[RFC v5 32/38] powerpc: capture the violated protection key on fault
From: Ram Pai <hidden>
Date: 2017-07-05 21:24:48
Also in:
linux-arch, linux-mm, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Capture the protection key that got violated in paca. This value will be used by used to inform the signal handler. Signed-off-by: Ram Pai <redacted> --- arch/powerpc/include/asm/paca.h | 1 + arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/mm/fault.c | 3 +++ 3 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index c8bd1fc..0c06188 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h@@ -94,6 +94,7 @@ struct paca_struct { u64 dscr_default; /* per-CPU default DSCR */ #ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS u64 paca_amr; /* value of amr at exception */ + u16 paca_pkey; /* exception causing pkey */ #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ #ifdef CONFIG_PPC_STD_MMU_64
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 17f5d8a..7dff862 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c@@ -244,6 +244,7 @@ int main(void) #ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS OFFSET(PACA_AMR, paca_struct, paca_amr); + OFFSET(PACA_PKEY, paca_struct, paca_pkey); #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ OFFSET(ACCOUNT_STARTTIME, paca_struct, accounting.starttime);
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index a6710f5..c8674a7 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c@@ -265,6 +265,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, if (error_code & DSISR_KEYFAULT) { code = SEGV_PKUERR; get_paca()->paca_amr = read_amr(); + get_paca()->paca_pkey = get_pte_pkey(current->mm, address); goto bad_area_nosemaphore; } #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
@@ -290,6 +291,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); + /* * We want to do this outside mmap_sem, because reading code around nip * can result in fault, which will cause a deadlock when called with
@@ -453,6 +455,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE, is_exec, 0)) { get_paca()->paca_amr = read_amr(); + get_paca()->paca_pkey = vma_pkey(vma); code = SEGV_PKUERR; goto bad_area; }
--
1.7.1