git: 9bc7bbcf214b - stable/12 - arm: Make sure we can handle a thumb entry point.

[Olivier Houchard]

The branch stable/12 has been updated by cognet:

URL: https://cgit.FreeBSD.org/src/commit/?id=9bc7bbcf214b9e15b67e42706cef770ede541913

commit 9bc7bbcf214b9e15b67e42706cef770ede541913
Author:     Olivier Houchard <cognet at FreeBSD.org>
AuthorDate: 2021-06-30 20:56:50 +0000
Commit:     Olivier Houchard <cognet at FreeBSD.org>
CommitDate: 2021-07-07 20:24:56 +0000

    arm: Make sure we can handle a thumb entry point.
    
    Similarly to what's been done on arm64 with commit
    712c060c94fd447c91b0e6218c12a431206b487a, when executing a binary, if the
    entry point is a thumb symbol, then make sure we set the PSL_T flag, otherwise
    the CPU will interpret it in ARM mode, and that will likely leads to an
    undefined instruction.
    
    PR:     256899
    MFC after:      1 week
    
    (cherry picked from commit 8c3bd133dd52824e427e350c65eae1fd9eb5a3cd)
    Signed-off-by: Olivier Houchard <cognet at FreeBSD.org>
---
 sys/arm/arm/machdep.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/arm/arm/machdep.c b/sys/arm/arm/machdep.c
index f24df96ca3d6..a1354f303b3a 100644
--- a/sys/arm/arm/machdep.c
+++ b/sys/arm/arm/machdep.c
@@ -425,6 +425,8 @@ exec_setregs(struct thread *td, struct image_params *imgp, u_long stack)
 	tf->tf_svc_lr = 0x77777777;
 	tf->tf_pc = imgp->entry_addr;
 	tf->tf_spsr = PSR_USR32_MODE;
+	if ((register_t)imgp->entry_addr & 1)
+		tf->tf_spsr |= PSR_T;
 }