* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-01 5:48 ` [PATCH 2/6] powerpc: Provide syscall wrapper Rohan McLure
@ 2022-06-01 8:29 ` Christophe Leroy
2022-06-09 13:06 ` Christophe Leroy
2022-06-01 8:59 ` kernel test robot
` (4 subsequent siblings)
5 siblings, 1 reply; 31+ messages in thread
From: Christophe Leroy @ 2022-06-01 8:29 UTC (permalink / raw)
To: Rohan McLure, linuxppc-dev@lists.ozlabs.org
Cc: Andrew Donnellan, npiggin@gmail.com
Le 01/06/2022 à 07:48, Rohan McLure a écrit :
> [Vous ne recevez pas souvent de courriers de la part de rmclure@linux.ibm.com. Découvrez pourquoi cela peut être important à l'adresse https://aka.ms/LearnAboutSenderIdentification.]
>
> Syscall wrapper implemented as per s390, x86, arm64, providing the
> option for gprs to be cleared on entry to the kernel, reducing caller
> influence influence on speculation within syscall routine. The wrapper
> is a macro that emits syscall handler implementations with parameters
> passed by stack pointer.
Passing parameters by stack is going to be sub-optimal. Did you make any
measurement of the implied performance degradation ? We usually use the
null_syscall selftest for that everytime we touch syscall entries/exits.
Why going via stack ? The main advantage of a RISC processor like
powerpc is that, unlike x86, there are enough registers to avoid going
through memory. RISC processors are optimised with three operands
operations and many registers, and usually have slow memory in return.
>
> For platforms supporting this syscall wrapper, emit symbols with usual
> in-register parameters (`sys...`) to support calls to syscall handlers
> from within the kernel.
>
> Syscalls are wrapped on all platforms except Cell processor. SPUs require
> access syscall prototypes which are omitted with ARCH_HAS_SYSCALL_WRAPPER
> enabled.
This commit message isn't very clear, please describe in more details
what is done, how and why.
>
> Co-developed-by: Andrew Donnellan <ajd@linux.ibm.com>
> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
> Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
> ---
> arch/powerpc/Kconfig | 1 +
> arch/powerpc/include/asm/interrupt.h | 3 +-
> arch/powerpc/include/asm/syscall_wrapper.h | 92 ++++++++++++++++++++++
> arch/powerpc/include/asm/syscalls.h | 83 +++++++++++++------
> arch/powerpc/kernel/entry_32.S | 6 +-
> arch/powerpc/kernel/interrupt.c | 35 ++++----
> arch/powerpc/kernel/interrupt_64.S | 30 +++----
> arch/powerpc/kernel/sys_ppc32.c | 50 +++++++-----
> arch/powerpc/kernel/syscalls.c | 19 +++--
> arch/powerpc/kernel/systbl.S | 21 +++++
> arch/powerpc/kernel/vdso.c | 2 +
> 11 files changed, 255 insertions(+), 87 deletions(-)
> create mode 100644 arch/powerpc/include/asm/syscall_wrapper.h
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 174edabb74fa..e58287a70061 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -137,6 +137,7 @@ config PPC
> select ARCH_HAS_STRICT_KERNEL_RWX if (PPC_BOOK3S || PPC_8xx || 40x) && !HIBERNATION
> select ARCH_HAS_STRICT_KERNEL_RWX if FSL_BOOKE && !HIBERNATION && !RANDOMIZE_BASE
> select ARCH_HAS_STRICT_MODULE_RWX if ARCH_HAS_STRICT_KERNEL_RWX
> + select ARCH_HAS_SYSCALL_WRAPPER if !SPU_BASE
> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
> select ARCH_HAS_UACCESS_FLUSHCACHE
> select ARCH_HAS_UBSAN_SANITIZE_ALL
> diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
> index f964ef5c57d8..8e8949e4db7a 100644
> --- a/arch/powerpc/include/asm/interrupt.h
> +++ b/arch/powerpc/include/asm/interrupt.h
> @@ -636,8 +636,7 @@ static inline void interrupt_cond_local_irq_enable(struct pt_regs *regs)
> local_irq_enable();
> }
>
> -long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
> - unsigned long r0, struct pt_regs *regs);
> +long system_call_exception(unsigned long r0, struct pt_regs *regs);
> notrace unsigned long syscall_exit_prepare(unsigned long r3, struct pt_regs *regs, long scv);
> notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs);
> notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs);
> diff --git a/arch/powerpc/include/asm/syscall_wrapper.h b/arch/powerpc/include/asm/syscall_wrapper.h
> new file mode 100644
> index 000000000000..23da22b081e4
> --- /dev/null
> +++ b/arch/powerpc/include/asm/syscall_wrapper.h
> @@ -0,0 +1,92 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * syscall_wrapper.h - powerpc specific wrappers to syscall definitions
> + *
> + * Based on arch/{x86,arm64}/include/asm/syscall_wrapper.h
> + */
> +
> +#ifndef __ASM_SYSCALL_WRAPPER_H
> +#define __ASM_SYSCALL_WRAPPER_H
> +
> +struct pt_regs;
> +
> +#define SC_POWERPC_REGS_TO_ARGS(x, ...) \
> + __MAP(x,__SC_ARGS \
> + ,,regs->gpr[3],,regs->gpr[4],,regs->gpr[5] \
> + ,,regs->gpr[6],,regs->gpr[7],,regs->gpr[8])
> +
> +#ifdef CONFIG_COMPAT
> +
> +#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \
> + asmlinkage long __powerpc_compat_sys##name(const struct pt_regs *regs); \
> + ALLOW_ERROR_INJECTION(__powerpc_compat_sys##name, ERRNO); \
> + static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
> + static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
> + asmlinkage long __powerpc_compat_sys##name(const struct pt_regs *regs) \
> + { \
> + return __se_compat_sys##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
> + } \
> + static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
> + { \
> + return __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__)); \
> + } \
> + static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
> +
> +#define COMPAT_SYSCALL_DEFINE0(sname) \
> + asmlinkage long __powerpc_compat_sys_##sname(const struct pt_regs *__unused); \
> + ALLOW_ERROR_INJECTION(__powerpc_compat_sys_##sname, ERRNO); \
> + asmlinkage long __powerpc_compat_sys_##sname(const struct pt_regs *__unused)
> +
> +#define COND_SYSCALL_COMPAT(name) \
> + asmlinkage long __weak __powerpc_compat_sys_##name(const struct pt_regs *regs) \
> + { \
> + return sys_ni_syscall(); \
> + }
> +#define COMPAT_SYS_NI(name) \
> + SYSCALL_ALIAS(__powerpc_compat_sys_##name, sys_ni_posix_timers);
> +
> +#endif /* CONFIG_COMPAT */
> +
> +#define __SYSCALL_DEFINEx(x, name, ...) \
> + asmlinkage long __powerpc_sys##name(const struct pt_regs *regs); \
> + ALLOW_ERROR_INJECTION(__powerpc_sys##name, ERRNO); \
> + long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
> + static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
> + static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
> + asmlinkage long __powerpc_sys##name(const struct pt_regs *regs) \
> + { \
> + return __se_sys##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
> + } \
> + long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
> + { \
> + return __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
> + } \
> + static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
> + { \
> + long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
> + __MAP(x,__SC_TEST,__VA_ARGS__); \
> + __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
> + return ret; \
> + } \
> + static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
> +
> +#define SYSCALL_DEFINE0(sname) \
> + SYSCALL_METADATA(_##sname, 0); \
> + long sys_##name(void); \
> + asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused); \
> + ALLOW_ERROR_INJECTION(__powerpc_sys_##sname, ERRNO); \
> + long sys_##sname(void) \
> + { \
> + return __powerpc_sys_##sname(NULL); \
> + } \
> + asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused)
> +
> +#define COND_SYSCALL(name) \
> + asmlinkage long __weak __powerpc_sys_##name(const struct pt_regs *regs) \
> + { \
> + return sys_ni_syscall(); \
> + }
> +
> +#define SYS_NI(name) SYSCALL_ALIAS(__powerpc_sys_##name, sys_ni_posix_timers);
> +
> +#endif /* __ASM_SYSCALL_WRAPPER_H */
> diff --git a/arch/powerpc/include/asm/syscalls.h b/arch/powerpc/include/asm/syscalls.h
> index a2b13e55254f..75d8e1822caf 100644
> --- a/arch/powerpc/include/asm/syscalls.h
> +++ b/arch/powerpc/include/asm/syscalls.h
> @@ -8,14 +8,47 @@
> #include <linux/types.h>
> #include <linux/compat.h>
>
> +/*
> + * For PowerPC specific syscall implementations, wrapper takes exact name and
> + * return type for a given function.
> + */
> +
> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
> +#define PPC_SYSCALL_DEFINE(x, type, name, ...) \
> + asmlinkage type __powerpc_##name(const struct pt_regs *regs); \
> + ALLOW_ERROR_INJECTION(__powerpc_##name, ERRNO); \
> + type sys_##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
> + static type __se_##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
> + static inline type __do_##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
> + asmlinkage type __powerpc_##name(const struct pt_regs *regs) \
> + { \
> + return __se_##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
> + } \
> + type sys_##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
> + { \
> + return __do_##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
> + } \
> + static type __se_##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
> + { \
> + type ret = __do_##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
> + __MAP(x,__SC_TEST,__VA_ARGS__); \
> + __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
> + return ret; \
> + } \
> + static inline type __do_##name(__MAP(x,__SC_DECL,__VA_ARGS__))
> +#else
> +#define PPC_SYSCALL_DEFINE(x, type, name, ...) \
> + type name(__MAP(x,__SC_DECL,__VA_ARGS__))
> +#endif
> +
> struct rtas_args;
>
> asmlinkage long sys_mmap(unsigned long addr, size_t len,
> - unsigned long prot, unsigned long flags,
> - unsigned long fd, off_t offset);
> + unsigned long prot, unsigned long flags,
> + unsigned long fd, off_t offset);
This is a cleanup that is not part of the change. Please move in a
preparatory patch.
> asmlinkage long sys_mmap2(unsigned long addr, size_t len,
> - unsigned long prot, unsigned long flags,
> - unsigned long fd, unsigned long pgoff);
> + unsigned long prot, unsigned long flags,
> + unsigned long fd, unsigned long pgoff);
Same.
> asmlinkage long ppc64_personality(unsigned long personality);
> asmlinkage long sys_rtas(struct rtas_args __user *uargs);
> int ppc_select(int n, fd_set __user *inp, fd_set __user *outp,
> @@ -24,32 +57,38 @@ long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
> u32 len_high, u32 len_low);
>
> #ifdef CONFIG_COMPAT
> -unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
> - unsigned long prot, unsigned long flags,
> - unsigned long fd, unsigned long pgoff);
> +asmlinkage unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
> + unsigned long prot, unsigned long flags,
> + unsigned long fd, unsigned long pgoff);
There was some discussion in the past that asmlinkage is useless. Is
that change and the ones below really necessary ?
If really needed, is that directly linked to this patch or should it be
in a preparation patch ?
>
> -compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count,
> - u32 reg6, u32 pos1, u32 pos2);
> +asmlinkage compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf,
> + compat_size_t count,
> + u32 reg6, u32 pos1, u32 pos2);
>
> -compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf, compat_size_t count,
> - u32 reg6, u32 pos1, u32 pos2);
> +asmlinkage compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf,
> + compat_size_t count,
> + u32 reg6, u32 pos1, u32 pos2);
>
> -compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offset1, u32 offset2, u32 count);
> +asmlinkage compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offset1,
> + u32 offset2, u32 count);
>
> -int compat_sys_truncate64(const char __user *path, u32 reg4,
> - unsigned long len1, unsigned long len2);
> +asmlinkage int compat_sys_truncate64(const char __user *path, u32 reg4,
> + unsigned long len1, unsigned long len2);
>
> -long compat_sys_fallocate(int fd, int mode, u32 offset1, u32 offset2, u32 len1, u32 len2);
> +asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offset1,
> + u32 offset2, u32 len1, u32 len2);
>
> -int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long len1,
> - unsigned long len2);
> +asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4,
> + unsigned long len1, unsigned long len2);
>
> -long ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
> - size_t len, int advice);
> +asmlinkage long ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
> + size_t len, int advice);
>
> -long compat_sys_sync_file_range2(int fd, unsigned int flags,
> - unsigned int offset1, unsigned int offset2,
> - unsigned int nbytes1, unsigned int nbytes2);
> +asmlinkage long compat_sys_sync_file_range2(int fd, unsigned int flags,
> + unsigned int offset1,
> + unsigned int offset2,
> + unsigned int nbytes1,
> + unsigned int nbytes2);
> #endif
>
> #endif /* __KERNEL__ */
> diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
> index 7748c278d13c..2343c577b971 100644
> --- a/arch/powerpc/kernel/entry_32.S
> +++ b/arch/powerpc/kernel/entry_32.S
> @@ -121,9 +121,9 @@ transfer_to_syscall:
> SAVE_NVGPRS(r1)
> kuep_lock
>
> - /* Calling convention has r9 = orig r0, r10 = regs */
> - addi r10,r1,STACK_FRAME_OVERHEAD
> - mr r9,r0
> + /* Calling convention has r3 = orig r0, r4 = regs */
> + addi r4,r1,STACK_FRAME_OVERHEAD
> + mr r3,r0
> bl system_call_exception
>
> ret_from_syscall:
> diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
> index 784ea3289c84..a38329ede1a1 100644
> --- a/arch/powerpc/kernel/interrupt.c
> +++ b/arch/powerpc/kernel/interrupt.c
> @@ -24,7 +24,11 @@
> unsigned long global_dbcr0[NR_CPUS];
> #endif
>
> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
> +typedef long (*syscall_fn)(struct pt_regs *);
> +#else
> typedef long (*syscall_fn)(long, long, long, long, long, long);
> +#endif
>
> #ifdef CONFIG_PPC_BOOK3S_64
> DEFINE_STATIC_KEY_FALSE(interrupt_exit_not_reentrant);
> @@ -74,15 +78,13 @@ static notrace __always_inline bool prep_irq_for_enabled_exit(bool restartable)
> }
>
> /* Has to run notrace because it is entered not completely "reconciled" */
> -notrace long system_call_exception(long r3, long r4, long r5,
> - long r6, long r7, long r8,
> - unsigned long r0, struct pt_regs *regs)
> +notrace long system_call_exception(unsigned long r0, struct pt_regs *regs)
> {
> syscall_fn f;
>
> kuap_lock();
>
> - regs->orig_gpr3 = r3;
> + regs->orig_gpr3 = regs->gpr[3];
>
> if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
> BUG_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED);
> @@ -196,12 +198,6 @@ notrace long system_call_exception(long r3, long r4, long r5,
> r0 = do_syscall_trace_enter(regs);
> if (unlikely(r0 >= NR_syscalls))
> return regs->gpr[3];
> - r3 = regs->gpr[3];
> - r4 = regs->gpr[4];
> - r5 = regs->gpr[5];
> - r6 = regs->gpr[6];
> - r7 = regs->gpr[7];
> - r8 = regs->gpr[8];
>
> } else if (unlikely(r0 >= NR_syscalls)) {
> if (unlikely(trap_is_unsupported_scv(regs))) {
> @@ -218,18 +214,23 @@ notrace long system_call_exception(long r3, long r4, long r5,
> if (unlikely(is_compat_task())) {
> f = (void *)compat_sys_call_table[r0];
>
> - r3 &= 0x00000000ffffffffULL;
> - r4 &= 0x00000000ffffffffULL;
> - r5 &= 0x00000000ffffffffULL;
> - r6 &= 0x00000000ffffffffULL;
> - r7 &= 0x00000000ffffffffULL;
> - r8 &= 0x00000000ffffffffULL;
> + regs->gpr[3] &= 0x00000000ffffffffULL;
> + regs->gpr[4] &= 0x00000000ffffffffULL;
> + regs->gpr[5] &= 0x00000000ffffffffULL;
> + regs->gpr[6] &= 0x00000000ffffffffULL;
> + regs->gpr[7] &= 0x00000000ffffffffULL;
> + regs->gpr[8] &= 0x00000000ffffffffULL;
>
> } else {
> f = (void *)sys_call_table[r0];
> }
>
> - return f(r3, r4, r5, r6, r7, r8);
> + #ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
> + return f(regs);
> + #else
> + return f(regs->gpr[3], regs->gpr[4], regs->gpr[5],
> + regs->gpr[6], regs->gpr[7], regs->gpr[8]);
> + #endif
> }
>
> static notrace void booke_load_dbcr0(void)
> diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
> index 7bab2d7de372..b11c2bd84827 100644
> --- a/arch/powerpc/kernel/interrupt_64.S
> +++ b/arch/powerpc/kernel/interrupt_64.S
> @@ -91,9 +91,9 @@ _ASM_NOKPROBE_SYMBOL(system_call_vectored_\name)
> li r11,\trapnr
> std r11,_TRAP(r1)
> std r12,_CCR(r1)
> - addi r10,r1,STACK_FRAME_OVERHEAD
> + addi r4,r1,STACK_FRAME_OVERHEAD
> ld r11,exception_marker@toc(r2)
> - std r11,-16(r10) /* "regshere" marker */
> + std r11,-16(r4) /* "regshere" marker */
>
> BEGIN_FTR_SECTION
> HMT_MEDIUM
> @@ -108,8 +108,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> * but this is the best we can do.
