I'd vote to keep naming consistent. This is also way nicer for
userspace.
I tested this patch on the akpm branch:
ssh://git@xxxxxxxxxxxxxxxxxxx/pub/scm/linux/kernel/git/next/linux-next.git akpm
It can be applied directly on top of Minchan's patch:
https://lore.kernel.org/lkml/20200516012055.126205-1-minchan@xxxxxxxxxx
Here's also the adapted commit message:
Based on discussion[1], people didn't feel we need to support both
pid and pidfd for every new coming API[2] so this patch keeps only
pidfd. This patch also changes flags's type with "unsigned int".
So finally, the API is as follows,
ssize_t pidfd_madvise(int pidfd, const struct iovec *iovec,
unsigned long vlen, int advice, unsigned int flags);
DESCRIPTION
The pidfd_madvise() system call is used to give advice or directions
to the kernel about the address ranges from external process as well as
local process. It provides the advice to address ranges of process
described by iovec and vlen. The goal of such advice is to improve system
or application performance.
The pidfd selects the process referred to by the PID file descriptor
specified in pidfd. (See pidofd_open(2) for further information)
The pointer iovec points to an array of iovec structures, defined in
<sys/uio.h> as:
struct iovec {
void *iov_base; /* starting address */
size_t iov_len; /* number of bytes to be advised */
};
The iovec describes address ranges beginning at address(iov_base)
and with size length of bytes(iov_len).
The vlen represents the number of elements in iovec.
The advice is indicated in the advice argument, which is one of the
following at this moment if the target process specified by idtype and
id is external.
MADV_COLD
MADV_PAGEOUT
MADV_MERGEABLE
MADV_UNMERGEABLE
Permission to provide a hint to external process is governed by a
ptrace access mode PTRACE_MODE_ATTACH_FSCREDS check; see ptrace(2).
The pidfd_madvise supports every advice madvise(2) has if target
process is in same thread group with calling process so user could
use pidfd_madvise(2) to extend existing madvise(2) to support
vector address ranges.
RETURN VALUE
On success, pidfd_madvise() returns the number of bytes advised.
This return value may be less than the total number of requested
bytes, if an error occurred. The caller should check return value
to determine whether a partial advice occurred.
[1] https://lore.kernel.org/linux-mm/20200509124817.xmrvsrq3mla6b76k@wittgenstein/
[2] https://lore.kernel.org/linux-mm/9d849087-3359-c4ab-fbec-859e8186c509@xxxxxxxxxxxxx/
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
Reviewed-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
---
arch/alpha/kernel/syscalls/syscall.tbl | 2 +-
arch/arm/tools/syscall.tbl | 2 +-
arch/arm64/include/asm/unistd32.h | 4 ++--
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_n32.tbl | 2 +-
arch/mips/kernel/syscalls/syscall_n64.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/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 | 4 ++--
arch/xtensa/kernel/syscalls/syscall.tbl | 2 +-
include/linux/compat.h | 2 +-
include/linux/syscalls.h | 2 +-
include/uapi/asm-generic/unistd.h | 6 +++---
kernel/sys_ni.c | 4 ++--
mm/madvise.c | 18 +++++++++---------
22 files changed, 35 insertions(+), 35 deletions(-)
diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index b249824c8267..2e125f20e182 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -481,4 +481,4 @@
550 common watch_mount sys_watch_mount
551 common watch_sb sys_watch_sb
552 common fsinfo sys_fsinfo
-553 common process_madvise sys_process_madvise
+553 common pidfd_madvise sys_pidfd_madvise
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 7b3832d920ee..e65949d0019a 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -455,4 +455,4 @@
