On Sat, Jan 11, 2020 at 08:34:52AM +0100, SeongJae Park wrote: > On Fri, 10 Jan 2020 13:34:31 -0800 Minchan Kim <minchan@xxxxxxxxxx> wrote: > > > There are usecases that System Management Software(SMS) want to give > > a memory hint to other processes because it's not known to the > > application. In the case of Android, ActivityManagerService daemon > > manges app's life cycle and that daemon must be able to initiate > > reclaim on its own without any app involvement. > > > > To solve the issue, this patch introduces new syscall process_madvise(2). > > It uses pidfd of an external processs to give the hint. > > > > int process_madvise(int pidfd, void *addr, size_t length, int advise, > > unsigned long flag); > > > > Since it could affect other process's address range, only privileged > > process(CAP_SYS_PTRACE) or something else(e.g., being the same UID) > > gives it the right to ptrace the process could use it successfully. > > The flag argument is reserved for future use if we need to extend the > > API. > > > > Supporting all hints madvise has/will supported/support to process_madvise > > is rather risky. Because we are not sure all hints make sense from external > > process and implementation for the hint may rely on the caller being > > in the current context so it could be error-prone. Thus, I just limited > > hints as MADV_[COLD|PAGEOUT] in this patch. > > > > If someone want to add other hints, we could hear hear the usecase and > > review it for each hint. It's more safe for maintainace rather than > > introducing a buggy syscall but hard to fix it later. > > > > Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> > > --- > > arch/alpha/kernel/syscalls/syscall.tbl | 1 + > > arch/arm/tools/syscall.tbl | 1 + > > arch/arm64/include/asm/unistd.h | 2 +- > > arch/arm64/include/asm/unistd32.h | 2 + > > arch/ia64/kernel/syscalls/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_n64.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 | 5 +- > > kernel/sys_ni.c | 1 + > > mm/madvise.c | 64 +++++++++++++++++++++ > > 21 files changed, 89 insertions(+), 2 deletions(-) > > > > diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl > > index e56950f23b49..776c61803315 100644 > > --- a/arch/alpha/kernel/syscalls/syscall.tbl > > +++ b/arch/alpha/kernel/syscalls/syscall.tbl > > @@ -477,3 +477,4 @@ > > # 545 reserved for clone3 > > 546 common watch_devices sys_watch_devices > > 547 common openat2 sys_openat2 > > +548 common process_madvise sys_process_madvise > > diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl > > index 7fb2f4d59210..a43381542276 100644 > > --- a/arch/arm/tools/syscall.tbl > > +++ b/arch/arm/tools/syscall.tbl > > @@ -451,3 +451,4 @@ > > 435 common clone3 sys_clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +438 common process_madvise sys_process_madvise > > diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h > > index 8aa00ccb0b96..b722e47377a5 100644 > > --- a/arch/arm64/include/asm/unistd.h > > +++ b/arch/arm64/include/asm/unistd.h > > @@ -38,7 +38,7 @@ > > #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 438 > > +#define __NR_compat_syscalls 439 > > #endif > > > > #define __ARCH_WANT_SYS_CLONE > > diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h > > index 31f0ce25719e..5c82557d408f 100644 > > --- a/arch/arm64/include/asm/unistd32.h > > +++ b/arch/arm64/include/asm/unistd32.h > > @@ -883,6 +883,8 @@ __SYSCALL(__NR_clone3, sys_clone3) > > __SYSCALL(__NR_watch_devices, sys_watch_devices) > > #define __NR_openat2 437 > > __SYSCALL(__NR_openat2, sys_openat2) > > +#define __NR_openat2 438 > > Shouldn't this be '#define __NR_process_madvise 438'? > > > +__SYSCALL(__NR_process_madvise, process_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 b9aa59931905..c156abc9a298 100644 > > --- a/arch/ia64/kernel/syscalls/syscall.tbl > > +++ b/arch/ia64/kernel/syscalls/syscall.tbl > > @@ -358,3 +358,4 @@ > > # 435 reserved for clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +438 common process_madvise sys_process_madvise > > diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl > > index 868c1ef89d35..5b6034b6650f 100644 > > --- a/arch/m68k/kernel/syscalls/syscall.tbl > > +++ b/arch/m68k/kernel/syscalls/syscall.tbl > > @@ -437,3 +437,4 @@ > > # 435 reserved for clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +438 common process_madvise sys_process_madvise > > diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl > > index 544b4cef18b3..4bef584af09c 100644 > > --- a/arch/microblaze/kernel/syscalls/syscall.tbl > > +++ b/arch/microblaze/kernel/syscalls/syscall.tbl > > @@ -443,3 +443,4 @@ > > 435 common clone3 sys_clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +438 common process_madvise sys_process_madvise > > diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl > > index 05e8aee5dae7..94fbd0fcccce 