> */
>
> - /* Calling convention has r9 = orig r0, r10 = regs */
> - mr r9,r0
> + /* Calling convention has r3 = orig r0, r4 = regs */
> + mr r3,r0
> bl system_call_exception
>
> .Lsyscall_vectored_\name\()_exit:
> @@ -285,9 +285,9 @@ END_BTB_FLUSH_SECTION
> std r10,_LINK(r1)
> std r11,_TRAP(r1)
> std r12,_CCR(r1)
> - addi r10,r1,STACK_FRAME_OVERHEAD
> + addi r4,r1,STACK_FRAME_OVERHEAD
> ld r11,exception_marker@toc(r2)
> - std r11,-16(r10) /* "regshere" marker */
> + std r11,-16(r4) /* "regshere" marker */
>
> #ifdef CONFIG_PPC_BOOK3S
> li r11,1
> @@ -308,8 +308,8 @@ END_BTB_FLUSH_SECTION
> wrteei 1
> #endif
>
> - /* Calling convention has r9 = orig r0, r10 = regs */
> - mr r9,r0
> + /* Calling convention has r3 = orig r0, r4 = regs */
> + mr r3,r0
> bl system_call_exception
>
> .Lsyscall_exit:
> @@ -353,16 +353,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
> cmpdi r3,0
> bne .Lsyscall_restore_regs
> /* Zero volatile regs that may contain sensitive kernel data */
> - li r0,0
> - li r4,0
> - li r5,0
> - li r6,0
> - li r7,0
> - li r8,0
> - li r9,0
> - li r10,0
> - li r11,0
> - li r12,0
> + ZERO_GPR(0)
> + ZERO_GPRS(4, 12)
> mtctr r0
> mtspr SPRN_XER,r0
> .Lsyscall_restore_regs_cont:
> @@ -388,7 +380,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> REST_NVGPRS(r1)
> mtctr r3
> mtspr SPRN_XER,r4
> - ld r0,GPR0(r1)
> + REST_GPR(0, r1)
> REST_GPRS(4, 12, r1)
> b .Lsyscall_restore_regs_cont
> .Lsyscall_rst_end:
> diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
> index 16ff0399a257..aa7869dbef36 100644
> --- a/arch/powerpc/kernel/sys_ppc32.c
> +++ b/arch/powerpc/kernel/sys_ppc32.c
> @@ -48,9 +48,10 @@
> #include <asm/syscalls.h>
> #include <asm/switch_to.h>
>
> -unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
> - unsigned long prot, unsigned long flags,
> - unsigned long fd, unsigned long pgoff)
> +PPC_SYSCALL_DEFINE(6, unsigned long, compat_sys_mmap2,
> + unsigned long, addr, size_t, len,
> + unsigned long, prot, unsigned long, flags,
> + unsigned long, fd, unsigned long, pgoff)
This could be done in a separate patch, as it also addresses other
topics like the syscall ftracing. Same for all syscalls in this file.
> {
> /* This should remain 12 even if PAGE_SIZE changes */
> return sys_mmap(addr, len, prot, flags, fd, pgoff << 12);
> @@ -68,52 +69,63 @@ unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
> #define merge_64(high, low) ((u64)high << 32) | low
> #endif
>
> -compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count,
> - u32 reg6, u32 pos1, u32 pos2)
> +PPC_SYSCALL_DEFINE(6, compat_ssize_t, compat_sys_pread64,
> + unsigned int, fd,
> + char __user *, ubuf, compat_size_t, count,
> + u32, reg6, u32, pos1, u32, pos2)
> {
> return ksys_pread64(fd, ubuf, count, merge_64(pos1, pos2));
> }
>
> -compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf, compat_size_t count,
> - u32 reg6, u32 pos1, u32 pos2)
> +PPC_SYSCALL_DEFINE(6, compat_ssize_t, compat_sys_pwrite64,
> + unsigned int, fd,
> + const char __user *, ubuf, compat_size_t, count,
> + u32, reg6, u32, pos1, u32, pos2)
> {
> return ksys_pwrite64(fd, ubuf, count, merge_64(pos1, pos2));
> }
>
> -compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offset1, u32 offset2, u32 count)
> +PPC_SYSCALL_DEFINE(5, compat_ssize_t, compat_sys_readahead,
> + int, fd, u32, r4,
> + u32, offset1, u32, offset2, u32, count)
> {
> return ksys_readahead(fd, merge_64(offset1, offset2), count);
> }
>
> -asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
> - unsigned long len1, unsigned long len2)
> +PPC_SYSCALL_DEFINE(4, int, compat_sys_truncate64,
> + const char __user *, path, u32, reg4,
> + unsigned long, len1, unsigned long, len2)
> {
> return ksys_truncate(path, merge_64(len1, len2));
> }
>
> -asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offset1, u32 offset2,
> - u32 len1, u32 len2)
> +PPC_SYSCALL_DEFINE(6, long, compat_sys_fallocate,
> + int, fd, int, mode, u32, offset1, u32, offset2,
> + u32, len1, u32, len2)
> {
> return ksys_fallocate(fd, mode, ((loff_t)offset1 << 32) | offset2,
> merge_64(len1, len2));
> }
>
> -asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long len1,
> - unsigned long len2)
> +PPC_SYSCALL_DEFINE(4, int, compat_sys_ftruncate64,
> + unsigned int, fd, u32, reg4, unsigned long, len1,
> + unsigned long, len2)
> {
> return ksys_ftruncate(fd, merge_64(len1, len2));
> }
>
> -long ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
> - size_t len, int advice)
> +PPC_SYSCALL_DEFINE(6, long, ppc32_fadvise64,
> + int, fd, u32, unused, u32, offset1, u32, offset2,
> + size_t, len, int, advice)
> {
> return ksys_fadvise64_64(fd, merge_64(offset1, offset2), len,
> advice);
> }
>
> -asmlinkage long compat_sys_sync_file_range2(int fd, unsigned int flags,
> - unsigned offset1, unsigned offset2,
> - unsigned nbytes1, unsigned nbytes2)
> +PPC_SYSCALL_DEFINE(6, long, compat_sys_sync_file_range2, int, fd,
> + unsigned int, flags,
> + unsigned int, offset1, unsigned int, offset2,
> + unsigned int, nbytes1, unsigned int, nbytes2)
> {
> loff_t offset = merge_64(offset1, offset2);
> loff_t nbytes = merge_64(nbytes1, nbytes2);
> diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
> index c4f5b4ce926f..c64cdb5c4435 100644
> --- a/arch/powerpc/kernel/syscalls.c
> +++ b/arch/powerpc/kernel/syscalls.c
> @@ -64,14 +64,20 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
> }
>
> #ifdef CONFIG_PPC32
> +asmlinkage long sys_old_select(struct sel_arg_struct __user *arg);
> +asmlinkage long sys_select(int n, fd_set __user *inp, fd_set __user *outp,
> + fd_set __user *exp,
> + struct __kernel_old_timeval __user *tvp);
> +
Those prototypes should go in a header file. I see you do it in a later
patch. Should be done here directly.
> /*
> * Due to some executables calling the wrong select we sometimes
> * get wrong args. This determines how the args are being passed
> * (a single ptr to them all args passed) then calls
> * sys_select() with the appropriate args. -- Cort
> */
> -int
> -ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct __kernel_old_timeval __user *tvp)
> +PPC_SYSCALL_DEFINE(5, long, ppc_select,
> + int, n, fd_set __user *, inp, fd_set __user *, outp,
> + fd_set __user *, exp, struct __kernel_old_timeval __user *, tvp)
> {
> if ( (unsigned long)n >= 4096 )
> return sys_old_select((void __user *)n);
> @@ -81,7 +87,9 @@ ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, s
> #endif
>
> #ifdef CONFIG_PPC64
> -long ppc64_personality(unsigned long personality)
> +asmlinkage long sys_personality(unsigned int personality);
Same.
> +
> +PPC_SYSCALL_DEFINE(1, long, ppc64_personality, unsigned long, personality)
> {
> long ret;
>
> @@ -95,8 +103,9 @@ long ppc64_personality(unsigned long personality)
> }
> #endif
>
> -long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
> - u32 len_high, u32 len_low)
> +PPC_SYSCALL_DEFINE(6, long, ppc_fadvise64_64,
> + int, fd, int, advice, u32, offset_high, u32, offset_low,
> + u32, len_high, u32, len_low)
> {
> return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low,
> (u64)len_high << 32 | len_low, advice);
> diff --git a/arch/powerpc/kernel/systbl.S b/arch/powerpc/kernel/systbl.S
> index cb3358886203..70cc7120fce2 100644
> --- a/arch/powerpc/kernel/systbl.S
> +++ b/arch/powerpc/kernel/systbl.S
> @@ -16,11 +16,32 @@
>
> #ifdef CONFIG_PPC64
> .p2align 3
> +#endif
> +
> +/* Where the syscall wrapper macro is used, handler functions expect parameters
> + to reside on the stack. We still emit symbols with register-mapped
> + parameters, which are distinguished by a prefix. */
> +
> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
> +
> +#define __powerpc_sys_ni_syscall sys_ni_syscall
> +
> +#ifdef CONFIG_PPC64
> +#define __SYSCALL(nr, entry) .8byte __powerpc_##entry
Isn't .8bytes the same as .long on PPC64 ?
> +#else
> +#define __SYSCALL(nr, entry) .long __powerpc_##entry
> +#endif
> +
> +#else
> +
> +#ifdef CONFIG_PPC64
> #define __SYSCALL(nr, entry) .8byte entry
> #else
> #define __SYSCALL(nr, entry) .long entry
> #endif
>
> +#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
> +
> #define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
> .globl sys_call_table
> sys_call_table:
> diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
> index 717f2c9a7573..dcf57c07dbad 100644
> --- a/arch/powerpc/kernel/vdso.c
> +++ b/arch/powerpc/kernel/vdso.c
> @@ -40,6 +40,8 @@
> extern char vdso32_start, vdso32_end;
> extern char vdso64_start, vdso64_end;
>
> +asmlinkage long sys_ni_syscall(void);
> +
Prototypes should go in a header file.
> /*
> * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
> * Once the early boot kernel code no longer needs to muck around
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-01 8:29 ` Christophe Leroy
@ 2022-06-09 13:06 ` Christophe Leroy
2022-06-16 5:42 ` Rohan McLure
0 siblings, 1 reply; 31+ messages in thread
From: Christophe Leroy @ 2022-06-09 13:06 UTC (permalink / raw)
To: Rohan McLure, linuxppc-dev; +Cc: Andrew Donnellan, npiggin
Le 01/06/2022 à 10:29, Christophe Leroy a écrit :
>
>
> Le 01/06/2022 à 07:48, Rohan McLure a écrit :
>> [Vous ne recevez pas souvent de courriers de la part de
>> rmclure@linux.ibm.com. Découvrez pourquoi cela peut être important à
>> l'adresse https://aka.ms/LearnAboutSenderIdentification.]
>>
>> Syscall wrapper implemented as per s390, x86, arm64, providing the
>> option for gprs to be cleared on entry to the kernel, reducing caller
>> influence influence on speculation within syscall routine. The wrapper
>> is a macro that emits syscall handler implementations with parameters
>> passed by stack pointer.
>
> Passing parameters by stack is going to be sub-optimal. Did you make any
> measurement of the implied performance degradation ? We usually use the
> null_syscall selftest for that everytime we touch syscall entries/exits.
I did a test with null_syscall on an 8xx. Surprisingly I get more than
20% improvement with your series.
Looking at the generated code in more details, we see that
system_call_exception() is lighter as now no stack frame is needed, the
compiler has enough registers available.
Before the patch:
c000c9ec <system_call_exception>:
c000c9ec: 94 21 ff f0 stwu r1,-16(r1)
c000c9f0: 93 e1 00 0c stw r31,12(r1)
c000c9f4: 7d 5f 53 78 mr r31,r10
c000c9f8: 81 4a 00 84 lwz r10,132(r10)
c000c9fc: 90 7f 00 88 stw r3,136(r31)
c000ca00: 71 4b 00 02 andi. r11,r10,2
c000ca04: 41 82 00 4c beq c000ca50 <system_call_exception+0x64>
c000ca08: 71 4b 40 00 andi. r11,r10,16384
c000ca0c: 41 82 00 50 beq c000ca5c <system_call_exception+0x70>
c000ca10: 71 4a 80 00 andi. r10,r10,32768
c000ca14: 41 82 00 54 beq c000ca68 <system_call_exception+0x7c>
c000ca18: 7c 50 13 a6 mtspr 80,r2
c000ca1c: 81 42 00 4c lwz r10,76(r2)
c000ca20: 71 4a 84 91 andi. r10,r10,33937
c000ca24: 40 82 00 50 bne c000ca74 <system_call_exception+0x88>
c000ca28: 28 09 01 c2 cmplwi r9,450
c000ca2c: 41 81 00 88 bgt c000cab4 <system_call_exception+0xc8>
c000ca30: 3d 40 c0 6f lis r10,-16273
c000ca34: 55 29 10 3a rlwinm r9,r9,2,0,29
c000ca38: 39 4a c1 c5 addi r10,r10,-15931
c000ca3c: 7d 2a 48 2e lwzx r9,r10,r9
c000ca40: 83 e1 00 0c lwz r31,12(r1)
c000ca44: 7d 29 03 a6 mtctr r9
c000ca48: 38 21 00 10 addi r1,r1,16
c000ca4c: 4e 80 04 20 bctr
...
After the patch:
c000cc94 <system_call_exception>:
c000cc94: 81 24 00 84 lwz r9,132(r4)
c000cc98: 81 44 00 0c lwz r10,12(r4)
c000cc9c: 71 28 00 02 andi. r8,r9,2
c000cca0: 91 44 00 88 stw r10,136(r4)
c000cca4: 41 82 00 48 beq c000ccec <system_call_exception+0x58>
c000cca8: 71 2a 40 00 andi. r10,r9,16384
c000ccac: 41 82 00 44 beq c000ccf0 <system_call_exception+0x5c>
c000ccb0: 71 29 80 00 andi. r9,r9,32768
c000ccb4: 41 82 00 40 beq c000ccf4 <system_call_exception+0x60>
c000ccb8: 7c 50 13 a6 mtspr 80,r2
c000ccbc: 81 22 00 4c lwz r9,76(r2)
c000ccc0: 71 29 84 91 andi. r9,r9,33937
c000ccc4: 40 82 00 34 bne c000ccf8 <system_call_exception+0x64>
c000ccc8: 28 03 01 c2 cmplwi r3,450
c000cccc: 41 81 00 78 bgt c000cd44 <system_call_exception+0xb0>
c000ccd0: 3d 20 c0 70 lis r9,-16272
c000ccd4: 54 63 10 3a rlwinm r3,r3,2,0,29
c000ccd8: 39 29 81 c5 addi r9,r9,-32315
c000ccdc: 7d 29 18 2e lwzx r9,r9,r3
c000cce0: 7c 83 23 78 mr r3,r4
c000cce4: 7d 29 03 a6 mtctr r9
c000cce8: 4e 80 04 20 bctr
...
>
> Why going via stack ? The main advantage of a RISC processor like
> powerpc is that, unlike x86, there are enough registers to avoid going
> through memory. RISC processors are optimised with three operands
> operations and many registers, and usually have slow memory in return.
Well, thinking about it once more. In fact registers are saved to the
stack anyway. At the start of syscall functions they are likely to still
be hot in the cache, so reading them back is just a few cycles. And it
eventually provide the compiler the opportunity to organise stuff better.
>
>>
>> For platforms supporting this syscall wrapper, emit symbols with usual
>> in-register parameters (`sys...`) to support calls to syscall handlers
>> from within the kernel.
>>
>> Syscalls are wrapped on all platforms except Cell processor. SPUs require
>> access syscall prototypes which are omitted with ARCH_HAS_SYSCALL_WRAPPER
>> enabled.
