161 lines
5.1 KiB
Diff
161 lines
5.1 KiB
Diff
From 4323e979bd1745e10ae29667c290bff7f74d38e4 Mon Sep 17 00:00:00 2001
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From: "H.J. Lu" <hjl.tools@gmail.com>
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Date: Thu, 13 Jan 2022 14:45:46 -0800
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Subject: [PATCH v2 09/15] x86: Check PT_GNU_PROPERTY early
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The PT_GNU_PROPERTY segment is scanned before PT_NOTE. For binaries
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with the PT_GNU_PROPERTY segment, we can check it to avoid scan of
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the PT_NOTE segment.
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---
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sysdeps/x86/dl-prop.h | 120 ++++++++++++++++++++++++++++--------------
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1 file changed, 80 insertions(+), 40 deletions(-)
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diff --git a/sysdeps/x86/dl-prop.h b/sysdeps/x86/dl-prop.h
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index 87702df040..ca07b83701 100644
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--- a/sysdeps/x86/dl-prop.h
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+++ b/sysdeps/x86/dl-prop.h
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@@ -81,6 +81,60 @@ _dl_open_check (struct link_map *m)
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#endif
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}
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+/* Check the GNU property and return its value. It returns:
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+ -1: Skip this note.
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+ 0: Stop checking.
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+ 1: Continue to check.
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+ */
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+static inline int
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+_dl_check_gnu_property (unsigned int type, unsigned int datasz,
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+ void *ptr, unsigned int *feature_1_and,
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+ unsigned int *needed_1,
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+ unsigned int *isa_1_needed)
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+{
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+ if (type == GNU_PROPERTY_X86_FEATURE_1_AND
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+ || type == GNU_PROPERTY_X86_ISA_1_NEEDED
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+ || type == GNU_PROPERTY_1_NEEDED)
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+ {
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+ /* The sizes of types which we are searching for are
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+ 4 bytes. There is no point to continue if this
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+ note is ill-formed. */
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+ if (datasz != 4)
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+ return -1;
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+
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+ /* NB: Stop the scan only after seeing all types which
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+ we are searching for. */
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+ _Static_assert (((GNU_PROPERTY_X86_ISA_1_NEEDED
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+ > GNU_PROPERTY_X86_FEATURE_1_AND)
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+ && (GNU_PROPERTY_X86_FEATURE_1_AND
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+ > GNU_PROPERTY_1_NEEDED)),
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+ "GNU_PROPERTY_X86_ISA_1_NEEDED > "
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+ "GNU_PROPERTY_X86_FEATURE_1_AND && "
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+ "GNU_PROPERTY_X86_FEATURE_1_AND > "
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+ "GNU_PROPERTY_1_NEEDED");
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+ if (type == GNU_PROPERTY_X86_FEATURE_1_AND)
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+ *feature_1_and = *(unsigned int *) ptr;
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+ else if (type == GNU_PROPERTY_1_NEEDED)
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+ *needed_1 = *(unsigned int *) ptr;
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+ else
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+ {
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+ *isa_1_needed = *(unsigned int *) ptr;
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+
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+ /* Keep searching for the next GNU property note
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+ generated by the older linker. */
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+ return 0;
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+ }
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+ }
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+ else if (type > GNU_PROPERTY_X86_ISA_1_NEEDED)
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+ {
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+ /* Stop the scan since property type is in ascending
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+ order. */
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+ return 0;
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+ }
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+
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+ return 1;
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+}
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+
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static inline void __attribute__ ((unused))
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_dl_process_property_note (struct link_map *l, const ElfW(Nhdr) *note,
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const ElfW(Addr) size, const ElfW(Addr) align)
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@@ -141,45 +195,14 @@ _dl_process_property_note (struct link_map *l, const ElfW(Nhdr) *note,
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last_type = type;
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- if (type == GNU_PROPERTY_X86_FEATURE_1_AND
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- || type == GNU_PROPERTY_X86_ISA_1_NEEDED
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- || type == GNU_PROPERTY_1_NEEDED)
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- {
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- /* The sizes of types which we are searching for are
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- 4 bytes. There is no point to continue if this
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- note is ill-formed. */
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- if (datasz != 4)
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- return;
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-
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- /* NB: Stop the scan only after seeing all types which
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- we are searching for. */
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- _Static_assert (((GNU_PROPERTY_X86_ISA_1_NEEDED
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- > GNU_PROPERTY_X86_FEATURE_1_AND)
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- && (GNU_PROPERTY_X86_FEATURE_1_AND
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- > GNU_PROPERTY_1_NEEDED)),
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- "GNU_PROPERTY_X86_ISA_1_NEEDED > "
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- "GNU_PROPERTY_X86_FEATURE_1_AND && "
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- "GNU_PROPERTY_X86_FEATURE_1_AND > "
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- "GNU_PROPERTY_1_NEEDED");
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- if (type == GNU_PROPERTY_X86_FEATURE_1_AND)
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- feature_1_and = *(unsigned int *) ptr;
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- else if (type == GNU_PROPERTY_1_NEEDED)
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- needed_1 = *(unsigned int *) ptr;
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- else
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- {
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- isa_1_needed = *(unsigned int *) ptr;
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-
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- /* Keep searching for the next GNU property note
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- generated by the older linker. */
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- break;
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- }
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- }
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- else if (type > GNU_PROPERTY_X86_ISA_1_NEEDED)
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- {
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- /* Stop the scan since property type is in ascending
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- order. */
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- break;
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- }
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+ int result = _dl_check_gnu_property (type, datasz, ptr,
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+ &feature_1_and,
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+ &needed_1,
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+ &isa_1_needed);
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+ if (result == -1)
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+ return; /* Skip this note. */
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+ else if (result == 0)
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+ break; /* Stop checking. */
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/* Check the next property item. */
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ptr += ALIGN_UP (datasz, sizeof (ElfW(Addr)));
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@@ -217,7 +240,24 @@ static inline int __attribute__ ((always_inline))
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_dl_process_gnu_property (struct link_map *l, int fd, uint32_t type,
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uint32_t datasz, void *data)
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{
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- return 0;
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+ /* This is called on each GNU property. */
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+ unsigned int needed_1 = 0;
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+ unsigned int feature_1_and = 0;
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+ unsigned int isa_1_needed = 0;
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+ int result = _dl_check_gnu_property (type, datasz, data,
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+ &feature_1_and, &needed_1,
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+ &isa_1_needed);
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+ if (needed_1 != 0)
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+ l->l_1_needed = needed_1;
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+ if (isa_1_needed != 0)
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+ l->l_x86_isa_1_needed = isa_1_needed;
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+ if (feature_1_and != 0)
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+ l->l_x86_feature_1_and = feature_1_and;
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+ if ((needed_1 | isa_1_needed | feature_1_and) != 0)
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+ l->l_property = lc_property_valid;
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+ else if (l->l_property == lc_property_unknown)
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+ l->l_property = lc_property_none;
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+ return result <= 0 ? 0 : result;
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}
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#endif /* _DL_PROP_H */
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--
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2.40.1
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