diff options
Diffstat (limited to 'static-vars-on-stack.patch')
| -rw-r--r-- | static-vars-on-stack.patch | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/static-vars-on-stack.patch b/static-vars-on-stack.patch new file mode 100644 index 000000000000..ce97a331dec0 --- /dev/null +++ b/static-vars-on-stack.patch @@ -0,0 +1,75 @@ +Description: Put pointers to static variables as arguments on the new stack + to get it working with gcc 7. +Author: Bernhard Übelacker <bernhardu@mailbox.org> +Forwarded: no +Bug-Debian: https://bugs.debian.org/898553 +Last-Update: 2018-07-06 + +Index: b/grub/asmstub.c +=================================================================== +--- a/grub/asmstub.c ++++ b/grub/asmstub.c +@@ -123,32 +123,42 @@ + char *scratch, *simstack; + int i; + +- auto void doit (void); ++ auto void doit_wrapper (void); ++ auto void doit (jmp_buf *p_env_for_exit, int *p_status); + ++ void doit_wrapper (void) ++ { ++ asm volatile ("movl %%esp, %0\n\t" ++ "movl %2, %%esp\n\t" /* Make sure our stack lives in the simulated memory area. */ ++ "pushl %1\n\t" /* Put realstack on the new stack */ ++ "pushl %3\n\t" /* Put &status on the new stack */ ++ "pushl %4\n\t" /* Put &env_for_exit on the new stack */ ++ "call *%5\n\t" /* Call doit */ ++ "popl %0\n\t" /* Remove &env_for_exit from the stack */ ++ "popl %0\n\t" /* Remove &status from the stack */ ++ "popl %0\n\t" /* Retrieve realstack from the new stack */ ++ "movl %1, %%esp\n" /* Switch back to the original stack */ ++ : "=&r" (realstack) ++ : "0" (realstack), "r" (simstack), "r" (&status), "r" (&env_for_exit), "r" (doit)); ++ } ++ + /* We need a nested function so that we get a clean stack frame, + regardless of how the code is optimized. */ +- void doit (void) ++ void doit (jmp_buf *p_env_for_exit, int *p_status) + { +- /* Make sure our stack lives in the simulated memory area. */ +- asm volatile ("movl %%esp, %0\n\tmovl %1, %%esp\n" +- : "=&r" (realstack) : "r" (simstack)); +- + /* Do a setjmp here for the stop command. */ +- if (! setjmp (env_for_exit)) ++ if (! setjmp (*p_env_for_exit)) + { + /* Actually enter the generic stage2 code. */ +- status = 0; ++ *p_status = 0; + init_bios_info (); + } + else + { + /* If ERRNUM is non-zero, then set STATUS to non-zero. */ + if (errnum) +- status = 1; ++ *p_status = 1; + } +- +- /* Replace our stack before we use any local variables. */ +- asm volatile ("movl %0, %%esp\n" : : "r" (realstack)); + } + + assert (grub_scratch_mem == 0); +@@ -211,7 +221,7 @@ + + /* Set our stack, and go for it. */ + simstack = (char *) PROTSTACKINIT; +- doit (); ++ doit_wrapper (); + + /* I don't know if this is necessary really. */ + sync (); |