* [PATCH 2/2] powerpc: xmon: remove unused variables
2023-08-09 13:10 [PATCH 1/2] powerpc: mark more local variables as volatile Arnd Bergmann
@ 2023-08-09 13:10 ` Arnd Bergmann
2023-08-09 13:17 ` [PATCH 1/2] powerpc: mark more local variables as volatile Christophe Leroy
2023-08-23 11:55 ` Michael Ellerman
2 siblings, 0 replies; 5+ messages in thread
From: Arnd Bergmann @ 2023-08-09 13:10 UTC (permalink / raw)
To: Michael Ellerman, Benjamin Herrenschmidt
Cc: Nathan Lynch, Arnd Bergmann, Hugh Dickins, Gustavo A. R. Silva,
linux-kernel, Nicholas Piggin, Andrew Morton, linuxppc-dev
From: Arnd Bergmann <arnd@arndb.de>
Randconfig testing with W=1 showed up these warnings that I'd like to enable
by default:
arch/powerpc/xmon/xmon.c: In function 'dump_tlb_book3e':
arch/powerpc/xmon/xmon.c:3833:42: error: variable 'lrat' set but not used [-Werror=unused-but-set-variable]
3833 | int i, tlb, ntlbs, pidsz, lpidsz, rasz, lrat = 0;
| ^~~~
arch/powerpc/xmon/xmon.c:3831:23: error: variable 'lpidmask' set but not used [-Werror=unused-but-set-variable]
3831 | u32 mmucfg, pidmask, lpidmask;
| ^~~~~~~~
arch/powerpc/xmon/xmon.c:3831:14: error: variable 'pidmask' set but not used [-Werror=unused-but-set-variable]
3831 | u32 mmucfg, pidmask, lpidmask;
| ^~~~~~~
Just remove these as they have been unused since the code was added in 2010.
Fixes: 03247157f7391 ("powerpc/book3e: Add TLB dump in xmon for Book3E")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
arch/powerpc/xmon/xmon.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 9e12b75850d75..e35f13842ce15 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -3828,9 +3828,9 @@ static void dump_tlb_44x(void)
#ifdef CONFIG_PPC_BOOK3E_64
static void dump_tlb_book3e(void)
{
- u32 mmucfg, pidmask, lpidmask;
+ u32 mmucfg;
u64 ramask;
- int i, tlb, ntlbs, pidsz, lpidsz, rasz, lrat = 0;
+ int i, tlb, ntlbs, pidsz, lpidsz, rasz;
int mmu_version;
static const char *pgsz_names[] = {
" 1K",
@@ -3874,12 +3874,8 @@ static void dump_tlb_book3e(void)
pidsz = ((mmucfg >> 6) & 0x1f) + 1;
lpidsz = (mmucfg >> 24) & 0xf;
rasz = (mmucfg >> 16) & 0x7f;
- if ((mmu_version > 1) && (mmucfg & 0x10000))
- lrat = 1;
printf("Book3E MMU MAV=%d.0,%d TLBs,%d-bit PID,%d-bit LPID,%d-bit RA\n",
mmu_version, ntlbs, pidsz, lpidsz, rasz);
- pidmask = (1ul << pidsz) - 1;
- lpidmask = (1ul << lpidsz) - 1;
ramask = (1ull << rasz) - 1;
for (tlb = 0; tlb < ntlbs; tlb++) {
--
2.39.2
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH 1/2] powerpc: mark more local variables as volatile
2023-08-09 13:10 [PATCH 1/2] powerpc: mark more local variables as volatile Arnd Bergmann
2023-08-09 13:10 ` [PATCH 2/2] powerpc: xmon: remove unused variables Arnd Bergmann
@ 2023-08-09 13:17 ` Christophe Leroy
2023-08-09 13:35 ` Arnd Bergmann
2023-08-23 11:55 ` Michael Ellerman
2 siblings, 1 reply; 5+ messages in thread
From: Christophe Leroy @ 2023-08-09 13:17 UTC (permalink / raw)
To: Arnd Bergmann, Michael Ellerman
Cc: Nathan Lynch, Arnd Bergmann, linuxppc-dev, Hugh Dickins,
Gustavo A. R. Silva, Nicholas Piggin, linux-kernel,
Maninder Singh, Andrew Morton, Jiri Slaby
Le 09/08/2023 à 15:10, Arnd Bergmann a écrit :
> From: Arnd Bergmann <arnd@arndb.de>
>
> A while ago I created a2305e3de8193 ("powerpc: mark local variables
> around longjmp as volatile") in order to allow building powerpc with
> -Wextra enabled on gcc-11.
