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llvm-project/lld/test/ELF/arm-fix-cortex-a8-nopatch.s

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[ELF][ARM] Implement --fix-cortex-a8 to fix erratum 657417 The --fix-cortex-a8 option implements a linker workaround for the coretex-a8 erratum 657417. A summary of the erratum conditions is: - A 32-bit Thumb-2 branch instruction B.w, Bcc.w, BL, BLX spans two 4KiB regions. - The destination of the branch is to the first 4KiB region. - The instruction before the branch is a 32-bit Thumb-2 non-branch instruction. The linker fix is to redirect the branch to a patch not in the first 4KiB region. The patch forwards the branch on to its target. The cortex-a8, is an old CPU, with the first implementation of this workaround in ld.bfd appearing in 2009. The cortex-a8 has been used in early Android Phones and there are some critical applications that still need to run on a cortex-a8 that have the erratum. The patch is applied roughly 10 times on LLD and 20 on Clang when they are built with --fix-cortex-a8 on an Arm system. The formal erratum description is avaliable in the ARM Core Cortex-A8 (AT400/AT401) Errata Notice document. This is available from Arm on request but it seems to be findable via a web search. Differential Revision: https://reviews.llvm.org/D67284 llvm-svn: 371965
2019-09-16 17:38:38 +08:00
// REQUIRES: arm
// RUN: llvm-mc -filetype=obj -triple=armv7a-linux-gnueabihf --arm-add-build-attributes %s -o %t.o
// RUN: ld.lld --fix-cortex-a8 -verbose %t.o -o %t2
[ELF][ARM] Increase default max-page-size from 4096 to 6536 See http://lists.llvm.org/pipermail/llvm-dev/2020-April/140549.html For the record, GNU ld changed to 64k max page size in 2014 https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=7572ca8989ead4c3425a1500bc241eaaeffa2c89 "[RFC] ld/ARM: Increase maximum page size to 64kB" Android driver forced 4k page size in AArch64 (D55029) and ARM (D77746). A binary linked with max-page-size=4096 does not run on a system with a higher page size configured. There are some systems out there that do this and it leads to the binary getting `Killed!` by the kernel. In the non-linker-script cases, when linked with -z noseparate-code (default), the max-page-size increase should not cause any size difference. There may be some VMA usage differences, though. Reviewed By: psmith, MaskRay Differential Revision: https://reviews.llvm.org/D77330
2020-04-18 23:06:37 +08:00
// RUN: llvm-objdump -d %t2 --start-address=0x21ffa --stop-address=0x22002 --no-show-raw-insn | FileCheck --check-prefix=CALLSITE1 %s
// RUN: llvm-objdump -d %t2 --start-address=0x22ffa --stop-address=0x23002 --no-show-raw-insn | FileCheck --check-prefix=CALLSITE2 %s
// RUN: llvm-objdump -d %t2 --start-address=0x23ffa --stop-address=0x24002 --no-show-raw-insn | FileCheck --check-prefix=CALLSITE3 %s
// RUN: llvm-objdump -d %t2 --start-address=0x24ffa --stop-address=0x25006 --no-show-raw-insn | FileCheck --check-prefix=CALLSITE4 %s
// RUN: llvm-objdump -d %t2 --start-address=0x25ffe --stop-address=0x26002 --no-show-raw-insn | FileCheck --check-prefix=CALLSITE5 %s
// RUN: llvm-objdump -d %t2 --start-address=0x27000 --stop-address=0x28004 --no-show-raw-insn | FileCheck --check-prefix=CALLSITE6 %s
// RUN: llvm-objdump -d %t2 --start-address=0x28002 --stop-address=0x29006 --no-show-raw-insn | FileCheck --check-prefix=CALLSITE7 %s
[ELF][ARM] Implement --fix-cortex-a8 to fix erratum 657417 The --fix-cortex-a8 option implements a linker workaround for the coretex-a8 erratum 657417. A summary of the erratum conditions is: - A 32-bit Thumb-2 branch instruction B.w, Bcc.w, BL, BLX spans two 4KiB regions. - The destination of the branch is to the first 4KiB region. - The instruction before the branch is a 32-bit Thumb-2 non-branch instruction. The linker fix is to redirect the branch to a patch not in the first 4KiB region. The patch forwards the branch on to its target. The cortex-a8, is an old CPU, with the first implementation of this workaround in ld.bfd appearing in 2009. The cortex-a8 has been used in early Android Phones and there are some critical applications that still need to run on a cortex-a8 that have the erratum. The patch is applied roughly 10 times on LLD and 20 on Clang when they are built with --fix-cortex-a8 on an Arm system. The formal erratum description is avaliable in the ARM Core Cortex-A8 (AT400/AT401) Errata Notice document. This is available from Arm on request but it seems to be findable via a web search. Differential Revision: https://reviews.llvm.org/D67284 llvm-svn: 371965
2019-09-16 17:38:38 +08:00
/// Test boundary conditions of the cortex-a8 erratum. The following cases
/// should not trigger the Erratum
.syntax unified
.thumb
.text
.global _start
.balign 4096
.thumb_func
_start:
nop.w
.space 4086
.thumb_func
target:
/// 32-bit branch spans 2 4KiB regions, preceded by a 32-bit branch so no patch
/// expected.
