* [COMMITTED 2.34,2.35] hppa: Remove _dl_skip_args usage (BZ# 29165)
@ 2022-06-10 12:21 Adhemerval Zanella
0 siblings, 0 replies; only message in thread
From: Adhemerval Zanella @ 2022-06-10 12:21 UTC (permalink / raw)
To: libc-stable; +Cc: Carlos O'Donell
Different than other architectures, hppa creates an unrelated stack
frame where ld.so argc/argv adjustments done by ad43cac44a6860eaefc
is not done on the argc/argv saved/restore by _dl_start_user.
Instead load _dl_argc and _dl_argv directlty instead of adjust them
using _dl_skip_args value.
Checked on hppa-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 6242602273feb8d68cd51cff0ad21b3c8ee11fc6)
---
NEWS | 1 +
sysdeps/hppa/dl-machine.h | 36 ++++++++++++++----------------------
2 files changed, 15 insertions(+), 22 deletions(-)
diff --git a/NEWS b/NEWS
index fe37985bc2..fdd46be860 100644
--- a/NEWS
+++ b/NEWS
@@ -101,6 +101,7 @@ The following bugs are resolved with this release:
[29078] <dlfcn.h> functions unusable during early auditing
[29097] time: fchmodat does not handle 64 bit time_t for
AT_SYMLINK_NOFOLLOW
+ [29165] libc: [Regression] broken argv adjustment
[29203] libc: daemon is not y2038 aware
[29204] libc: getusershell is not 2038 aware
[29207] libc: posix_fallocate fallback implementation is not y2038
diff --git a/sysdeps/hppa/dl-machine.h b/sysdeps/hppa/dl-machine.h
index ac66f04418..df6269209f 100644
--- a/sysdeps/hppa/dl-machine.h
+++ b/sysdeps/hppa/dl-machine.h
@@ -374,10 +374,6 @@ asm ( \
"_start:\n" \
/* The kernel does not give us an initial stack frame. */ \
" ldo 64(%sp),%sp\n" \
- /* Save the relevant arguments (yes, those are the correct \
- registers, the kernel is weird) in their stack slots. */ \
-" stw %r25,-40(%sp)\n" /* argc */ \
-" stw %r24,-44(%sp)\n" /* argv */ \
\
/* We need the LTP, and we need it now. \
$PIC_pcrel$0 points 8 bytes past the current instruction, \
@@ -435,12 +431,7 @@ asm ( \
So, obviously, we can't just pass %sp to _dl_start. That's \
okay, argv-4 will do just fine. \
\
- The pleasant part of this is that if we need to skip \
- arguments we can just decrement argc and move argv, because \
- the stack pointer is utterly unrelated to the location of \
- the environment and argument vectors. */ \
- \
- /* This is always within range so we'll be okay. */ \
+ This is always within range so we'll be okay. */ \
" bl _dl_start,%rp\n" \
" ldo -4(%r24),%r26\n" \
\
@@ -450,22 +441,23 @@ asm ( \
/* Save the entry point in %r3. */ \
" copy %ret0,%r3\n" \
\
- /* See if we were called as a command with the executable file \
- name as an extra leading argument. */ \
-" addil LT'_dl_skip_args,%r19\n" \
-" ldw RT'_dl_skip_args(%r1),%r20\n" \
-" ldw 0(%r20),%r20\n" \
- \
-" ldw -40(%sp),%r25\n" /* argc */ \
-" comib,= 0,%r20,.Lnofix\n" /* FIXME: Mispredicted branch */\
-" ldw -44(%sp),%r24\n" /* argv (delay slot) */ \
+ /* The loader adjusts argc, argv, env, and the aux vectors \
+ directly on the stack to remove any arguments used for \
+ direct loader invocation. Thus, argc and argv must be \
+ reloaded from from _dl_argc and _dl_argv. */ \
\
-" sub %r25,%r20,%r25\n" \
+ /* Load argc from _dl_argc. */ \
+" addil LT'_dl_argc,%r19\n" \
+" ldw RT'_dl_argc(%r1),%r20\n" \
+" ldw 0(%r20),%r25\n" \
" stw %r25,-40(%sp)\n" \
-" sh2add %r20,%r24,%r24\n" \
+ \
+ /* Same for argv with _dl_argv. */ \
+" addil LT'_dl_argv,%r19\n" \
+" ldw RT'_dl_argv(%r1),%r20\n" \
+" ldw 0(%r20),%r24\n" \
" stw %r24,-44(%sp)\n" \
\
-".Lnofix:\n" \
/* Call _dl_init(main_map, argc, argv, envp). */ \
" addil LT'_rtld_local,%r19\n" \
" ldw RT'_rtld_local(%r1),%r26\n" \
--
2.34.1
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