440 common watch_mount sys_watch_mount
441 common watch_sb sys_watch_sb
442 common fsinfo sys_fsinfo
-443 common process_madvise sys_process_madvise
+443 common pidfd_madvise sys_pidfd_madvise
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index f8dafe900cb9..0f18d84f5ec0 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -891,8 +891,8 @@ __SYSCALL(__NR_watch_mount, sys_watch_mount)
__SYSCALL(__NR_watch_sb, sys_watch_sb)
#define __NR_fsinfo 442
__SYSCALL(__NR_fsinfo, sys_fsinfo)
-#define __NR_process_madvise 443
-__SYSCALL(__NR_process_madvise, compat_sys_process_madvise)
+#define __NR_pidfd_madvise 443
+__SYSCALL(__NR_pidfd_madvise, compat_sys_pidfd_madvise)
/*
* 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 6636a1aef36b..494b8af8207d 100644
--- a/arch/ia64/kernel/syscalls/syscall.tbl
+++ b/arch/ia64/kernel/syscalls/syscall.tbl
@@ -362,4 +362,4 @@
440 common watch_mount sys_watch_mount
441 common watch_sb sys_watch_sb
442 common fsinfo sys_fsinfo
-443 common process_madvise sys_process_madvise
+443 common pidfd_madvise sys_pidfd_madvise
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 8cd84a7fbf57..e7397ab813d3 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -441,4 +441,4 @@
440 common watch_mount sys_watch_mount
441 common watch_sb sys_watch_sb
442 common fsinfo sys_fsinfo
-443 common process_madvise sys_process_madvise
+443 common pidfd_madvise sys_pidfd_madvise
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index f581a02257ec..f70a0abcbe99 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -447,4 +447,4 @@
440 common watch_mount sys_watch_mount
441 common watch_sb sys_watch_sb
442 common fsinfo sys_fsinfo
-443 common process_madvise sys_process_madvise
+443 common pidfd_madvise sys_pidfd_madvise
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index c85bdc3abe55..b6a992f2a255 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -380,4 +380,4 @@
440 n32 watch_mount sys_watch_mount
441 n32 watch_sb sys_watch_sb
442 n32 fsinfo sys_fsinfo
-443 n32 process_madvise compat_sys_process_madvise
+443 n32 pidfd_madvise compat_sys_pidfd_madvise
diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
index 9e08c40d3cb9..8638beaf724d 100644
--- a/arch/mips/kernel/syscalls/syscall_n64.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
@@ -356,4 +356,4 @@
440 n64 watch_mount sys_watch_mount
441 n64 watch_sb sys_watch_sb
442 n64 fsinfo sys_fsinfo
-443 n64 process_madvise sys_process_madvise
+443 n64 pidfd_madvise sys_pidfd_madvise
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index a2b591d7c874..7228e9c91263 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -429,4 +429,4 @@
440 o32 watch_mount sys_watch_mount
441 o32 watch_sb sys_watch_sb
442 o32 fsinfo sys_fsinfo
-443 o32 process_madvise sys_process_madvise compat_sys_process_madvise
+443 o32 pidfd_madvise sys_pidfd_madvise compat_sys_pidfd_madvise
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index 98e7442e4d7a..14991103f5e2 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -439,4 +439,4 @@
440 common watch_mount sys_watch_mount
441 common watch_sb sys_watch_sb
442 common fsinfo sys_fsinfo
-443 common process_madvise sys_process_madvise compat_sys_process_madvise
+443 common pidfd_madvise sys_pidfd_madvise compat_sys_pidfd_madvise
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 72fb9dd88e16..a4a286c222aa 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -531,4 +531,4 @@
440 common watch_mount sys_watch_mount
441 common watch_sb sys_watch_sb
442 common fsinfo sys_fsinfo
-443 common process_madvise sys_process_madvise compat_sys_process_madvise
+443 common pidfd_madvise sys_pidfd_madvise compat_sys_pidfd_madvise
