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Makefile: Remove -N ldflag to prevent linker RWX warning

PATCH New Rahul Pathak 3 participants 3 messages Dec 25, 2022 – Jan 6, 2023 Kbuild

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Rahul Pathak

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#0 lore raw

PATCH 1/1 Makefile: Remove -N ldflag to prevent linker RWX warning

-N option coalesce all sections into single LOAD segment which causes data and other sections to have executable permission causing warning with new binutils ld 2.39.
New ld emits warning when any segment have all three permissions RWX.

ld.bfd: warning: test.elf has a LOAD segment with RWX permissions ld.bfd: warning: fw_dynamic.elf has a LOAD segment with RWX permissions ld.bfd: warning: fw_jump.elf has a LOAD segment with RWX permissions ld.bfd: warning: fw_payload.elf has a LOAD segment with RWX permissions

This option was added in below commit -
commit: eeab92f2423e ("Makefile: Convert to a more standard format")

Removing -N option allows to have text and rodata into one LOAD segment and other sections into separate LOAD segment which prevents RWX permissions on single LOAD segment. Here X == E

Current
LOAD 0x0000000000000120 0x0000000080000000 0x0000000080000000

                 0x000000000001d4d0 0x0000000000032ed8  RWE    0x10

-N removed
LOAD 0x0000000000001000 0x0000000080000000 0x0000000080000000

                 0x00000000000198cc 0x00000000000198cc  R E    0x1000
  LOAD           0x000000000001b000 0x000000008001a000 0x000000008001a000
                 0x00000000000034d0 0x0000000000018ed8  RW     0x1000
Signed-off-by Rahul Pathak <[email protected]>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Makefile +1 -1
index 92203c5a2ac0..b742d6dbc5e5 100644
@@ -369,7 +369,7 @@ ASFLAGS		+=	$(firmware-asflags-y)
 ARFLAGS		=	rcs
 
 ELFFLAGS	+=	$(USE_LD_FLAG)
-ELFFLAGS	+=	-Wl,--build-id=none -Wl,-N
+ELFFLAGS	+=	-Wl,--build-id=none
 ELFFLAGS	+=	$(platform-ldflags-y)
 ELFFLAGS	+=	$(firmware-ldflags-y)
Signature · 1 line
2.34.1
#1 lore raw

PATCH 1/1 Makefile: Remove -N ldflag to prevent linker RWX warning

Quoted 23 lines · Rahul Pathak

-N option coalesce all sections into single LOAD segment which causes data and other sections to have executable permission causing warning with new binutils ld 2.39.
New ld emits warning when any segment have all three permissions RWX.

ld.bfd: warning: test.elf has a LOAD segment with RWX permissions ld.bfd: warning: fw_dynamic.elf has a LOAD segment with RWX permissions ld.bfd: warning: fw_jump.elf has a LOAD segment with RWX permissions ld.bfd: warning: fw_payload.elf has a LOAD segment with RWX permissions

This option was added in below commit -
commit: eeab92f2423e ("Makefile: Convert to a more standard format")

Removing -N option allows to have text and rodata into one LOAD segment and other sections into separate LOAD segment which prevents RWX permissions on single LOAD segment. Here X == E

Current
LOAD 0x0000000000000120 0x0000000080000000 0x0000000080000000

                 0x000000000001d4d0 0x0000000000032ed8  RWE    0x10

-N removed
LOAD 0x0000000000001000 0x0000000080000000 0x0000000080000000

Quoted 8 lines
                 0x00000000000198cc 0x00000000000198cc  R E    0x1000
  LOAD           0x000000000001b000 0x000000008001a000 0x000000008001a000
                 0x00000000000034d0 0x0000000000018ed8  RW     0x1000
Signed-off-by Rahul Pathak <[email protected]>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

fw_dynamic.bin still works for me on D1 with this change, so:

Tested-by Samuel Holland <[email protected]>
Applied
#2 lore raw

PATCH 1/1 Makefile: Remove -N ldflag to prevent linker RWX warning

In reply to Rahul Pathak
Quoted 22 lines · Rahul Pathak

-N option coalesce all sections into single LOAD segment which causes data and other sections to have executable permission causing warning with new binutils ld 2.39.
New ld emits warning when any segment have all three permissions RWX.

ld.bfd: warning: test.elf has a LOAD segment with RWX permissions ld.bfd: warning: fw_dynamic.elf has a LOAD segment with RWX permissions ld.bfd: warning: fw_jump.elf has a LOAD segment with RWX permissions ld.bfd: warning: fw_payload.elf has a LOAD segment with RWX permissions

This option was added in below commit -
commit: eeab92f2423e ("Makefile: Convert to a more standard format")

Removing -N option allows to have text and rodata into one LOAD segment and other sections into separate LOAD segment which prevents RWX permissions on single LOAD segment. Here X == E

Current
LOAD 0x0000000000000120 0x0000000080000000 0x0000000080000000

                 0x000000000001d4d0 0x0000000000032ed8  RWE    0x10
Quoted 7 lines

-N removed
LOAD 0x0000000000001000 0x0000000080000000 0x0000000080000000

                 0x00000000000198cc 0x00000000000198cc  R E    0x1000
  LOAD           0x000000000001b000 0x000000008001a000 0x000000008001a000
                 0x00000000000034d0 0x0000000000018ed8  RW     0x1000
Signed-off-by Rahul Pathak <[email protected]>

Looks good to me.

Reviewed-by Anup Patel <[email protected]>

Applied this patch to the riscv/opensbi repo.

Thanks,
Anup

Quoted 25 lines
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Makefile +1 -2
index 92203c5a2ac0..b742d6dbc5e5 100644
@@ -369,7 +369,7 @@ ASFLAGS             +=      $(firmware-asflags-y)
 ARFLAGS                =       rcs
 
 ELFFLAGS       +=      $(USE_LD_FLAG)
-ELFFLAGS       +=      -Wl,--build-id=none -Wl,-N
+ELFFLAGS       +=      -Wl,--build-id=none
 ELFFLAGS       +=      $(platform-ldflags-y)
 ELFFLAGS       +=      $(firmware-ldflags-y)
 
--

2.34.1

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