b.w target
b.w target
[ELF][ARM] Increase default max-page-size from 4096 to 6536 See http://lists.llvm.org/pipermail/llvm-dev/2020-April/140549.html For the record, GNU ld changed to 64k max page size in 2014 https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=7572ca8989ead4c3425a1500bc241eaaeffa2c89 "[RFC] ld/ARM: Increase maximum page size to 64kB" Android driver forced 4k page size in AArch64 (D55029) and ARM (D77746). A binary linked with max-page-size=4096 does not run on a system with a higher page size configured. There are some systems out there that do this and it leads to the binary getting `Killed!` by the kernel. In the non-linker-script cases, when linked with -z noseparate-code (default), the max-page-size increase should not cause any size difference. There may be some VMA usage differences, though. Reviewed By: psmith, MaskRay Differential Revision: https://reviews.llvm.org/D77330
2020-04-18 23:06:37 +08:00
// CALLSITE1: 00021ffa <target>:
[ARMInstPrinter] Print the target address of a branch instruction This follows other patches that changed printing immediate values of branch instructions to target addresses, see D76580 (x86), D76591 (PPC), D77853 (AArch64). As observing immediate values might sometimes be useful, they are printed as comments for branch instructions. // llvm-objdump -d output (before) 000200b4 <_start>: 200b4: ff ff ff fa blx #-4 <thumb> 000200b8 <thumb>: 200b8: ff f7 fc ef blx #-8 <_start> // llvm-objdump -d output (after) 000200b4 <_start>: 200b4: ff ff ff fa blx 0x200b8 <thumb> @ imm = #-4 000200b8 <thumb>: 200b8: ff f7 fc ef blx 0x200b4 <_start> @ imm = #-8 // GNU objdump -d. 000200b4 <_start>: 200b4: faffffff blx 200b8 <thumb> 000200b8 <thumb>: 200b8: f7ff effc blx 200b4 <_start> Differential Revision: https://reviews.llvm.org/D104701
2021-06-30 17:34:52 +08:00
// CALLSITE1-NEXT: 21ffa: b.w 0x21ffa <target>
// CALLSITE1-NEXT: 21ffe: b.w 0x21ffa <target>
[ELF][ARM] Implement --fix-cortex-a8 to fix erratum 657417 The --fix-cortex-a8 option implements a linker workaround for the coretex-a8 erratum 657417. A summary of the erratum conditions is: - A 32-bit Thumb-2 branch instruction B.w, Bcc.w, BL, BLX spans two 4KiB regions. - The destination of the branch is to the first 4KiB region. - The instruction before the branch is a 32-bit Thumb-2 non-branch instruction. The linker fix is to redirect the branch to a patch not in the first 4KiB region. The patch forwards the branch on to its target. The cortex-a8, is an old CPU, with the first implementation of this workaround in ld.bfd appearing in 2009. The cortex-a8 has been used in early Android Phones and there are some critical applications that still need to run on a cortex-a8 that have the erratum. The patch is applied roughly 10 times on LLD and 20 on Clang when they are built with --fix-cortex-a8 on an Arm system. The formal erratum description is avaliable in the ARM Core Cortex-A8 (AT400/AT401) Errata Notice document. This is available from Arm on request but it seems to be findable via a web search. Differential Revision: https://reviews.llvm.org/D67284 llvm-svn: 371965
2019-09-16 17:38:38 +08:00
.space 4088
.type target2, %function
target2:
/// 32-bit Branch and link spans 2 4KiB regions, preceded by a 16-bit
/// instruction so no patch expected.
