[PATCH v6 11/19] arm64:ilp32: support core dump generation for ILP32

Yury Norov
2015-11-17T21:16:51Z

From: Andrew Pinski <apinski@cavium.com>

This patch supports core dumping on ILP32.
We need a few extra macros (COMPAT_PR_REG_SIZE and COMPAT_PRSTATUS_SIZE) due
to size differences of the register sets.

Reviewed-by: David Daney <ddaney@caviumnetworks.com>

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Andrew Pinski <Andrew.Pinski@caviumnetworks.com>
---
arch/arm64/include/asm/elf.h | 87 ++++++++++++++++++++++++++++++++++++++------
arch/arm64/kernel/ptrace.c | 12 +++---
arch/arm64/kernel/vdso.c | 8 ++++
3 files changed, 89 insertions(+), 18 deletions(-)

diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
index 01e032c..8f13dac 100644
--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -134,7 +134,11 @@ typedef struct user_fpsimd_state elf_fpregset_t;
*/
#define ELF_PLAT_INIT(_r, load_addr) (_r)->regs[0] = 0

-#define SET_PERSONALITY(ex) clear_thread_flag(TIF_32BIT);
+#define SET_PERSONALITY(ex) \
+do { \
+ clear_thread_flag(TIF_32BIT_AARCH64); \
+ clear_thread_flag(TIF_32BIT); \
+} while (0)

#define ARCH_DLINFO \
do { \
@@ -166,12 +170,15 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm,

#define COMPAT_ELF_ET_DYN_BASE (2 * TASK_SIZE_32 / 3)

+extern int aarch32_setup_vectors_page(struct linux_binprm *bprm,
+ int uses_interp);
+
#ifdef CONFIG_AARCH32_EL0

/* AArch32 registers. */
#define COMPAT_A32_ELF_NGREG 18
-typedef unsigned int compat_elf_greg_t;
-typedef compat_elf_greg_t compat_elf_gregset_t[COMPAT_A32_ELF_NGREG];
+typedef unsigned int compat_a32_elf_greg_t;
+typedef compat_a32_elf_greg_t compat_a32_elf_gregset_t[COMPAT_A32_ELF_NGREG];

/* AArch32 EABI. */
#define EF_ARM_EABI_MASK 0xff000000
@@ -179,24 +186,80 @@ typedef compat_elf_greg_t compat_elf_gregset_t[COMPAT_A32_ELF_NGREG];
((x)->e_flags & EF_ARM_EABI_MASK))

#define compat_start_thread compat_start_thread
-#define COMPAT_SET_PERSONALITY(ex) set_thread_flag(TIF_32BIT);
-#define COMPAT_ARCH_DLINFO
-extern int aarch32_setup_vectors_page(struct linux_binprm *bprm,
- int uses_interp);
-#define compat_arch_setup_additional_pages \
- aarch32_setup_vectors_page
+#define COMPAT_A32_SET_PERSONALITY(ex) \
+do { \
+ clear_thread_flag(TIF_32BIT_AARCH64); \
+ set_thread_flag(TIF_32BIT); \
+} while (0)
+#define COMPAT_A32_ARCH_DLINFO do {} while (0)

#else

typedef elf_greg_t compat_elf_greg_t;
typedef elf_gregset_t compat_elf_gregset_t;
#define compat_a32_elf_check_arch(x) 0
-#define COMPAT_SET_PERSONALITY(ex)
-#define COMPAT_ARCH_DLINFO
+#define COMPAT_A32_SET_PERSONALITY(ex) do {} while (0)
+#define COMPAT_A32_ARCH_DLINFO do {} while (0)
+#endif
+
+/* If ILP32 is turned on, we want to define the compat_elf_greg_t to the non compat
+ one and define PR_REG_SIZE/PRSTATUS_SIZE/SET_PR_FPVALID so we pick up the correct
+ ones for AARCH32. Note also the definition of the macros have to be correct for
+ LP64 as this file is included in the standard binfmt_elf.c. */
+#ifdef CONFIG_ARM64_ILP32
+typedef elf_greg_t compat_elf_greg_t;
+typedef elf_gregset_t compat_elf_gregset_t;
+#define PR_REG_SIZE(S) (is_a32_compat_task() ? 72 : 272)
+#define PRSTATUS_SIZE(S) (is_a32_compat_task() ? 124 : (is_ilp32_compat_task() ? 352 : 392))
+#define SET_PR_FPVALID(S, V) \
+do { \
+ *(int *) (((void *) &((S)->pr_reg)) + PR_REG_SIZE((S)->pr_reg)) = (V); \
+} while (0)
+#else
+typedef compat_a32_elf_greg_t compat_elf_greg_t;
+typedef compat_a32_elf_gregset_t compat_elf_gregset_t;
+#endif

