[PATCH 1/5] riscv: use ".L" local labels in assembly when applicable

From: Clément Léger
Date: Wed Oct 04 2023 - 10:34:50 EST

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For the sake of coherency, use local labels in assembly when
applicable. This also avoid kprobes being confused when applying a
kprobe since the size of function is computed by checking where the
next visible symbol is located. This might end up in computing some
function size to be way shorter than expected and thus failing to apply
kprobes to the specified offset.

Signed-off-by: Clément Léger <cleger@xxxxxxxxxxxx>
---
arch/riscv/kernel/entry.S | 10 +++----
arch/riscv/kernel/head.S | 18 ++++++-------
arch/riscv/kernel/mcount.S | 10 +++----
arch/riscv/lib/memmove.S | 54 +++++++++++++++++++-------------------
4 files changed, 46 insertions(+), 46 deletions(-)

diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 143a2bb3e697..64ac0dd6176b 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -21,9 +21,9 @@ SYM_CODE_START(handle_exception)
* register will contain 0, and we should continue on the current TP.
*/
csrrw tp, CSR_SCRATCH, tp
- bnez tp, _save_context
+ bnez tp, .Lsave_context

-_restore_kernel_tpsp:
+.Lrestore_kernel_tpsp:
csrr tp, CSR_SCRATCH
REG_S sp, TASK_TI_KERNEL_SP(tp)

@@ -35,7 +35,7 @@ _restore_kernel_tpsp:
REG_L sp, TASK_TI_KERNEL_SP(tp)
#endif

-_save_context:
+.Lsave_context:
REG_S sp, TASK_TI_USER_SP(tp)
REG_L sp, TASK_TI_KERNEL_SP(tp)
addi sp, sp, -(PT_SIZE_ON_STACK)
@@ -205,10 +205,10 @@ SYM_CODE_START_LOCAL(handle_kernel_stack_overflow)
REG_S x30, PT_T5(sp)
REG_S x31, PT_T6(sp)

- la ra, restore_caller_reg
+ la ra, .Lrestore_caller_reg
tail get_overflow_stack

-restore_caller_reg:
+.Lrestore_caller_reg:
//save per-cpu overflow stack
REG_S a0, -8(sp)
//restore caller register from shadow_stack
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index 3710ea5d160f..7e1b83f18a50 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -168,12 +168,12 @@ secondary_start_sbi:
XIP_FIXUP_OFFSET a0
call relocate_enable_mmu
#endif
- call setup_trap_vector
+ call .Lsetup_trap_vector
tail smp_callin
#endif /* CONFIG_SMP */

.align 2
-setup_trap_vector:
+.Lsetup_trap_vector:
/* Set trap vector to exception handler */
la a0, handle_exception
csrw CSR_TVEC, a0
@@ -210,7 +210,7 @@ ENTRY(_start_kernel)
* not implement PMPs, so we set up a quick trap handler to just skip
* touching the PMPs on any trap.
*/
- la a0, pmp_done
+ la a0, .Lpmp_done
csrw CSR_TVEC, a0

li a0, -1
@@ -218,7 +218,7 @@ ENTRY(_start_kernel)
li a0, (PMP_A_NAPOT | PMP_R | PMP_W | PMP_X)
csrw CSR_PMPCFG0, a0
.align 2
-pmp_done:
+.Lpmp_done:

/*
* The hartid in a0 is expected later on, and we have no firmware
@@ -282,12 +282,12 @@ pmp_done:
/* Clear BSS for flat non-ELF images */
la a3, __bss_start
la a4, __bss_stop
- ble a4, a3, clear_bss_done
-clear_bss:
+ ble a4, a3, .Lclear_bss_done
+.Lclear_bss:
REG_S zero, (a3)
add a3, a3, RISCV_SZPTR
- blt a3, a4, clear_bss
-clear_bss_done:
+ blt a3, a4, .Lclear_bss
+.Lclear_bss_done:
#endif
la a2, boot_cpu_hartid
XIP_FIXUP_OFFSET a2
@@ -311,7 +311,7 @@ clear_bss_done:
call relocate_enable_mmu
#endif /* CONFIG_MMU */