nop
nop
bl target2
[ELF][ARM] Increase default max-page-size from 4096 to 6536 See http://lists.llvm.org/pipermail/llvm-dev/2020-April/140549.html For the record, GNU ld changed to 64k max page size in 2014 https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=7572ca8989ead4c3425a1500bc241eaaeffa2c89 "[RFC] ld/ARM: Increase maximum page size to 64kB" Android driver forced 4k page size in AArch64 (D55029) and ARM (D77746). A binary linked with max-page-size=4096 does not run on a system with a higher page size configured. There are some systems out there that do this and it leads to the binary getting `Killed!` by the kernel. In the non-linker-script cases, when linked with -z noseparate-code (default), the max-page-size increase should not cause any size difference. There may be some VMA usage differences, though. Reviewed By: psmith, MaskRay Differential Revision: https://reviews.llvm.org/D77330
2020-04-18 23:06:37 +08:00
// CALLSITE2: 00022ffa <target2>:
// CALLSITE2-NEXT: 22ffa: nop
// CALLSITE2-NEXT: 22ffc: nop
[ARMInstPrinter] Print the target address of a branch instruction This follows other patches that changed printing immediate values of branch instructions to target addresses, see D76580 (x86), D76591 (PPC), D77853 (AArch64). As observing immediate values might sometimes be useful, they are printed as comments for branch instructions. // llvm-objdump -d output (before) 000200b4 <_start>: 200b4: ff ff ff fa blx #-4 <thumb> 000200b8 <thumb>: 200b8: ff f7 fc ef blx #-8 <_start> // llvm-objdump -d output (after) 000200b4 <_start>: 200b4: ff ff ff fa blx 0x200b8 <thumb> @ imm = #-4 000200b8 <thumb>: 200b8: ff f7 fc ef blx 0x200b4 <_start> @ imm = #-8 // GNU objdump -d. 000200b4 <_start>: 200b4: faffffff blx 200b8 <thumb> 000200b8 <thumb>: 200b8: f7ff effc blx 200b4 <_start> Differential Revision: https://reviews.llvm.org/D104701
2021-06-30 17:34:52 +08:00
// CALLSITE2-NEXT: 22ffe: bl 0x22ffa <target2>
[ELF][ARM] Implement --fix-cortex-a8 to fix erratum 657417 The --fix-cortex-a8 option implements a linker workaround for the coretex-a8 erratum 657417. A summary of the erratum conditions is: - A 32-bit Thumb-2 branch instruction B.w, Bcc.w, BL, BLX spans two 4KiB regions. - The destination of the branch is to the first 4KiB region. - The instruction before the branch is a 32-bit Thumb-2 non-branch instruction. The linker fix is to redirect the branch to a patch not in the first 4KiB region. The patch forwards the branch on to its target. The cortex-a8, is an old CPU, with the first implementation of this workaround in ld.bfd appearing in 2009. The cortex-a8 has been used in early Android Phones and there are some critical applications that still need to run on a cortex-a8 that have the erratum. The patch is applied roughly 10 times on LLD and 20 on Clang when they are built with --fix-cortex-a8 on an Arm system. The formal erratum description is avaliable in the ARM Core Cortex-A8 (AT400/AT401) Errata Notice document. This is available from Arm on request but it seems to be findable via a web search. Differential Revision: https://reviews.llvm.org/D67284 llvm-svn: 371965
2019-09-16 17:38:38 +08:00
.space 4088
.type target3, %function
target3:
/// 32-bit conditional branch spans 2 4KiB regions, preceded by a 32-bit
/// non branch instruction, branch is backwards but outside 4KiB region. So
/// expect no patch.
