hello,everyone,I'm reading LDD3.Topics about oops,it said the code bellow would cause a fault condition because "this method copies a string to a local variable,unfortunately,the string is longer than the destination array".Well,hard to understand....Is that right?I thought the fault should be caused by the wrong memset,it overwrite the function stack,the value of __user is 0xff now.will anyone tell me what happened here?Thanks;
It's writing 20 bytes to an array 4 bytes long, rampaging 16 more bytes across memory it shouldn't, trashing things like local variable values, function parameters, and return locations, all of which are kept in the same general area of stack here.
You're both right, in other words. There's many possible problems that could be caused by this, not just corruption of the return vector. If you're lucky, it crashes immediately. If you're unlucky, it puts bizarre values into your local variables and function parameters, causing behavior that's very difficult to rationally explain.
Solaris 2.6, using CDE:
agh. I accidentally set an ugly palette as my Home Session. The problem is, when I change the palette back to Default, I am informed that my change will be apparent in my next session. But when I log out and in, it's still the Ugly Palette. Doesn't matter if I set the... (1 Reply)
When ever i mount any of my 2 scsi cdroms, I get a kernel crash with the folfollowing oops kernel output.
I understand that it is impossible to anwser my question WHY but could you give me some advice where i should look to debug the problem or advice me some tools to detect what might be... (3 Replies)
I have directory/dns server running sparc solaris 9.
while troubleshooting another issue, i overwrote the aliases file on accident.
my question is: is there any way to revert this?
any help super appreciated...especially since this a production box! (2 Replies)
Hi All,
Can any one please differenciate between the Data Abstraction and Encapsulation? If possible, with code.
Thanks in Advance,
Naga:cool: (2 Replies)
I've been tearing my hair out over this: vsftp does not work on any of my RedHat Server 5.x systems - I keep getting a variation on 500 OOPS: vsftpd: cannot locate user specified in 'ftp_username':ftp or 500 OOPS: cannot locate user entry:nobody (different errors on different systems). I spent... (2 Replies)
Hi all,
When i load my block device driver in Fedoracore10 kernel 2.6.27. i got this type of error kernel panic - not syncing : Fatal exception in interrupt. I am unable to save the log file....
Can any one help me.....
regards
sundar (4 Replies)
I can belive I really did this... chmod 777 /home :eek:
I have my /home directory synced to another machine.
Can anyone tell me how to get the permissions from
back up server /home to production server /home
It's important that I dont over write the files on the... (1 Reply)
I've been fighting this for about a year: vsftp does not work on any of my RedHat Server 5.x systems - I keep getting a variation on 500 OOPS: vsftpd: cannot locate user specified in 'ftp_username':ftp or 500 OOPS: cannot locate user entry:nobody (different errors on different systems). I spent... (0 Replies)
Discussion started by: thomn8r
0 Replies
LEARN ABOUT SUNOS
memccpy
memory(3C) Standard C Library Functions memory(3C)NAME
memory, memccpy, memchr, memcmp, memcpy, memmove, memset - memory operations
SYNOPSIS
#include <string.h>
void *memccpy(void *restrict s1, const void *restrict s2, int c, size_t n);
void *memchr(const void *s, int c, size_t n);
int memcmp(const void *s1, const void *s2, size_t n);
void *memcpy(void *restrict s1, const void *restrict s2, size_t n);
void *memmove(void *s1, const void *s2, size_t n);
void *memset(void *s, int c, size_t n);
ISO C++
#include <string.h>
const void *memchr(const void *s, int c, size_t n);
#include <cstring>
void *std::memchr(void *s, int c, size_t n);
DESCRIPTION
These functions operate as efficiently as possible on memory areas (arrays of bytes bounded by a count, not terminated by a null charac-
ter). They do not check for the overflow of any receiving memory area.
The memccpy() function copies bytes from memory area s2 into s1, stopping after the first occurrence of c (converted to an unsigned char)
has been copied, or after n bytes have been copied, whichever comes first. It returns a pointer to the byte after the copy of c in s1, or a
null pointer if c was not found in the first n bytes of s2.
The memchr() function returns a pointer to the first occurrence of c (converted to an unsigned char) in the first n bytes (each interpreted
as an unsigned char) of memory area s, or a null pointer if c does not occur.
The memcmp() function compares its arguments, looking at the first n bytes (each interpreted as an unsigned char), and returns an integer
less than, equal to, or greater than 0, according as s1 is lexicographically less than, equal to, or greater than s2 when taken to be
unsigned characters.
The memcpy() function copies n bytes from memory area s2 to s1. It returns s1. If copying takes place between objects that overlap, the
behavior is undefined.
The memmove() function copies n bytes from memory area s2 to memory area s1. Copying between objects that overlap will take place cor-
rectly. It returns s1.
The memset() function sets the first n bytes in memory area s to the value of c (converted to an unsigned char). It returns s.
USAGE
Using memcpy() might be faster than using memmove() if the application knows that the objects being copied do not overlap.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO string(3C), attributes(5), standards(5)SunOS 5.10 1 Nov 2003 memory(3C)