Skip to main content

Browse the archive

https://github.com/torvalds/linux
17 May 2024, 09:02:56 UTC
Revision 8afafa6fba7809c0785018b77c95b19e58b35b94 authored by Naveen N. Rao on 15 September 2017, 10:08:21 UTC, committed by Michael Ellerman on 20 September 2017, 10:21:24 UTC 
powerpc/kprobes: Update optprobes to use emulate_update_regs()
 
Optprobes depended on an updated regs->nip from analyse_instr() to
identify the location to branch back from the optprobes trampoline.
However, since commit 3cdfcbfd32b9d ("powerpc: Change analyse_instr so
it doesn't modify *regs"), analyse_instr() doesn't update the registers
anymore.  Due to this, we end up branching back from the optprobes
trampoline to the same branch into the trampoline resulting in a loop.

Fix this by calling out to emulate_update_regs() before using the nip.
Additionally, explicitly compare the return value from analyse_instr()
to 1, rather than just checking for !0 so as to guard against any
future changes to analyse_instr() that may result in -1 being returned
in more scenarios.

Fixes: 3cdfcbfd32b9d ("powerpc: Change analyse_instr so it doesn't modify *regs")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
1 parent b134165
History
Tip revision: 8afafa6fba7809c0785018b77c95b19e58b35b94 authored by Naveen N. Rao on 15 September 2017, 10:08:21 UTC
powerpc/kprobes: Update optprobes to use emulate_update_regs()
Tip revision: 8afafa6
File Mode Size
Documentation
arch
block
certs
crypto
drivers
firmware
fs
include
init
ipc
kernel
lib
mm
net
samples
scripts
security
sound
tools
usr
virt
.cocciconfig -rw-r--r-- 59 bytes
.get_maintainer.ignore -rw-r--r-- 31 bytes
.gitattributes -rw-r--r-- 30 bytes
.gitignore -rw-r--r-- 1.3 KB
.mailmap -rw-r--r-- 8.1 KB
COPYING -rw-r--r-- 18.3 KB
CREDITS -rw-r--r-- 96.1 KB
Kbuild -rw-r--r-- 2.2 KB
Kconfig -rw-r--r-- 252 bytes
MAINTAINERS -rw-r--r-- 419.8 KB
Makefile -rw-r--r-- 58.2 KB
README -rw-r--r-- 722 bytes

README

back to top