From 1180fa861b0ca8c8399aad79bb40821eee4b802c Mon Sep 17 00:00:00 2001 From: Leandro Lupori Date: Mon, 5 Aug 2019 13:22:02 +0000 Subject: [PATCH] [PPC64] Fix rtld direct exec mode Instead of restoring the saved values of argc, argv and envp, these must be loaded from the stack that _rtld() modifies. This fixes rtld direct exec mode. E.g.: /libexec/ld-elf.so.1 /bin/ls Reviewed by: jhibbits Differential Revision: https://reviews.freebsd.org/D21131 --- libexec/rtld-elf/powerpc64/rtld_start.S | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/libexec/rtld-elf/powerpc64/rtld_start.S b/libexec/rtld-elf/powerpc64/rtld_start.S index c274b6f617e..2d7fb898086 100644 --- a/libexec/rtld-elf/powerpc64/rtld_start.S +++ b/libexec/rtld-elf/powerpc64/rtld_start.S @@ -38,9 +38,12 @@ _ENTRY(_rtld_start) stdu %r1,-144(%r1) /* 16-byte aligned stack for reg saves + exit_proc & obj _rtld args + backchain & lrsave stack frame */ - std %r3,96(%r1) /* argc */ + + /* Save and restore only initial argv, because _rtld will modify + * argv and envp if invoked explicitly, making it necessary to + * load the (possibly) adjusted values from the stack. + */ std %r4,104(%r1) /* argv */ - std %r5,112(%r1) /* envp */ /* std %r6,120(%r1) *//* obj (always 0) */ /* std %r7,128(%r1) *//* cleanup (always 0) */ std %r8,136(%r1) /* ps_strings */ @@ -94,9 +97,14 @@ _ENTRY(_rtld_start) /* * Restore args, with new obj/exit proc */ - ld %r3,96(%r1) /* argc */ - ld %r4,104(%r1) /* argv */ - ld %r5,112(%r1) /* envp */ + ld %r4,104(%r1) /* argv */ + ld %r3,-8(%r4) /* argc */ + + /* envp = argv + argc + 1 */ + addi %r5,%r3,1 + sldi %r5,%r5,3 /* x8 */ + add %r5,%r4,%r5 + ld %r6,120(%r1) /* obj */ ld %r7,128(%r1) /* exit proc */ ld %r8,136(%r1) /* ps_strings */