README.fragment.md

ltool: a set of simple tools

This repository contains few tools that I wrote over the years to check something once. They are kind of like my throw-away shell scripts, only in C and for low-level stuff. They are not big enough nor important enough to have their own repository, but still, they needed too much energy to stay in /tmp, so here they are.

Those tools are mainly linux/x86 oriented.

• bufpipe: buffer stdin to be used as a regular file
• close_range: close a range of file descriptors
• coredump_filter: get/set coredump_filter flags
• cpuid: pretty print information from the CPUID instruction
• dumpauxv: pretty print a auxv file
• dumpvdso: dump vDSO (wip)
• fxsave: pretty print the result of FXSAVE x86 instruction
• getpid32: print pid and wait
• getpid: print self or parent pid
• get_ss: print segment selectors
• hpet: get info about local hpet (wip)
• lsholes: show holes/data in sparse files
• mem_cat: dump memory of another process (wip)
• memfd_secret: open a memfd_secret fd for the provided command
• mmapable: tell if a file supports the mmap file operation
• parse_segm: convert x86 segmented address to linear address
• rdpid: read the processor ID with RDPID x86 instruction
• rdrand: print random numbers generated with the RDRAND instruction
• rdtsc: print RDTSC
• readcmos: read the CMOS clock register
• readio: read an io port
• segm2linear: convert an x86 real-mode segmented address to a linear address
• setcpuid: enable or disable CPUID instruction
• set_no_new_privs: set the no_new_privs thread attribute
• set_ptracer: set this process ptracer
• set_tsc: cause SIGSEGV when the process tries to read timestamp counter
• sgdt: get the base and limit of SGDT, SLDT, SIDT, and STR instructions
• smsw: pretty print the result of the SMSW instruction
• speculation: control the process speculation configuration
• statvfs: get filesystem statistics
• udpsend: send something over UDP
• vmcall: execute vmcall instruction in userland (fails)
• writeio: write to an io port
• x86_int: execute INT instruction
• xgetbv: pretty print the result of the XGETBV instruction

Dependencies

• scdoc for documentation
• pandoc to update README.md

Utils