[PATCH 3.16 136/305] arm64: Provide "model name" in /proc/cpuinfo for PER_LINUX32 tasks

Ben Hutchings
2016-08-14T11:15:40Z

From: Catalin Marinas <catalin.marinas@arm.com>

commit e47b020a323d1b2a7b1e9aac86e99eae19463630 upstream.

This patch brings the PER_LINUX32 /proc/cpuinfo format more in line with
the 32-bit ARM one by providing an additional line:

model name : ARMv8 Processor rev X (v8l)

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
[bwh: Backported to 3.16:
- Adjust filename, context
- Open-code MIDR_REVISION()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/arm64/include/asm/elf.h | 4 ++--
arch/arm64/kernel/setup.c | 8 +++++++-
2 files changed, 9 insertions(+), 3 deletions(-)

--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -161,14 +161,14 @@ struct mm_struct;
extern unsigned long arch_randomize_brk(struct mm_struct *mm);
#define arch_randomize_brk arch_randomize_brk

-#ifdef CONFIG_COMPAT
-
#ifdef __AARCH64EB__
#define COMPAT_ELF_PLATFORM ("v8b")
#else
#define COMPAT_ELF_PLATFORM ("v8l")
#endif

+#ifdef CONFIG_COMPAT
+
#define COMPAT_ELF_ET_DYN_BASE (randomize_et_dyn(2 * TASK_SIZE_32 / 3))

/* AArch32 registers. */
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -44,6 +44,8 @@
#include <linux/of_platform.h>
#include <linux/efi.h>
#include <linux/personality.h>
+#include <linux/compat.h>
+#include <linux/elf.h>

#include <asm/fixmap.h>
#include <asm/cputype.h>
@@ -489,6 +491,7 @@ static const char *compat_hwcap_str[] =
static int c_show(struct seq_file *m, void *v)
{
int i, j;
+ bool compat = personality(current->personality) == PER_LINUX32;

for_each_online_cpu(i) {
struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, i);
@@ -500,6 +503,9 @@ static int c_show(struct seq_file *m, vo
* "processor". Give glibc what it expects.
*/
#ifdef CONFIG_SMP
+ if (compat)
+ seq_printf(m, "model name\t: ARMv8 Processor rev %d (%s)\n",
+ midr & 0xf, COMPAT_ELF_PLATFORM);
seq_printf(m, "processor\t: %d\n", i);
#endif

@@ -514,7 +520,7 @@ static int c_show(struct seq_file *m, vo
* software which does already (at least for 32-bit).
*/
seq_puts(m, "Features\t:");
- if (personality(current->personality) == PER_LINUX32) {
+ if (compat) {
#ifdef CONFIG_COMPAT
for (j = 0; compat_hwcap_str[j]; j++)
if (compat_elf_hwcap & (1 << j))