From be5d6f4884021208ae0e73379c83e51500ad3a8d Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 21 Oct 2020 10:37:39 -0700 Subject: [PATCH] linux-user: Set PAGE_TARGET_1 for TARGET_PROT_BTI Transform the prot bit to a qemu internal page bit, and save it in the page tables. Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson Message-id: 20201021173749.111103-3-richard.henderson@linaro.org Signed-off-by: Peter Maydell --- include/exec/cpu-all.h | 2 ++ linux-user/mmap.c | 16 ++++++++++++++++ linux-user/syscall_defs.h | 4 ++++ target/arm/cpu.h | 5 +++++ target/arm/translate-a64.c | 4 ++-- 5 files changed, 29 insertions(+), 2 deletions(-) diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h index 61e13b5038..656a2a8788 100644 --- a/include/exec/cpu-all.h +++ b/include/exec/cpu-all.h @@ -274,6 +274,8 @@ extern intptr_t qemu_host_page_mask; /* FIXME: Code that sets/uses this is broken and needs to go away. */ #define PAGE_RESERVED 0x0020 #endif +/* Target-specific bits that will be used via page_get_flags(). */ +#define PAGE_TARGET_1 0x0080 #if defined(CONFIG_USER_ONLY) void page_dump(FILE *f); diff --git a/linux-user/mmap.c b/linux-user/mmap.c index f261563420..00c05e6a0f 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -83,6 +83,22 @@ static int validate_prot_to_pageflags(int *host_prot, int prot) *host_prot = (prot & (PROT_READ | PROT_WRITE)) | (prot & PROT_EXEC ? PROT_READ : 0); +#ifdef TARGET_AARCH64 + /* + * The PROT_BTI bit is only accepted if the cpu supports the feature. + * Since this is the unusual case, don't bother checking unless + * the bit has been requested. If set and valid, record the bit + * within QEMU's page_flags. + */ + if (prot & TARGET_PROT_BTI) { + ARMCPU *cpu = ARM_CPU(thread_cpu); + if (cpu_isar_feature(aa64_bti, cpu)) { + valid |= TARGET_PROT_BTI; + page_flags |= PAGE_BTI; + } + } +#endif + return prot & ~valid ? 0 : page_flags; } diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h index 731c3d5341..cabbfb762d 100644 --- a/linux-user/syscall_defs.h +++ b/linux-user/syscall_defs.h @@ -1277,6 +1277,10 @@ struct target_winsize { #define TARGET_PROT_SEM 0x08 #endif +#ifdef TARGET_AARCH64 +#define TARGET_PROT_BTI 0x10 +#endif + /* Common */ #define TARGET_MAP_SHARED 0x01 /* Share changes */ #define TARGET_MAP_PRIVATE 0x02 /* Changes are private */ diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 49cd5cabcf..c18a916766 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -3446,6 +3446,11 @@ static inline MemTxAttrs *typecheck_memtxattrs(MemTxAttrs *x) #define arm_tlb_mte_tagged(x) (typecheck_memtxattrs(x)->target_tlb_bit1) /* + * AArch64 usage of the PAGE_TARGET_* bits for linux-user. + */ +#define PAGE_BTI PAGE_TARGET_1 + +/* * Naming convention for isar_feature functions: * Functions which test 32-bit ID registers should have _aa32_ in * their name. Functions which test 64-bit ID registers should have diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index 7188808341..072754fa24 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -14507,10 +14507,10 @@ static void disas_data_proc_simd_fp(DisasContext *s, uint32_t insn) */ static bool is_guarded_page(CPUARMState *env, DisasContext *s) { + uint64_t addr = s->base.pc_first; #ifdef CONFIG_USER_ONLY - return false; /* FIXME */ + return page_get_flags(addr) & PAGE_BTI; #else - uint64_t addr = s->base.pc_first; int mmu_idx = arm_to_core_mmu_idx(s->mmu_idx); unsigned int index = tlb_index(env, mmu_idx, addr); CPUTLBEntry *entry = tlb_entry(env, mmu_idx, addr); -- 2.11.4.GIT