From: Michael Meissner <meissner@linux.ibm.com>
To: gcc-patches@gcc.gnu.org,
Michael Meissner <meissner@linux.ibm.com>,
Segher Boessenkool <segher@kernel.crashing.org>,
David Edelsohn <dje.gcc@gmail.com>,
Bill Schmidt <wschmidt@linux.ibm.com>,
Peter Bergner <bergner@linux.ibm.com>,
Will Schmidt <will_schmidt@vnet.ibm.com>
Subject: [PATCH] Fix logic error in 32-bit trampolines, PR target/98952
Date: Fri, 9 Apr 2021 17:09:07 -0400 [thread overview]
Message-ID: <20210409210907.GA5325@ibm-toto.the-meissners.org> (raw)
Fix logic error in 32-bit trampolines, PR target/98952.
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 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 did a bootstrap build on a big endian power8 system that supports both
32-bit and 64-bit executables, and there were no regressions. Can I check
this patch into the trunk?
libgcc/
2021-04-09 Michael Meissner <meissner@linux.ibm.com>
PR target/98952
* config/rs6000/tramp.S (__trampoline_setup): Fix trampoline size
comparison in 32-bit.
---
libgcc/config/rs6000/tramp.S | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/libgcc/config/rs6000/tramp.S b/libgcc/config/rs6000/tramp.S
index 4236a82b402..6b61d892da6 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
--
2.22.0
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meissner@linux.ibm.com, phone: +1 (978) 899-4797
next reply other threads:[~2021-04-09 21:09 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-09 21:09 Michael Meissner [this message]
2021-04-12 22:02 ` will schmidt
2021-04-22 22:50 ` Segher Boessenkool
2021-04-19 19:54 ` Ping: " Michael Meissner
2021-04-22 22:56 ` Segher Boessenkool
2021-04-23 22:24 ` Michael Meissner
2021-04-23 23:58 ` Segher Boessenkool
2021-04-25 13:45 ` Bill Schmidt
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