Imagelibrary/binutils-gdb
1
0
Fork 1
mirror of https://github.com/bminor/binutils-gdb.git synced 2025-12-26 17:18:55 +00:00
Code Issues Packages Projects Releases Wiki Activity

Fix PR gdb/19676: Disable displaced stepping if /proc not mounted

Browse Source 
On GNU/Linux archs that support displaced stepping, if /proc is not
mounted, GDB gets stuck not able to step past breakpoints:

 (gdb) c
 Continuing.
 dl_main (phdr=<optimized out>, phnum=<optimized out>, user_entry=<optimized out>, auxv=<optimized out>) at rtld.c:2163
 2163      LIBC_PROBE (init_complete, 2, LM_ID_BASE, r);
 Cannot find AT_ENTRY auxiliary vector entry.
 (gdb) c
 Continuing.
 dl_main (phdr=<optimized out>, phnum=<optimized out>, user_entry=<optimized out>, auxv=<optimized out>) at rtld.c:2163
 2163      LIBC_PROBE (init_complete, 2, LM_ID_BASE, r);
 Cannot find AT_ENTRY auxiliary vector entry.
 (gdb)

That's because GDB can't figure out where the scratch pad is.

This is a regression introduced by the earlier changes to make the
Linux native target always work in non-stop mode.

This commit makes GDB detect the case and fallback to stepping over
breakpoints in-line.

gdb/ChangeLog:
2016-03-15  Pedro Alves  <palves@redhat.com>

	PR gdb/19676
	* infrun.c (displaced_step_prepare): Also disable displaced
	stepping on NOT_SUPPORTED_ERROR.
	* linux-tdep.c (linux_displaced_step_location): If reading auxv
	fails, throw NOT_SUPPORTED_ERROR instead of generic error.
This commit is contained in:
Pedro Alves
2016-03-15 16:33:04 +00:00
parent 2a60e18f8f
commit 16b4184277
3 changed files with 12 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
gdb/linux-tdep.c
View File

@@ -2426,7 +2426,8 @@ linux_displaced_step_location (struct gdbarch *gdbarch)
location. The auxiliary vector gets us the PowerPC-side entry
point address instead. */
if (target_auxv_search (&current_target, AT_ENTRY, &addr) <= 0)
error (_("Cannot find AT_ENTRY auxiliary vector entry."));
throw_error (NOT_SUPPORTED_ERROR,
_("Cannot find AT_ENTRY auxiliary vector entry."));
/* Make certain that the address points at real code, and not a
function descriptor. */