> This commit message isn't very clear, please describe in more details
> what is done, how and why.
>
Christophe
^ permalink raw reply [flat|nested] 31+ messages in thread
* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-09 13:06 ` Christophe Leroy
@ 2022-06-16 5:42 ` Rohan McLure
2022-06-16 7:20 ` Arnd Bergmann
0 siblings, 1 reply; 31+ messages in thread
From: Rohan McLure @ 2022-06-16 5:42 UTC (permalink / raw)
To: Christophe Leroy; +Cc: linuxppc-dev, Andrew Donnellan, npiggin
> Le 01/06/2022 à 10:29, Christophe Leroy a écrit :
>> Le 01/06/2022 à 07:48, Rohan McLure a écrit :
>>> [Vous ne recevez pas souvent de courriers de la part de rmclure@linux.ibm.com. Découvrez pourquoi cela peut être important à l'adresse https://aka.ms/LearnAboutSenderIdentification.]
>>>
>>> Syscall wrapper implemented as per s390, x86, arm64, providing the
>>> option for gprs to be cleared on entry to the kernel, reducing caller
>>> influence influence on speculation within syscall routine. The wrapper
>>> is a macro that emits syscall handler implementations with parameters
>>> passed by stack pointer.
>> Passing parameters by stack is going to be sub-optimal. Did you make any measurement of the implied performance degradation ? We usually use the null_syscall selftest for that everytime we touch syscall entries/exits.
>
> I did a test with null_syscall on an 8xx. Surprisingly I get more than 20% improvement with your series.
>
> Looking at the generated code in more details, we see that system_call_exception() is lighter as now no stack frame is needed, the compiler has enough registers available.
>
> Before the patch:
>
> c000c9ec <system_call_exception>:
> c000c9ec: 94 21 ff f0 stwu r1,-16(r1)
> c000c9f0: 93 e1 00 0c stw r31,12(r1)
> c000c9f4: 7d 5f 53 78 mr r31,r10
> c000c9f8: 81 4a 00 84 lwz r10,132(r10)
> c000c9fc: 90 7f 00 88 stw r3,136(r31)
> c000ca00: 71 4b 00 02 andi. r11,r10,2
> c000ca04: 41 82 00 4c beq c000ca50 <system_call_exception+0x64>
> c000ca08: 71 4b 40 00 andi. r11,r10,16384
> c000ca0c: 41 82 00 50 beq c000ca5c <system_call_exception+0x70>
> c000ca10: 71 4a 80 00 andi. r10,r10,32768
> c000ca14: 41 82 00 54 beq c000ca68 <system_call_exception+0x7c>
> c000ca18: 7c 50 13 a6 mtspr 80,r2
> c000ca1c: 81 42 00 4c lwz r10,76(r2)
> c000ca20: 71 4a 84 91 andi. r10,r10,33937
> c000ca24: 40 82 00 50 bne c000ca74 <system_call_exception+0x88>
> c000ca28: 28 09 01 c2 cmplwi r9,450
> c000ca2c: 41 81 00 88 bgt c000cab4 <system_call_exception+0xc8>
> c000ca30: 3d 40 c0 6f lis r10,-16273
> c000ca34: 55 29 10 3a rlwinm r9,r9,2,0,29
> c000ca38: 39 4a c1 c5 addi r10,r10,-15931
> c000ca3c: 7d 2a 48 2e lwzx r9,r10,r9
> c000ca40: 83 e1 00 0c lwz r31,12(r1)
> c000ca44: 7d 29 03 a6 mtctr r9
> c000ca48: 38 21 00 10 addi r1,r1,16
> c000ca4c: 4e 80 04 20 bctr
> ...
>
> After the patch:
> c000cc94 <system_call_exception>:
> c000cc94: 81 24 00 84 lwz r9,132(r4)
> c000cc98: 81 44 00 0c lwz r10,12(r4)
> c000cc9c: 71 28 00 02 andi. r8,r9,2
> c000cca0: 91 44 00 88 stw r10,136(r4)
> c000cca4: 41 82 00 48 beq c000ccec <system_call_exception+0x58>
> c000cca8: 71 2a 40 00 andi. r10,r9,16384
> c000ccac: 41 82 00 44 beq c000ccf0 <system_call_exception+0x5c>
> c000ccb0: 71 29 80 00 andi. r9,r9,32768
> c000ccb4: 41 82 00 40 beq c000ccf4 <system_call_exception+0x60>
> c000ccb8: 7c 50 13 a6 mtspr 80,r2
> c000ccbc: 81 22 00 4c lwz r9,76(r2)
> c000ccc0: 71 29 84 91 andi. r9,r9,33937
> c000ccc4: 40 82 00 34 bne c000ccf8 <system_call_exception+0x64>
> c000ccc8: 28 03 01 c2 cmplwi r3,450
> c000cccc: 41 81 00 78 bgt c000cd44 <system_call_exception+0xb0>
> c000ccd0: 3d 20 c0 70 lis r9,-16272
> c000ccd4: 54 63 10 3a rlwinm r3,r3,2,0,29
> c000ccd8: 39 29 81 c5 addi r9,r9,-32315
> c000ccdc: 7d 29 18 2e lwzx r9,r9,r3
> c000cce0: 7c 83 23 78 mr r3,r4
> c000cce4: 7d 29 03 a6 mtctr r9
> c000cce8: 4e 80 04 20 bctr
> ...
>
>
>
>> Why going via stack ? The main advantage of a RISC processor like powerpc is that, unlike x86, there are enough registers to avoid going through memory. RISC processors are optimised with three operands operations and many registers, and usually have slow memory in return.
>
> Well, thinking about it once more. In fact registers are saved to the stack anyway. At the start of syscall functions they are likely to still be hot in the cache, so reading them back is just a few cycles. And it eventually provide the compiler the opportunity to organise stuff better.
>
>
>>>
>>> For platforms supporting this syscall wrapper, emit symbols with usual
>>> in-register parameters (`sys...`) to support calls to syscall handlers
>>> from within the kernel.
>>>
>>> Syscalls are wrapped on all platforms except Cell processor. SPUs require
>>> access syscall prototypes which are omitted with ARCH_HAS_SYSCALL_WRAPPER
>>> enabled.
>> This commit message isn't very clear, please describe in more details what is done, how and why.
>
>
> Christophe
Thanks for checking this Christophe.
>> Why going via stack ? The main advantage of a RISC processor like powerpc is that, unlike x86, there are enough registers to avoid going through memory. RISC processors are optimised with three operands operations and many registers, and usually have slow memory in return.
>
> Well, thinking about it once more. In fact registers are saved to the stack anyway. At the start of syscall functions they are likely to still be hot in the cache, so reading them back is just a few cycles. And it eventually provide the compiler the opportunity to organise stuff better.
Sorry for the delay in performance results - took me a while to verify
these results on real hardware. On a Power9 I’m seeing ~5.6% performance
improvement on null_syscall, even with register clearing enabled.
The upshot of the syscall wrapper was primarily to adopt common
behaviour to other architectures, and to enable register clearing. As it
stands, prior to this patch series we already save register state into a
pt_regs struct, and so may as well pass arguments by the stack as
performance results are favourable.
>>> For platforms supporting this syscall wrapper, emit symbols with usual
>>> in-register parameters (`sys...`) to support calls to syscall handlers
>>> from within the kernel.
>>>
>>> Syscalls are wrapped on all platforms except Cell processor. SPUs require
>>> access syscall prototypes which are omitted with ARCH_HAS_SYSCALL_WRAPPER
>>> enabled.
>> This commit message isn't very clear, please describe in more details what is done, how and why.
Here is a hack which addresses the fact that handlers for the select and
ppc64_personality syscalls will tail-call generic implementations via
their sys_... symbol, passing arguments with the usual in-register
calling convention. This commit resolves this issue by emitting external
linkage functions with both in-register and in-stack conventions
(__powerpc_sys... and sys_... respectively), but the best way forward is
probably to remove dependence on sys_... handlers alltogether. There’s
simply too much code bloat in emitting both, and direct calls to syscall
handlers should in general be avoided. I would much rather remove all such
references in the kernel as arm has done before proceeding.
As for SPU's, the issue here is that include/linux/syscalls.h only
provides prototypes for sys_... handlers. So spu_callbacks.c must
reference these symbols for the translation unit to compile. A solution
may be for spu_syscall_table to be made extern linkage and populated in
the same manner as systbl.S. I suggest we simply omit support for sycall
wrappers with the Cell processor.
Rohan
^ permalink raw reply [flat|nested] 31+ messages in thread
* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-16 5:42 ` Rohan McLure
@ 2022-06-16 7:20 ` Arnd Bergmann
0 siblings, 0 replies; 31+ messages in thread
From: Arnd Bergmann @ 2022-06-16 7:20 UTC (permalink / raw)
To: Rohan McLure; +Cc: linuxppc-dev, Andrew Donnellan, Nicholas Piggin
On Thu, Jun 16, 2022 at 7:42 AM Rohan McLure <rmclure@linux.ibm.com> wrote:
>
> As for SPU's, the issue here is that include/linux/syscalls.h only
> provides prototypes for sys_... handlers. So spu_callbacks.c must
> reference these symbols for the translation unit to compile. A solution
> may be for spu_syscall_table to be made extern linkage and populated in
> the same manner as systbl.S. I suggest we simply omit support for sycall
> wrappers with the Cell processor.
The compat syscalls should all be declared in linux/compat.h.
I think in general the C based syscall tables are better because
they enforce the presence of a declaration for each syscall, and that
helps with type safety.
Arnd
^ permalink raw reply [flat|nested] 31+ messages in thread
* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-01 5:48 ` [PATCH 2/6] powerpc: Provide syscall wrapper Rohan McLure
2022-06-01 8:29 ` Christophe Leroy
@ 2022-06-01 8:59 ` kernel test robot
2022-06-01 9:35 ` kernel test robot
` (3 subsequent siblings)
5 siblings, 0 replies; 31+ messages in thread
From: kernel test robot @ 2022-06-01 8:59 UTC (permalink / raw)
To: Rohan McLure, linuxppc-dev
Cc: Rohan McLure, kbuild-all, Andrew Donnellan, npiggin
Hi Rohan,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on v5.18]
[also build test WARNING on next-20220601]
[cannot apply to powerpc/next scottwood/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Rohan-McLure/powerpc-Add-ZERO_GPRS-macros-for-register-clears/20220601-135400
base: 4b0986a3613c92f4ec1bdc7f60ec66fea135991f
config: powerpc-allyesconfig (https://download.01.org/0day-ci/archive/20220601/202206011624.sRj0DSyf-lkp@intel.com/config)
compiler: powerpc-linux-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/c3efdfac99806b0d7ef4ee781283404448addc69
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Rohan-McLure/powerpc-Add-ZERO_GPRS-macros-for-register-clears/20220601-135400
git checkout c3efdfac99806b0d7ef4ee781283404448addc69
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/kernel/
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
In file included from include/linux/syscalls.h:98,
from arch/powerpc/kernel/syscalls.c:19:
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_switch_endian' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
arch/powerpc/kernel/syscalls.c:114:1: note: in expansion of macro 'SYSCALL_DEFINE0'
114 | SYSCALL_DEFINE0(switch_endian)
| ^~~~~~~~~~~~~~~
vim +/sys_switch_endian +78 arch/powerpc/include/asm/syscall_wrapper.h
49
50 #define __SYSCALL_DEFINEx(x, name, ...) \
51 asmlinkage long __powerpc_sys##name(const struct pt_regs *regs); \
52 ALLOW_ERROR_INJECTION(__powerpc_sys##name, ERRNO); \
53 long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
54 static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
55 static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
56 asmlinkage long __powerpc_sys##name(const struct pt_regs *regs) \
57 { \
58 return __se_sys##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
59 } \
60 long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
61 { \
62 return __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
63 } \
64 static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
65 { \
66 long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
67 __MAP(x,__SC_TEST,__VA_ARGS__); \
68 __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
69 return ret; \
70 } \
71 static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
72
73 #define SYSCALL_DEFINE0(sname) \
74 SYSCALL_METADATA(_##sname, 0); \
75 long sys_##name(void); \
76 asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused); \
77 ALLOW_ERROR_INJECTION(__powerpc_sys_##sname, ERRNO); \
> 78 long sys_##sname(void) \
79 { \
80 return __powerpc_sys_##sname(NULL); \
81 } \
82 asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused)
83
--
0-DAY CI Kernel Test Service
https://01.org/lkp
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-01 5:48 ` [PATCH 2/6] powerpc: Provide syscall wrapper Rohan McLure
2022-06-01 8:29 ` Christophe Leroy
2022-06-01 8:59 ` kernel test robot
@ 2022-06-01 9:35 ` kernel test robot
2022-06-01 12:23 ` kernel test robot
` (2 subsequent siblings)
5 siblings, 0 replies; 31+ messages in thread
From: kernel test robot @ 2022-06-01 9:35 UTC (permalink / raw)
To: Rohan McLure, linuxppc-dev
Cc: Rohan McLure, kbuild-all, Andrew Donnellan, npiggin
Hi Rohan,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on v5.18]
[also build test ERROR on next-20220601]
[cannot apply to powerpc/next scottwood/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Rohan-McLure/powerpc-Add-ZERO_GPRS-macros-for-register-clears/20220601-135400
base: 4b0986a3613c92f4ec1bdc7f60ec66fea135991f
config: powerpc-allnoconfig (https://download.01.org/0day-ci/archive/20220601/202206011740.FugDNwNm-lkp@intel.com/config)
compiler: powerpc-linux-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/c3efdfac99806b0d7ef4ee781283404448addc69
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Rohan-McLure/powerpc-Add-ZERO_GPRS-macros-for-register-clears/20220601-135400
git checkout c3efdfac99806b0d7ef4ee781283404448addc69
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/kernel/ fs/ kernel/ mm/
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All error/warnings (new ones prefixed by >>):
In file included from include/linux/syscalls.h:98,
from arch/powerpc/kernel/syscalls.c:19:
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: error: no previous prototype for 'sys_switch_endian' [-Werror=missing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
arch/powerpc/kernel/syscalls.c:114:1: note: in expansion of macro 'SYSCALL_DEFINE0'
114 | SYSCALL_DEFINE0(switch_endian)
| ^~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
--
kernel/fork.c:163:13: warning: no previous prototype for 'arch_release_task_struct' [-Wmissing-prototypes]
163 | void __weak arch_release_task_struct(struct task_struct *tsk)
| ^~~~~~~~~~~~~~~~~~~~~~~~
kernel/fork.c:854:20: warning: no previous prototype for 'arch_task_cache_init' [-Wmissing-prototypes]
854 | void __init __weak arch_task_cache_init(void) { }
| ^~~~~~~~~~~~~~~~~~~~
In file included from include/linux/syscalls.h:98,
from kernel/fork.c:55:
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_fork' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/fork.c:2695:1: note: in expansion of macro 'SYSCALL_DEFINE0'
2695 | SYSCALL_DEFINE0(fork)
| ^~~~~~~~~~~~~~~
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_vfork' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/fork.c:2711:1: note: in expansion of macro 'SYSCALL_DEFINE0'
2711 | SYSCALL_DEFINE0(vfork)
| ^~~~~~~~~~~~~~~
--
In file included from include/linux/syscalls.h:98,
from kernel/signal.c:30:
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_restart_syscall' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/signal.c:3004:1: note: in expansion of macro 'SYSCALL_DEFINE0'
3004 | SYSCALL_DEFINE0(restart_syscall)
| ^~~~~~~~~~~~~~~
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_sgetmask' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/signal.c:4568:1: note: in expansion of macro 'SYSCALL_DEFINE0'
4568 | SYSCALL_DEFINE0(sgetmask)
| ^~~~~~~~~~~~~~~
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_pause' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/signal.c:4607:1: note: in expansion of macro 'SYSCALL_DEFINE0'
4607 | SYSCALL_DEFINE0(pause)
| ^~~~~~~~~~~~~~~
--
In file included from include/linux/compat.h:34,
from kernel/sys.c:47:
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_getpid' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/sys.c:933:1: note: in expansion of macro 'SYSCALL_DEFINE0'
933 | SYSCALL_DEFINE0(getpid)
| ^~~~~~~~~~~~~~~
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_gettid' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/sys.c:939:1: note: in expansion of macro 'SYSCALL_DEFINE0'
939 | SYSCALL_DEFINE0(gettid)
| ^~~~~~~~~~~~~~~
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_getppid' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/sys.c:950:1: note: in expansion of macro 'SYSCALL_DEFINE0'
950 | SYSCALL_DEFINE0(getppid)
| ^~~~~~~~~~~~~~~
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_getuid' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/sys.c:961:1: note: in expansion of macro 'SYSCALL_DEFINE0'
961 | SYSCALL_DEFINE0(getuid)
| ^~~~~~~~~~~~~~~
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_geteuid' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/sys.c:967:1: note: in expansion of macro 'SYSCALL_DEFINE0'
967 | SYSCALL_DEFINE0(geteuid)
| ^~~~~~~~~~~~~~~
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_getgid' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/sys.c:973:1: note: in expansion of macro 'SYSCALL_DEFINE0'
973 | SYSCALL_DEFINE0(getgid)
| ^~~~~~~~~~~~~~~
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_getegid' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/sys.c:979:1: note: in expansion of macro 'SYSCALL_DEFINE0'
979 | SYSCALL_DEFINE0(getegid)
| ^~~~~~~~~~~~~~~
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_getpgrp' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/sys.c:1154:1: note: in expansion of macro 'SYSCALL_DEFINE0'
1154 | SYSCALL_DEFINE0(getpgrp)
| ^~~~~~~~~~~~~~~
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_setsid' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/sys.c:1233:1: note: in expansion of macro 'SYSCALL_DEFINE0'
1233 | SYSCALL_DEFINE0(setsid)
| ^~~~~~~~~~~~~~~
--
In file included from include/linux/syscalls.h:98,
from mm/mlock.c:19:
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_munlockall' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
mm/mlock.c:725:1: note: in expansion of macro 'SYSCALL_DEFINE0'
725 | SYSCALL_DEFINE0(munlockall)
| ^~~~~~~~~~~~~~~
--
In file included from include/linux/syscalls.h:98,
from fs/open.c:27:
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_vhangup' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
fs/open.c:1375:1: note: in expansion of macro 'SYSCALL_DEFINE0'
1375 | SYSCALL_DEFINE0(vhangup)
| ^~~~~~~~~~~~~~~
--
In file included from include/linux/syscalls.h:98,
from fs/sync.c:15:
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_sync' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
fs/sync.c:111:1: note: in expansion of macro 'SYSCALL_DEFINE0'
111 | SYSCALL_DEFINE0(sync)
| ^~~~~~~~~~~~~~~
--
kernel/sched/core.c:5235:20: warning: no previous prototype for 'task_sched_runtime' [-Wmissing-prototypes]
5235 | unsigned long long task_sched_runtime(struct task_struct *p)
| ^~~~~~~~~~~~~~~~~~
In file included from include/linux/syscalls.h:98,
from include/linux/syscalls_api.h:1,
from kernel/sched/core.c:13:
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: warning: no previous prototype for 'sys_sched_yield' [-Wmissing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
kernel/sched/core.c:8150:1: note: in expansion of macro 'SYSCALL_DEFINE0'
8150 | SYSCALL_DEFINE0(sched_yield)
| ^~~~~~~~~~~~~~~
kernel/sched/core.c:9426:13: warning: no previous prototype for 'sched_init_smp' [-Wmissing-prototypes]
9426 | void __init sched_init_smp(void)
| ^~~~~~~~~~~~~~
kernel/sched/core.c:9454:13: warning: no previous prototype for 'sched_init' [-Wmissing-prototypes]
9454 | void __init sched_init(void)
| ^~~~~~~~~~
vim +/sys_switch_endian +78 arch/powerpc/include/asm/syscall_wrapper.h
49
50 #define __SYSCALL_DEFINEx(x, name, ...) \
51 asmlinkage long __powerpc_sys##name(const struct pt_regs *regs); \
52 ALLOW_ERROR_INJECTION(__powerpc_sys##name, ERRNO); \
53 long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
54 static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
55 static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
56 asmlinkage long __powerpc_sys##name(const struct pt_regs *regs) \
57 { \
58 return __se_sys##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
59 } \
60 long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
61 { \
62 return __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
63 } \
64 static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
65 { \
66 long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
67 __MAP(x,__SC_TEST,__VA_ARGS__); \
68 __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
69 return ret; \
70 } \
71 static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
72
73 #define SYSCALL_DEFINE0(sname) \
74 SYSCALL_METADATA(_##sname, 0); \
75 long sys_##name(void); \
76 asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused); \
77 ALLOW_ERROR_INJECTION(__powerpc_sys_##sname, ERRNO); \
> 78 long sys_##sname(void) \
79 { \
80 return __powerpc_sys_##sname(NULL); \
81 } \
82 asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused)
83
--
0-DAY CI Kernel Test Service
https://01.org/lkp
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-01 5:48 ` [PATCH 2/6] powerpc: Provide syscall wrapper Rohan McLure
` (2 preceding siblings ...)