+#ifdef CONFIG_ARM64_ILP32
+#define compat_ilp32_elf_check_arch(x) ((x)->e_machine == EM_AARCH64)
+#define COMPAT_ILP32_SET_PERSONALITY(ex) \
+do { \
+ set_thread_flag(TIF_32BIT_AARCH64); \
+ clear_thread_flag(TIF_32BIT); \
+} while (0)
+#define COMPAT_ILP32_ARCH_DLINFO \
+do { \
+ NEW_AUX_ENT(AT_SYSINFO_EHDR, \
+ (elf_addr_t)(long)current->mm->context.vdso); \
+} while (0)
+#else
+#define compat_ilp32_elf_check_arch(x) 0
+#define COMPAT_ILP32_SET_PERSONALITY(ex) do {} while (0)
+#define COMPAT_ILP32_ARCH_DLINFO do {} while (0)
#endif

-#define compat_elf_check_arch(x) compat_a32_elf_check_arch(x)
+#define compat_elf_check_arch(x) (compat_a32_elf_check_arch(x) || compat_ilp32_elf_check_arch(x))
+#define COMPAT_SET_PERSONALITY(ex) \
+do { \
+ if (compat_a32_elf_check_arch(&ex)) \
+ COMPAT_A32_SET_PERSONALITY(ex); \
+ else \
+ COMPAT_ILP32_SET_PERSONALITY(ex); \
+} while (0)
+
+/* ILP32 uses the "LP64-like" vdso pages */
+#define compat_arch_setup_additional_pages \
+ (is_a32_compat_task() \
+ ? &aarch32_setup_vectors_page \
+ : &(arch_setup_additional_pages))
+
+#define COMPAT_ARCH_DLINFO \
+do { \
+ if (is_a32_compat_task()) \
+ COMPAT_A32_ARCH_DLINFO; \
+ else \
+ COMPAT_ILP32_ARCH_DLINFO; \
+} while (0)

#endif /* CONFIG_COMPAT */

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index d2e428c..22d0d5e 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -854,8 +854,8 @@ static const struct user_regset aarch32_regsets[] = {
[REGSET_COMPAT_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = COMPAT_A32_ELF_NGREG,
- .size = sizeof(compat_elf_greg_t),
- .align = sizeof(compat_elf_greg_t),
+ .size = sizeof(compat_a32_elf_greg_t),
+ .align = sizeof(compat_a32_elf_greg_t),
.get = compat_gpr_get,
.set = compat_gpr_set
},
@@ -946,7 +946,7 @@ static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
tmp = tsk->mm->start_data;
else if (off == COMPAT_PT_TEXT_END_ADDR)
tmp = tsk->mm->end_code;
- else if (off < sizeof(compat_elf_gregset_t))
+ else if (off < sizeof(compat_a32_elf_gregset_t))
return copy_regset_to_user(tsk, &user_aarch32_view,
REGSET_COMPAT_GPR, off,
sizeof(compat_ulong_t), ret);
@@ -967,7 +967,7 @@ static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
if (off & 3 || off >= COMPAT_USER_SZ)
return -EIO;

- if (off >= sizeof(compat_elf_gregset_t))
+ if (off >= sizeof(compat_a32_elf_gregset_t))
return 0;

set_fs(KERNEL_DS);
@@ -1130,7 +1130,7 @@ long compat_a32_arch_ptrace(struct task_struct *child, compat_long_t request,
ret = copy_regset_to_user(child,
&user_aarch32_view,
REGSET_COMPAT_GPR,
- 0, sizeof(compat_elf_gregset_t),
+ 0, sizeof(compat_a32_elf_gregset_t),
datap);
break;

@@ -1138,7 +1138,7 @@ long compat_a32_arch_ptrace(struct task_struct *child, compat_long_t request,
ret = copy_regset_from_user(child,
&user_aarch32_view,
REGSET_COMPAT_GPR,
- 0, sizeof(compat_elf_gregset_t),
+ 0, sizeof(compat_a32_elf_gregset_t),
datap);
break;

diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 26352a6..b239b9b 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -107,6 +107,14 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)

return PTR_ERR_OR_ZERO(ret);
}
+#else
+int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
+{
+ (void) bprm;
+ (void) uses_interp;
+
+ return -EINVAL;
+}
#endif /* CONFIG_AARCH32_EL0 */

static struct vm_special_mapping vdso_spec[2];
--
2.1.4