Hi Christian,
On Tue, May 19, 2020 at 09:45:18AM +0200, Christian Brauner wrote:
> On Fri, May 15, 2020 at 06:20:55PM -0700, Minchan Kim wrote:
> > 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 process_madvise(int pidfd, const struct iovec *iovec,
> > unsigned long vlen, int advice, unsigned int flags);
> >
> > DESCRIPTION
> > The process_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 process_madvise supports every advice madvise(2) has if target
> > process is in same thread group with calling process so user could
> > use process_madvise(2) to extend existing madvise(2) to support
> > vector address ranges.
> >
> > RETURN VALUE
> > On success, process_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>
>
> Thanks for the ping Minchan, and sorry for not replying earlier to this.
>
> Also, sorry that i delayed the patch but this here really seems a way
> cleaner api to me and feels less hackish. In general this patch seems
> fine to me.
Thanks.
> But two comments below:
>
> > ---
> > mm/madvise.c | 42 +++++++++++++-----------------------------
> > 1 file changed, 13 insertions(+), 29 deletions(-)
> >
> > diff --git a/mm/madvise.c b/mm/madvise.c
> > index d3fbbe52d230..35c9b220146a 100644
> > --- a/mm/madvise.c
> > +++ b/mm/madvise.c
> > @@ -1229,8 +1229,8 @@ static int process_madvise_vec(struct task_struct *target_task,
> > return ret;
> > }
> >
> > -static ssize_t do_process_madvise(int which, pid_t upid, struct iov_iter *iter,
> > - int behavior, unsigned long flags)
> > +static ssize_t do_process_madvise(int pidfd, struct iov_iter *iter,
> > + int behavior, unsigned int flags)
> > {
> > ssize_t ret;
> > struct pid *pid;
> > @@ -1241,26 +1241,12 @@ static ssize_t do_process_madvise(int which, pid_t upid, struct iov_iter *iter,
> > if (flags != 0)
> > return -EINVAL;
> >
> > - switch (which) {
> > - case P_PID:
> > - if (upid <= 0)
> > - return -EINVAL;
> > -
> > - pid = find_get_pid(upid);
> > - if (!pid)
> > - return -ESRCH;
> > - break;
> > - case P_PIDFD:
> > - if (upid < 0)
> > - return -EINVAL;
> > -
> > - pid = pidfd_get_pid(upid);
> > - if (IS_ERR(pid))
> > - return PTR_ERR(pid);
> > - break;
> > - default:
> > + if (pidfd < 0)
> > return -EINVAL;
>
> When garbage file descriptors are passed EBADF needs to be returned, not
> EINVAL. That's the case with most apis and also with pidfds, compare:
True. Let me cook a patch for that.
>
> int main(void)
> {
>
> if (syscall(__NR_openat, -1, "tmp", O_RDONLY) < 0)
> printf("%m - openat(-1)\n");
>
> if (syscall(__NR_fcntl, -1, F_GETFL) < 0)
> printf("%m - fcntl(-1)\n");
>
> if (syscall(__NR_dup, -1) < 0)
> printf("%m - dup(-1)\n");
>
> if (syscall(__NR_close, -1) < 0)
> printf("%m - close(-1)\n");
>
> if (syscall(__NR_pidfd_getfd, -1, 0) < 0)
> printf("%m - pidfd_getfd(-1)\n");
>
> if (syscall(__NR_pidfd_send_signal, -1, 0, NULL, 0) < 0)
> printf("%m - pidfd_getfd(-1)\n");
>
> exit(EXIT_SUCCESS);
> }
>
> which all give:
>
> Bad file descriptor - openat(-1)
> Bad file descriptor - fcntl(-1)
> Bad file descriptor - dup(-1)
> Bad file descriptor - close(-1)
> Bad file descriptor - pidfd_getfd(-1)
> Bad file descriptor - pidfd_send_signal(-1)
>
> In addition, I have one more request/proposal. I really think that
> consistent api naming is something we should consider so I'd propose:
>
> From eef84697f1f19be4de1416d7d86975c319620569 Mon Sep 17 00:00:00 2001
> From: Christian Brauner <christian.brauner@xxxxxxxxxx>
> Date: Tue, 19 May 2020 08:26:07 +0200
> Subject: [PATCH] mm: retain consistent pidfd syscall naming
>
> 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 agree if the syscall aimed for creating the particular fd(e.g., pidfd_open,
pidfd_getfd, timefd_create, memfd_create, eventfd, signalfd).
However, this process_madvise is not the case. Since fd is general concept
to cover various type's resources's handle, API naming doesn't follow the
particular type since they are created/opened in general.
I think it's more consistent with other APIs in the Linux since we follow
general concept.
>
> 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
>
