Merge tag 'xfs-4.15-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

[sfrench/cifs-2.6.git] / arch / arm / kernel / signal.c

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index b67ae12503f30c3ba113f1d8c7a943d17e9db717..bd8810d4acb393b78ee186a8719526d463eebc8b 100644 (file)
--- 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;