On Sat, Aug 26, 2023 at 11:43 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Sat, Aug 26, 2023 at 11:35:31PM +0800, Huacai Chen wrote: > > On Sat, Aug 26, 2023 at 11:22 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > > On Sat, Aug 26, 2023 at 10:23:41PM +0800, Huacai Chen wrote: > > > > This is a port of commit 379eb01c21795edb4c ("riscv: Ensure the value > > > > of FP registers in the core dump file is up to date"). > > > > > > > > The values of FP/SIMD registers in the core dump file come from the > > > > thread.fpu. However, kernel saves the FP/SIMD registers only before > > > > scheduling out the process. If no process switch happens during the > > > > exception handling, kernel will not have a chance to save the latest > > > > values of FP/SIMD registers. So it may cause their values in the core > > > > dump file incorrect. To solve this problem, force fpr_get()/simd_get() > > > > to save the FP/SIMD registers into the thread.fpu if the target task > > > > equals the current task. > > > > > > > > Cc: stable@xxxxxxxxxxxxxxx > > > > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx> > > > > --- > > > > V2: Rename get_fpu_regs() to save_fpu_regs(). > > > > > > What stable tree(s) is this for? > > For 5.19+, but before 6.4 we should remove the call site in simd_get() > > because that function doesn't exist. > > But this commit is already in the following released kernels: > 5.10.62 5.13.14 5.14 Do you means commit 379eb01c21795edb4c ("riscv: Ensure the value of FP registers in the core dump file is up to date")? That is a reference commit, not a Fixes tag. This patch is for LoongArch and LoongArch only exists after 5.19. > so how can it be backported? > > totally confused, > > greg k-h