[RFC v5 30/38] powerpc: capture AMR register content on pkey violation
From: Ram Pai <hidden>
Date: 2017-07-05 21:23:54
Also in:
linux-arch, linux-mm, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
capture AMR register contents, and save it in paca whenever a pkey violation is detected. This value will be needed to deliver pkey-violation signal to the task. Signed-off-by: Ram Pai <redacted> --- arch/powerpc/include/asm/paca.h | 3 +++ arch/powerpc/kernel/asm-offsets.c | 5 +++++ arch/powerpc/mm/fault.c | 2 ++ 3 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 1c09f8f..c8bd1fc 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h@@ -92,6 +92,9 @@ struct paca_struct { struct dtl_entry *dispatch_log_end; #endif /* CONFIG_PPC_STD_MMU_64 */ u64 dscr_default; /* per-CPU default DSCR */ +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS + u64 paca_amr; /* value of amr at exception */ +#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 709e234..17f5d8a 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c@@ -241,6 +241,11 @@ int main(void) OFFSET(PACAHWCPUID, paca_struct, hw_cpu_id); OFFSET(PACAKEXECSTATE, paca_struct, kexec_state); OFFSET(PACA_DSCR_DEFAULT, paca_struct, dscr_default); + +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS + OFFSET(PACA_AMR, paca_struct, paca_amr); +#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ + OFFSET(ACCOUNT_STARTTIME, paca_struct, accounting.starttime); OFFSET(ACCOUNT_STARTTIME_USER, paca_struct, accounting.starttime_user); OFFSET(ACCOUNT_USER_TIME, paca_struct, accounting.utime);
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index ea74fe2..a6710f5 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c@@ -264,6 +264,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, #ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS if (error_code & DSISR_KEYFAULT) { code = SEGV_PKUERR; + get_paca()->paca_amr = read_amr(); goto bad_area_nosemaphore; } #endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
@@ -451,6 +452,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address, #ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE, is_exec, 0)) { + get_paca()->paca_amr = read_amr(); code = SEGV_PKUERR; goto bad_area; }
--
1.7.1