Changeset 3e40b4e in mainline

Timestamp:

2019-01-22T15:51:15Z (5 years ago)

Author:

Vojtech Horky <vojtech.horky@…>

Parents:

05cb995

git-author:

Vojtech Horky <vojtech.horky@…> (2019-01-22 15:51:00)

git-committer:

Vojtech Horky <vojtech.horky@…> (2019-01-22 15:51:15)

Message:

ppc32, arm32: clobber memory on syscall

As the syscall may touch arbitrary memory, we need to prevent the
compiler to cache some values in registers.

This is a follow-up on the previous commit where this was fixed for
MIPS32.

Location:

uspace/lib/c/arch

Files:

• arm32/src/syscall.c (modified) (1 diff)
• ppc32/src/syscall.c (modified) (1 diff)

uspace/lib/c/arch/arm32/src/syscall.c

@@ -70 +70 @@
               "r" (__arm_reg_r5),
               "r" (__arm_reg_r6)
+            :
+              /*
+               * Clobber memory too as some arguments might be
+               * actually pointers.
+               */
+              "memory"
         );
 

uspace/lib/c/arch/ppc32/src/syscall.c

@@ -58 +58 @@
               "r" (__ppc32_reg_r8),
               "r" (__ppc32_reg_r9)
+            :
+              /*
+               * Clobber memory too as some arguments might be
+               * actually pointers.
+               */
+              "memory"
         );