[Qemu-devel] [PULL 13/14] linux-user/elfload.c: Fix A64 code which was incorrectly acting like A32

[riku.voipio@linaro.org]

From: Peter Maydell <peter.maydell@linaro.org>

The ARM target-specific code in elfload.c was incorrectly allowing
the 64-bit ARM target to use most of the existing 32-bit definitions:
most noticably this meant that our HWCAP bits passed to the guest
were wrong, and register handling when dumping core was totally
broken. Fix this by properly separating the 64 and 32 bit code,
since they have more differences than similarities.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-stable@nongnu.org
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
---
 linux-user/elfload.c | 86 ++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 73 insertions(+), 13 deletions(-)

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index d372300..ad07c43 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -267,17 +267,15 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUX86State *en
 
 #ifdef TARGET_ARM
 
+#ifndef TARGET_AARCH64
+/* 32 bit ARM definitions */
+
 #define ELF_START_MMAP 0x80000000
 
 #define elf_check_arch(x) ((x) == ELF_MACHINE)
 
 #define ELF_ARCH        ELF_MACHINE
-
-#ifdef TARGET_AARCH64
-#define ELF_CLASS       ELFCLASS64
-#else
 #define ELF_CLASS       ELFCLASS32
-#endif
 
 static inline void init_thread(struct target_pt_regs *regs,
                                struct image_info *infop)
@@ -285,10 +283,6 @@ static inline void init_thread(struct target_pt_regs *regs,
     abi_long stack = infop->start_stack;
     memset(regs, 0, sizeof(*regs));
 
-#ifdef TARGET_AARCH64
-    regs->pc = infop->entry & ~0x3ULL;
-    regs->sp = stack;
-#else
     regs->ARM_cpsr = 0x10;
     if (infop->entry & 1)
         regs->ARM_cpsr |= CPSR_T;
@@ -302,7 +296,6 @@ static inline void init_thread(struct target_pt_regs *regs,
     /* For uClinux PIC binaries.  */
     /* XXX: Linux does this only on ARM with no MMU (do we care ?) */
     regs->ARM_r10 = infop->start_data;
-#endif
 }
 
 #define ELF_NREG    18
@@ -360,7 +353,6 @@ enum
     ARM_HWCAP_ARM_EVTSTRM   = 1 << 21,
 };
 
-#ifndef TARGET_AARCH64
 /* The commpage only exists for 32 bit kernels */
 
 #define TARGET_HAS_VALIDATE_GUEST_SPACE
@@ -422,7 +414,6 @@ static int validate_guest_space(unsigned long guest_base,
 
     return 1; /* All good */
 }
-#endif
 
 #define ELF_HWCAP get_elf_hwcap()
 
@@ -462,7 +453,76 @@ static uint32_t get_elf_hwcap(void)
     return hwcaps;
 }
 
-#endif
+#else
+/* 64 bit ARM definitions */
+#define ELF_START_MMAP 0x80000000
+
+#define elf_check_arch(x) ((x) == ELF_MACHINE)
+
+#define ELF_ARCH        ELF_MACHINE
+#define ELF_CLASS       ELFCLASS64
+#define ELF_PLATFORM    "aarch64"
+
+static inline void init_thread(struct target_pt_regs *regs,
+                               struct image_info *infop)
+{
+    abi_long stack = infop->start_stack;
+    memset(regs, 0, sizeof(*regs));
+
+    regs->pc = infop->entry & ~0x3ULL;
+    regs->sp = stack;
+}
+
+#define ELF_NREG    34
+typedef target_elf_greg_t  target_elf_gregset_t[ELF_NREG];
+
+static void elf_core_copy_regs(target_elf_gregset_t *regs,
+                               const CPUARMState *env)
+{
+    int i;
+
+    for (i = 0; i < 32; i++) {
+        (*regs)[i] = tswapreg(env->xregs[i]);
+    }
+    (*regs)[32] = tswapreg(env->pc);
+    (*regs)[33] = tswapreg(pstate_read((CPUARMState *)env));
+}
+
+#define USE_ELF_CORE_DUMP
+#define ELF_EXEC_PAGESIZE       4096
+
+enum {
+    ARM_HWCAP_A64_FP            = 1 << 0,
+    ARM_HWCAP_A64_ASIMD         = 1 << 1,
+    ARM_HWCAP_A64_EVTSTRM       = 1 << 2,
+    ARM_HWCAP_A64_AES           = 1 << 3,
+    ARM_HWCAP_A64_PMULL         = 1 << 4,
+    ARM_HWCAP_A64_SHA1          = 1 << 5,
+    ARM_HWCAP_A64_SHA2          = 1 << 6,
+    ARM_HWCAP_A64_CRC32         = 1 << 7,
+};
+
+#define ELF_HWCAP get_elf_hwcap()
+
+static uint32_t get_elf_hwcap(void)
+{
+    ARMCPU *cpu = ARM_CPU(thread_cpu);
+    uint32_t hwcaps = 0;
+
+    hwcaps |= ARM_HWCAP_A64_FP;
+    hwcaps |= ARM_HWCAP_A64_ASIMD;
+
+    /* probe for the extra features */
+#define GET_FEATURE(feat, hwcap) \
+    do { if (arm_feature(&cpu->env, feat)) { hwcaps |= hwcap; } } while (0)
+    GET_FEATURE(ARM_FEATURE_V8_AES, ARM_HWCAP_A64_PMULL);
+#undef GET_FEATURE
+
+    return hwcaps;
+}
+
+#endif /* not TARGET_AARCH64 */
+#endif /* TARGET_ARM */
 
 #ifdef TARGET_UNICORE32
 
-- 
2.0.0.rc0