nop.w
beq.w target2
[ELF][ARM] Increase default max-page-size from 4096 to 6536 See http://lists.llvm.org/pipermail/llvm-dev/2020-April/140549.html For the record, GNU ld changed to 64k max page size in 2014 https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=7572ca8989ead4c3425a1500bc241eaaeffa2c89 "[RFC] ld/ARM: Increase maximum page size to 64kB" Android driver forced 4k page size in AArch64 (D55029) and ARM (D77746). A binary linked with max-page-size=4096 does not run on a system with a higher page size configured. There are some systems out there that do this and it leads to the binary getting `Killed!` by the kernel. In the non-linker-script cases, when linked with -z noseparate-code (default), the max-page-size increase should not cause any size difference. There may be some VMA usage differences, though. Reviewed By: psmith, MaskRay Differential Revision: https://reviews.llvm.org/D77330
2020-04-18 23:06:37 +08:00
// CALLSITE3: 00023ffa <target3>:
// CALLSITE3-NEXT: 23ffa: nop.w
[ARMInstPrinter] Print the target address of a branch instruction This follows other patches that changed printing immediate values of branch instructions to target addresses, see D76580 (x86), D76591 (PPC), D77853 (AArch64). As observing immediate values might sometimes be useful, they are printed as comments for branch instructions. // llvm-objdump -d output (before) 000200b4 <_start>: 200b4: ff ff ff fa blx #-4 <thumb> 000200b8 <thumb>: 200b8: ff f7 fc ef blx #-8 <_start> // llvm-objdump -d output (after) 000200b4 <_start>: 200b4: ff ff ff fa blx 0x200b8 <thumb> @ imm = #-4 000200b8 <thumb>: 200b8: ff f7 fc ef blx 0x200b4 <_start> @ imm = #-8 // GNU objdump -d. 000200b4 <_start>: 200b4: faffffff blx 200b8 <thumb> 000200b8 <thumb>: 200b8: f7ff effc blx 200b4 <_start> Differential Revision: https://reviews.llvm.org/D104701
2021-06-30 17:34:52 +08:00
// CALLSITE3-NEXT: 23ffe: beq.w 0x22ffa <target2>
[ELF][ARM] Implement --fix-cortex-a8 to fix erratum 657417 The --fix-cortex-a8 option implements a linker workaround for the coretex-a8 erratum 657417. A summary of the erratum conditions is: - A 32-bit Thumb-2 branch instruction B.w, Bcc.w, BL, BLX spans two 4KiB regions. - The destination of the branch is to the first 4KiB region. - The instruction before the branch is a 32-bit Thumb-2 non-branch instruction. The linker fix is to redirect the branch to a patch not in the first 4KiB region. The patch forwards the branch on to its target. The cortex-a8, is an old CPU, with the first implementation of this workaround in ld.bfd appearing in 2009. The cortex-a8 has been used in early Android Phones and there are some critical applications that still need to run on a cortex-a8 that have the erratum. The patch is applied roughly 10 times on LLD and 20 on Clang when they are built with --fix-cortex-a8 on an Arm system. The formal erratum description is avaliable in the ARM Core Cortex-A8 (AT400/AT401) Errata Notice document. This is available from Arm on request but it seems to be findable via a web search. Differential Revision: https://reviews.llvm.org/D67284 llvm-svn: 371965
2019-09-16 17:38:38 +08:00
.space 4088
.type source4, %function
source4:
/// 32-bit conditional branch spans 2 4KiB regions, preceded by a 32-bit
/// non branch instruction, branch is forwards to 2nd region so expect no patch.
