Imagelibrary/binutils-gdb
1
0
Fork 1
mirror of https://github.com/bminor/binutils-gdb.git synced 2025-11-16 12:34:43 +00:00
Code Issues Packages Projects Releases Wiki Activity

gdbreplay: Calculate the checksum if missing

Browse Source 
Recalculate the checksum and replace whatever is at the end
of the packet with the newly calculated checksum. Then
replay the packet with the checksum added.

The motivation for this change is that I'd like to add a TCL test
which starts a communication with gdbsever setting the remotelog file.
Then, it modifies the remotelog, injects an error message instead of
the expected replay to some packet in order to test GDB reacts to
the error response properly.

Approved-By: Tom Tromey <tom@tromey.com>
This commit is contained in:
Alexandra Hájková
2024-11-18 17:23:33 +01:00
parent 3b00205cd8
commit 280cdb642b
1 changed files with 48 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

52
gdbserver/gdbreplay.cc
View File

@@ -402,6 +402,20 @@ expect (FILE *fp)
}
}
/* Calculate checksum for the packet stored in buffer buf. Store
the checksum in a hexadecimal format in a checksum_hex variable. */
static void
recalculate_csum (const std::string &buf, int cnt, unsigned char *checksum_hex)
{
unsigned char csum = 0;
for (int i = 0; i < cnt; i++)
csum += buf[i];
checksum_hex[0] = tohex ((csum >> 4) & 0xf);
checksum_hex[1] = tohex (csum & 0xf);
}
/* Play data back to gdb from fp (after skipping leading blank) up until a
\n is read from fp (which is discarded and not sent to gdb). */
@@ -409,7 +423,10 @@ static void
play (FILE *fp)
{
int fromlog;
char ch;
int where_csum = 0, offset = 1;
unsigned char checksum[2] = {0, 0};
std::string line;
if ((fromlog = logchar (fp, false)) != ' ')
{
@@ -418,10 +435,37 @@ play (FILE *fp)
}
while ((fromlog = logchar (fp, false)) != EOL)
{
ch = fromlog;
if (write (remote_desc_out, &ch, 1) != 1)
remote_error ("Error during write to gdb");
line.push_back (fromlog);
if (line[line.length ()] == '#')
where_csum = line.length ();
}
/* Packet starts with '+$' or '$', we don't want to calculate those
to the checksum, substract the offset to adjust the line length.
If the line starts with '$', the offset remains set to 1. */
if (line[0] == '+')
offset = 2;
/* If '#' is missing at the end of the line, add it and adjust the line
length. */
if (where_csum == 0)
{
where_csum = line.length ();
line.push_back ('#');
}
recalculate_csum (line.substr (offset), where_csum - offset, checksum);
/* Check if the checksum is missing and adjust the line length to be able
to fit the checksum. */
if (where_csum + 1 >= line.length ())
line.resize (where_csum + 3);
/* Replace what is at the end of the packet with the checksum. */
line[where_csum + 1] = checksum[0];
line[where_csum + 2] = checksum[1];
if (write (remote_desc_out, line.data (), line.size ()) != line.size ())
remote_error ("Error during write to gdb");
}
static void