diff mbox series

[v2,1/7] mm: Add process_vm_mmap() syscall declaration

Message ID 155836080726.2441.11153759042802992469.stgit@localhost.localdomain (mailing list archive)
State New, archived
Headers show
Series mm: process_vm_mmap() -- syscall for duplication a process mapping | expand

Commit Message

Kirill Tkhai May 20, 2019, 2 p.m. UTC 
Similar to process_vm_readv() and process_vm_writev(),
add declarations of a new syscall, which will allow
to map memory from or to another process.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
---
 arch/x86/entry/syscalls/syscall_32.tbl |    1 +
 arch/x86/entry/syscalls/syscall_64.tbl |    2 ++
 include/linux/syscalls.h               |    5 +++++
 include/uapi/asm-generic/unistd.h      |    5 ++++-
 init/Kconfig                           |    9 +++++----
 kernel/sys_ni.c                        |    2 ++
 6 files changed, 19 insertions(+), 5 deletions(-)

Comments

Ira Weiny May 21, 2019, 12:28 a.m. UTC | #1 
On Mon, May 20, 2019 at 05:00:07PM +0300, Kirill Tkhai wrote:
> Similar to process_vm_readv() and process_vm_writev(),
> add declarations of a new syscall, which will allow
> to map memory from or to another process.

Shouldn't this be the last patch in the series so that the syscall is actually
implemented first?

Ira

> 
> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
> ---
>  arch/x86/entry/syscalls/syscall_32.tbl |    1 +
>  arch/x86/entry/syscalls/syscall_64.tbl |    2 ++
>  include/linux/syscalls.h               |    5 +++++
>  include/uapi/asm-generic/unistd.h      |    5 ++++-
>  init/Kconfig                           |    9 +++++----
>  kernel/sys_ni.c                        |    2 ++
>  6 files changed, 19 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
> index ad968b7bac72..99d6e0085576 100644
> --- a/arch/x86/entry/syscalls/syscall_32.tbl
> +++ b/arch/x86/entry/syscalls/syscall_32.tbl
> @@ -438,3 +438,4 @@
>  431	i386	fsconfig		sys_fsconfig			__ia32_sys_fsconfig
>  432	i386	fsmount			sys_fsmount			__ia32_sys_fsmount
>  433	i386	fspick			sys_fspick			__ia32_sys_fspick
> +434	i386	process_vm_mmap		sys_process_vm_mmap		__ia32_compat_sys_process_vm_mmap
> diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
> index b4e6f9e6204a..46d7d2898f7a 100644
> --- a/arch/x86/entry/syscalls/syscall_64.tbl
> +++ b/arch/x86/entry/syscalls/syscall_64.tbl
> @@ -355,6 +355,7 @@
>  431	common	fsconfig		__x64_sys_fsconfig
>  432	common	fsmount			__x64_sys_fsmount
>  433	common	fspick			__x64_sys_fspick
> +434	common	process_vm_mmap		__x64_sys_process_vm_mmap
>  
>  #
>  # x32-specific system call numbers start at 512 to avoid cache impact
> @@ -398,3 +399,4 @@
>  545	x32	execveat		__x32_compat_sys_execveat/ptregs
>  546	x32	preadv2			__x32_compat_sys_preadv64v2
>  547	x32	pwritev2		__x32_compat_sys_pwritev64v2
> +548	x32	process_vm_mmap		__x32_compat_sys_process_vm_mmap
> diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
> index e2870fe1be5b..7d8ae36589cf 100644
> --- a/include/linux/syscalls.h
> +++ b/include/linux/syscalls.h
> @@ -997,6 +997,11 @@ asmlinkage long sys_fspick(int dfd, const char __user *path, unsigned int flags)
>  asmlinkage long sys_pidfd_send_signal(int pidfd, int sig,
>  				       siginfo_t __user *info,
>  				       unsigned int flags);
> +asmlinkage long sys_process_vm_mmap(pid_t pid,
> +				    unsigned long src_addr,
> +				    unsigned long len,
> +				    unsigned long dst_addr,
> +				    unsigned long flags);
>  
>  /*
>   * Architecture-specific system calls
> diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
> index a87904daf103..b7aaa5ae02da 100644
> --- a/include/uapi/asm-generic/unistd.h
> +++ b/include/uapi/asm-generic/unistd.h
> @@ -844,9 +844,12 @@ __SYSCALL(__NR_fsconfig, sys_fsconfig)
>  __SYSCALL(__NR_fsmount, sys_fsmount)
>  #define __NR_fspick 433
>  __SYSCALL(__NR_fspick, sys_fspick)
> +#define __NR_process_vm_mmap 424
> +__SC_COMP(__NR_process_vm_mmap, sys_process_vm_mmap, \
> +          compat_sys_process_vm_mmap)
>  
>  #undef __NR_syscalls
> -#define __NR_syscalls 434
> +#define __NR_syscalls 435
>  
>  /*
>   * 32 bit systems traditionally used different
> diff --git a/init/Kconfig b/init/Kconfig
> index 8b9ffe236e4f..604db5f14718 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -320,13 +320,14 @@ config POSIX_MQUEUE_SYSCTL
>  	default y
>  
>  config CROSS_MEMORY_ATTACH
> -	bool "Enable process_vm_readv/writev syscalls"
> +	bool "Enable process_vm_readv/writev/mmap syscalls"
>  	depends on MMU
>  	default y
>  	help
> -	  Enabling this option adds the system calls process_vm_readv and
> -	  process_vm_writev which allow a process with the correct privileges
> -	  to directly read from or write to another process' address space.
> +	  Enabling this option adds the system calls process_vm_readv,
> +	  process_vm_writev and process_vm_mmap, which allow a process
> +	  with the correct privileges to directly read from or write to
> +	  or mmap another process' address space.
>  	  See the man page for more details.
>  
>  config USELIB
> diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
> index 4d9ae5ea6caf..6f51634f4f7e 100644
> --- a/kernel/sys_ni.c
> +++ b/kernel/sys_ni.c
> @@ -316,6 +316,8 @@ COND_SYSCALL(process_vm_readv);
>  COND_SYSCALL_COMPAT(process_vm_readv);
>  COND_SYSCALL(process_vm_writev);
>  COND_SYSCALL_COMPAT(process_vm_writev);
> +COND_SYSCALL(process_vm_mmap);
> +COND_SYSCALL_COMPAT(process_vm_mmap);
>  
>  /* compare kernel pointers */
>  COND_SYSCALL(kcmp);
>
Kirill Tkhai May 21, 2019, 8:29 a.m. UTC | #2 
Hi, Ira,

