[v2] riscv: perf: Drop defining `perf_instruction_pointer()` and `perf_misc_flags()`

Commit Message

Prabhakar Nov. 16, 2024, 4:05 p.m. UTC

From: Lad Prabhakar <[e-mail]>

With commit 2c47e7a74f44 ("perf/core: Correct perf sampling with guest
VMs"), the perf core now handles the functionality previously requiring
arch-specific definitions of `perf_instruction_pointer()` and
`perf_misc_flags()`. As these definitions are no longer necessary for
RISC-V, this patch removes their implementation and declarations.

This change also fixes the following build issue on RISC-V:

    ./include/linux/perf_event.h:1679:84: error: macro "perf_misc_flags" passed 2 arguments, but takes just 1
    ./include/linux/perf_event.h:1679:22: error: 'perf_misc_flags' redeclared as different kind of symbol
    ./include/linux/perf_event.h:1680:22: error: conflicting types for 'perf_instruction_pointer'; have 'long unsigned int(struct perf_event *, struct pt_regs *)'

The above errors arise from conflicts between the core definitions in
`linux/perf_event.h` and the RISC-V-specific definitions in
`arch/riscv/include/asm/perf_event.h`. Removing the RISC-V-specific
definitions resolves these issues and aligns the architecture with the
updated perf core.

Fixes: 2c47e7a74f44 ("perf/core: Correct perf sampling with guest VMs")
Reported-by: Chris Paterson <[e-mail]>
Signed-off-by: Lad Prabhakar <[e-mail]>
Reviewed-by: Andrew Jones <[e-mail]>
---
v1->v2
- Update commit message to say it fixes build issue
- Included RB tag from Andrew
---
 arch/riscv/include/asm/perf_event.h |  3 ---
 arch/riscv/kernel/perf_callchain.c  | 28 ----------------------------
 2 files changed, 31 deletions(-)

Patch

diff --git a/arch/riscv/include/asm/perf_event.h b/arch/riscv/include/asm/perf_event.h
index 38926b4a902d..bcc928fd3785 100644
--- a/arch/riscv/include/asm/perf_event.h
+++ b/arch/riscv/include/asm/perf_event.h
@@ -10,9 +10,6 @@ 
 
 #ifdef CONFIG_PERF_EVENTS
 #include <linux/perf_event.h>
-extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
-extern unsigned long perf_misc_flags(struct pt_regs *regs);
-#define perf_misc_flags(regs) perf_misc_flags(regs)
 #define perf_arch_bpf_user_pt_regs(regs) (struct user_regs_struct *)regs
 
 #define perf_arch_fetch_caller_regs(regs, __ip) { \
diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c
index c2c81a80f816..b465bc9eb870 100644
--- a/arch/riscv/kernel/perf_callchain.c
+++ b/arch/riscv/kernel/perf_callchain.c
@@ -46,31 +46,3 @@  void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
 
 	walk_stackframe(NULL, regs, fill_callchain, entry);
 }
-
-unsigned long perf_instruction_pointer(struct pt_regs *regs)
-{
-	if (perf_guest_state())
-		return perf_guest_get_ip();
-
-	return instruction_pointer(regs);
-}
-
-unsigned long perf_misc_flags(struct pt_regs *regs)
-{
-	unsigned int guest_state = perf_guest_state();
-	unsigned long misc = 0;
-
-	if (guest_state) {
-		if (guest_state & PERF_GUEST_USER)
-			misc |= PERF_RECORD_MISC_GUEST_USER;
-		else
-			misc |= PERF_RECORD_MISC_GUEST_KERNEL;
-	} else {
-		if (user_mode(regs))
-			misc |= PERF_RECORD_MISC_USER;
-		else
-			misc |= PERF_RECORD_MISC_KERNEL;
-	}
-
-	return misc;
-}