Unable to build sysdig module on 5.0 kernels

[ Impact ]

 * The DKMS package fails to install on 5.0 kernels.

[ Test Case ]

 * Install the 'sysdig-dkms' package. It should build and install without any compilation failures.

[ Proposed Fix ]

 * Port the following patches:
   - https://github.com/draios/sysdig/commit/2c8f0263382bf64800faec5fba5cc3e005d9fb1e.patch
   - https://github.com/draios/sysdig/commit/3248bf70d677abe6f60bb9f8275a774600ed77e8.patch

Note: No real context adjustments required, offset updates were required to apply the patch to fixup the syscall table; "quilt refresh" updated offsets on the patch that was already in the package.

[ Regression Potential ]

 * Low. These changes are conditionally compiled.

[ Testing ]

The following instructions were used to test these changes on the 4.15 kernel that Bionic 18.04 ships with as well as the 5.0 kernel that is included in the HWE edge package on an amd64 environment.

- Create a Bionic 18.04 VM
- Enable the "-proposed" repository and install the linux-generic-hwe-18.04-edge package or install the .debs from here: https://launchpad.net/~canonical-kernel-team/+archive/ubuntu/ppa/+packages?field.name_filter=linux-hwe-edge&field.status_filter=published&field.series_filter=bionic
- Install "sysdig-dkms" and confirm that installation fails because the module cannot be compiled
- Remove the failed install "sudo apt remove sysdig-dkms"
- Pull the sources with "pull-lp-source sysdig bionic"
- Apply the debdiff with "debdiff-apply < path-to-file.debdiff"
- Build the package with "debuild -b -uc -us"
- Install the package produced from the previous step with "sudo dpkg -i path-to-file.deb"
- Verify the installation completed successfully. You can also check to see if it appears with "sudo dkms status"

---

ubuntu_sysdig_smoke_test failed because the module cannot be built on Bionic 5.0.0 kernel:

 Error! Bad return status for module build on kernel: 5.0.0-13-generic (x86_64)
 Consult /var/lib/dkms/sysdig/0.19.1/build/make.log for more information.
 Setting up libjsoncpp1:amd64 (1.7.4-3) ...
 Setting up sysdig (0.19.1-1ubuntu1) ...
 Processing triggers for libc-bin (2.27-3ubuntu1) ...
'dkms status -m sysdig | grep installed'
'cat /var/lib/dkms/sysdig/*/build/make.log'
 DKMS make.log for sysdig-0.19.1 for kernel 5.0.0-13-generic (x86_64)
 Thu Apr 25 14:14:16 UTC 2019
 make: Entering directory '/usr/src/linux-headers-5.0.0-13-generic'
 CC [M] /var/lib/dkms/sysdig/0.19.1/build/main.o
 CC [M] /var/lib/dkms/sysdig/0.19.1/build/dynamic_params_table.o
 CC [M] /var/lib/dkms/sysdig/0.19.1/build/flags_table.o
 CC [M] /var/lib/dkms/sysdig/0.19.1/build/ppm_events.o
 CC [M] /var/lib/dkms/sysdig/0.19.1/build/ppm_fillers.o
 CC [M] /var/lib/dkms/sysdig/0.19.1/build/event_table.o
 CC [M] /var/lib/dkms/sysdig/0.19.1/build/syscall_table.o
 CC [M] /var/lib/dkms/sysdig/0.19.1/build/ppm_cputime.o
 /var/lib/dkms/sysdig/0.19.1/build/main.c: In function ‘page_fault_probe’:
 /var/lib/dkms/sysdig/0.19.1/build/main.c:2045:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 struct event_data_t event_data;
 ^~~~~~
 /var/lib/dkms/sysdig/0.19.1/build/ppm_events.c: In function ‘ppm_copy_from_user’:
 /var/lib/dkms/sysdig/0.19.1/build/ppm_events.c:99:48: error: macro "access_ok" passed 3 arguments, but takes just 2
 if (likely(ppm_access_ok(VERIFY_READ, from, n)))
 ^
 In file included from ./include/linux/export.h:45:0,
 from ./include/linux/linkage.h:7,
 from ./arch/x86/include/asm/cache.h:5,
 from ./include/linux/cache.h:6,
 from ./include/linux/time.h:5,
 from ./include/linux/compat.h:10,
 from /var/lib/dkms/sysdig/0.19.1/build/ppm_events.c:21:
 /var/lib/dkms/sysdig/0.19.1/build/ppm_events.c:59:23: error: ‘access_ok’ undeclared (first use in this function); did you mean ‘access_flags’?
 #define ppm_access_ok access_ok
 ^
 ./include/linux/compiler.h:76:40: note: in definition of macro ‘likely’
 # define likely(x) __builtin_expect(!!(x), 1)
 ^
 /var/lib/dkms/sysdig/0.19.1/build/ppm_events.c:99:13: note: in expansion of macro ‘ppm_access_ok’
 if (likely(ppm_access_ok(VERIFY_READ, from, n)))
 ^~~~~~~~~~~~~
 /var/lib/dkms/sysdig/0.19.1/build/ppm_events.c:59:23: note: each undeclared identifier is reported only once for each function it appears in
 #define ppm_access_ok access_ok
 ^
 ./include/linux/compiler.h:76:40: note: in definition of macro ‘likely’
 # define likely(x) __builtin_expect(!!(x), 1)
 ^
 /var/lib/dkms/sysdig/0.19.1/build/ppm_events.c:99:13: note: in expansion of macro ‘ppm_access_ok’
 if (likely(ppm_access_ok(VERIFY_READ, from, n)))
 ^~~~~~~~~~~~~
 /var/lib/dkms/sysdig/0.19.1/build/ppm_events.c: In function ‘ppm_strncpy_from_user’:
 /var/lib/dkms/sysdig/0.19.1/build/ppm_events.c:130:54: error: macro "access_ok" passed 3 arguments, but takes just 2
 if (!ppm_access_ok(VERIFY_READ, from, bytes_to_read)) {
 ^
 /var/lib/dkms/sysdig/0.19.1/build/ppm_events.c:59:23: error: ‘access_ok’ undeclared (first use in this function); did you mean ‘access_flags’?
 #define ppm_access_ok access_ok
 ^
 /var/lib/dkms/sysdig/0.19.1/build/ppm_events.c:130:8: note: in expansion of macro ‘ppm_access_ok’
 if (!ppm_access_ok(VERIFY_READ, from, bytes_to_read)) {
 ^~~~~~~~~~~~~
 scripts/Makefile.build:284: recipe for target '/var/lib/dkms/sysdig/0.19.1/build/ppm_events.o' failed
 make[1]: *** [/var/lib/dkms/sysdig/0.19.1/build/ppm_events.o] Error 1
 make[1]: *** Waiting for unfinished jobs....
 Makefile:1584: recipe for target '_module_/var/lib/dkms/sysdig/0.19.1/build' failed
 make: *** [_module_/var/lib/dkms/sysdig/0.19.1/build] Error 2
 make: Leaving directory '/usr/src/linux-headers-5.0.0-13-generic'