nop.w
beq.w target4
.thumb_func
target4:
nop.w
[ELF][ARM] Increase default max-page-size from 4096 to 6536 See http://lists.llvm.org/pipermail/llvm-dev/2020-April/140549.html For the record, GNU ld changed to 64k max page size in 2014 https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=7572ca8989ead4c3425a1500bc241eaaeffa2c89 "[RFC] ld/ARM: Increase maximum page size to 64kB" Android driver forced 4k page size in AArch64 (D55029) and ARM (D77746). A binary linked with max-page-size=4096 does not run on a system with a higher page size configured. There are some systems out there that do this and it leads to the binary getting `Killed!` by the kernel. In the non-linker-script cases, when linked with -z noseparate-code (default), the max-page-size increase should not cause any size difference. There may be some VMA usage differences, though. Reviewed By: psmith, MaskRay Differential Revision: https://reviews.llvm.org/D77330
2020-04-18 23:06:37 +08:00
// CALLSITE4: 00024ffa <source4>:
// CALLSITE4-NEXT: 24ffa: nop.w
[ARMInstPrinter] Print the target address of a branch instruction This follows other patches that changed printing immediate values of branch instructions to target addresses, see D76580 (x86), D76591 (PPC), D77853 (AArch64). As observing immediate values might sometimes be useful, they are printed as comments for branch instructions. // llvm-objdump -d output (before) 000200b4 <_start>: 200b4: ff ff ff fa blx #-4 <thumb> 000200b8 <thumb>: 200b8: ff f7 fc ef blx #-8 <_start> // llvm-objdump -d output (after) 000200b4 <_start>: 200b4: ff ff ff fa blx 0x200b8 <thumb> @ imm = #-4 000200b8 <thumb>: 200b8: ff f7 fc ef blx 0x200b4 <_start> @ imm = #-8 // GNU objdump -d. 000200b4 <_start>: 200b4: faffffff blx 200b8 <thumb> 000200b8 <thumb>: 200b8: f7ff effc blx 200b4 <_start> Differential Revision: https://reviews.llvm.org/D104701
2021-06-30 17:34:52 +08:00
// CALLSITE4-NEXT: 24ffe: beq.w 0x25002 <target4>
[ELF][ARM] Increase default max-page-size from 4096 to 6536 See http://lists.llvm.org/pipermail/llvm-dev/2020-April/140549.html For the record, GNU ld changed to 64k max page size in 2014 https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=7572ca8989ead4c3425a1500bc241eaaeffa2c89 "[RFC] ld/ARM: Increase maximum page size to 64kB" Android driver forced 4k page size in AArch64 (D55029) and ARM (D77746). A binary linked with max-page-size=4096 does not run on a system with a higher page size configured. There are some systems out there that do this and it leads to the binary getting `Killed!` by the kernel. In the non-linker-script cases, when linked with -z noseparate-code (default), the max-page-size increase should not cause any size difference. There may be some VMA usage differences, though. Reviewed By: psmith, MaskRay Differential Revision: https://reviews.llvm.org/D77330
2020-04-18 23:06:37 +08:00
// CALLSITE4: 00025002 <target4>:
// CALLSITE4-NEXT: 25002: nop.w
[ELF][ARM] Implement --fix-cortex-a8 to fix erratum 657417 The --fix-cortex-a8 option implements a linker workaround for the coretex-a8 erratum 657417. A summary of the erratum conditions is: - A 32-bit Thumb-2 branch instruction B.w, Bcc.w, BL, BLX spans two 4KiB regions. - The destination of the branch is to the first 4KiB region. - The instruction before the branch is a 32-bit Thumb-2 non-branch instruction. The linker fix is to redirect the branch to a patch not in the first 4KiB region. The patch forwards the branch on to its target. The cortex-a8, is an old CPU, with the first implementation of this workaround in ld.bfd appearing in 2009. The cortex-a8 has been used in early Android Phones and there are some critical applications that still need to run on a cortex-a8 that have the erratum. The patch is applied roughly 10 times on LLD and 20 on Clang when they are built with --fix-cortex-a8 on an Arm system. The formal erratum description is avaliable in the ARM Core Cortex-A8 (AT400/AT401) Errata Notice document. This is available from Arm on request but it seems to be findable via a web search. Differential Revision: https://reviews.llvm.org/D67284 llvm-svn: 371965
2019-09-16 17:38:38 +08:00
.space 4084
.type target5, %function
target5:
/// 32-bit conditional branch spans 2 4KiB regions, preceded by the encoding of
/// a 32-bit thumb instruction, but in ARM state (illegal instruction), we
/// should not decode and match it as Thumb, expect no patch.