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index b731fcb03f1b..ec11df661285 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -444,4 +444,4 @@
440 common watch_mount sys_watch_mount sys_watch_mount
441 common watch_sb sys_watch_sb sys_watch_sb
442 common fsinfo sys_fsinfo sys_fsinfo
-443 common process_madvise sys_process_madvise compat_sys_process_madvise
+443 common pidfd_madvise sys_pidfd_madvise compat_sys_pidfd_madvise
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index e7a4804e23cf..62c4926e3150 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -444,4 +444,4 @@
440 common watch_mount sys_watch_mount
441 common watch_sb sys_watch_sb
442 common fsinfo sys_fsinfo
-443 common process_madvise sys_process_madvise
+443 common pidfd_madvise sys_pidfd_madvise
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index d6126ee2f51d..50ccfc41d3a0 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -487,4 +487,4 @@
440 common watch_mount sys_watch_mount
441 common watch_sb sys_watch_sb
442 common fsinfo sys_fsinfo
-443 common process_madvise sys_process_madvise compat_sys_process_madvise
+443 common pidfd_madvise sys_pidfd_madvise compat_sys_pidfd_madvise
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 686d59df1e12..6b16b95c58a0 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -446,4 +446,4 @@
440 i386 watch_mount sys_watch_mount
441 i386 watch_sb sys_watch_sb
442 i386 fsinfo sys_fsinfo
-443 i386 process_madvise sys_process_madvise compat_sys_process_madvise
+443 i386 pidfd_madvise sys_pidfd_madvise compat_sys_pidfd_madvise
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index b345b35b3308..3662a0f4b682 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -363,7 +363,7 @@
440 common watch_mount sys_watch_mount
441 common watch_sb sys_watch_sb
442 common fsinfo sys_fsinfo
-443 64 process_madvise sys_process_madvise
+443 64 pidfd_madvise sys_pidfd_madvise
#
# x32-specific system call numbers start at 512 to avoid cache impact
@@ -407,4 +407,4 @@
545 x32 execveat compat_sys_execveat
546 x32 preadv2 compat_sys_preadv64v2
547 x32 pwritev2 compat_sys_pwritev64v2
-548 x32 process_madvise compat_sys_process_madvise
+548 x32 pidfd_madvise compat_sys_pidfd_madvise
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 96cb07095e4c..a2510c81ab35 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -412,4 +412,4 @@
440 common watch_mount sys_watch_mount
441 common watch_sb sys_watch_sb
442 common fsinfo sys_fsinfo
-443 common process_madvise sys_process_madvise
+443 common pidfd_madvise sys_pidfd_madvise
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 2e2f0a2700ab..f9eca29244f5 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -827,7 +827,7 @@ asmlinkage long compat_sys_pwritev64v2(unsigned long fd,
unsigned long vlen, loff_t pos, rwf_t flags);
#endif
-asmlinkage ssize_t compat_sys_process_madvise(compat_int_t which,
+asmlinkage ssize_t compat_sys_pidfd_madvise(compat_int_t which,
compat_pid_t upid, const struct compat_iovec __user *vec,
compat_ulong_t vlen, compat_int_t behavior,
compat_ulong_t flags);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 2cbd3660e8e6..5c4949606502 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -879,7 +879,7 @@ asmlinkage long sys_munlockall(void);
asmlinkage long sys_mincore(unsigned long start, size_t len,
unsigned char __user * vec);
asmlinkage long sys_madvise(unsigned long start, size_t len, int behavior);
-asmlinkage long sys_process_madvise(int which, pid_t upid,
+asmlinkage long sys_pidfd_madvise(int which, pid_t upid,
const struct iovec __user *vec, unsigned long vlen,
int behavior, unsigned long flags);
asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 6a5856c9d9b4..40dd1b66858e 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -863,9 +863,9 @@ __SYSCALL(__NR_watch_mount, sys_watch_mount)
__SYSCALL(__NR_watch_sb, sys_watch_sb)
#define __NR_fsinfo 442
__SYSCALL(__NR_fsinfo, sys_fsinfo)
-#define __NR_process_madvise 443
-__SC_COMP(__NR_process_madvise, sys_process_madvise, \
- compat_sys_process_madvise)
+#define __NR_pidfd_madvise 443
+__SC_COMP(__NR_pidfd_madvise, sys_pidfd_madvise, \
+ compat_sys_pidfd_madvise)
#undef __NR_syscalls
#define __NR_syscalls 444
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index fad48ace1123..6b7cc69617f8 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -287,8 +287,8 @@ COND_SYSCALL(mlockall);
COND_SYSCALL(munlockall);
COND_SYSCALL(mincore);
COND_SYSCALL(madvise);
-COND_SYSCALL(process_madvise);
-COND_SYSCALL_COMPAT(process_madvise);
+COND_SYSCALL(pidfd_madvise);
+COND_SYSCALL_COMPAT(pidfd_madvise);
COND_SYSCALL(remap_file_pages);
COND_SYSCALL(mbind);
COND_SYSCALL_COMPAT(mbind);
diff --git a/mm/madvise.c b/mm/madvise.c
index 35c9b220146a..d8b9e9c54275 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1008,7 +1008,7 @@ madvise_behavior_valid(int behavior)
}
static bool
-process_madvise_behavior_valid(int behavior)
+pidfd_madvise_behavior_valid(int behavior)
{
switch (behavior) {
case MADV_COLD:
@@ -1211,7 +1211,7 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
return do_madvise(current, current->mm, start, len_in, behavior);
}
-static int process_madvise_vec(struct task_struct *target_task,
+static int pidfd_madvise_vec(struct task_struct *target_task,
struct mm_struct *mm, struct iov_iter *iter, int behavior)
{
struct iovec iovec;
@@ -1229,7 +1229,7 @@ static int process_madvise_vec(struct task_struct *target_task,
return ret;
}
-static ssize_t do_process_madvise(int pidfd, struct iov_iter *iter,
+static ssize_t do_pidfd_madvise(int pidfd, struct iov_iter *iter,
int behavior, unsigned int flags)
{
ssize_t ret;
@@ -1255,7 +1255,7 @@ static ssize_t do_process_madvise(int pidfd, struct iov_iter *iter,
}
if (task->mm != current->mm &&
- !process_madvise_behavior_valid(behavior)) {
+ !pidfd_madvise_behavior_valid(behavior)) {
ret = -EINVAL;
goto release_task;
}
@@ -1266,7 +1266,7 @@ static ssize_t do_process_madvise(int pidfd, struct iov_iter *iter,
goto release_task;
}
- ret = process_madvise_vec(task, mm, iter, behavior);
+ ret = pidfd_madvise_vec(task, mm, iter, behavior);
if (ret >= 0)
ret = total_len - iov_iter_count(iter);
@@ -1278,7 +1278,7 @@ static ssize_t do_process_madvise(int pidfd, struct iov_iter *iter,
return ret;
}
-SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec,
+SYSCALL_DEFINE5(pidfd_madvise, int, pidfd, const struct iovec __user *, vec,
unsigned long, vlen, int, behavior, unsigned int, flags)
{
ssize_t ret;
@@ -1288,14 +1288,14 @@ SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec,
ret = import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack), &iov, &iter);
if (ret >= 0) {
- ret = do_process_madvise(pidfd, &iter, behavior, flags);
+ ret = do_pidfd_madvise(pidfd, &iter, behavior, flags);
kfree(iov);
}
return ret;
}
#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE5(process_madvise, compat_int_t, pidfd,
+COMPAT_SYSCALL_DEFINE5(pidfd_madvise, compat_int_t, pidfd,
const struct compat_iovec __user *, vec,
compat_ulong_t, vlen,
compat_int_t, behavior,
@@ -1310,7 +1310,7 @@ COMPAT_SYSCALL_DEFINE5(process_madvise, compat_int_t, pidfd,
ret = compat_import_iovec(READ, vec, vlen, ARRAY_SIZE(iovstack),
&iov, &iter);
if (ret >= 0) {
- ret = do_process_madvise(pidfd, &iter, behavior, flags);
+ ret = do_pidfd_madvise(pidfd, &iter, behavior, flags);
kfree(iov);
}
return ret;
--
2.26.2