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Diffstat (limited to 'subx/examples/ex12.subx')
| -rw-r--r-- | subx/examples/ex12.subx | 45 |
1 files changed, 0 insertions, 45 deletions
diff --git a/subx/examples/ex12.subx b/subx/examples/ex12.subx deleted file mode 100644 index 358da1d3..00000000 --- a/subx/examples/ex12.subx +++ /dev/null @@ -1,45 +0,0 @@ -# Example showing mmap syscall. -# Create a new segment using mmap, save the address, write to it. -# -# To run (from the subx directory): -# $ ./subx translate examples/ex12.subx -o examples/ex12 -# $ ./subx run examples/ex12 -# You shouldn't get a segmentation fault. - -== code 0x09000000 -# instruction effective address register displacement immediate -# . op subop mod rm32 base index scale r32 -# . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes - -Entry: - # syscall(mmap, 0x1000) - bb/copy-to-EBX Mmap-new-segment/imm32 - b8/copy-to-EAX 0x5a/imm32/mmap - cd/syscall 0x80/imm8 - - # write to *EAX to check that we have access to the newly-allocated segment - c7 0/subop/copy 0/mod/direct 0/rm32/EAX . . . . . 0x34/imm32 # copy to *EAX - - # syscall(exit, EAX) - 89/copy 3/mod/direct 3/rm32/EBX . . . 0/r32/EAX . . # copy EAX to EBX - b8/copy-to-EAX 1/imm32/exit - cd/syscall 0x80/imm8 - -== data 0x0a000000 - -# various constants used here were found in the Linux sources (search for file mman-common.h) -Mmap-new-segment: # type mmap_arg_struct - # addr - 0/imm32 - # len - 0x100/imm32 - # protection flags - 3/imm32 # PROT_READ | PROT_WRITE - # sharing flags - 0x22/imm32 # MAP_PRIVATE | MAP_ANONYMOUS - # fd - -1/imm32 # since MAP_ANONYMOUS is specified - # offset - 0/imm32 # since MAP_ANONYMOUS is specified - -# . . vim:nowrap:textwidth=0 |