2022-06-01 9:35 ` kernel test robot
@ 2022-06-01 12:23 ` kernel test robot
2022-06-01 14:33 ` Christophe Leroy
2022-06-03 9:04 ` Arnd Bergmann
5 siblings, 0 replies; 31+ messages in thread
From: kernel test robot @ 2022-06-01 12:23 UTC (permalink / raw)
To: Rohan McLure, linuxppc-dev
Cc: Rohan McLure, kbuild-all, Andrew Donnellan, npiggin
Hi Rohan,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on v5.18]
[also build test ERROR on next-20220601]
[cannot apply to powerpc/next scottwood/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/intel-lab-lkp/linux/commits/Rohan-McLure/powerpc-Add-ZERO_GPRS-macros-for-register-clears/20220601-135400
base: 4b0986a3613c92f4ec1bdc7f60ec66fea135991f
config: powerpc64-allnoconfig (https://download.01.org/0day-ci/archive/20220601/202206012020.14R31W6c-lkp@intel.com/config)
compiler: powerpc64-linux-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/c3efdfac99806b0d7ef4ee781283404448addc69
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Rohan-McLure/powerpc-Add-ZERO_GPRS-macros-for-register-clears/20220601-135400
git checkout c3efdfac99806b0d7ef4ee781283404448addc69
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/kernel/
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
In file included from include/linux/syscalls.h:98,
from arch/powerpc/kernel/signal_64.c:23:
>> arch/powerpc/include/asm/syscall_wrapper.h:78:14: error: no previous prototype for 'sys_rt_sigreturn' [-Werror=missing-prototypes]
78 | long sys_##sname(void) \
| ^~~~
arch/powerpc/kernel/signal_64.c:736:1: note: in expansion of macro 'SYSCALL_DEFINE0'
736 | SYSCALL_DEFINE0(rt_sigreturn)
| ^~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
vim +/sys_rt_sigreturn +78 arch/powerpc/include/asm/syscall_wrapper.h
49
50 #define __SYSCALL_DEFINEx(x, name, ...) \
51 asmlinkage long __powerpc_sys##name(const struct pt_regs *regs); \
52 ALLOW_ERROR_INJECTION(__powerpc_sys##name, ERRNO); \
53 long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
54 static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
55 static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
56 asmlinkage long __powerpc_sys##name(const struct pt_regs *regs) \
57 { \
58 return __se_sys##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
59 } \
60 long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
61 { \
62 return __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
63 } \
64 static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
65 { \
66 long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
67 __MAP(x,__SC_TEST,__VA_ARGS__); \
68 __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
69 return ret; \
70 } \
71 static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
72
73 #define SYSCALL_DEFINE0(sname) \
74 SYSCALL_METADATA(_##sname, 0); \
75 long sys_##name(void); \
76 asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused); \
77 ALLOW_ERROR_INJECTION(__powerpc_sys_##sname, ERRNO); \
> 78 long sys_##sname(void) \
79 { \
80 return __powerpc_sys_##sname(NULL); \
81 } \
82 asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused)
83
--
0-DAY CI Kernel Test Service
https://01.org/lkp
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-01 5:48 ` [PATCH 2/6] powerpc: Provide syscall wrapper Rohan McLure
` (3 preceding siblings ...)
2022-06-01 12:23 ` kernel test robot
@ 2022-06-01 14:33 ` Christophe Leroy
2022-06-03 3:24 ` Rohan McLure
2022-06-03 9:04 ` Arnd Bergmann
5 siblings, 1 reply; 31+ messages in thread
From: Christophe Leroy @ 2022-06-01 14:33 UTC (permalink / raw)
To: Rohan McLure, linuxppc-dev@lists.ozlabs.org
Cc: Andrew Donnellan, npiggin@gmail.com
Le 01/06/2022 à 07:48, Rohan McLure a écrit :
> [Vous ne recevez pas souvent de courriers de la part de rmclure@linux.ibm.com. Découvrez pourquoi cela peut être important à l'adresse https://aka.ms/LearnAboutSenderIdentification.]
>
> Syscall wrapper implemented as per s390, x86, arm64, providing the
> option for gprs to be cleared on entry to the kernel, reducing caller
> influence influence on speculation within syscall routine. The wrapper
> is a macro that emits syscall handler implementations with parameters
> passed by stack pointer.
>
> For platforms supporting this syscall wrapper, emit symbols with usual
> in-register parameters (`sys...`) to support calls to syscall handlers
> from within the kernel.
>
> Syscalls are wrapped on all platforms except Cell processor. SPUs require
> access syscall prototypes which are omitted with ARCH_HAS_SYSCALL_WRAPPER
> enabled.
>
Also wondering why I get duplicated syscall functions. Shouldn't the
sys_ ones go away once we implement the __powerpc_sys_ ones ?
c001e9a0 <sys_fork>:
c001e9a0: 94 21 ff b0 stwu r1,-80(r1)
c001e9a4: 7c 08 02 a6 mflr r0
c001e9a8: 38 a0 00 40 li r5,64
c001e9ac: 38 80 00 00 li r4,0
c001e9b0: 38 61 00 08 addi r3,r1,8
c001e9b4: 90 01 00 54 stw r0,84(r1)
c001e9b8: 4b ff 6d 55 bl c001570c <memset>
c001e9bc: 38 61 00 08 addi r3,r1,8
c001e9c0: 39 20 00 11 li r9,17
c001e9c4: 91 21 00 1c stw r9,28(r1)
c001e9c8: 4b ff fb 31 bl c001e4f8 <kernel_clone>
c001e9cc: 80 01 00 54 lwz r0,84(r1)
c001e9d0: 38 21 00 50 addi r1,r1,80
c001e9d4: 7c 08 03 a6 mtlr r0
c001e9d8: 4e 80 00 20 blr
c001e9dc <__powerpc_sys_fork>:
c001e9dc: 94 21 ff b0 stwu r1,-80(r1)
c001e9e0: 7c 08 02 a6 mflr r0
c001e9e4: 38 a0 00 40 li r5,64
c001e9e8: 38 80 00 00 li r4,0
c001e9ec: 38 61 00 08 addi r3,r1,8
c001e9f0: 90 01 00 54 stw r0,84(r1)
c001e9f4: 4b ff 6d 19 bl c001570c <memset>
c001e9f8: 38 61 00 08 addi r3,r1,8
c001e9fc: 39 20 00 11 li r9,17
c001ea00: 91 21 00 1c stw r9,28(r1)
c001ea04: 4b ff fa f5 bl c001e4f8 <kernel_clone>
c001ea08: 80 01 00 54 lwz r0,84(r1)
c001ea0c: 38 21 00 50 addi r1,r1,80
c001ea10: 7c 08 03 a6 mtlr r0
c001ea14: 4e 80 00 20 blr
c001ea18 <sys_vfork>:
c001ea18: 94 21 ff b0 stwu r1,-80(r1)
c001ea1c: 7c 08 02 a6 mflr r0
c001ea20: 38 a0 00 38 li r5,56
c001ea24: 38 80 00 00 li r4,0
c001ea28: 38 61 00 10 addi r3,r1,16
c001ea2c: 90 01 00 54 stw r0,84(r1)
c001ea30: 4b ff 6c dd bl c001570c <memset>
c001ea34: 38 61 00 08 addi r3,r1,8
c001ea38: 39 40 00 00 li r10,0
c001ea3c: 39 60 41 00 li r11,16640
c001ea40: 39 20 00 11 li r9,17
c001ea44: 91 41 00 08 stw r10,8(r1)
c001ea48: 91 61 00 0c stw r11,12(r1)
c001ea4c: 91 21 00 1c stw r9,28(r1)
c001ea50: 4b ff fa a9 bl c001e4f8 <kernel_clone>
c001ea54: 80 01 00 54 lwz r0,84(r1)
c001ea58: 38 21 00 50 addi r1,r1,80
c001ea5c: 7c 08 03 a6 mtlr r0
c001ea60: 4e 80 00 20 blr
c001ea64 <__powerpc_sys_vfork>:
c001ea64: 94 21 ff b0 stwu r1,-80(r1)
c001ea68: 7c 08 02 a6 mflr r0
c001ea6c: 38 a0 00 38 li r5,56
c001ea70: 38 80 00 00 li r4,0
c001ea74: 38 61 00 10 addi r3,r1,16
c001ea78: 90 01 00 54 stw r0,84(r1)
c001ea7c: 4b ff 6c 91 bl c001570c <memset>
c001ea80: 38 61 00 08 addi r3,r1,8
c001ea84: 39 40 00 00 li r10,0
c001ea88: 39 60 41 00 li r11,16640
c001ea8c: 39 20 00 11 li r9,17
c001ea90: 91 41 00 08 stw r10,8(r1)
c001ea94: 91 61 00 0c stw r11,12(r1)
c001ea98: 91 21 00 1c stw r9,28(r1)
c001ea9c: 4b ff fa 5d bl c001e4f8 <kernel_clone>
c001eaa0: 80 01 00 54 lwz r0,84(r1)
c001eaa4: 38 21 00 50 addi r1,r1,80
c001eaa8: 7c 08 03 a6 mtlr r0
c001eaac: 4e 80 00 20 blr
Christophe
> Co-developed-by: Andrew Donnellan <ajd@linux.ibm.com>
> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
> Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
> ---
> arch/powerpc/Kconfig | 1 +
> arch/powerpc/include/asm/interrupt.h | 3 +-
> arch/powerpc/include/asm/syscall_wrapper.h | 92 ++++++++++++++++++++++
> arch/powerpc/include/asm/syscalls.h | 83 +++++++++++++------
> arch/powerpc/kernel/entry_32.S | 6 +-
> arch/powerpc/kernel/interrupt.c | 35 ++++----
> arch/powerpc/kernel/interrupt_64.S | 30 +++----
> arch/powerpc/kernel/sys_ppc32.c | 50 +++++++-----
> arch/powerpc/kernel/syscalls.c | 19 +++--
> arch/powerpc/kernel/systbl.S | 21 +++++
> arch/powerpc/kernel/vdso.c | 2 +
> 11 files changed, 255 insertions(+), 87 deletions(-)
> create mode 100644 arch/powerpc/include/asm/syscall_wrapper.h
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 174edabb74fa..e58287a70061 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -137,6 +137,7 @@ config PPC
> select ARCH_HAS_STRICT_KERNEL_RWX if (PPC_BOOK3S || PPC_8xx || 40x) && !HIBERNATION
> select ARCH_HAS_STRICT_KERNEL_RWX if FSL_BOOKE && !HIBERNATION && !RANDOMIZE_BASE
> select ARCH_HAS_STRICT_MODULE_RWX if ARCH_HAS_STRICT_KERNEL_RWX
> + select ARCH_HAS_SYSCALL_WRAPPER if !SPU_BASE
> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
> select ARCH_HAS_UACCESS_FLUSHCACHE
> select ARCH_HAS_UBSAN_SANITIZE_ALL
> diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
> index f964ef5c57d8..8e8949e4db7a 100644
> --- a/arch/powerpc/include/asm/interrupt.h
> +++ b/arch/powerpc/include/asm/interrupt.h
> @@ -636,8 +636,7 @@ static inline void interrupt_cond_local_irq_enable(struct pt_regs *regs)
> local_irq_enable();
> }
>
> -long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
> - unsigned long r0, struct pt_regs *regs);
> +long system_call_exception(unsigned long r0, struct pt_regs *regs);
> notrace unsigned long syscall_exit_prepare(unsigned long r3, struct pt_regs *regs, long scv);
> notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs);
> notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs);
> diff --git a/arch/powerpc/include/asm/syscall_wrapper.h b/arch/powerpc/include/asm/syscall_wrapper.h
> new file mode 100644
> index 000000000000..23da22b081e4
> --- /dev/null
> +++ b/arch/powerpc/include/asm/syscall_wrapper.h
> @@ -0,0 +1,92 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * syscall_wrapper.h - powerpc specific wrappers to syscall definitions
> + *
> + * Based on arch/{x86,arm64}/include/asm/syscall_wrapper.h
> + */
> +
> +#ifndef __ASM_SYSCALL_WRAPPER_H
> +#define __ASM_SYSCALL_WRAPPER_H
> +
> +struct pt_regs;
> +
> +#define SC_POWERPC_REGS_TO_ARGS(x, ...) \
> + __MAP(x,__SC_ARGS \
> + ,,regs->gpr[3],,regs->gpr[4],,regs->gpr[5] \
> + ,,regs->gpr[6],,regs->gpr[7],,regs->gpr[8])
> +
> +#ifdef CONFIG_COMPAT
> +
> +#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \
> + asmlinkage long __powerpc_compat_sys##name(const struct pt_regs *regs); \
> + ALLOW_ERROR_INJECTION(__powerpc_compat_sys##name, ERRNO); \
> + static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
> + static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
> + asmlinkage long __powerpc_compat_sys##name(const struct pt_regs *regs) \
> + { \
> + return __se_compat_sys##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
> + } \
> + static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
> + { \
> + return __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__)); \
> + } \
> + static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
> +
> +#define COMPAT_SYSCALL_DEFINE0(sname) \
> + asmlinkage long __powerpc_compat_sys_##sname(const struct pt_regs *__unused); \
> + ALLOW_ERROR_INJECTION(__powerpc_compat_sys_##sname, ERRNO); \
> + asmlinkage long __powerpc_compat_sys_##sname(const struct pt_regs *__unused)
> +
> +#define COND_SYSCALL_COMPAT(name) \
> + asmlinkage long __weak __powerpc_compat_sys_##name(const struct pt_regs *regs) \
> + { \
> + return sys_ni_syscall(); \
> + }
> +#define COMPAT_SYS_NI(name) \
> + SYSCALL_ALIAS(__powerpc_compat_sys_##name, sys_ni_posix_timers);
> +
> +#endif /* CONFIG_COMPAT */
> +
> +#define __SYSCALL_DEFINEx(x, name, ...) \
> + asmlinkage long __powerpc_sys##name(const struct pt_regs *regs); \
> + ALLOW_ERROR_INJECTION(__powerpc_sys##name, ERRNO); \
> + long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
> + static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
> + static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
> + asmlinkage long __powerpc_sys##name(const struct pt_regs *regs) \
> + { \
> + return __se_sys##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
> + } \
> + long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
> + { \
> + return __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
> + } \
> + static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
> + { \
> + long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
> + __MAP(x,__SC_TEST,__VA_ARGS__); \
> + __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
> + return ret; \
> + } \
> + static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
> +
> +#define SYSCALL_DEFINE0(sname) \
> + SYSCALL_METADATA(_##sname, 0); \
> + long sys_##name(void); \
> + asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused); \
> + ALLOW_ERROR_INJECTION(__powerpc_sys_##sname, ERRNO); \
> + long sys_##sname(void) \
> + { \
> + return __powerpc_sys_##sname(NULL); \
> + } \
> + asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused)
> +
> +#define COND_SYSCALL(name) \
> + asmlinkage long __weak __powerpc_sys_##name(const struct pt_regs *regs) \
> + { \
> + return sys_ni_syscall(); \
> + }
> +
> +#define SYS_NI(name) SYSCALL_ALIAS(__powerpc_sys_##name, sys_ni_posix_timers);
> +
> +#endif /* __ASM_SYSCALL_WRAPPER_H */
> diff --git a/arch/powerpc/include/asm/syscalls.h b/arch/powerpc/include/asm/syscalls.h
> index a2b13e55254f..75d8e1822caf 100644
> --- a/arch/powerpc/include/asm/syscalls.h
> +++ b/arch/powerpc/include/asm/syscalls.h
> @@ -8,14 +8,47 @@
> #include <linux/types.h>
> #include <linux/compat.h>
>
> +/*
> + * For PowerPC specific syscall implementations, wrapper takes exact name and
> + * return type for a given function.