On 21.05.2019 03:28, Ira Weiny wrote:
> On Mon, May 20, 2019 at 05:00:07PM +0300, Kirill Tkhai wrote:
>> Similar to process_vm_readv() and process_vm_writev(),
>> add declarations of a new syscall, which will allow
>> to map memory from or to another process.
> 
> Shouldn't this be the last patch in the series so that the syscall is actually
> implemented first?

It looks like there is no dependencies in the last patch to declarations made
in the first patch, so we really can move it.

I'll make this after there are accumulated some commentaries about the logic
to reduce number of patch series.

[...]

Thanks,
Kirill
diff mbox series

Patch

diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index ad968b7bac72..99d6e0085576 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -438,3 +438,4 @@ 
 431	i386	fsconfig		sys_fsconfig			__ia32_sys_fsconfig
 432	i386	fsmount			sys_fsmount			__ia32_sys_fsmount
 433	i386	fspick			sys_fspick			__ia32_sys_fspick
+434	i386	process_vm_mmap		sys_process_vm_mmap		__ia32_compat_sys_process_vm_mmap
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index b4e6f9e6204a..46d7d2898f7a 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -355,6 +355,7 @@ 
 431	common	fsconfig		__x64_sys_fsconfig
 432	common	fsmount			__x64_sys_fsmount
 433	common	fspick			__x64_sys_fspick
+434	common	process_vm_mmap		__x64_sys_process_vm_mmap
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact
@@ -398,3 +399,4 @@ 
 545	x32	execveat		__x32_compat_sys_execveat/ptregs
 546	x32	preadv2			__x32_compat_sys_preadv64v2
 547	x32	pwritev2		__x32_compat_sys_pwritev64v2
+548	x32	process_vm_mmap		__x32_compat_sys_process_vm_mmap
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index e2870fe1be5b..7d8ae36589cf 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -997,6 +997,11 @@  asmlinkage long sys_fspick(int dfd, const char __user *path, unsigned int flags)
 asmlinkage long sys_pidfd_send_signal(int pidfd, int sig,
 				       siginfo_t __user *info,
 				       unsigned int flags);
+asmlinkage long sys_process_vm_mmap(pid_t pid,
+				    unsigned long src_addr,
+				    unsigned long len,
+				    unsigned long dst_addr,
+				    unsigned long flags);
 
 /*
  * Architecture-specific system calls
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index a87904daf103..b7aaa5ae02da 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -844,9 +844,12 @@  __SYSCALL(__NR_fsconfig, sys_fsconfig)
 __SYSCALL(__NR_fsmount, sys_fsmount)
 #define __NR_fspick 433
 __SYSCALL(__NR_fspick, sys_fspick)
+#define __NR_process_vm_mmap 424
+__SC_COMP(__NR_process_vm_mmap, sys_process_vm_mmap, \
+          compat_sys_process_vm_mmap)
 
 #undef __NR_syscalls
-#define __NR_syscalls 434
+#define __NR_syscalls 435
 
 /*
  * 32 bit systems traditionally used different
diff --git a/init/Kconfig b/init/Kconfig
index 8b9ffe236e4f..604db5f14718 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -320,13 +320,14 @@  config POSIX_MQUEUE_SYSCTL
 	default y
 
 config CROSS_MEMORY_ATTACH
-	bool "Enable process_vm_readv/writev syscalls"
+	bool "Enable process_vm_readv/writev/mmap syscalls"
 	depends on MMU
 	default y
 	help
-	  Enabling this option adds the system calls process_vm_readv and
-	  process_vm_writev which allow a process with the correct privileges
-	  to directly read from or write to another process' address space.
+	  Enabling this option adds the system calls process_vm_readv,
+	  process_vm_writev and process_vm_mmap, which allow a process
+	  with the correct privileges to directly read from or write to
+	  or mmap another process' address space.
 	  See the man page for more details.
 
 config USELIB
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 4d9ae5ea6caf..6f51634f4f7e 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -316,6 +316,8 @@  COND_SYSCALL(process_vm_readv);
 COND_SYSCALL_COMPAT(process_vm_readv);
 COND_SYSCALL(process_vm_writev);
 COND_SYSCALL_COMPAT(process_vm_writev);
+COND_SYSCALL(process_vm_mmap);
+COND_SYSCALL_COMPAT(process_vm_mmap);
 
 /* compare kernel pointers */
 COND_SYSCALL(kcmp);