.arm
.inst 0x800f3af /// nop.w encoding in Thumb
.thumb
.thumb_func
source5:
beq.w target5
[ELF][ARM] Increase default max-page-size from 4096 to 6536 See http://lists.llvm.org/pipermail/llvm-dev/2020-April/140549.html For the record, GNU ld changed to 64k max page size in 2014 https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=7572ca8989ead4c3425a1500bc241eaaeffa2c89 "[RFC] ld/ARM: Increase maximum page size to 64kB" Android driver forced 4k page size in AArch64 (D55029) and ARM (D77746). A binary linked with max-page-size=4096 does not run on a system with a higher page size configured. There are some systems out there that do this and it leads to the binary getting `Killed!` by the kernel. In the non-linker-script cases, when linked with -z noseparate-code (default), the max-page-size increase should not cause any size difference. There may be some VMA usage differences, though. Reviewed By: psmith, MaskRay Differential Revision: https://reviews.llvm.org/D77330
2020-04-18 23:06:37 +08:00
// CALLSITE5: 00025ffe <source5>:
[ARMInstPrinter] Print the target address of a branch instruction This follows other patches that changed printing immediate values of branch instructions to target addresses, see D76580 (x86), D76591 (PPC), D77853 (AArch64). As observing immediate values might sometimes be useful, they are printed as comments for branch instructions. // llvm-objdump -d output (before) 000200b4 <_start>: 200b4: ff ff ff fa blx #-4 <thumb> 000200b8 <thumb>: 200b8: ff f7 fc ef blx #-8 <_start> // llvm-objdump -d output (after) 000200b4 <_start>: 200b4: ff ff ff fa blx 0x200b8 <thumb> @ imm = #-4 000200b8 <thumb>: 200b8: ff f7 fc ef blx 0x200b4 <_start> @ imm = #-8 // GNU objdump -d. 000200b4 <_start>: 200b4: faffffff blx 200b8 <thumb> 000200b8 <thumb>: 200b8: f7ff effc blx 200b4 <_start> Differential Revision: https://reviews.llvm.org/D104701
2021-06-30 17:34:52 +08:00
// CALLSITE5-NEXT: 25ffe: beq.w 0x25ffa <target5>
[ELF][ARM] Implement --fix-cortex-a8 to fix erratum 657417 The --fix-cortex-a8 option implements a linker workaround for the coretex-a8 erratum 657417. A summary of the erratum conditions is: - A 32-bit Thumb-2 branch instruction B.w, Bcc.w, BL, BLX spans two 4KiB regions. - The destination of the branch is to the first 4KiB region. - The instruction before the branch is a 32-bit Thumb-2 non-branch instruction. The linker fix is to redirect the branch to a patch not in the first 4KiB region. The patch forwards the branch on to its target. The cortex-a8, is an old CPU, with the first implementation of this workaround in ld.bfd appearing in 2009. The cortex-a8 has been used in early Android Phones and there are some critical applications that still need to run on a cortex-a8 that have the erratum. The patch is applied roughly 10 times on LLD and 20 on Clang when they are built with --fix-cortex-a8 on an Arm system. The formal erratum description is avaliable in the ARM Core Cortex-A8 (AT400/AT401) Errata Notice document. This is available from Arm on request but it seems to be findable via a web search. Differential Revision: https://reviews.llvm.org/D67284 llvm-svn: 371965
2019-09-16 17:38:38 +08:00
/// Edge case where two word sequence starts at offset 0xffc, check that
/// we don't match. In this case the branch will be completely in the 2nd
/// region and the branch will target the second region. This will pass a
/// branch destination in the same region test, but not the branch must have
/// and address of the form xxxxxffe.
.space 4090
.type target6, %function
nop.w
/// Make sure target of branch is in the same 4KiB region as the branch.
target6:
bl target6
[ELF][ARM] Increase default max-page-size from 4096 to 6536 See http://lists.llvm.org/pipermail/llvm-dev/2020-April/140549.html For the record, GNU ld changed to 64k max page size in 2014 https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=7572ca8989ead4c3425a1500bc241eaaeffa2c89 "[RFC] ld/ARM: Increase maximum page size to 64kB" Android driver forced 4k page size in AArch64 (D55029) and ARM (D77746). A binary linked with max-page-size=4096 does not run on a system with a higher page size configured. There are some systems out there that do this and it leads to the binary getting `Killed!` by the kernel. In the non-linker-script cases, when linked with -z noseparate-code (default), the max-page-size increase should not cause any size difference. There may be some VMA usage differences, though. Reviewed By: psmith, MaskRay Differential Revision: https://reviews.llvm.org/D77330