> + */
> +
> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
> +#define PPC_SYSCALL_DEFINE(x, type, name, ...) \
> + asmlinkage type __powerpc_##name(const struct pt_regs *regs); \
> + ALLOW_ERROR_INJECTION(__powerpc_##name, ERRNO); \
> + type sys_##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
> + static type __se_##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
> + static inline type __do_##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
> + asmlinkage type __powerpc_##name(const struct pt_regs *regs) \
> + { \
> + return __se_##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
> + } \
> + type sys_##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
> + { \
> + return __do_##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
> + } \
> + static type __se_##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
> + { \
> + type ret = __do_##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
> + __MAP(x,__SC_TEST,__VA_ARGS__); \
> + __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
> + return ret; \
> + } \
> + static inline type __do_##name(__MAP(x,__SC_DECL,__VA_ARGS__))
> +#else
> +#define PPC_SYSCALL_DEFINE(x, type, name, ...) \
> + type name(__MAP(x,__SC_DECL,__VA_ARGS__))
> +#endif
> +
> struct rtas_args;
>
> asmlinkage long sys_mmap(unsigned long addr, size_t len,
> - unsigned long prot, unsigned long flags,
> - unsigned long fd, off_t offset);
> + unsigned long prot, unsigned long flags,
> + unsigned long fd, off_t offset);
> asmlinkage long sys_mmap2(unsigned long addr, size_t len,
> - unsigned long prot, unsigned long flags,
> - unsigned long fd, unsigned long pgoff);
> + unsigned long prot, unsigned long flags,
> + unsigned long fd, unsigned long pgoff);
> asmlinkage long ppc64_personality(unsigned long personality);
> asmlinkage long sys_rtas(struct rtas_args __user *uargs);
> int ppc_select(int n, fd_set __user *inp, fd_set __user *outp,
> @@ -24,32 +57,38 @@ long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
> u32 len_high, u32 len_low);
>
> #ifdef CONFIG_COMPAT
> -unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
> - unsigned long prot, unsigned long flags,
> - unsigned long fd, unsigned long pgoff);
> +asmlinkage unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
> + unsigned long prot, unsigned long flags,
> + unsigned long fd, unsigned long pgoff);
>
> -compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count,
> - u32 reg6, u32 pos1, u32 pos2);
> +asmlinkage compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf,
> + compat_size_t count,
> + u32 reg6, u32 pos1, u32 pos2);
>
> -compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf, compat_size_t count,
> - u32 reg6, u32 pos1, u32 pos2);
> +asmlinkage compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf,
> + compat_size_t count,
> + u32 reg6, u32 pos1, u32 pos2);
>
> -compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offset1, u32 offset2, u32 count);
> +asmlinkage compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offset1,
> + u32 offset2, u32 count);
>
> -int compat_sys_truncate64(const char __user *path, u32 reg4,
> - unsigned long len1, unsigned long len2);
> +asmlinkage int compat_sys_truncate64(const char __user *path, u32 reg4,
> + unsigned long len1, unsigned long len2);
>
> -long compat_sys_fallocate(int fd, int mode, u32 offset1, u32 offset2, u32 len1, u32 len2);
> +asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offset1,
> + u32 offset2, u32 len1, u32 len2);
>
> -int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long len1,
> - unsigned long len2);
> +asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4,
> + unsigned long len1, unsigned long len2);
>
> -long ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
> - size_t len, int advice);
> +asmlinkage long ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
> + size_t len, int advice);
>
> -long compat_sys_sync_file_range2(int fd, unsigned int flags,
> - unsigned int offset1, unsigned int offset2,
> - unsigned int nbytes1, unsigned int nbytes2);
> +asmlinkage long compat_sys_sync_file_range2(int fd, unsigned int flags,
> + unsigned int offset1,
> + unsigned int offset2,
> + unsigned int nbytes1,
> + unsigned int nbytes2);
> #endif
>
> #endif /* __KERNEL__ */
> diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
> index 7748c278d13c..2343c577b971 100644
> --- a/arch/powerpc/kernel/entry_32.S
> +++ b/arch/powerpc/kernel/entry_32.S
> @@ -121,9 +121,9 @@ transfer_to_syscall:
> SAVE_NVGPRS(r1)
> kuep_lock
>
> - /* Calling convention has r9 = orig r0, r10 = regs */
> - addi r10,r1,STACK_FRAME_OVERHEAD
> - mr r9,r0
> + /* Calling convention has r3 = orig r0, r4 = regs */
> + addi r4,r1,STACK_FRAME_OVERHEAD
> + mr r3,r0
> bl system_call_exception
>
> ret_from_syscall:
> diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
> index 784ea3289c84..a38329ede1a1 100644
> --- a/arch/powerpc/kernel/interrupt.c
> +++ b/arch/powerpc/kernel/interrupt.c
> @@ -24,7 +24,11 @@
> unsigned long global_dbcr0[NR_CPUS];
> #endif
>
> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
> +typedef long (*syscall_fn)(struct pt_regs *);
> +#else
> typedef long (*syscall_fn)(long, long, long, long, long, long);
> +#endif
>
> #ifdef CONFIG_PPC_BOOK3S_64
> DEFINE_STATIC_KEY_FALSE(interrupt_exit_not_reentrant);
> @@ -74,15 +78,13 @@ static notrace __always_inline bool prep_irq_for_enabled_exit(bool restartable)
> }
>
> /* Has to run notrace because it is entered not completely "reconciled" */
> -notrace long system_call_exception(long r3, long r4, long r5,
> - long r6, long r7, long r8,
> - unsigned long r0, struct pt_regs *regs)
> +notrace long system_call_exception(unsigned long r0, struct pt_regs *regs)
> {
> syscall_fn f;
>
> kuap_lock();
>
> - regs->orig_gpr3 = r3;
> + regs->orig_gpr3 = regs->gpr[3];
>
> if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
> BUG_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED);
> @@ -196,12 +198,6 @@ notrace long system_call_exception(long r3, long r4, long r5,
> r0 = do_syscall_trace_enter(regs);
> if (unlikely(r0 >= NR_syscalls))
> return regs->gpr[3];
> - r3 = regs->gpr[3];
> - r4 = regs->gpr[4];
> - r5 = regs->gpr[5];
> - r6 = regs->gpr[6];
> - r7 = regs->gpr[7];
> - r8 = regs->gpr[8];
>
> } else if (unlikely(r0 >= NR_syscalls)) {
> if (unlikely(trap_is_unsupported_scv(regs))) {
> @@ -218,18 +214,23 @@ notrace long system_call_exception(long r3, long r4, long r5,
> if (unlikely(is_compat_task())) {
> f = (void *)compat_sys_call_table[r0];
>
> - r3 &= 0x00000000ffffffffULL;
> - r4 &= 0x00000000ffffffffULL;
> - r5 &= 0x00000000ffffffffULL;
> - r6 &= 0x00000000ffffffffULL;
> - r7 &= 0x00000000ffffffffULL;
> - r8 &= 0x00000000ffffffffULL;
> + regs->gpr[3] &= 0x00000000ffffffffULL;
> + regs->gpr[4] &= 0x00000000ffffffffULL;
> + regs->gpr[5] &= 0x00000000ffffffffULL;
> + regs->gpr[6] &= 0x00000000ffffffffULL;
> + regs->gpr[7] &= 0x00000000ffffffffULL;
> + regs->gpr[8] &= 0x00000000ffffffffULL;
>
> } else {
> f = (void *)sys_call_table[r0];
> }
>
> - return f(r3, r4, r5, r6, r7, r8);
> + #ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
> + return f(regs);
> + #else
> + return f(regs->gpr[3], regs->gpr[4], regs->gpr[5],
> + regs->gpr[6], regs->gpr[7], regs->gpr[8]);
> + #endif
> }
>
> static notrace void booke_load_dbcr0(void)
> diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
> index 7bab2d7de372..b11c2bd84827 100644
> --- a/arch/powerpc/kernel/interrupt_64.S
> +++ b/arch/powerpc/kernel/interrupt_64.S
> @@ -91,9 +91,9 @@ _ASM_NOKPROBE_SYMBOL(system_call_vectored_\name)
> li r11,\trapnr
> std r11,_TRAP(r1)
> std r12,_CCR(r1)
> - addi r10,r1,STACK_FRAME_OVERHEAD
> + addi r4,r1,STACK_FRAME_OVERHEAD
> ld r11,exception_marker@toc(r2)
> - std r11,-16(r10) /* "regshere" marker */
> + std r11,-16(r4) /* "regshere" marker */
>
> BEGIN_FTR_SECTION
> HMT_MEDIUM
> @@ -108,8 +108,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> * but this is the best we can do.
