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| author | Andrew Cagney <cagney@redhat.com> | 2003-08-26 19:34:53 +0000 |
|---|---|---|
| committer | Andrew Cagney <cagney@redhat.com> | 2003-08-26 19:34:53 +0000 |
| commit | cc7ad3eab346356ca03eab6d987401d12fbffd45 (patch) | |
| tree | f81a0d3daa84fd72f76ba5fb45587ddba2b103bf /gdb/i386-linux-nat.c | |
| parent | af8b88dd22728115a948af995888e982bb3942b6 (diff) | |
| download | gdb-cc7ad3eab346356ca03eab6d987401d12fbffd45.zip gdb-cc7ad3eab346356ca03eab6d987401d12fbffd45.tar.gz gdb-cc7ad3eab346356ca03eab6d987401d12fbffd45.tar.bz2 | |
2003-08-26 Andrew Cagney <cagney@redhat.com>
* i386-linux-nat.c (ps_get_thread_area): Make "desc" four "int"s
in size. Add comments.
Diffstat (limited to 'gdb/i386-linux-nat.c')
| -rw-r--r-- | gdb/i386-linux-nat.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/gdb/i386-linux-nat.c b/gdb/i386-linux-nat.c index 4e348d9..dbf91b7 100644 --- a/gdb/i386-linux-nat.c +++ b/gdb/i386-linux-nat.c @@ -687,11 +687,31 @@ i386_linux_dr_set (int regnum, unsigned long value) perror_with_name ("Couldn't write debug register"); } +/* Called by libthread_db. Return's a pointer to the thread local + storage (or it's descriptor). */ extern ps_err_e ps_get_thread_area(const struct ps_prochandle *ph, lwpid_t lwpid, int idx, void **base) { - unsigned long int desc[3]; + /* NOTE: cagney/2003-08-26: The definition of this buffer is found + in the kernel header <asm-i386/ldt.h>. It, after padding, is 4 x + 4 byte integers in size: "entry_number", "base_addr", "limit", + and a bunch of status bits. + + The values returned by this ptrace call should be part of the + regcache buffer, and ps_get_thread_area should channel its + request through the regcache. That way remote targets could + provide the value using the remote protocol and not this direct + call. + + Is this function needed? I'm guessing that the "base" is the + address of a a descriptor that libthread_db uses to find the + thread local address base that GDB needs. Perhaphs that + descriptor is defined by the ABI. Anyway, given that + libthread_db calls this function without prompting (gdb + requesting tls base) I guess it needs info in there anyway. */ + unsigned int desc[4]; + gdb_assert (sizeof (int) == 4); #define PTRACE_GET_THREAD_AREA 25 if (ptrace (PTRACE_GET_THREAD_AREA, |