Re: [PATCH v7 3/5] powerpc: Rework and improve STRICT_KERNEL_RWX patching
flat view
From: Christophe Leroy <hidden>
Date: 2022-03-12 07:31:39
Hi Jordan Le 10/11/2021 à 01:37, Jordan Niethe a écrit :
From: "Christopher M. Riedl" <redacted> 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 <redacted> Signed-off-by: Jordan Niethe <redacted> --- v7: still pass addr to map_patch_area()
This patch doesn-t apply, can you rebase the series ? Thanks Christophe
quoted hunk ↗ jump to hunk
--- 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 */