Re: [PATCH] siginfo: add signal info for seccomp related SIGSYS

[Bernhard Reutner-Fischer]

On Sun, May 17, 2015 at 10:49:23PM +0200, Daniel Golle wrote:
> uClibc doesn't define signal info for the SIGSYS signal which is issued
> in case of hitting a syscall prohibited by seccomp.
> This is sad as it makes debugging seccomp filter policies impossible on
> some architectures (at least ARM and PowerPC, maybe also others) which
> do not coincidentally set si_value.sival_int as the syscall number.
> 
> To fix this, import the definitions and macros needed from glibc.

Applied, thanks!
___
uClibc mailing list
uClibc@uclibc.org
http://lists.busybox.net/mailman/listinfo/uclibc

[PATCH] siginfo: add signal info for seccomp related SIGSYS

[Daniel Golle]

uClibc doesn't define signal info for the SIGSYS signal which is issued
in case of hitting a syscall prohibited by seccomp.
This is sad as it makes debugging seccomp filter policies impossible on
some architectures (at least ARM and PowerPC, maybe also others) which
do not coincidentally set si_value.sival_int as the syscall number.

To fix this, import the definitions and macros needed from glibc.

Signed-off-by: Daniel Golle 
---
Patch was also submitted to openwrt-devel, see
http://patchwork.ozlabs.org/patch/473215/
---
 libc/sysdeps/linux/alpha/bits/siginfo.h  | 11 +++
 libc/sysdeps/linux/common/bits/siginfo.h | 11 +++
 libc/sysdeps/linux/ia64/bits/siginfo.h   | 11 +++
 libc/sysdeps/linux/mips/bits/siginfo.h   | 11 +++
 libc/sysdeps/linux/sparc/bits/siginfo.h  | 11 +++
 5 files changed, 55 insertions(+)

diff --git a/libc/sysdeps/linux/alpha/bits/siginfo.h 
b/libc/sysdeps/linux/alpha/bits/siginfo.h
index 0a37ad0..7e476aa 100644
--- a/libc/sysdeps/linux/alpha/bits/siginfo.h
+++ b/libc/sysdeps/linux/alpha/bits/siginfo.h
@@ -97,6 +97,14 @@ typedef struct siginfo
int si_band;/* Band event for SIGPOLL.  */
int si_fd;
  } _sigpoll;
+
+   /* SIGSYS.  */
+   struct
+ {
+   void *_call_addr;   /* Calling user insn.  */
+   int _syscall;   /* Triggering system call number.  */
+   unsigned int _arch; /* AUDIT_ARCH_* of syscall.  */
+ } _sigsys;
   } _sifields;
   } siginfo_t;
 
@@ -115,6 +123,9 @@ typedef struct siginfo
 # define si_addr   _sifields._sigfault.si_addr
 # define si_band   _sifields._sigpoll.si_band
 # define si_fd _sifields._sigpoll.si_fd
+# define si_call_addr  _sifields._sigsys._call_addr
+# define si_syscall_sifields._sigsys._syscall
+# define si_arch   _sifields._sigsys._arch
 
 
 /* Values for `si_code'.  Positive values are reserved for kernel-generated
diff --git a/libc/sysdeps/linux/common/bits/siginfo.h 
b/libc/sysdeps/linux/common/bits/siginfo.h
index c26e066..724f756 100644
--- a/libc/sysdeps/linux/common/bits/siginfo.h
+++ b/libc/sysdeps/linux/common/bits/siginfo.h
@@ -103,6 +103,14 @@ typedef struct siginfo
long int si_band;   /* Band event for SIGPOLL.  */
int si_fd;
  } _sigpoll;
+
+   /* SIGSYS.  */
+   struct
+ {
+   void *_call_addr;   /* Calling user insn.  */
+   int _syscall;   /* Triggering system call number.  */
+   unsigned int _arch; /* AUDIT_ARCH_* of syscall.  */
+ } _sigsys;
   } _sifields;
   } siginfo_t;
 
@@ -121,6 +129,9 @@ typedef struct siginfo
 # define si_addr   _sifields._sigfault.si_addr
 # define si_band   _sifields._sigpoll.si_band
 # define si_fd _sifields._sigpoll.si_fd
+# define si_call_addr  _sifields._sigsys._call_addr
+# define si_syscall_sifields._sigsys._syscall
+# define si_arch   _sifields._sigsys._arch
 
 
 /* Values for `si_code'.  Positive values are reserved for kernel-generated
diff --git a/libc/sysdeps/linux/ia64/bits/siginfo.h 
b/libc/sysdeps/linux/ia64/bits/siginfo.h
index 3ac988b..df18b36 100644
--- a/libc/sysdeps/linux/ia64/bits/siginfo.h
+++ b/libc/sysdeps/linux/ia64/bits/siginfo.h
@@ -102,6 +102,14 @@ typedef struct siginfo
long int si_band;   /* Band event for SIGPOLL.  */
int si_fd;
  } _sigpoll;
+
+   /* SIGSYS.  */
+   struct
+ {
+   void *_call_addr;   /* Calling user insn.  */
+   int _syscall;   /* Triggering system call number.  */
+   unsigned int _arch; /* AUDIT_ARCH_* of syscall.  */
+ } _sigsys;
   } _sifields;
   } siginfo_t;
 
@@ -120,6 +128,9 @@ typedef struct siginfo
 # define si_addr   _sifields._sigfault.si_addr
 # define si_band   _sifields._sigpoll.si_band
 # define si_fd _sifields._sigpoll.si_fd
+# define si_call_addr  _sifields._sigsys._call_addr
+# define si_syscall_sifields._sigsys._syscall
+# define si_arch   _sifields._sigsys._arch
 
 # ifdef __USE_GNU
 #  define si_imm   _sifields._sigfault._si_imm
diff --git a/libc/sysdeps/linux/mips/bits/siginfo.h 
b/libc/sysdeps/linux/mips/bits/siginfo.h
index 5199d4d..b204301 100644
--- a/libc/sysdeps/linux/mips/bits/siginfo.h
+++ b/libc/sysdeps/linux/mips/bits/siginfo.h
@@ -108,6 +108,14 @@ typedef struct siginfo
long int si_band;   /* Band event for SIGPOLL.  */
int si_fd;
  } _sigpoll;
+
+   /* SIGSYS.  */
+   struct
+ {
+   void *_call_addr;   /* Calling user insn.  */
+   int _syscall;   /* Triggering system call number.  */
+   unsigned int _arch; /* AUDIT_ARCH_* of syscall.  */
+ } _sigsys;
   } _sifields;
   } siginfo_t;
 
@@ -127,6 +135,9 @@ typedef struct siginfo
 # define si_addr_lsb   _sifields._sigfault.si_addr_lsb
 # define si_band   _sifields._sigpoll.si_band
 # define si_fd