- call setup_trap_vector
+ call .Lsetup_trap_vector
/* Restore C environment */
la tp, init_task
la sp, init_thread_union + THREAD_SIZE
diff --git a/arch/riscv/kernel/mcount.S b/arch/riscv/kernel/mcount.S
index 8818a8fa9ff3..ab4dd0594fe7 100644
--- a/arch/riscv/kernel/mcount.S
+++ b/arch/riscv/kernel/mcount.S
@@ -85,16 +85,16 @@ ENTRY(MCOUNT_NAME)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
la t0, ftrace_graph_return
REG_L t1, 0(t0)
- bne t1, t4, do_ftrace_graph_caller
+ bne t1, t4, .Ldo_ftrace_graph_caller

la t3, ftrace_graph_entry
REG_L t2, 0(t3)
la t6, ftrace_graph_entry_stub
- bne t2, t6, do_ftrace_graph_caller
+ bne t2, t6, .Ldo_ftrace_graph_caller
#endif
la t3, ftrace_trace_function
REG_L t5, 0(t3)
- bne t5, t4, do_trace
+ bne t5, t4, .Ldo_trace
ret

#ifdef CONFIG_FUNCTION_GRAPH_TRACER
@@ -102,7 +102,7 @@ ENTRY(MCOUNT_NAME)
* A pseudo representation for the function graph tracer:
* prepare_to_return(&ra_to_caller_of_caller, ra_to_caller)
*/
-do_ftrace_graph_caller:
+.Ldo_ftrace_graph_caller:
addi a0, s0, -SZREG
mv a1, ra
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
@@ -118,7 +118,7 @@ do_ftrace_graph_caller:
* A pseudo representation for the function tracer:
* (*ftrace_trace_function)(ra_to_caller, ra_to_caller_of_caller)
*/
-do_trace:
+.Ldo_trace:
REG_L a1, -SZREG(s0)
mv a0, ra

diff --git a/arch/riscv/lib/memmove.S b/arch/riscv/lib/memmove.S
index 838ff2022fe3..1930b388c3a0 100644
--- a/arch/riscv/lib/memmove.S
+++ b/arch/riscv/lib/memmove.S
@@ -26,8 +26,8 @@ SYM_FUNC_START_WEAK(memmove)
*/

/* Return if nothing to do */
- beq a0, a1, return_from_memmove
- beqz a2, return_from_memmove
+ beq a0, a1, .Lreturn_from_memmove
+ beqz a2, .Lreturn_from_memmove

/*
* Register Uses
@@ -60,7 +60,7 @@ SYM_FUNC_START_WEAK(memmove)
* small enough not to bother.
*/
andi t0, a2, -(2 * SZREG)
- beqz t0, byte_copy
+ beqz t0, .Lbyte_copy

/*
* Now solve for t5 and t6.
@@ -87,14 +87,14 @@ SYM_FUNC_START_WEAK(memmove)
*/
xor t0, a0, a1
andi t1, t0, (SZREG - 1)
- beqz t1, coaligned_copy
+ beqz t1, .Lcoaligned_copy
/* Fall through to misaligned fixup copy */

-misaligned_fixup_copy:
- bltu a1, a0, misaligned_fixup_copy_reverse
+.Lmisaligned_fixup_copy:
+ bltu a1, a0, .Lmisaligned_fixup_copy_reverse

-misaligned_fixup_copy_forward:
- jal t0, byte_copy_until_aligned_forward
+.Lmisaligned_fixup_copy_forward:
+ jal t0, .Lbyte_copy_until_aligned_forward

andi a5, a1, (SZREG - 1) /* Find the alignment offset of src (a1) */
slli a6, a5, 3 /* Multiply by 8 to convert that to bits to shift */
@@ -153,10 +153,10 @@ misaligned_fixup_copy_forward:
mv t3, t6 /* Fix the dest pointer in case the loop was broken */

add a1, t3, a5 /* Restore the src pointer */
- j byte_copy_forward /* Copy any remaining bytes */
+ j .Lbyte_copy_forward /* Copy any remaining bytes */