> */
>
> - /* Calling convention has r9 = orig r0, r10 = regs */
> - mr r9,r0
> + /* Calling convention has r3 = orig r0, r4 = regs */
> + mr r3,r0
> bl system_call_exception
>
> .Lsyscall_vectored_\name\()_exit:
> @@ -285,9 +285,9 @@ END_BTB_FLUSH_SECTION
> std r10,_LINK(r1)
> std r11,_TRAP(r1)
> std r12,_CCR(r1)
> - addi r10,r1,STACK_FRAME_OVERHEAD
> + addi r4,r1,STACK_FRAME_OVERHEAD
> ld r11,exception_marker@toc(r2)
> - std r11,-16(r10) /* "regshere" marker */
> + std r11,-16(r4) /* "regshere" marker */
>
> #ifdef CONFIG_PPC_BOOK3S
> li r11,1
> @@ -308,8 +308,8 @@ END_BTB_FLUSH_SECTION
> wrteei 1
> #endif
>
> - /* Calling convention has r9 = orig r0, r10 = regs */
> - mr r9,r0
> + /* Calling convention has r3 = orig r0, r4 = regs */
> + mr r3,r0
> bl system_call_exception
>
> .Lsyscall_exit:
> @@ -353,16 +353,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
> cmpdi r3,0
> bne .Lsyscall_restore_regs
> /* Zero volatile regs that may contain sensitive kernel data */
> - li r0,0
> - li r4,0
> - li r5,0
> - li r6,0
> - li r7,0
> - li r8,0
> - li r9,0
> - li r10,0
> - li r11,0
> - li r12,0
> + ZERO_GPR(0)
> + ZERO_GPRS(4, 12)
> mtctr r0
> mtspr SPRN_XER,r0
> .Lsyscall_restore_regs_cont:
> @@ -388,7 +380,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> REST_NVGPRS(r1)
> mtctr r3
> mtspr SPRN_XER,r4
> - ld r0,GPR0(r1)
> + REST_GPR(0, r1)
> REST_GPRS(4, 12, r1)
> b .Lsyscall_restore_regs_cont
> .Lsyscall_rst_end:
> diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
> index 16ff0399a257..aa7869dbef36 100644
> --- a/arch/powerpc/kernel/sys_ppc32.c
> +++ b/arch/powerpc/kernel/sys_ppc32.c
> @@ -48,9 +48,10 @@
> #include <asm/syscalls.h>
> #include <asm/switch_to.h>
>
> -unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
> - unsigned long prot, unsigned long flags,
> - unsigned long fd, unsigned long pgoff)
> +PPC_SYSCALL_DEFINE(6, unsigned long, compat_sys_mmap2,
> + unsigned long, addr, size_t, len,
> + unsigned long, prot, unsigned long, flags,
> + unsigned long, fd, unsigned long, pgoff)
> {
> /* This should remain 12 even if PAGE_SIZE changes */
> return sys_mmap(addr, len, prot, flags, fd, pgoff << 12);
> @@ -68,52 +69,63 @@ unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
> #define merge_64(high, low) ((u64)high << 32) | low
> #endif
>
> -compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count,
> - u32 reg6, u32 pos1, u32 pos2)
> +PPC_SYSCALL_DEFINE(6, compat_ssize_t, compat_sys_pread64,
> + unsigned int, fd,
> + char __user *, ubuf, compat_size_t, count,
> + u32, reg6, u32, pos1, u32, pos2)
> {
> return ksys_pread64(fd, ubuf, count, merge_64(pos1, pos2));
> }
>
> -compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf, compat_size_t count,
> - u32 reg6, u32 pos1, u32 pos2)
> +PPC_SYSCALL_DEFINE(6, compat_ssize_t, compat_sys_pwrite64,
> + unsigned int, fd,
> + const char __user *, ubuf, compat_size_t, count,
> + u32, reg6, u32, pos1, u32, pos2)
> {
> return ksys_pwrite64(fd, ubuf, count, merge_64(pos1, pos2));
> }
>
> -compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offset1, u32 offset2, u32 count)
> +PPC_SYSCALL_DEFINE(5, compat_ssize_t, compat_sys_readahead,
> + int, fd, u32, r4,
> + u32, offset1, u32, offset2, u32, count)
> {
> return ksys_readahead(fd, merge_64(offset1, offset2), count);
> }
>
> -asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
> - unsigned long len1, unsigned long len2)
> +PPC_SYSCALL_DEFINE(4, int, compat_sys_truncate64,
> + const char __user *, path, u32, reg4,
> + unsigned long, len1, unsigned long, len2)
> {
> return ksys_truncate(path, merge_64(len1, len2));
> }
>
> -asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offset1, u32 offset2,
> - u32 len1, u32 len2)
> +PPC_SYSCALL_DEFINE(6, long, compat_sys_fallocate,
> + int, fd, int, mode, u32, offset1, u32, offset2,
> + u32, len1, u32, len2)
> {
> return ksys_fallocate(fd, mode, ((loff_t)offset1 << 32) | offset2,
> merge_64(len1, len2));
> }
>
> -asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long len1,
> - unsigned long len2)
> +PPC_SYSCALL_DEFINE(4, int, compat_sys_ftruncate64,
> + unsigned int, fd, u32, reg4, unsigned long, len1,
> + unsigned long, len2)
> {
> return ksys_ftruncate(fd, merge_64(len1, len2));
> }
>
> -long ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
> - size_t len, int advice)
> +PPC_SYSCALL_DEFINE(6, long, ppc32_fadvise64,
> + int, fd, u32, unused, u32, offset1, u32, offset2,
> + size_t, len, int, advice)
> {
> return ksys_fadvise64_64(fd, merge_64(offset1, offset2), len,
> advice);
> }
>
> -asmlinkage long compat_sys_sync_file_range2(int fd, unsigned int flags,
> - unsigned offset1, unsigned offset2,
> - unsigned nbytes1, unsigned nbytes2)
> +PPC_SYSCALL_DEFINE(6, long, compat_sys_sync_file_range2, int, fd,
> + unsigned int, flags,
> + unsigned int, offset1, unsigned int, offset2,
> + unsigned int, nbytes1, unsigned int, nbytes2)
> {
> loff_t offset = merge_64(offset1, offset2);
> loff_t nbytes = merge_64(nbytes1, nbytes2);
> diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
> index c4f5b4ce926f..c64cdb5c4435 100644
> --- a/arch/powerpc/kernel/syscalls.c
> +++ b/arch/powerpc/kernel/syscalls.c
> @@ -64,14 +64,20 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
> }
>
> #ifdef CONFIG_PPC32
> +asmlinkage long sys_old_select(struct sel_arg_struct __user *arg);
> +asmlinkage long sys_select(int n, fd_set __user *inp, fd_set __user *outp,
> + fd_set __user *exp,
> + struct __kernel_old_timeval __user *tvp);
> +
> /*
> * Due to some executables calling the wrong select we sometimes
> * get wrong args. This determines how the args are being passed
> * (a single ptr to them all args passed) then calls
> * sys_select() with the appropriate args. -- Cort
> */
> -int
> -ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct __kernel_old_timeval __user *tvp)
> +PPC_SYSCALL_DEFINE(5, long, ppc_select,
> + int, n, fd_set __user *, inp, fd_set __user *, outp,
> + fd_set __user *, exp, struct __kernel_old_timeval __user *, tvp)
> {
> if ( (unsigned long)n >= 4096 )
> return sys_old_select((void __user *)n);
> @@ -81,7 +87,9 @@ ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, s
> #endif
>
> #ifdef CONFIG_PPC64
> -long ppc64_personality(unsigned long personality)
> +asmlinkage long sys_personality(unsigned int personality);
> +
> +PPC_SYSCALL_DEFINE(1, long, ppc64_personality, unsigned long, personality)
> {
> long ret;
>
> @@ -95,8 +103,9 @@ long ppc64_personality(unsigned long personality)
> }
> #endif
>
> -long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
> - u32 len_high, u32 len_low)
> +PPC_SYSCALL_DEFINE(6, long, ppc_fadvise64_64,
> + int, fd, int, advice, u32, offset_high, u32, offset_low,
> + u32, len_high, u32, len_low)
> {
> return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low,
> (u64)len_high << 32 | len_low, advice);
> diff --git a/arch/powerpc/kernel/systbl.S b/arch/powerpc/kernel/systbl.S
> index cb3358886203..70cc7120fce2 100644
> --- a/arch/powerpc/kernel/systbl.S
> +++ b/arch/powerpc/kernel/systbl.S
> @@ -16,11 +16,32 @@
>
> #ifdef CONFIG_PPC64
> .p2align 3
> +#endif
> +
> +/* Where the syscall wrapper macro is used, handler functions expect parameters
> + to reside on the stack. We still emit symbols with register-mapped
> + parameters, which are distinguished by a prefix. */
> +
> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
> +
> +#define __powerpc_sys_ni_syscall sys_ni_syscall
> +
> +#ifdef CONFIG_PPC64
> +#define __SYSCALL(nr, entry) .8byte __powerpc_##entry
> +#else
> +#define __SYSCALL(nr, entry) .long __powerpc_##entry
> +#endif
> +
> +#else
> +
> +#ifdef CONFIG_PPC64
> #define __SYSCALL(nr, entry) .8byte entry
> #else
> #define __SYSCALL(nr, entry) .long entry
> #endif
>
> +#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
> +
> #define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
> .globl sys_call_table
> sys_call_table:
> diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
> index 717f2c9a7573..dcf57c07dbad 100644
> --- a/arch/powerpc/kernel/vdso.c
> +++ b/arch/powerpc/kernel/vdso.c
> @@ -40,6 +40,8 @@
> extern char vdso32_start, vdso32_end;
> extern char vdso64_start, vdso64_end;
>
> +asmlinkage long sys_ni_syscall(void);
> +
> /*
> * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
> * Once the early boot kernel code no longer needs to muck around
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-01 14:33 ` Christophe Leroy
@ 2022-06-03 3:24 ` Rohan McLure
2022-06-03 7:09 ` Andrew Donnellan
0 siblings, 1 reply; 31+ messages in thread
From: Rohan McLure @ 2022-06-03 3:24 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Andrew Donnellan, npiggin@gmail.com
Thanks for your comment. I comment briefly here on how files like
arch/powerpc/kernel/syscalls.c implement ppc specialisations of
various syscalls, with implementations that themselves call syscall
symbols.
>> For platforms supporting this syscall wrapper, emit symbols with usual
>> in-register parameters (`sys...`) to support calls to syscall handlers
>> from within the kernel.
The implementation of ppc_personality can be immediately reworked to
call ksys_personality, but I can’t do the same for sys_old_select for
example, which is required to implement ppc_select. As such we emit both
symbols (sys_... and __powerpc...) so that ppc implementations can
efficiently call other implementations without needing to allocate
another pt_regs onto the stack.
This does admittedly introduce some code bloat into the binary. I see
a couple ways of fixing this:
1. Remove all calls to syscall implementations via sys_... symbols from
within the kernel.
2. Restrict which syscall implementations receive a sys_... symbol to
limit the number of duplicated functions.
Do you have any suggestions on how I might fix this?
> On 2 Jun 2022, at 12:33 am, Christophe Leroy <christophe.leroy@csgroup.eu> wrote:
>
>
>
> Le 01/06/2022 à 07:48, Rohan McLure a écrit :
>> [Vous ne recevez pas souvent de courriers de la part de rmclure@linux.ibm.com. Découvrez pourquoi cela peut être important à l'adresse https://aka.ms/LearnAboutSenderIdentification.]
>>
>> Syscall wrapper implemented as per s390, x86, arm64, providing the
>> option for gprs to be cleared on entry to the kernel, reducing caller
>> influence influence on speculation within syscall routine. The wrapper
>> is a macro that emits syscall handler implementations with parameters
>> passed by stack pointer.
>>
>> For platforms supporting this syscall wrapper, emit symbols with usual
>> in-register parameters (`sys...`) to support calls to syscall handlers
>> from within the kernel.
>>
>> Syscalls are wrapped on all platforms except Cell processor. SPUs require
>> access syscall prototypes which are omitted with ARCH_HAS_SYSCALL_WRAPPER
>> enabled.
>>
>
> Also wondering why I get duplicated syscall functions. Shouldn't the
> sys_ ones go away once we implement the __powerpc_sys_ ones ?
>
> c001e9a0 <sys_fork>:
> c001e9a0: 94 21 ff b0 stwu r1,-80(r1)
> c001e9a4: 7c 08 02 a6 mflr r0
> c001e9a8: 38 a0 00 40 li r5,64
> c001e9ac: 38 80 00 00 li r4,0
> c001e9b0: 38 61 00 08 addi r3,r1,8
> c001e9b4: 90 01 00 54 stw r0,84(r1)
> c001e9b8: 4b ff 6d 55 bl c001570c <memset>
> c001e9bc: 38 61 00 08 addi r3,r1,8
> c001e9c0: 39 20 00 11 li r9,17
> c001e9c4: 91 21 00 1c stw r9,28(r1)
> c001e9c8: 4b ff fb 31 bl c001e4f8 <kernel_clone>
> c001e9cc: 80 01 00 54 lwz r0,84(r1)
> c001e9d0: 38 21 00 50 addi r1,r1,80
> c001e9d4: 7c 08 03 a6 mtlr r0
> c001e9d8: 4e 80 00 20 blr
>
> c001e9dc <__powerpc_sys_fork>:
> c001e9dc: 94 21 ff b0 stwu r1,-80(r1)
> c001e9e0: 7c 08 02 a6 mflr r0
> c001e9e4: 38 a0 00 40 li r5,64
> c001e9e8: 38 80 00 00 li r4,0
> c001e9ec: 38 61 00 08 addi r3,r1,8
> c001e9f0: 90 01 00 54 stw r0,84(r1)
> c001e9f4: 4b ff 6d 19 bl c001570c <memset>
> c001e9f8: 38 61 00 08 addi r3,r1,8
> c001e9fc: 39 20 00 11 li r9,17
> c001ea00: 91 21 00 1c stw r9,28(r1)
> c001ea04: 4b ff fa f5 bl c001e4f8 <kernel_clone>
> c001ea08: 80 01 00 54 lwz r0,84(r1)
> c001ea0c: 38 21 00 50 addi r1,r1,80
> c001ea10: 7c 08 03 a6 mtlr r0
> c001ea14: 4e 80 00 20 blr
>
> c001ea18 <sys_vfork>:
> c001ea18: 94 21 ff b0 stwu r1,-80(r1)
> c001ea1c: 7c 08 02 a6 mflr r0
> c001ea20: 38 a0 00 38 li r5,56
> c001ea24: 38 80 00 00 li r4,0
> c001ea28: 38 61 00 10 addi r3,r1,16
> c001ea2c: 90 01 00 54 stw r0,84(r1)
> c001ea30: 4b ff 6c dd bl c001570c <memset>
> c001ea34: 38 61 00 08 addi r3,r1,8
> c001ea38: 39 40 00 00 li r10,0
> c001ea3c: 39 60 41 00 li r11,16640
> c001ea40: 39 20 00 11 li r9,17
> c001ea44: 91 41 00 08 stw r10,8(r1)
> c001ea48: 91 61 00 0c stw r11,12(r1)
> c001ea4c: 91 21 00 1c stw r9,28(r1)
> c001ea50: 4b ff fa a9 bl c001e4f8 <kernel_clone>
> c001ea54: 80 01 00 54 lwz r0,84(r1)
> c001ea58: 38 21 00 50 addi r1,r1,80
> c001ea5c: 7c 08 03 a6 mtlr r0
> c001ea60: 4e 80 00 20 blr
>
> c001ea64 <__powerpc_sys_vfork>:
> c001ea64: 94 21 ff b0 stwu r1,-80(r1)
> c001ea68: 7c 08 02 a6 mflr r0
> c001ea6c: 38 a0 00 38 li r5,56
> c001ea70: 38 80 00 00 li r4,0
> c001ea74: 38 61 00 10 addi r3,r1,16
> c001ea78: 90 01 00 54 stw r0,84(r1)
> c001ea7c: 4b ff 6c 91 bl c001570c <memset>
> c001ea80: 38 61 00 08 addi r3,r1,8
> c001ea84: 39 40 00 00 li r10,0
> c001ea88: 39 60 41 00 li r11,16640
> c001ea8c: 39 20 00 11 li r9,17
> c001ea90: 91 41 00 08 stw r10,8(r1)
> c001ea94: 91 61 00 0c stw r11,12(r1)
> c001ea98: 91 21 00 1c stw r9,28(r1)
> c001ea9c: 4b ff fa 5d bl c001e4f8 <kernel_clone>
> c001eaa0: 80 01 00 54 lwz r0,84(r1)
> c001eaa4: 38 21 00 50 addi r1,r1,80
> c001eaa8: 7c 08 03 a6 mtlr r0
> c001eaac: 4e 80 00 20 blr
>
>
>
> Christophe
>
>
>> Co-developed-by: Andrew Donnellan <ajd@linux.ibm.com>
>> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
>> Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
>> ---
>> arch/powerpc/Kconfig | 1 +
>> arch/powerpc/include/asm/interrupt.h | 3 +-
>> arch/powerpc/include/asm/syscall_wrapper.h | 92 ++++++++++++++++++++++
>> arch/powerpc/include/asm/syscalls.h | 83 +++++++++++++------
>> arch/powerpc/kernel/entry_32.S | 6 +-
>> arch/powerpc/kernel/interrupt.c | 35 ++++----
>> arch/powerpc/kernel/interrupt_64.S | 30 +++----
>> arch/powerpc/kernel/sys_ppc32.c | 50 +++++++-----
>> arch/powerpc/kernel/syscalls.c | 19 +++--
>> arch/powerpc/kernel/systbl.S | 21 +++++
>> arch/powerpc/kernel/vdso.c | 2 +
>> 11 files changed, 255 insertions(+), 87 deletions(-)
>> create mode 100644 arch/powerpc/include/asm/syscall_wrapper.h
>>
>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>> index 174edabb74fa..e58287a70061 100644
>> --- a/arch/powerpc/Kconfig
>> +++ b/arch/powerpc/Kconfig
>> @@ -137,6 +137,7 @@ config PPC
>> select ARCH_HAS_STRICT_KERNEL_RWX if (PPC_BOOK3S || PPC_8xx || 40x) && !HIBERNATION
>> select ARCH_HAS_STRICT_KERNEL_RWX if FSL_BOOKE && !HIBERNATION && !RANDOMIZE_BASE
>> select ARCH_HAS_STRICT_MODULE_RWX if ARCH_HAS_STRICT_KERNEL_RWX
>> + select ARCH_HAS_SYSCALL_WRAPPER if !SPU_BASE
>> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
>> select ARCH_HAS_UACCESS_FLUSHCACHE
>> select ARCH_HAS_UBSAN_SANITIZE_ALL
>> diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
>> index f964ef5c57d8..8e8949e4db7a 100644
>> --- a/arch/powerpc/include/asm/interrupt.h
>> +++ b/arch/powerpc/include/asm/interrupt.h
>> @@ -636,8 +636,7 @@ static inline void interrupt_cond_local_irq_enable(struct pt_regs *regs)
>> local_irq_enable();
>> }
>>
>> -long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8,
>> - unsigned long r0, struct pt_regs *regs);
>> +long system_call_exception(unsigned long r0, struct pt_regs *regs);
>> notrace unsigned long syscall_exit_prepare(unsigned long r3, struct pt_regs *regs, long scv);
>> notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs);
>> notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs);
>> diff --git a/arch/powerpc/include/asm/syscall_wrapper.h b/arch/powerpc/include/asm/syscall_wrapper.h
>> new file mode 100644
>> index 000000000000..23da22b081e4
>> --- /dev/null
>> +++ b/arch/powerpc/include/asm/syscall_wrapper.h
>> @@ -0,0 +1,92 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * syscall_wrapper.h - powerpc specific wrappers to syscall definitions
>> + *
>> + * Based on arch/{x86,arm64}/include/asm/syscall_wrapper.h
>> + */
>> +
>> +#ifndef __ASM_SYSCALL_WRAPPER_H
>> +#define __ASM_SYSCALL_WRAPPER_H
>> +
>> +struct pt_regs;
>> +
>> +#define SC_POWERPC_REGS_TO_ARGS(x, ...) \
>> + __MAP(x,__SC_ARGS \
>> + ,,regs->gpr[3],,regs->gpr[4],,regs->gpr[5] \
>> + ,,regs->gpr[6],,regs->gpr[7],,regs->gpr[8])
>> +
>> +#ifdef CONFIG_COMPAT
>> +
>> +#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \
>> + asmlinkage long __powerpc_compat_sys##name(const struct pt_regs *regs); \
>> + ALLOW_ERROR_INJECTION(__powerpc_compat_sys##name, ERRNO); \
>> + static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
>> + static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
>> + asmlinkage long __powerpc_compat_sys##name(const struct pt_regs *regs) \
>> + { \
>> + return __se_compat_sys##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
>> + } \
>> + static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
>> + { \
>> + return __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__)); \
>> + } \
>> + static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
>> +
>> +#define COMPAT_SYSCALL_DEFINE0(sname) \
>> + asmlinkage long __powerpc_compat_sys_##sname(const struct pt_regs *__unused); \
>> + ALLOW_ERROR_INJECTION(__powerpc_compat_sys_##sname, ERRNO); \
>> + asmlinkage long __powerpc_compat_sys_##sname(const struct pt_regs *__unused)
>> +
>> +#define COND_SYSCALL_COMPAT(name) \
>> + asmlinkage long __weak __powerpc_compat_sys_##name(const struct pt_regs *regs) \
>> + { \
>> + return sys_ni_syscall(); \
>> + }
>> +#define COMPAT_SYS_NI(name) \
>> + SYSCALL_ALIAS(__powerpc_compat_sys_##name, sys_ni_posix_timers);
>> +
>> +#endif /* CONFIG_COMPAT */
>> +
>> +#define __SYSCALL_DEFINEx(x, name, ...) \
>> + asmlinkage long __powerpc_sys##name(const struct pt_regs *regs); \
>> + ALLOW_ERROR_INJECTION(__powerpc_sys##name, ERRNO); \
>> + long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
>> + static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
>> + static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
>> + asmlinkage long __powerpc_sys##name(const struct pt_regs *regs) \
>> + { \
>> + return __se_sys##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
>> + } \
>> + long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
>> + { \
>> + return __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
>> + } \
>> + static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
>> + { \
>> + long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
>> + __MAP(x,__SC_TEST,__VA_ARGS__); \
>> + __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
>> + return ret; \
>> + } \
>> + static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
>> +
>> +#define SYSCALL_DEFINE0(sname) \
>> + SYSCALL_METADATA(_##sname, 0); \
>> + long sys_##name(void); \
>> + asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused); \
>> + ALLOW_ERROR_INJECTION(__powerpc_sys_##sname, ERRNO); \
>> + long sys_##sname(void) \
>> + { \
>> + return __powerpc_sys_##sname(NULL); \
>> + } \
>> + asmlinkage long __powerpc_sys_##sname(const struct pt_regs *__unused)
>> +
>> +#define COND_SYSCALL(name) \
>> + asmlinkage long __weak __powerpc_sys_##name(const struct pt_regs *regs) \
>> + { \
>> + return sys_ni_syscall(); \
>> + }
>> +
>> +#define SYS_NI(name) SYSCALL_ALIAS(__powerpc_sys_##name, sys_ni_posix_timers);
>> +
>> +#endif /* __ASM_SYSCALL_WRAPPER_H */
>> diff --git a/arch/powerpc/include/asm/syscalls.h b/arch/powerpc/include/asm/syscalls.h
>> index a2b13e55254f..75d8e1822caf 100644
>> --- a/arch/powerpc/include/asm/syscalls.h
>> +++ b/arch/powerpc/include/asm/syscalls.h
>> @@ -8,14 +8,47 @@
>> #include <linux/types.h>
>> #include <linux/compat.h>
>>
>> +/*
>> + * For PowerPC specific syscall implementations, wrapper takes exact name and
>> + * return type for a given function.