2020-04-18 23:06:37 +08:00
// CALLSITE6: 00027000 <target6>:
[ARMInstPrinter] Print the target address of a branch instruction This follows other patches that changed printing immediate values of branch instructions to target addresses, see D76580 (x86), D76591 (PPC), D77853 (AArch64). As observing immediate values might sometimes be useful, they are printed as comments for branch instructions. // llvm-objdump -d output (before) 000200b4 <_start>: 200b4: ff ff ff fa blx #-4 <thumb> 000200b8 <thumb>: 200b8: ff f7 fc ef blx #-8 <_start> // llvm-objdump -d output (after) 000200b4 <_start>: 200b4: ff ff ff fa blx 0x200b8 <thumb> @ imm = #-4 000200b8 <thumb>: 200b8: ff f7 fc ef blx 0x200b4 <_start> @ imm = #-8 // GNU objdump -d. 000200b4 <_start>: 200b4: faffffff blx 200b8 <thumb> 000200b8 <thumb>: 200b8: f7ff effc blx 200b4 <_start> Differential Revision: https://reviews.llvm.org/D104701
2021-06-30 17:34:52 +08:00
// CALLSITE6-NEXT: 27000: bl 0x27000 <target6>
[ELF][ARM] Implement --fix-cortex-a8 to fix erratum 657417 The --fix-cortex-a8 option implements a linker workaround for the coretex-a8 erratum 657417. A summary of the erratum conditions is: - A 32-bit Thumb-2 branch instruction B.w, Bcc.w, BL, BLX spans two 4KiB regions. - The destination of the branch is to the first 4KiB region. - The instruction before the branch is a 32-bit Thumb-2 non-branch instruction. The linker fix is to redirect the branch to a patch not in the first 4KiB region. The patch forwards the branch on to its target. The cortex-a8, is an old CPU, with the first implementation of this workaround in ld.bfd appearing in 2009. The cortex-a8 has been used in early Android Phones and there are some critical applications that still need to run on a cortex-a8 that have the erratum. The patch is applied roughly 10 times on LLD and 20 on Clang when they are built with --fix-cortex-a8 on an Arm system. The formal erratum description is avaliable in the ARM Core Cortex-A8 (AT400/AT401) Errata Notice document. This is available from Arm on request but it seems to be findable via a web search. Differential Revision: https://reviews.llvm.org/D67284 llvm-svn: 371965
2019-09-16 17:38:38 +08:00
/// Edge case where two word sequence starts at offset 0xffe, check that
/// we don't match. In this case the branch will be completely in the 2nd
/// region and the branch will target the second region. This will pass a
/// branch destination in the same region test, but not the branch must have
/// and address of the form xxxxxffe.
.space 4090
.type target7, %function
nop.w
/// Make sure target of branch is in the same 4KiB region as the branch.
target7:
bl target7
[ELF][ARM] Increase default max-page-size from 4096 to 6536 See http://lists.llvm.org/pipermail/llvm-dev/2020-April/140549.html For the record, GNU ld changed to 64k max page size in 2014 https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=7572ca8989ead4c3425a1500bc241eaaeffa2c89 "[RFC] ld/ARM: Increase maximum page size to 64kB" Android driver forced 4k page size in AArch64 (D55029) and ARM (D77746). A binary linked with max-page-size=4096 does not run on a system with a higher page size configured. There are some systems out there that do this and it leads to the binary getting `Killed!` by the kernel. In the non-linker-script cases, when linked with -z noseparate-code (default), the max-page-size increase should not cause any size difference. There may be some VMA usage differences, though. Reviewed By: psmith, MaskRay Differential Revision: https://reviews.llvm.org/D77330
2020-04-18 23:06:37 +08:00
// CALLSITE7: 00028002 <target7>:
[ARMInstPrinter] Print the target address of a branch instruction This follows other patches that changed printing immediate values of branch instructions to target addresses, see D76580 (x86), D76591 (PPC), D77853 (AArch64). As observing immediate values might sometimes be useful, they are printed as comments for branch instructions. // llvm-objdump -d output (before) 000200b4 <_start>: 200b4: ff ff ff fa blx #-4 <thumb> 000200b8 <thumb>: 200b8: ff f7 fc ef blx #-8 <_start> // llvm-objdump -d output (after) 000200b4 <_start>: 200b4: ff ff ff fa blx 0x200b8 <thumb> @ imm = #-4 000200b8 <thumb>: 200b8: ff f7 fc ef blx 0x200b4 <_start> @ imm = #-8 // GNU objdump -d. 000200b4 <_start>: 200b4: faffffff blx 200b8 <thumb> 000200b8 <thumb>: 200b8: f7ff effc blx 200b4 <_start> Differential Revision: https://reviews.llvm.org/D104701
2021-06-30 17:34:52 +08:00
// CALLSITE7: 28002: bl 0x28002 <target7>