-misaligned_fixup_copy_reverse:
- jal t0, byte_copy_until_aligned_reverse
+.Lmisaligned_fixup_copy_reverse:
+ jal t0, .Lbyte_copy_until_aligned_reverse

andi a5, a4, (SZREG - 1) /* Find the alignment offset of src (a4) */
slli a6, a5, 3 /* Multiply by 8 to convert that to bits to shift */
@@ -215,18 +215,18 @@ misaligned_fixup_copy_reverse:
mv t4, t5 /* Fix the dest pointer in case the loop was broken */

add a4, t4, a5 /* Restore the src pointer */
- j byte_copy_reverse /* Copy any remaining bytes */
+ j .Lbyte_copy_reverse /* Copy any remaining bytes */

/*
* Simple copy loops for SZREG co-aligned memory locations.
* These also make calls to do byte copies for any unaligned
* data at their terminations.
*/
-coaligned_copy:
- bltu a1, a0, coaligned_copy_reverse
+.Lcoaligned_copy:
+ bltu a1, a0, .Lcoaligned_copy_reverse

-coaligned_copy_forward:
- jal t0, byte_copy_until_aligned_forward
+.Lcoaligned_copy_forward:
+ jal t0, .Lbyte_copy_until_aligned_forward

1:
REG_L t1, ( 0 * SZREG)(a1)
@@ -235,10 +235,10 @@ coaligned_copy_forward:
REG_S t1, (-1 * SZREG)(t3)
bne t3, t6, 1b

- j byte_copy_forward /* Copy any remaining bytes */
+ j .Lbyte_copy_forward /* Copy any remaining bytes */

-coaligned_copy_reverse:
- jal t0, byte_copy_until_aligned_reverse
+.Lcoaligned_copy_reverse:
+ jal t0, .Lbyte_copy_until_aligned_reverse

1:
REG_L t1, (-1 * SZREG)(a4)
@@ -247,7 +247,7 @@ coaligned_copy_reverse:
REG_S t1, ( 0 * SZREG)(t4)
bne t4, t5, 1b

- j byte_copy_reverse /* Copy any remaining bytes */
+ j .Lbyte_copy_reverse /* Copy any remaining bytes */

/*
* These are basically sub-functions within the function. They
@@ -258,7 +258,7 @@ coaligned_copy_reverse:
* up from where they were left and we avoid code duplication
* without any overhead except the call in and return jumps.
*/
-byte_copy_until_aligned_forward:
+.Lbyte_copy_until_aligned_forward:
beq t3, t5, 2f
1:
lb t1, 0(a1)
@@ -269,7 +269,7 @@ byte_copy_until_aligned_forward:
2:
jalr zero, 0x0(t0) /* Return to multibyte copy loop */

-byte_copy_until_aligned_reverse:
+.Lbyte_copy_until_aligned_reverse:
beq t4, t6, 2f
1:
lb t1, -1(a4)
@@ -285,10 +285,10 @@ byte_copy_until_aligned_reverse:
* These will byte copy until they reach the end of data to copy.
* At that point, they will call to return from memmove.
*/
-byte_copy:
- bltu a1, a0, byte_copy_reverse
+.Lbyte_copy:
+ bltu a1, a0, .Lbyte_copy_reverse

-byte_copy_forward:
+.Lbyte_copy_forward:
beq t3, t4, 2f
1:
lb t1, 0(a1)
@@ -299,7 +299,7 @@ byte_copy_forward:
2:
ret

-byte_copy_reverse:
+.Lbyte_copy_reverse:
beq t4, t3, 2f
1:
lb t1, -1(a4)
@@ -309,7 +309,7 @@ byte_copy_reverse:
bne t4, t3, 1b
2:

-return_from_memmove:
+.Lreturn_from_memmove:
ret

SYM_FUNC_END(memmove)
--
2.42.0

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