>> + */
>> +
>> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
>> +#define PPC_SYSCALL_DEFINE(x, type, name, ...) \
>> + asmlinkage type __powerpc_##name(const struct pt_regs *regs); \
>> + ALLOW_ERROR_INJECTION(__powerpc_##name, ERRNO); \
>> + type sys_##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
>> + static type __se_##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
>> + static inline type __do_##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
>> + asmlinkage type __powerpc_##name(const struct pt_regs *regs) \
>> + { \
>> + return __se_##name(SC_POWERPC_REGS_TO_ARGS(x,__VA_ARGS__)); \
>> + } \
>> + type sys_##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
>> + { \
>> + return __do_##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
>> + } \
>> + static type __se_##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
>> + { \
>> + type ret = __do_##name(__MAP(x,__SC_CAST,__VA_ARGS__)); \
>> + __MAP(x,__SC_TEST,__VA_ARGS__); \
>> + __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
>> + return ret; \
>> + } \
>> + static inline type __do_##name(__MAP(x,__SC_DECL,__VA_ARGS__))
>> +#else
>> +#define PPC_SYSCALL_DEFINE(x, type, name, ...) \
>> + type name(__MAP(x,__SC_DECL,__VA_ARGS__))
>> +#endif
>> +
>> struct rtas_args;
>>
>> asmlinkage long sys_mmap(unsigned long addr, size_t len,
>> - unsigned long prot, unsigned long flags,
>> - unsigned long fd, off_t offset);
>> + unsigned long prot, unsigned long flags,
>> + unsigned long fd, off_t offset);
>> asmlinkage long sys_mmap2(unsigned long addr, size_t len,
>> - unsigned long prot, unsigned long flags,
>> - unsigned long fd, unsigned long pgoff);
>> + unsigned long prot, unsigned long flags,
>> + unsigned long fd, unsigned long pgoff);
>> asmlinkage long ppc64_personality(unsigned long personality);
>> asmlinkage long sys_rtas(struct rtas_args __user *uargs);
>> int ppc_select(int n, fd_set __user *inp, fd_set __user *outp,
>> @@ -24,32 +57,38 @@ long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
>> u32 len_high, u32 len_low);
>>
>> #ifdef CONFIG_COMPAT
>> -unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
>> - unsigned long prot, unsigned long flags,
>> - unsigned long fd, unsigned long pgoff);
>> +asmlinkage unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
>> + unsigned long prot, unsigned long flags,
>> + unsigned long fd, unsigned long pgoff);
>>
>> -compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count,
>> - u32 reg6, u32 pos1, u32 pos2);
>> +asmlinkage compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf,
>> + compat_size_t count,
>> + u32 reg6, u32 pos1, u32 pos2);
>>
>> -compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf, compat_size_t count,
>> - u32 reg6, u32 pos1, u32 pos2);
>> +asmlinkage compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf,
>> + compat_size_t count,
>> + u32 reg6, u32 pos1, u32 pos2);
>>
>> -compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offset1, u32 offset2, u32 count);
>> +asmlinkage compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offset1,
>> + u32 offset2, u32 count);
>>
>> -int compat_sys_truncate64(const char __user *path, u32 reg4,
>> - unsigned long len1, unsigned long len2);
>> +asmlinkage int compat_sys_truncate64(const char __user *path, u32 reg4,
>> + unsigned long len1, unsigned long len2);
>>
>> -long compat_sys_fallocate(int fd, int mode, u32 offset1, u32 offset2, u32 len1, u32 len2);
>> +asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offset1,
>> + u32 offset2, u32 len1, u32 len2);
>>
>> -int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long len1,
>> - unsigned long len2);
>> +asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4,
>> + unsigned long len1, unsigned long len2);
>>
>> -long ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
>> - size_t len, int advice);
>> +asmlinkage long ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
>> + size_t len, int advice);
>>
>> -long compat_sys_sync_file_range2(int fd, unsigned int flags,
>> - unsigned int offset1, unsigned int offset2,
>> - unsigned int nbytes1, unsigned int nbytes2);
>> +asmlinkage long compat_sys_sync_file_range2(int fd, unsigned int flags,
>> + unsigned int offset1,
>> + unsigned int offset2,
>> + unsigned int nbytes1,
>> + unsigned int nbytes2);
>> #endif
>>
>> #endif /* __KERNEL__ */
>> diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
>> index 7748c278d13c..2343c577b971 100644
>> --- a/arch/powerpc/kernel/entry_32.S
>> +++ b/arch/powerpc/kernel/entry_32.S
>> @@ -121,9 +121,9 @@ transfer_to_syscall:
>> SAVE_NVGPRS(r1)
>> kuep_lock
>>
>> - /* Calling convention has r9 = orig r0, r10 = regs */
>> - addi r10,r1,STACK_FRAME_OVERHEAD
>> - mr r9,r0
>> + /* Calling convention has r3 = orig r0, r4 = regs */
>> + addi r4,r1,STACK_FRAME_OVERHEAD
>> + mr r3,r0
>> bl system_call_exception
>>
>> ret_from_syscall:
>> diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
>> index 784ea3289c84..a38329ede1a1 100644
>> --- a/arch/powerpc/kernel/interrupt.c
>> +++ b/arch/powerpc/kernel/interrupt.c
>> @@ -24,7 +24,11 @@
>> unsigned long global_dbcr0[NR_CPUS];
>> #endif
>>
>> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
>> +typedef long (*syscall_fn)(struct pt_regs *);
>> +#else
>> typedef long (*syscall_fn)(long, long, long, long, long, long);
>> +#endif
>>
>> #ifdef CONFIG_PPC_BOOK3S_64
>> DEFINE_STATIC_KEY_FALSE(interrupt_exit_not_reentrant);
>> @@ -74,15 +78,13 @@ static notrace __always_inline bool prep_irq_for_enabled_exit(bool restartable)
>> }
>>
>> /* Has to run notrace because it is entered not completely "reconciled" */
>> -notrace long system_call_exception(long r3, long r4, long r5,
>> - long r6, long r7, long r8,
>> - unsigned long r0, struct pt_regs *regs)
>> +notrace long system_call_exception(unsigned long r0, struct pt_regs *regs)
>> {
>> syscall_fn f;
>>
>> kuap_lock();
>>
>> - regs->orig_gpr3 = r3;
>> + regs->orig_gpr3 = regs->gpr[3];
>>
>> if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
>> BUG_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED);
>> @@ -196,12 +198,6 @@ notrace long system_call_exception(long r3, long r4, long r5,
>> r0 = do_syscall_trace_enter(regs);
>> if (unlikely(r0 >= NR_syscalls))
>> return regs->gpr[3];
>> - r3 = regs->gpr[3];
>> - r4 = regs->gpr[4];
>> - r5 = regs->gpr[5];
>> - r6 = regs->gpr[6];
>> - r7 = regs->gpr[7];
>> - r8 = regs->gpr[8];
>>
>> } else if (unlikely(r0 >= NR_syscalls)) {
>> if (unlikely(trap_is_unsupported_scv(regs))) {
>> @@ -218,18 +214,23 @@ notrace long system_call_exception(long r3, long r4, long r5,
>> if (unlikely(is_compat_task())) {
>> f = (void *)compat_sys_call_table[r0];
>>
>> - r3 &= 0x00000000ffffffffULL;
>> - r4 &= 0x00000000ffffffffULL;
>> - r5 &= 0x00000000ffffffffULL;
>> - r6 &= 0x00000000ffffffffULL;
>> - r7 &= 0x00000000ffffffffULL;
>> - r8 &= 0x00000000ffffffffULL;
>> + regs->gpr[3] &= 0x00000000ffffffffULL;
>> + regs->gpr[4] &= 0x00000000ffffffffULL;
>> + regs->gpr[5] &= 0x00000000ffffffffULL;
>> + regs->gpr[6] &= 0x00000000ffffffffULL;
>> + regs->gpr[7] &= 0x00000000ffffffffULL;
>> + regs->gpr[8] &= 0x00000000ffffffffULL;
>>
>> } else {
>> f = (void *)sys_call_table[r0];
>> }
>>
>> - return f(r3, r4, r5, r6, r7, r8);
>> + #ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
>> + return f(regs);
>> + #else
>> + return f(regs->gpr[3], regs->gpr[4], regs->gpr[5],
>> + regs->gpr[6], regs->gpr[7], regs->gpr[8]);
>> + #endif
>> }
>>
>> static notrace void booke_load_dbcr0(void)
>> diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
>> index 7bab2d7de372..b11c2bd84827 100644
>> --- a/arch/powerpc/kernel/interrupt_64.S
>> +++ b/arch/powerpc/kernel/interrupt_64.S
>> @@ -91,9 +91,9 @@ _ASM_NOKPROBE_SYMBOL(system_call_vectored_\name)
>> li r11,\trapnr
>> std r11,_TRAP(r1)
>> std r12,_CCR(r1)
>> - addi r10,r1,STACK_FRAME_OVERHEAD
>> + addi r4,r1,STACK_FRAME_OVERHEAD
>> ld r11,exception_marker@toc(r2)
>> - std r11,-16(r10) /* "regshere" marker */
>> + std r11,-16(r4) /* "regshere" marker */
>>
>> BEGIN_FTR_SECTION
>> HMT_MEDIUM
>> @@ -108,8 +108,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
>> * but this is the best we can do.
