From 9a30a3f06b908e4e781324c2e813cd1db87119df Mon Sep 17 00:00:00 2001 From: Michael Meissner Date: Fri, 23 Apr 2021 18:16:03 -0400 Subject: Fix logic error in 32-bit trampolines. The test in the PowerPC 32-bit trampoline support is backwards. It aborts if the trampoline size is greater than the expected size. It should abort when the trampoline size is less than the expected size. I fixed the test so the operands are reversed. I then folded the load immediate into the compare instruction. I verified this by creating a 32-bit trampoline program and manually changing the size of the trampoline to be 48 instead of 40. The program aborted with the larger size. I updated this code and ran the test again and it passed. I added a test case that runs on PowerPC 32-bit Linux systems and it calls the __trampoline_setup function with a larger buffer size than the compiler uses. The test is not run on 64-bit systems, since the function __trampoline_setup is not called. I also limited the test to just Linux systems, in case trampolines are handled differently in other systems. libgcc/ 2021-04-23 Michael Meissner PR target/98952 * config/rs6000/tramp.S (__trampoline_setup, elfv1 #ifdef): Fix trampoline size comparison in 32-bit by reversing test and combining load immediate with compare. (__trampoline_setup, elfv2 #ifdef): Fix trampoline size comparison in 32-bit by reversing test and combining load immediate with compare. gcc/testsuite/ 2021-04-23 Michael Meissner PR target/98952 * gcc.target/powerpc/pr98952.c: New test. --- libgcc/config/rs6000/tramp.S | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'libgcc') diff --git a/libgcc/config/rs6000/tramp.S b/libgcc/config/rs6000/tramp.S index 4236a82..68baf16 100644 --- a/libgcc/config/rs6000/tramp.S +++ b/libgcc/config/rs6000/tramp.S @@ -64,8 +64,7 @@ FUNC_START(__trampoline_setup) mflr r11 addi r7,r11,trampoline_initial-4-.LCF0 /* trampoline address -4 */ - li r8,trampoline_size /* verify that the trampoline is big enough */ - cmpw cr1,r8,r4 + cmpwi cr1,r4,trampoline_size /* verify that the trampoline is big enough */ srwi r4,r4,2 /* # words to move */ addi r9,r3,-4 /* adjust pointer for lwzu */ mtctr r4 @@ -156,8 +155,7 @@ FUNC_START(__trampoline_setup) ld 7,.LC0@toc@l(7) /* trampoline address -8 */ #endif - li r8,trampoline_size /* verify that the trampoline is big enough */ - cmpw cr1,r8,r4 + cmpwi cr1,r4,trampoline_size /* verify that the trampoline is big enough */ srwi r4,r4,3 /* # doublewords to move */ addi r9,r3,-8 /* adjust pointer for stdu */ mtctr r4 -- cgit v1.1