36 lines
1.4 KiB
Diff
36 lines
1.4 KiB
Diff
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commit 63295e4fda1f6dab4bf7442706fe303bf283036c
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Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
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Date: Mon Feb 5 16:10:24 2024 +0000
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arm: Remove wrong ldr from _dl_start_user (BZ 31339)
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The commit 49d877a80b29d3002887b084eec6676d9f5fec18 (arm: Remove
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_dl_skip_args usage) removed the _SKIP_ARGS literal, which was
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previously loader to r4 on loader _start. However, the cleanup did not
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remove the following 'ldr r4, [sl, r4]' on _dl_start_user, used to check
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to skip the arguments after ld self-relocations.
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In my testing, the kernel initially set r4 to 0, which makes the
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ldr instruction just read the _GLOBAL_OFFSET_TABLE_. However, since r4
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is a callee-saved register; a different runtime might not zero
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initialize it and thus trigger an invalid memory access.
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Checked on arm-linux-gnu.
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Reported-by: Adrian Ratiu <adrian.ratiu@collabora.com>
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Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
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(cherry picked from commit 1e25112dc0cb2515d27d8d178b1ecce778a9d37a)
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diff --git a/sysdeps/arm/dl-machine.h b/sysdeps/arm/dl-machine.h
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index b857bbc868ea2ce4..dd1a0f6b6e7a5ea8 100644
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--- a/sysdeps/arm/dl-machine.h
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+++ b/sysdeps/arm/dl-machine.h
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@@ -139,7 +139,6 @@ _start:\n\
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_dl_start_user:\n\
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adr r6, .L_GET_GOT\n\
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add sl, sl, r6\n\
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- ldr r4, [sl, r4]\n\
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@ save the entry point in another register\n\
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mov r6, r0\n\
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@ get the original arg count\n\
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