From: Ilya Leoshkevich iii@linux.ibm.com
[ Upstream commit 8731acc5068eb3f422a45c760d32198175c756f8 ]
gcc's -freorder-blocks-and-partition option makes it group frequently and infrequently used code in .text.hot and .text.unlikely sections respectively. At least when building modules on s390, this option is used by default.
gdb assumes that all code is located in .text section, and that .text section is located at module load address. With such modules this is no longer the case: there is code in .text.hot and .text.unlikely, and either of them might precede .text.
Fix by explicitly telling gdb the addresses of code sections.
It might be tempting to do this for all sections, not only the ones in the white list. Unfortunately, gdb appears to have an issue, when telling it about e.g. loadable .note.gnu.build-id section causes it to think that non-loadable .note.Linux section is loaded at address 0, which in turn causes NULL pointers to be resolved to bogus symbols. So keep using the white list approach for the time being.
Link: http://lkml.kernel.org/r/20191028152734.13065-1-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich iii@linux.ibm.com Reviewed-by: Jan Kiszka jan.kiszka@siemens.com Cc: Kieran Bingham kbingham@kernel.org Cc: Heiko Carstens heiko.carstens@de.ibm.com Cc: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- scripts/gdb/linux/symbols.py | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/scripts/gdb/linux/symbols.py b/scripts/gdb/linux/symbols.py index 627750cb420d0..9b71c65504a38 100644 --- a/scripts/gdb/linux/symbols.py +++ b/scripts/gdb/linux/symbols.py @@ -99,7 +99,8 @@ lx-symbols command.""" attrs[n]['name'].string(): attrs[n]['address'] for n in range(int(sect_attrs['nsections']))} args = [] - for section_name in [".data", ".data..read_mostly", ".rodata", ".bss"]: + for section_name in [".data", ".data..read_mostly", ".rodata", ".bss", + ".text", ".text.hot", ".text.unlikely"]: address = section_name_to_address.get(section_name) if address: args.append(" -s {name} {addr}".format(