100644 > > --- a/arch/mips/kernel/syscalls/syscall_n32.tbl > > +++ b/arch/mips/kernel/syscalls/syscall_n32.tbl > > @@ -376,3 +376,4 @@ > > 435 n32 clone3 __sys_clone3 > > 436 n32 watch_devices sys_watch_devices > > 437 n32 openat2 sys_openat2 > > +437 n32 process_madivse sys_process_madvise > > Shouldn't the number for the 'process_madvise' be '438' instead of '437'? > > > diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl > > index 24d6c01328fb..4e6982c429d5 100644 > > --- a/arch/mips/kernel/syscalls/syscall_n64.tbl > > +++ b/arch/mips/kernel/syscalls/syscall_n64.tbl > > @@ -352,3 +352,4 @@ > > 435 n64 clone3 __sys_clone3 > > 436 n64 watch_devices sys_watch_devices > > 437 n64 openat2 sys_openat2 > > +437 n64 process_madvise sys_process_madvise > > 438? Same for below 5 changes. > > > diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl > > index 4b5f77a4e1a2..3aa990caf9dc 100644 > > --- a/arch/parisc/kernel/syscalls/syscall.tbl > > +++ b/arch/parisc/kernel/syscalls/syscall.tbl > > @@ -435,3 +435,4 @@ > > 435 common clone3 sys_clone3_wrapper > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +437 common process_madvise sys_process_madvise > > diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl > > index 9716dc85a517..30e727a23f33 100644 > > --- a/arch/powerpc/kernel/syscalls/syscall.tbl > > +++ b/arch/powerpc/kernel/syscalls/syscall.tbl > > @@ -519,3 +519,4 @@ > > 435 nospu clone3 ppc_clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +437 common process_madvise sys_process_madvise > > diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl > > index 7da330f8b03e..75722e5ff496 100644 > > --- a/arch/s390/kernel/syscalls/syscall.tbl > > +++ b/arch/s390/kernel/syscalls/syscall.tbl > > @@ -440,3 +440,4 @@ > > 435 common clone3 sys_clone3 sys_clone3 > > 436 common watch_devices sys_watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 sys_openat2 > > +437 common process_madvise sys_process_madvise sys_process_madvise > > diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl > > index bb7e68e25337..7d7bc7befad3 100644 > > --- a/arch/sh/kernel/syscalls/syscall.tbl > > +++ b/arch/sh/kernel/syscalls/syscall.tbl > > @@ -440,3 +440,4 @@ > > # 435 reserved for clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +437 common process_madvise sys_process_madvise > > diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl > > index 646a1fad7218..581d331ff62f 100644 > > --- a/arch/sparc/kernel/syscalls/syscall.tbl > > +++ b/arch/sparc/kernel/syscalls/syscall.tbl > > @@ -483,3 +483,4 @@ > > # 435 reserved for clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +437 common process_madvise sys_process_madvise > > diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl > > index 57c53acee290..76a2c266fe7e 100644 > > --- a/arch/x86/entry/syscalls/syscall_32.tbl > > +++ b/arch/x86/entry/syscalls/syscall_32.tbl > > @@ -442,3 +442,4 @@ > > 435 i386 clone3 sys_clone3 __ia32_sys_clone3 > > 436 i386 watch_devices sys_watch_devices __ia32_sys_watch_devices > > 437 i386 openat2 sys_openat2 __ia32_sys_openat2 > > +438 i386 process_madvise sys_process_madvise __ia32_sys_process_madvise > > diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl > > index 1dd8d21f6500..b697cd8620cb 100644 > > --- a/arch/x86/entry/syscalls/syscall_64.tbl > > +++ b/arch/x86/entry/syscalls/syscall_64.tbl > > @@ -359,6 +359,7 @@ > > 435 common clone3 __x64_sys_clone3/ptregs > > 436 common watch_devices __x64_sys_watch_devices > > 437 common openat2 __x64_sys_openat2 > > +438 common process_madvise __x64_sys_process_madvise > > > > # > > # x32-specific system call numbers start at 512 to avoid cache impact > > diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl > > index 0f48ab7bd75b..2e9813ecfd7d 100644 > > --- a/arch/xtensa/kernel/syscalls/syscall.tbl > > +++ b/arch/xtensa/kernel/syscalls/syscall.tbl > > @@ -408,3 +408,4 @@ > > 435 common clone3 sys_clone3 > > 436 common watch_devices sys_watch_devices > > 437 common openat2 sys_openat2 > > +438 common process_madvise sys_process_madvise > > diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h > > index 433c8c85636e..1b58a11ff49f 100644 > > --- a/include/linux/syscalls.h > > +++ b/include/linux/syscalls.h > > @@ -877,6 +877,8 @@ 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 pidfd, unsigned long start, > > + size_t len, int behavior, unsigned long 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 33f3856a9c3c..4bcd8d366f38 100644 > > --- a/include/uapi/asm-generic/unistd.h > > +++ b/include/uapi/asm-generic/unistd.h > > @@ -856,8 +856,11 @@ __SYSCALL(__NR_watch_devices, sys_watch_devices) > > #define __NR_openat2 437 > > __SYSCALL(__NR_openat2, sys_openat2) > > > > +#define __NR_openat2 438 > > Shouldn't this be '#define __NR_process_madvise 438'? > Hi SeongJae, I fixed all you pointed out. Thanks for the review.
