Hi Jordan
Le 10/11/2021 à 01:37, Jordan Niethe a écrit :
> From: "Christopher M. Riedl" <c...@bluescreens.de>
>
> Rework code-patching with STRICT_KERNEL_RWX to prepare for a later patch
> which uses a temporary mm for patching under the Book3s64 Radix MMU.
> Make improvements by adding a WARN_ON when the patchsite doesn't match
> after patching and return the error from __patch_instruction() properly.
>
> Signed-off-by: Christopher M. Riedl <c...@bluescreens.de>
> Signed-off-by: Jordan Niethe <jniet...@gmail.com>
> ---
> v7: still pass addr to map_patch_area()
This patch doesn-t apply, can you rebase the series ?
Thanks
Christophe
> ---
> arch/powerpc/lib/code-patching.c | 20 ++++++++++----------
> 1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/arch/powerpc/lib/code-patching.c
> b/arch/powerpc/lib/code-patching.c
> index 29a30c3068ff..d586bf9c7581 100644
> --- a/arch/powerpc/lib/code-patching.c
> +++ b/arch/powerpc/lib/code-patching.c
> @@ -75,6 +75,7 @@ static inline void stop_using_temp_mm(struct temp_mm_state
> prev_state)
> }
>
> static DEFINE_PER_CPU(struct vm_struct *, text_poke_area);
> +static DEFINE_PER_CPU(unsigned long, cpu_patching_addr);
>
> static int text_area_cpu_up(unsigned int cpu)
> {
> @@ -87,6 +88,7 @@ static int text_area_cpu_up(unsigned int cpu)
> return -1;
> }
> this_cpu_write(text_poke_area, area);
> + this_cpu_write(cpu_patching_addr, (unsigned long)area->addr);
>
> return 0;
> }
> @@ -172,11 +174,10 @@ static inline int unmap_patch_area(unsigned long addr)
>
> static int do_patch_instruction(u32 *addr, struct ppc_inst instr)
> {
> - int err;
> + int err, rc = 0;
> u32 *patch_addr = NULL;
> unsigned long flags;
> unsigned long text_poke_addr;
> - unsigned long kaddr = (unsigned long)addr;
>
> /*
> * During early early boot patch_instruction is called
> @@ -188,15 +189,13 @@ static int do_patch_instruction(u32 *addr, struct
> ppc_inst instr)
>
> local_irq_save(flags);
>
> - text_poke_addr = (unsigned long)__this_cpu_read(text_poke_area)->addr;
> - if (map_patch_area(addr, text_poke_addr)) {
> - err = -1;
> + text_poke_addr = __this_cpu_read(cpu_patching_addr);
> + err = map_patch_area(addr, text_poke_addr);
> + if (err)
> goto out;
> - }
> -
> - patch_addr = (u32 *)(text_poke_addr + (kaddr & ~PAGE_MASK));
>
> - __patch_instruction(addr, instr, patch_addr);
> + patch_addr = (u32 *)(text_poke_addr | offset_in_page(addr));
> + rc = __patch_instruction(addr, instr, patch_addr);
>
> err = unmap_patch_area(text_poke_addr);
> if (err)
> @@ -204,8 +203,9 @@ static int do_patch_instruction(u32 *addr, struct
> ppc_inst instr)
>
> out:
> local_irq_restore(flags);
> + WARN_ON(!ppc_inst_equal(ppc_inst_read(addr), instr));
>
> - return err;
> + return rc ? rc : err;
> }
> #else /* !CONFIG_STRICT_KERNEL_RWX */
>
