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Diffstat (limited to 'arch/arm/kernel/signal.c')
-rw-r--r--arch/arm/kernel/signal.c53
1 files changed, 38 insertions, 15 deletions
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index b67ae12503f3..bd8810d4acb3 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -19,11 +19,12 @@
#include <asm/elf.h>
#include <asm/cacheflush.h>
#include <asm/traps.h>
-#include <asm/ucontext.h>
#include <asm/unistd.h>
#include <asm/vfp.h>
-extern const unsigned long sigreturn_codes[7];
+#include "signal.h"
+
+extern const unsigned long sigreturn_codes[17];
static unsigned long signal_return_offset;
@@ -172,15 +173,6 @@ static int restore_vfp_context(char __user **auxp)
/*
* Do a signal return; undo the signal stack. These are aligned to 64-bit.
*/
-struct sigframe {
- struct ucontext uc;
- unsigned long retcode[2];
-};
-
-struct rt_sigframe {
- struct siginfo info;
- struct sigframe sig;
-};
static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
{
@@ -366,9 +358,20 @@ setup_return(struct pt_regs *regs, struct ksignal *ksig,
unsigned long __user *rc, void __user *frame)
{
unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler;
+ unsigned long handler_fdpic_GOT = 0;
unsigned long retcode;
- int thumb = 0;
+ unsigned int idx, thumb = 0;
unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT);
+ bool fdpic = IS_ENABLED(CONFIG_BINFMT_ELF_FDPIC) &&
+ (current->personality & FDPIC_FUNCPTRS);
+
+ if (fdpic) {
+ unsigned long __user *fdpic_func_desc =
+ (unsigned long __user *)handler;
+ if (__get_user(handler, &fdpic_func_desc[0]) ||
+ __get_user(handler_fdpic_GOT, &fdpic_func_desc[1]))
+ return 1;
+ }
cpsr |= PSR_ENDSTATE;
@@ -408,9 +411,26 @@ setup_return(struct pt_regs *regs, struct ksignal *ksig,
if (ksig->ka.sa.sa_flags & SA_RESTORER) {
retcode = (unsigned long)ksig->ka.sa.sa_restorer;
+ if (fdpic) {
+ /*
+ * We need code to load the function descriptor.
+ * That code follows the standard sigreturn code
+ * (6 words), and is made of 3 + 2 words for each
+ * variant. The 4th copied word is the actual FD
+ * address that the assembly code expects.
+ */
+ idx = 6 + thumb * 3;
+ if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+ idx += 5;
+ if (__put_user(sigreturn_codes[idx], rc ) ||
+ __put_user(sigreturn_codes[idx+1], rc+1) ||
+ __put_user(sigreturn_codes[idx+2], rc+2) ||
+ __put_user(retcode, rc+3))
+ return 1;
+ goto rc_finish;
+ }
} else {
- unsigned int idx = thumb << 1;
-
+ idx = thumb << 1;
if (ksig->ka.sa.sa_flags & SA_SIGINFO)
idx += 3;
@@ -422,6 +442,7 @@ setup_return(struct pt_regs *regs, struct ksignal *ksig,
__put_user(sigreturn_codes[idx+1], rc+1))
return 1;
+rc_finish:
#ifdef CONFIG_MMU
if (cpsr & MODE32_BIT) {
struct mm_struct *mm = current->mm;
@@ -441,7 +462,7 @@ setup_return(struct pt_regs *regs, struct ksignal *ksig,
* the return code written onto the stack.
*/
flush_icache_range((unsigned long)rc,
- (unsigned long)(rc + 2));
+ (unsigned long)(rc + 3));
retcode = ((unsigned long)rc) + thumb;
}
@@ -451,6 +472,8 @@ setup_return(struct pt_regs *regs, struct ksignal *ksig,
regs->ARM_sp = (unsigned long)frame;
regs->ARM_lr = retcode;
regs->ARM_pc = handler;
+ if (fdpic)
+ regs->ARM_r9 = handler_fdpic_GOT;
regs->ARM_cpsr = cpsr;
return 0;