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Questions tagged [mprotect]

88 questions
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Android mprotect() not changing protections

I've been trying to use mprotect() to change protections on a certain region of memory on Android. However whatever I do I cannot cause the region to be writeable (whatever I do it still seems to remain PROT_READ|PROT_EXEC. Maybe there's something…
David Kaplan
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Hook function call linux mint

some days ago I wrote a simple hook/detour by patching a single call instruction. It worked on Ubuntu 12.xyz (32bit), now I updated to Linux Mint 17.1(32bit) and I get Segmentation fault. I have two projects target project which calls a function…
al-eax
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C SIGSEGV Handler & Mprotect

I'm constructing a program which uses mprotect() to restrict a block of memory from accessing. When the memory is requested, a SIGSEGV is thrown which I listen for using a signal() call. Once the SIGSEGV has been detected, I need to somehow access…
pws5068
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C - Is it possible to mprotect something less than a page

And I'm really looking for any solution to this - my goal is to set an area smaller than the system's page size to PROT_READ, PROT_WRITE, PROT_EXEC or PROT_NONE. Is this possible? It seems mprotect just protects a multiple of the page size... If…
user3475234
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`mprotect`ing a custom ELF section leads to segmentation fault

I have come across this interesting StackOverflow post: How do you get the start and end addresses of a custom ELF section? and I thought whether it might be possible to apply mprotect() to the function which is stored in the custom ELF…
Jay
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how to get protection flags of a memory area, flags are PROT_READ /PROT_EXEC in mprotect

I use mprotect() to set protection flags to a memory area. Later on, I want to restore this memory area's protection flags. My question is, how to get protection flags of a memory area? the flags inclue PROT_READ ... My workaround is to parse…
flyingbin
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mprotect API on OS X Tiger

I'm trying to use mprotect API on MacOSX 10.4 (tiger), I tried every possible way I know , it always returns -1, with errno 13, which means "permission denied" while I'm trying to add the write permission to some executable code. The same code…
Danial
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Make all pages readable/writable/executable

I would like to grant full permissions (read, write, and execute) to all memory pages in an ELF binary. Ideally, I'd like to be able to do this as a transformation on a binary or object file, in the same way that symbols can be changed with objcopy.…
IanPudney
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Injected mprotect system call into traced process fails with EFAULT

I'm injecting an mprotect call into a traced process: static int inject_mprotect(pid_t child, void *addr, size_t len, int prot) { // Machine code: // int $0x80 (system call) // int3 (trap) char code[] =…
Chiggs
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How to get current program counter inside mprotect handler and update it

I want to get the current program counter(PC) value inside mprotect handler. From there I want to increase the value of PC by 'n' number of instruction so that the program will skip some instructions. I want to do all that for linux kernel version…
azizulhakim
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mprotect does not always collapse adjacent lines in /proc/pid/maps

I have a process where, after some time, a call to mprotect() fails with ENOMEM. The error is caused by "Internal kernel structures could not be allocated": at this point, the file /proc//maps contains 65531 lines, which is of course…
Armin Rigo
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Protecting allocated memory

I need to allocate dynamically some portions of memory, each with some protection - either RW or RX. I tried to allocate memory by malloc, but mprotect always returns -1 Invalid argument. My sample code: void *x = malloc(getpagesize()); mprotect(x,…
Ari
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C write/read detection on memory block

i like to ask if someone have any idea how to detect a write on alloc memory address. At first i used mprotect along with sigaction to force a segmentation fault when was made a write/read operation. Two negative factor with this approach among…
Majao
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SIGSEGV handler and mprotect and looping effect when injecting instructions at runtime. Handler can't get info->si_addr

I have looked at the various topics relating to this, but couldn't find this specific issue I am having. Things I looked at: Injecting code into executable at runtime C SIGSEGV Handler & Mprotect Can I write-protect every page in the address space…
Setzer
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run `make qemu` got error: `qemu_mprotect__osdep: mprotect failed: Permission denied`

I am trying do mit6.828 lab on mac m1. After installed riscv-tool-chain, I tried to run make qemu which seems to be used start the kernel, but at first I got this error: mkfs/mkfs fs.img README user/xargstest.sh user/_cat user/_echo user/_forktest…
Rezero
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