2024 Call memset plt

Call memset plt

Author: ulgj

August undefined, 2024

WebMay 26, 2012 · GCC does this automatically when the size is both known and small. However, GCC maps calls to memset () with a random length through a call to memset () via the PLT, which causes a branch misprediction since the branch predictor cache is cold. Is there a way to force GCC to do what I want (outside of inline assembly)? WebDec 14, 2024 · main: # @main push rbp mov rbp, rsp sub rsp, 32 mov byte ptr [rbp - 1], 1 lea rdi, [rbp - 32] xor esi, esi mov edx, 16 call memset@PLT xor eax, eax add rsp, 32 pop rbp ret Most of which is generated for setting the jump table. No branches here. Here, I compare the speed of the two approaches with -O0.

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WebOct 13, 2024 · The call is in range of a jal instruction when relaxed. Further relaxation causes the .text target address to decrease. An alignment directlve between .init.text and .text means that the .init.text starting address does not decrease during relaxation. Normally, the difference between two code addresses can only decrease during relaxation. WebSep 7, 2011 · 5. open takes an integer as the second parameter (you're getting it confused with fopen ). Your open line should be: fd = open ("/dev/chardev", O_RDWR); The … hold on q1

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Web通过使用与位置无关的代码以及PLT和全局偏移表(GOT)，对函数 printf@plt (在PLT中)的第一次调用是一个多阶段操作，其中将发生以下操作：您在PLT中调用 printf@plt 。它调 … WebAug 27, 2024 · call void @ llvm.memset.p0i8.i64(i8* nonnull %0, i8 0, i64 256, i32 16, i1 false) which then gets lowered to a libcall, causing your failure. On x86-64 Linux, FWIW, I don't see a call to memset@PLT (but the call to @ llvm.memset is there at the end of the optimizer), arguably because the memset is lowered to something else in the … WebMar 10, 2015 · Consistent with your comment on the other answer, the call to drop for the String that was left alone occurs after the "leaving inner scope" println. That does seem consistent with one's expectation that the y's scopes extend to the end of their block. ... (%rbp), %rdi movq %rdi, -152(%rbp) movq %rcx, %rdi callq memset@PLT jmp … hudson valley regional airport address

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WebApr 19, 2024 · However, the gcc still call memset with the code below: ```test.c #include struct Page_Table_Page { uint64_t pts[511][512]; }; void init_ptp(struct Page_Table_Page*const ptp) { *ptp=(struct Page_Table_Page){{{0}}}; } ``` compile with: ``` gcc-12 -O3 test.c -S -fno-tree-loop-distribute-patterns -fno-builtin-memset -fno-builtin ... WebFeb 16, 2010 · 0x001200f0: main+0x0540: call app_main dbx) dis 0x001200f0 dbx: warning: unknown language, 'ansic' assumed 0x001200f0: main+0x0540: call app_main … hudson valley regional airport airlinesWebMar 31, 2024 · Consider the following constructor: struct Foo([u8; 512]); impl Foo { fn new() -> Foo { Foo([42u8; 512]) } } (stupid newtype with large and stupid content to trigger a … hold on record csn

"WebAs we can see, call printf@plt will first go into the .plt sections. In this section, we found that it will dereference an pointer (rip+0x200c12) and jmp to it. We found that it will jump to the next instruction as shown in the … " - Call memset plt

Call memset plt

WebMar 31, 2024 · Consider the following constructor: struct Foo([u8; 512]); impl Foo { fn new() -> Foo { Foo([42u8; 512]) } } (stupid newtype with large and stupid content to trigger a recognizable memset call) Now, let's say we use the constructor in so...

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WebSep 8, 2015 · Product Actions Automate any workflow Packages Host and manage packages Security Find and fix vulnerabilities Codespaces Instant dev environments Copilot Write better code with AI Code review Manage code changes Issues Plan and track work Discussions Collaborate outside of code Explore WebApr 18, 2024 · example::foo: push rbx mov eax, 4096 call __rust_probestack sub rsp, rax mov rdi, rsp xor esi, esi mov edx, 4096 call memset@PLT mov edi, 4096 mov esi, 1 call __rust_alloc@PLT mov rbx, rax test rbx, rbx je.LBB1_1 mov rsi, rsp mov edx, 4096 mov rdi, rbx call memcpy@PLT mov rax, rbx add rsp, 4096 pop rbx ret.LBB1_1: call …

WebOct 13, 2024 · The call is in range of a jal instruction when relaxed. Further relaxation causes the .text target address to decrease. An alignment directlve between .init.text and … WebJan 18, 2007 · That's not a bug. Unlike x86-64, on i?86 when calling (or jumping to) a PLT slot in position independent code %ebx must be set to the calling function's PIC pointer. …

WebJun 26, 2024 · I am working with the matrix-matrix multiplication and I noticed that if I use 2D arrays, A[M][N], insted of 1D arrays to store a matrix, the access to that takes less time against the locality principle. WebAug 8, 2024 · 80484 b2: 68 54 85 04 08 push 0x8048554 80484 b7: e8 24 fe ff ff call 80482e0 < printf @ plt > # Verify in GDB (gdb) x / s 0x8048554 0x8048554: "%s argument\n" So the main function isn’t very interesting it just checks to see if the argument isn’t null otherwise calls func with the argument from the command line.

WebFeb 23, 2015 · - 'creds' value is address in _talloc_zero () after call memset@plt (saved pc) Ubuntu 12.04 x86 (samba 3.6.3): (confirmed code execution) - 'creds' value is '_ptr_server_name' value in ndr_pull_netr_ServerPasswordSet () function Ubuntu 12.04 x64 (samba 3.6.3): (only look at assembly, no test)

WebJul 30, 2013 · The problem isn't in the construction, the problem is that the memset doesn't really care what you are feeding into it, and will simply splat straight over anything you … hudson valley regional airport ed roseWebContribute to chaoshuaihaohao/demo development by creating an account on GitHub. hold on rqWebFeb 16, 2010 · 0x001200f0: main+0x0540: call app_main dbx) dis 0x001200f0 dbx: warning: unknown language, 'ansic' assumed 0x001200f0: main+0x0540: call app_main 0x001200f4: main+0x0544: ld [%fp + 0x4c], %o2 ... 0x0008a750: helloworld+0x0020: call memset [PLT] dbx) dis 0x0008a750 0x0008a750: helloworld+0x0020: call memset … hold on roblox id codeWebAug 19, 2013 · When I disassemble a .so file, How IDA Pro can show the information of a libc function (such as: memset) like this:.plt:000184D8 ; ===== S U B R O U T I N E ... hudson valley regional airport codeWebSep 29, 2016 · If I call memset on the resulting pointer, however, the initialization works just fine: (gdb) call memset (0x8d9d50, 0, 32) $89 = 9280848 (gdb) x/8xw 0x8d9d50 0x8d9d50: 0x00000000 0x00000000 0x00000000 0x00000000 0x8d9d60: 0x00000000 0x00000000 0x00000000 0x00000000 c gdb Share Improve this question Follow asked Sep 29, 2016 … hold on red beardWebAug 7, 2024 · Maybe worth to note that for large ranges (>256 items, apparently) the compiler actually emits a call to memset. – MB-F Aug 8, 2024 at 7:46 I could not … hold on quotes for loveWebNov 24, 2016 · It depends on your compiler. It shouldn't be any slower than calling memset () (because calling memset () is one option available to the compiler). The initializer is easier to read than imperatively overwriting the array; it also adapts well if the element type is changed to something where all-bit-zero isn't what you want. As an experiment ... holdon rapsaw