[Qemu-devel] [PATCH 4/4] linux-user/elfload.c: Support ARM HWCAP2 flags

[Peter Maydell <peter.maydell@linaro.org>]

The ARM kernel has chosen to spill into the HWCAP2 ELF feature bit flags
early, even though it hasn't yet exhausted all 32 bits of the HWCAP word.
Add support for setting this in the same way we do for HWCAP.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 include/elf.h        |  1 +
 linux-user/elfload.c | 30 +++++++++++++++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/include/elf.h b/include/elf.h
index 667af6f..1599ab2 100644
--- a/include/elf.h
+++ b/include/elf.h
@@ -254,6 +254,7 @@ typedef int64_t  Elf64_Sxword;
 #define AT_SECURE	23	/* boolean, was exec suid-like? */
 #define AT_BASE_PLATFORM 24	/* string identifying real platforms */
 #define AT_RANDOM	25	/* address of 16 random bytes */
+#define AT_HWCAP2       26      /* extension of AT_HWCAP */
 #define AT_EXECFN	31	/* filename of the executable */
 #define AT_SYSINFO	32	/* address of kernel entry point */
 #define AT_SYSINFO_EHDR	33	/* address of kernel vdso */
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index e1ff346..5db67cf 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -20,6 +20,7 @@
 #undef ARCH_DLINFO
 #undef ELF_PLATFORM
 #undef ELF_HWCAP
+#undef ELF_HWCAP2
 #undef ELF_CLASS
 #undef ELF_DATA
 #undef ELF_ARCH
@@ -353,6 +354,14 @@ enum
     ARM_HWCAP_ARM_EVTSTRM   = 1 << 21,
 };
 
+enum {
+    ARM_HWCAP2_ARM_AES      = 1 << 0,
+    ARM_HWCAP2_ARM_PMULL    = 1 << 1,
+    ARM_HWCAP2_ARM_SHA1     = 1 << 2,
+    ARM_HWCAP2_ARM_SHA2     = 1 << 3,
+    ARM_HWCAP2_ARM_CRC32    = 1 << 4,
+};
+
 /* The commpage only exists for 32 bit kernels */
 
 #define TARGET_HAS_VALIDATE_GUEST_SPACE
@@ -416,6 +425,7 @@ static int validate_guest_space(unsigned long guest_base,
 }
 
 #define ELF_HWCAP get_elf_hwcap()
+#define ELF_HWCAP2 get_elf_hwcap2()
 
 static uint32_t get_elf_hwcap(void)
 {
@@ -448,11 +458,22 @@ static uint32_t get_elf_hwcap(void)
      */
     GET_FEATURE(ARM_FEATURE_VFP3, ARM_HWCAP_ARM_VFPD32);
     GET_FEATURE(ARM_FEATURE_LPAE, ARM_HWCAP_ARM_LPAE);
-#undef GET_FEATURE
 
     return hwcaps;
 }
 
+static uint32_t get_elf_hwcap2(void)
+{
+    ARMCPU *cpu = ARM_CPU(thread_cpu);
+    uint32_t hwcaps = 0;
+
+    GET_FEATURE(ARM_FEATURE_V8_AES, ARM_HWCAP2_ARM_AES);
+    GET_FEATURE(ARM_FEATURE_CRC, ARM_HWCAP2_ARM_CRC32);
+    return hwcaps;
+}
+
+#undef GET_FEATURE
+
 #else
 /* 64 bit ARM definitions */
 #define ELF_START_MMAP 0x80000000
@@ -1486,6 +1507,9 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
 #ifdef DLINFO_ARCH_ITEMS
     size += DLINFO_ARCH_ITEMS * 2;
 #endif
+#ifdef ELF_HWCAP2
+    size += 2;
+#endif
     size += envc + argc + 2;
     size += 1;  /* argc itself */
     size *= n;
@@ -1519,6 +1543,10 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
     NEW_AUX_ENT(AT_CLKTCK, (abi_ulong) sysconf(_SC_CLK_TCK));
     NEW_AUX_ENT(AT_RANDOM, (abi_ulong) u_rand_bytes);
 
+#ifdef ELF_HWCAP2
+    NEW_AUX_ENT(AT_HWCAP2, (abi_ulong) ELF_HWCAP2);
+#endif
+
     if (k_platform)
         NEW_AUX_ENT(AT_PLATFORM, u_platform);
 #ifdef ARCH_DLINFO
-- 
1.9.2