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* [PATCH] RISC-V: PR27566, consider ELF_MAXPAGESIZE/COMMONPAGESIZE for gp relaxations.
@ 2023-05-12  9:15 Nelson Chu
  0 siblings, 0 replies; only message in thread
From: Nelson Chu @ 2023-05-12  9:15 UTC (permalink / raw)
  To: binutils, jim.wilson.gcc, palmer, andrew, lifang_xia; +Cc: nelson

For default linker script, if a symbol's value outsides the bounds of the
defined section, then it may cross the data segment alignment, so we should
reserve more size about MAXPAGESIZE and COMMONPAGESIZE when doing gp
relaxations.  Otherwise we may meet the truncated errors since the data
segment alignment might move the section forward.

bfd/
	* elfnn-riscv.c (_bfd_riscv_relax_lui): Consider MAXPAGESIZE and
	COMMONPAGESIZE if the symbol's value outsides the bounds of the
	defined section.
	(_bfd_riscv_relax_pc): Likewise.
ld/
	* testsuite/ld-riscv-elf/ld-riscv-elf.exp: Updated.
	* testsuite/ld-riscv-elf/relax-data-segment-align*: New testcase
	for pr27566.  Without this patch, the rv32 binutils will meet
	truncated errors for this testcase.
---
 bfd/elfnn-riscv.c                             | 29 +++++++++++++++++--
 ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp    |  1 +
 .../ld-riscv-elf/relax-data-segment-align.d   |  8 +++++
 .../ld-riscv-elf/relax-data-segment-align.s   | 16 ++++++++++
 4 files changed, 52 insertions(+), 2 deletions(-)
 create mode 100644 ld/testsuite/ld-riscv-elf/relax-data-segment-align.d
 create mode 100644 ld/testsuite/ld-riscv-elf/relax-data-segment-align.s

diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
index a23b91ac15c..26f965945d3 100644
--- a/bfd/elfnn-riscv.c
+++ b/bfd/elfnn-riscv.c
@@ -4512,6 +4512,9 @@ _bfd_riscv_relax_lui (bfd *abfd,
   bfd_vma gp = htab->params->relax_gp
 	       ? riscv_global_pointer_value (link_info)
 	       : 0;
+  bfd_vma data_segment_alignment = link_info->relro
+				   ? ELF_MAXPAGESIZE + ELF_COMMONPAGESIZE
+				   : ELF_MAXPAGESIZE;
   int use_rvc = elf_elfheader (abfd)->e_flags & EF_RISCV_RVC;
 
   BFD_ASSERT (rel->r_offset + 4 <= sec->size);
@@ -4536,6 +4539,16 @@ _bfd_riscv_relax_lui (bfd *abfd,
 	      htab->max_alignment_for_gp = max_alignment;
 	    }
 	}
+
+      /* PR27566, for default linker script, if a symbol's value outsides the
+	 bounds of the defined section, then it may cross the data segment
+	 alignment, so we should reserve more size about MAXPAGESIZE and
+	 COMMONPAGESIZE, since the data segment alignment might move the
+	 section forward.  */
+      if (symval < sec_addr (sym_sec)
+	  || symval > (sec_addr (sym_sec) + sym_sec->size))
+	max_alignment = data_segment_alignment > max_alignment
+			? data_segment_alignment : max_alignment;
     }
 
   /* Is the reference in range of x0 or gp?
@@ -4580,8 +4593,7 @@ _bfd_riscv_relax_lui (bfd *abfd,
       && ELFNN_R_TYPE (rel->r_info) == R_RISCV_HI20
       && VALID_CITYPE_LUI_IMM (RISCV_CONST_HIGH_PART (symval))
       && VALID_CITYPE_LUI_IMM (RISCV_CONST_HIGH_PART (symval)
-			    + (link_info->relro ? 2 * ELF_MAXPAGESIZE
-			       : ELF_MAXPAGESIZE)))
+			       + data_segment_alignment))
     {
       /* Replace LUI with C.LUI if legal (i.e., rd != x0 and rd != x2/sp).  */
       bfd_vma lui = bfd_getl32 (contents + rel->r_offset);
@@ -4726,6 +4738,9 @@ _bfd_riscv_relax_pc (bfd *abfd ATTRIBUTE_UNUSED,
   bfd_vma gp = htab->params->relax_gp
 	       ? riscv_global_pointer_value (link_info)
 	       : 0;
+  bfd_vma data_segment_alignment = link_info->relro
+				   ? ELF_MAXPAGESIZE + ELF_COMMONPAGESIZE
+				   : ELF_MAXPAGESIZE;
 
   BFD_ASSERT (rel->r_offset + 4 <= sec->size);
 
@@ -4800,6 +4815,16 @@ _bfd_riscv_relax_pc (bfd *abfd ATTRIBUTE_UNUSED,
 	      htab->max_alignment_for_gp = max_alignment;
 	    }
 	}
+
+      /* PR27566, for default linker script, if a symbol's value outsides the
+	 bounds of the defined section, then it may cross the data segment
+	 alignment, so we should reserve more size about MAXPAGESIZE and
+	 COMMONPAGESIZE, since the data segment alignment might move the
+	 section forward.  */
+      if (symval < sec_addr (sym_sec)
+	  || symval > (sec_addr (sym_sec) + sym_sec->size))
+	max_alignment = data_segment_alignment > max_alignment
+			? data_segment_alignment : max_alignment;
     }
 
   /* Is the reference in range of x0 or gp?
diff --git a/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp b/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
index 9e103b283f7..713e741c8af 100644
--- a/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
+++ b/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
@@ -172,6 +172,7 @@ if [istarget "riscv*-*-*"] {
     run_dump_test "attr-merge-priv-spec-failed-06"
     run_dump_test "attr-phdr"
     run_dump_test "relax-max-align-gp"
+    run_dump_test "relax-data-segment-align"
     run_ld_link_tests [list \
 	[list "Weak reference 32" "-T weakref.ld -m[riscv_choose_ilp32_emul]" "" \
 	    "-march=rv32i -mabi=ilp32" {weakref32.s} \
diff --git a/ld/testsuite/ld-riscv-elf/relax-data-segment-align.d b/ld/testsuite/ld-riscv-elf/relax-data-segment-align.d
new file mode 100644
index 00000000000..22aeb4c3f90
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/relax-data-segment-align.d
@@ -0,0 +1,8 @@
+#source: relax-data-segment-align.s
+#ld:
+#objdump: -d
+
+#failif
+#...
+.*gp.*
+#...
diff --git a/ld/testsuite/ld-riscv-elf/relax-data-segment-align.s b/ld/testsuite/ld-riscv-elf/relax-data-segment-align.s
new file mode 100644
index 00000000000..98718922fb5
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/relax-data-segment-align.s
@@ -0,0 +1,16 @@
+	.text
+	.globl _start
+_start:
+	.rept 6000
+	lla a0, symbol
+	.endr
+
+	.section .rodata
+	.set symbol, . + 4598
+	.fill 100, 4, 1
+
+	.data
+	.align 3
+	.rept 860
+	.long 0x1000
+	.endr
-- 
2.39.2 (Apple Git-143)


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2023-05-12  9:15 [PATCH] RISC-V: PR27566, consider ELF_MAXPAGESIZE/COMMONPAGESIZE for gp relaxations Nelson Chu

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