Should this be explained in
https://docs.kernel.org/process/volatile-considered-harmful.html ?
Christophe
>
> I tried this again with gcc-13 and found two more of the same issues,
> presumably based on slightly different optimization paths being taken
> here:
>
> arch/powerpc/xmon/xmon.c:3306:27: error: variable 'mm' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
> arch/powerpc/kexec/crash.c:353:22: error: variable 'i' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered]
>
> I checked a bunch of randconfigs and found only these two, so just
> address them the same way as the others.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> arch/powerpc/kexec/crash.c | 2 +-
> arch/powerpc/xmon/xmon.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
> index 252724ed666a3..ef5c2d25ec397 100644
> --- a/arch/powerpc/kexec/crash.c
> +++ b/arch/powerpc/kexec/crash.c
> @@ -350,7 +350,7 @@ EXPORT_SYMBOL(crash_shutdown_unregister);
>
> void default_machine_crash_shutdown(struct pt_regs *regs)
> {
> - unsigned int i;
> + volatile unsigned int i;
> int (*old_handler)(struct pt_regs *regs);
>
> if (TRAP(regs) == INTERRUPT_SYSTEM_RESET)
> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
> index 3b6f524c790e3..9e12b75850d75 100644
> --- a/arch/powerpc/xmon/xmon.c
> +++ b/arch/powerpc/xmon/xmon.c
> @@ -3303,7 +3303,7 @@ static void show_pte(unsigned long addr)
> {
> unsigned long tskv = 0;
> struct task_struct *volatile tsk = NULL;
> - struct mm_struct *mm;
> + struct mm_struct *volatile mm;
> pgd_t *pgdp;
> p4d_t *p4dp;
> pud_t *pudp;
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH 1/2] powerpc: mark more local variables as volatile
2023-08-09 13:10 [PATCH 1/2] powerpc: mark more local variables as volatile Arnd Bergmann
2023-08-09 13:10 ` [PATCH 2/2] powerpc: xmon: remove unused variables Arnd Bergmann
2023-08-09 13:17 ` [PATCH 1/2] powerpc: mark more local variables as volatile Christophe Leroy
@ 2023-08-23 11:55 ` Michael Ellerman
2 siblings, 0 replies; 5+ messages in thread
From: Michael Ellerman @ 2023-08-23 11:55 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Nathan Lynch, Arnd Bergmann, linuxppc-dev, Hugh Dickins,
Gustavo A. R. Silva, linux-kernel, Nicholas Piggin,
Maninder Singh, Andrew Morton, Jiri Slaby
On Wed, 09 Aug 2023 15:10:08 +0200, Arnd Bergmann wrote:
> A while ago I created a2305e3de8193 ("powerpc: mark local variables
> around longjmp as volatile") in order to allow building powerpc with
> -Wextra enabled on gcc-11.
>
> I tried this again with gcc-13 and found two more of the same issues,
> presumably based on slightly different optimization paths being taken
> here:
>
> [...]
Applied to powerpc/next.
[1/2] powerpc: mark more local variables as volatile
https://git.kernel.org/powerpc/c/0f7ce21ab5209426b00636636a5f2d9008738654
[2/2] powerpc: xmon: remove unused variables
https://git.kernel.org/powerpc/c/ef73dcaa31217c79adc548bf9045afb40ac75b82
cheers
^ permalink raw reply [flat|nested] 5+ messages in thread