On 11 November 2026 11:58:28 GMT, Madhavan Srinivasan <[email protected]> wrote: > >On 11/11/26 12:58 PM, Bradley Morgan wrote: >> On 11 November 2026 03:48:41 GMT, Ritesh Harjani <[email protected]> >> wrote: >>> Bradley Morgan <[email protected]> writes: >>> >>>> Commit 7dfbfb87c243 ("powerpc/ftrace: Activate >>>> HAVE_DYNAMIC_FTRACE_WITH_REGS on PPC32") made count_relocs() >>>> undercount the PLT entries the loader >>>> consumes: module_finalize_ftrace() now creates two trampolines >>>> (mod->arch.tramp for ftrace_caller() and mod->arch.tramp_regs for >>>> ftrace_regs_caller()), while count_relocs() reserves only one entry >>>> for ftrace. >>>> >>>> So the core .plt ends up one ppc_plt_entry (16 bytes) short. The >>>> walk in do_plt_call() scans for a free slot with >>>> "while (entry->jump[0])" and has no bound check, so once the last >>>> reserved slot is used up, the walk steps past the end of the section >>>> and patch_instruction() writes the 4-instruction trampoline into >>>> whatever module memory follows the .plt. >>>> >>>> Count the second entry, mirroring what module_64.c does for the same >>>> pair of stubs. >>>> >>>> Signed-off-by: Bradley Morgan <[email protected]> >>>> --- >>>> arch/powerpc/kernel/module_32.c | 3 +++ >>>> 1 file changed, 3 insertions(+) >>>> >>> Do we also need fixes and stable tag here? >>> >>> Fixes: 7dfbfb87c243 ("powerpc/ftrace: Activate >HAVE_DYNAMIC_FTRACE_WITH_REGS on PPC32") >>> Cc: [email protected] >> Hmm.. could the merger add that? If anyone merges.. :( >planned to be part of my fixes PR and will add it. >Thanks for the fix.
No worries, mind changing sob to this email? > >Maddy >>> >>> -ritesh >>> >> --- Thanks! > --- Thanks!