>> */
>>
>> - /* Calling convention has r9 = orig r0, r10 = regs */
>> - mr r9,r0
>> + /* Calling convention has r3 = orig r0, r4 = regs */
>> + mr r3,r0
>> bl system_call_exception
>>
>> .Lsyscall_vectored_\name\()_exit:
>> @@ -285,9 +285,9 @@ END_BTB_FLUSH_SECTION
>> std r10,_LINK(r1)
>> std r11,_TRAP(r1)
>> std r12,_CCR(r1)
>> - addi r10,r1,STACK_FRAME_OVERHEAD
>> + addi r4,r1,STACK_FRAME_OVERHEAD
>> ld r11,exception_marker@toc(r2)
>> - std r11,-16(r10) /* "regshere" marker */
>> + std r11,-16(r4) /* "regshere" marker */
>>
>> #ifdef CONFIG_PPC_BOOK3S
>> li r11,1
>> @@ -308,8 +308,8 @@ END_BTB_FLUSH_SECTION
>> wrteei 1
>> #endif
>>
>> - /* Calling convention has r9 = orig r0, r10 = regs */
>> - mr r9,r0
>> + /* Calling convention has r3 = orig r0, r4 = regs */
>> + mr r3,r0
>> bl system_call_exception
>>
>> .Lsyscall_exit:
>> @@ -353,16 +353,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
>> cmpdi r3,0
>> bne .Lsyscall_restore_regs
>> /* Zero volatile regs that may contain sensitive kernel data */
>> - li r0,0
>> - li r4,0
>> - li r5,0
>> - li r6,0
>> - li r7,0
>> - li r8,0
>> - li r9,0
>> - li r10,0
>> - li r11,0
>> - li r12,0
>> + ZERO_GPR(0)
>> + ZERO_GPRS(4, 12)
>> mtctr r0
>> mtspr SPRN_XER,r0
>> .Lsyscall_restore_regs_cont:
>> @@ -388,7 +380,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
>> REST_NVGPRS(r1)
>> mtctr r3
>> mtspr SPRN_XER,r4
>> - ld r0,GPR0(r1)
>> + REST_GPR(0, r1)
>> REST_GPRS(4, 12, r1)
>> b .Lsyscall_restore_regs_cont
>> .Lsyscall_rst_end:
>> diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
>> index 16ff0399a257..aa7869dbef36 100644
>> --- a/arch/powerpc/kernel/sys_ppc32.c
>> +++ b/arch/powerpc/kernel/sys_ppc32.c
>> @@ -48,9 +48,10 @@
>> #include <asm/syscalls.h>
>> #include <asm/switch_to.h>
>>
>> -unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
>> - unsigned long prot, unsigned long flags,
>> - unsigned long fd, unsigned long pgoff)
>> +PPC_SYSCALL_DEFINE(6, unsigned long, compat_sys_mmap2,
>> + unsigned long, addr, size_t, len,
>> + unsigned long, prot, unsigned long, flags,
>> + unsigned long, fd, unsigned long, pgoff)
>> {
>> /* This should remain 12 even if PAGE_SIZE changes */
>> return sys_mmap(addr, len, prot, flags, fd, pgoff << 12);
>> @@ -68,52 +69,63 @@ unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
>> #define merge_64(high, low) ((u64)high << 32) | low
>> #endif
>>
>> -compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count,
>> - u32 reg6, u32 pos1, u32 pos2)
>> +PPC_SYSCALL_DEFINE(6, compat_ssize_t, compat_sys_pread64,
>> + unsigned int, fd,
>> + char __user *, ubuf, compat_size_t, count,
>> + u32, reg6, u32, pos1, u32, pos2)
>> {
>> return ksys_pread64(fd, ubuf, count, merge_64(pos1, pos2));
>> }
>>
>> -compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf, compat_size_t count,
>> - u32 reg6, u32 pos1, u32 pos2)
>> +PPC_SYSCALL_DEFINE(6, compat_ssize_t, compat_sys_pwrite64,
>> + unsigned int, fd,
>> + const char __user *, ubuf, compat_size_t, count,
>> + u32, reg6, u32, pos1, u32, pos2)
>> {
>> return ksys_pwrite64(fd, ubuf, count, merge_64(pos1, pos2));
>> }
>>
>> -compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offset1, u32 offset2, u32 count)
>> +PPC_SYSCALL_DEFINE(5, compat_ssize_t, compat_sys_readahead,
>> + int, fd, u32, r4,
>> + u32, offset1, u32, offset2, u32, count)
>> {
>> return ksys_readahead(fd, merge_64(offset1, offset2), count);
>> }
>>
>> -asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
>> - unsigned long len1, unsigned long len2)
>> +PPC_SYSCALL_DEFINE(4, int, compat_sys_truncate64,
>> + const char __user *, path, u32, reg4,
>> + unsigned long, len1, unsigned long, len2)
>> {
>> return ksys_truncate(path, merge_64(len1, len2));
>> }
>>
>> -asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offset1, u32 offset2,
>> - u32 len1, u32 len2)
>> +PPC_SYSCALL_DEFINE(6, long, compat_sys_fallocate,
>> + int, fd, int, mode, u32, offset1, u32, offset2,
>> + u32, len1, u32, len2)
>> {
>> return ksys_fallocate(fd, mode, ((loff_t)offset1 << 32) | offset2,
>> merge_64(len1, len2));
>> }
>>
>> -asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long len1,
>> - unsigned long len2)
>> +PPC_SYSCALL_DEFINE(4, int, compat_sys_ftruncate64,
>> + unsigned int, fd, u32, reg4, unsigned long, len1,
>> + unsigned long, len2)
>> {
>> return ksys_ftruncate(fd, merge_64(len1, len2));
>> }
>>
>> -long ppc32_fadvise64(int fd, u32 unused, u32 offset1, u32 offset2,
>> - size_t len, int advice)
>> +PPC_SYSCALL_DEFINE(6, long, ppc32_fadvise64,
>> + int, fd, u32, unused, u32, offset1, u32, offset2,
>> + size_t, len, int, advice)
>> {
>> return ksys_fadvise64_64(fd, merge_64(offset1, offset2), len,
>> advice);
>> }
>>
>> -asmlinkage long compat_sys_sync_file_range2(int fd, unsigned int flags,
>> - unsigned offset1, unsigned offset2,
>> - unsigned nbytes1, unsigned nbytes2)
>> +PPC_SYSCALL_DEFINE(6, long, compat_sys_sync_file_range2, int, fd,
>> + unsigned int, flags,
>> + unsigned int, offset1, unsigned int, offset2,
>> + unsigned int, nbytes1, unsigned int, nbytes2)
>> {
>> loff_t offset = merge_64(offset1, offset2);
>> loff_t nbytes = merge_64(nbytes1, nbytes2);
>> diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
>> index c4f5b4ce926f..c64cdb5c4435 100644
>> --- a/arch/powerpc/kernel/syscalls.c
>> +++ b/arch/powerpc/kernel/syscalls.c
>> @@ -64,14 +64,20 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
>> }
>>
>> #ifdef CONFIG_PPC32
>> +asmlinkage long sys_old_select(struct sel_arg_struct __user *arg);
>> +asmlinkage long sys_select(int n, fd_set __user *inp, fd_set __user *outp,
>> + fd_set __user *exp,
>> + struct __kernel_old_timeval __user *tvp);
>> +
>> /*
>> * Due to some executables calling the wrong select we sometimes
>> * get wrong args. This determines how the args are being passed
>> * (a single ptr to them all args passed) then calls
>> * sys_select() with the appropriate args. -- Cort
>> */
>> -int
>> -ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct __kernel_old_timeval __user *tvp)
>> +PPC_SYSCALL_DEFINE(5, long, ppc_select,
>> + int, n, fd_set __user *, inp, fd_set __user *, outp,
>> + fd_set __user *, exp, struct __kernel_old_timeval __user *, tvp)
>> {
>> if ( (unsigned long)n >= 4096 )
>> return sys_old_select((void __user *)n);
>> @@ -81,7 +87,9 @@ ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, s
>> #endif
>>
>> #ifdef CONFIG_PPC64
>> -long ppc64_personality(unsigned long personality)
>> +asmlinkage long sys_personality(unsigned int personality);
>> +
>> +PPC_SYSCALL_DEFINE(1, long, ppc64_personality, unsigned long, personality)
>> {
>> long ret;
>>
>> @@ -95,8 +103,9 @@ long ppc64_personality(unsigned long personality)
>> }
>> #endif
>>
>> -long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
>> - u32 len_high, u32 len_low)
>> +PPC_SYSCALL_DEFINE(6, long, ppc_fadvise64_64,
>> + int, fd, int, advice, u32, offset_high, u32, offset_low,
>> + u32, len_high, u32, len_low)
>> {
>> return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low,
>> (u64)len_high << 32 | len_low, advice);
>> diff --git a/arch/powerpc/kernel/systbl.S b/arch/powerpc/kernel/systbl.S
>> index cb3358886203..70cc7120fce2 100644
>> --- a/arch/powerpc/kernel/systbl.S
>> +++ b/arch/powerpc/kernel/systbl.S
>> @@ -16,11 +16,32 @@
>>
>> #ifdef CONFIG_PPC64
>> .p2align 3
>> +#endif
>> +
>> +/* Where the syscall wrapper macro is used, handler functions expect parameters
>> + to reside on the stack. We still emit symbols with register-mapped
>> + parameters, which are distinguished by a prefix. */
>> +
>> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
>> +
>> +#define __powerpc_sys_ni_syscall sys_ni_syscall
>> +
>> +#ifdef CONFIG_PPC64
>> +#define __SYSCALL(nr, entry) .8byte __powerpc_##entry
>> +#else
>> +#define __SYSCALL(nr, entry) .long __powerpc_##entry
>> +#endif
>> +
>> +#else
>> +
>> +#ifdef CONFIG_PPC64
>> #define __SYSCALL(nr, entry) .8byte entry
>> #else
>> #define __SYSCALL(nr, entry) .long entry
>> #endif
>>
>> +#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
>> +
>> #define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
>> .globl sys_call_table
>> sys_call_table:
>> diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
>> index 717f2c9a7573..dcf57c07dbad 100644
>> --- a/arch/powerpc/kernel/vdso.c
>> +++ b/arch/powerpc/kernel/vdso.c
>> @@ -40,6 +40,8 @@
>> extern char vdso32_start, vdso32_end;
>> extern char vdso64_start, vdso64_end;
>>
>> +asmlinkage long sys_ni_syscall(void);
>> +
>> /*
>> * The vdso data page (aka. systemcfg for old ppc64 fans) is here.
>> * Once the early boot kernel code no longer needs to muck around
>> --
>> 2.34.1
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-03 3:24 ` Rohan McLure
@ 2022-06-03 7:09 ` Andrew Donnellan
2022-06-03 8:39 ` Christophe Leroy
0 siblings, 1 reply; 31+ messages in thread
From: Andrew Donnellan @ 2022-06-03 7:09 UTC (permalink / raw)
To: Rohan McLure, linuxppc-dev; +Cc: npiggin@gmail.com
On Fri, 2022-06-03 at 13:24 +1000, Rohan McLure wrote:
> The implementation of ppc_personality can be immediately reworked to
> call ksys_personality, but I can’t do the same for sys_old_select for
> example, which is required to implement ppc_select. As such we emit
> both
For ppc_select, I suggest we resurrect
https://lore.kernel.org/lkml/5811950d-ef14-d416-35e6-d694ef920a7d@csgroup.eu/T/#u
and just get rid of the hack.
Andrew
--
Andrew Donnellan OzLabs, ADL Canberra
ajd@linux.ibm.com IBM Australia Limited
^ permalink raw reply [flat|nested] 31+ messages in thread
* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-03 7:09 ` Andrew Donnellan
@ 2022-06-03 8:39 ` Christophe Leroy
2022-06-14 13:57 ` Andrew Donnellan
0 siblings, 1 reply; 31+ messages in thread
From: Christophe Leroy @ 2022-06-03 8:39 UTC (permalink / raw)
To: Andrew Donnellan, Rohan McLure, linuxppc-dev@lists.ozlabs.org
Cc: npiggin@gmail.com
Le 03/06/2022 à 09:09, Andrew Donnellan a écrit :
> On Fri, 2022-06-03 at 13:24 +1000, Rohan McLure wrote:
>> The implementation of ppc_personality can be immediately reworked to
>> call ksys_personality, but I can’t do the same for sys_old_select for
>> example, which is required to implement ppc_select. As such we emit
>> both
>
> For ppc_select, I suggest we resurrect
> https://lore.kernel.org/lkml/5811950d-ef14-d416-35e6-d694ef920a7d@csgroup.eu/T/#u
> and just get rid of the hack.
>
Not sure I understand, what would you like to resurrect ? You want to
resurrect the discussion, or revert commit fd69d544b0e7
("powerpc/syscalls: Use sys_old_select() in ppc_select()") ?
We are talking about a 25 years old ack ....
However calling sys_old_select() from ppc_select() is just a tail call
so I can't see why it would require duplicating the pt_regs.
c0004ddc <ppc_select>:
c0004ddc: 28 03 0f ff cmplwi r3,4095
c0004de0: 41 81 00 08 bgt c0004de8 <ppc_select+0xc>
c0004de4: 48 15 b9 98 b c016077c <__se_sys_select>
c0004de8: 48 15 bc c0 b c0160aa8 <__se_sys_old_select>
Christophe
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-03 8:39 ` Christophe Leroy
@ 2022-06-14 13:57 ` Andrew Donnellan
0 siblings, 0 replies; 31+ messages in thread
From: Andrew Donnellan @ 2022-06-14 13:57 UTC (permalink / raw)
To: Christophe Leroy, Rohan McLure, linuxppc-dev@lists.ozlabs.org
Cc: npiggin@gmail.com
On Fri, 2022-06-03 at 08:39 +0000, Christophe Leroy wrote:
>
>
> Le 03/06/2022 à 09:09, Andrew Donnellan a écrit :
> > On Fri, 2022-06-03 at 13:24 +1000, Rohan McLure wrote:
> > > The implementation of ppc_personality can be immediately reworked
> > > to
> > > call ksys_personality, but I can’t do the same for sys_old_select
> > > for
> > > example, which is required to implement ppc_select. As such we
> > > emit
> > > both
> >
> > For ppc_select, I suggest we resurrect
> >
> > https://lore.kernel.org/lkml/5811950d-ef14-d416-35e6-d694ef920a7d@csgroup.eu/T/#u
> > and just get rid of the hack.
> >
>
> Not sure I understand, what would you like to resurrect ? You want to
> resurrect the discussion, or revert commit fd69d544b0e7
> ("powerpc/syscalls: Use sys_old_select() in ppc_select()") ?
We should get rid of ppc_select(), if we can. If Arnd's history is
correct, there's little reason to keep it around and we should just get
rid of it.
--
Andrew Donnellan OzLabs, ADL Canberra
ajd@linux.ibm.com IBM Australia Limited
^ permalink raw reply [flat|nested] 31+ messages in thread
* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-01 5:48 ` [PATCH 2/6] powerpc: Provide syscall wrapper Rohan McLure
` (4 preceding siblings ...)
2022-06-01 14:33 ` Christophe Leroy
@ 2022-06-03 9:04 ` Arnd Bergmann
2022-06-15 1:47 ` Rohan McLure
5 siblings, 1 reply; 31+ messages in thread
From: Arnd Bergmann @ 2022-06-03 9:04 UTC (permalink / raw)
To: Rohan McLure; +Cc: linuxppc-dev, Andrew Donnellan, Nicholas Piggin
On Wed, Jun 1, 2022 at 7:48 AM Rohan McLure <rmclure@linux.ibm.com> wrote:
>
> Syscall wrapper implemented as per s390, x86, arm64, providing the
> option for gprs to be cleared on entry to the kernel, reducing caller
> influence influence on speculation within syscall routine. The wrapper
> is a macro that emits syscall handler implementations with parameters
> passed by stack pointer.
>
> For platforms supporting this syscall wrapper, emit symbols with usual
> in-register parameters (`sys...`) to support calls to syscall handlers
> from within the kernel.
Nice work!
> Syscalls are wrapped on all platforms except Cell processor. SPUs require
> access syscall prototypes which are omitted with ARCH_HAS_SYSCALL_WRAPPER
> enabled.
Right, I think it's ok to leave out the SPU side. In the long run, I
would like to
go back to requiring the prototypes for everything on all architectures, to
enforce type checking, but that's a separate piece of work.
> +/*
> + * For PowerPC specific syscall implementations, wrapper takes exact name and
> + * return type for a given function.
> + */
> +
> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
> +#define PPC_SYSCALL_DEFINE(x, type, name, ...) \
> + asmlinkage type __powerpc_##name(const struct pt_regs *regs); \
> + ALLOW_ERROR_INJECTION(__powerpc_##name, ERRNO); \
> + type sys_##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
> + static type __se_##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
> + static inline type __do_##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
What is the benefit of having a separate set of macros for this? I think that
adds more complexity than it saves in the end.
> @@ -68,52 +69,63 @@ unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
> #define merge_64(high, low) ((u64)high << 32) | low
> #endif
>
> -compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count,
> - u32 reg6, u32 pos1, u32 pos2)
> +PPC_SYSCALL_DEFINE(6, compat_ssize_t, compat_sys_pread64,
> + unsigned int, fd,
> + char __user *, ubuf, compat_size_t, count,
> + u32, reg6, u32, pos1, u32, pos2)
> {
> return ksys_pread64(fd, ubuf, count, merge_64(pos1, pos2));
> }
We now have generalized versions of most of these system calls, as of 5.19-rc1
with the addition of the riscv compat support. I think it would be
best to try removing
the powerpc private versions wherever possible and use the common version,
modifying it further where necessary.
If this doesn't work for some of the syscalls, can you use the
COMPAT_SYSCALL_DEFINE for those in place of PPC_SYSCALL_DEFINE?
Arnd
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-03 9:04 ` Arnd Bergmann
@ 2022-06-15 1:47 ` Rohan McLure
2022-06-15 10:13 ` Arnd Bergmann
0 siblings, 1 reply; 31+ messages in thread
From: Rohan McLure @ 2022-06-15 1:47 UTC (permalink / raw)
To: Arnd Bergmann; +Cc: linuxppc-dev, Andrew Donnellan, Nicholas Piggin
> On 3 Jun 2022, at 7:04 pm, Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Wed, Jun 1, 2022 at 7:48 AM Rohan McLure <rmclure@linux.ibm.com> wrote:
>>
>> Syscall wrapper implemented as per s390, x86, arm64, providing the
>> option for gprs to be cleared on entry to the kernel, reducing caller
>> influence influence on speculation within syscall routine. The wrapper
>> is a macro that emits syscall handler implementations with parameters
>> passed by stack pointer.
>>
>> For platforms supporting this syscall wrapper, emit symbols with usual
>> in-register parameters (`sys...`) to support calls to syscall handlers
>> from within the kernel.
>
> Nice work!
>
>> Syscalls are wrapped on all platforms except Cell processor. SPUs require
>> access syscall prototypes which are omitted with ARCH_HAS_SYSCALL_WRAPPER
>> enabled.
>
> Right, I think it's ok to leave out the SPU side. In the long run, I
> would like to
> go back to requiring the prototypes for everything on all architectures, to
> enforce type checking, but that's a separate piece of work.
>
>> +/*
>> + * For PowerPC specific syscall implementations, wrapper takes exact name and
>> + * return type for a given function.
>> + */
>> +
>> +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
>> +#define PPC_SYSCALL_DEFINE(x, type, name, ...) \
>> + asmlinkage type __powerpc_##name(const struct pt_regs *regs); \
>> + ALLOW_ERROR_INJECTION(__powerpc_##name, ERRNO); \
>> + type sys_##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
>> + static type __se_##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
>> + static inline type __do_##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
>
> What is the benefit of having a separate set of macros for this? I think that
> adds more complexity than it saves in the end.
>
>> @@ -68,52 +69,63 @@ unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
>> #define merge_64(high, low) ((u64)high << 32) | low
>> #endif
>>
>> -compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count,
>> - u32 reg6, u32 pos1, u32 pos2)
>> +PPC_SYSCALL_DEFINE(6, compat_ssize_t, compat_sys_pread64,
>> + unsigned int, fd,
>> + char __user *, ubuf, compat_size_t, count,
>> + u32, reg6, u32, pos1, u32, pos2)
>> {
>> return ksys_pread64(fd, ubuf, count, merge_64(pos1, pos2));
>> }
>
> We now have generalized versions of most of these system calls, as of 5.19-rc1
> with the addition of the riscv compat support. I think it would be
> best to try removing
> the powerpc private versions wherever possible and use the common version,
> modifying it further where necessary.
>
> If this doesn't work for some of the syscalls, can you use the
> COMPAT_SYSCALL_DEFINE for those in place of PPC_SYSCALL_DEFINE?
>
> Arnd
Hi Arnd,
Thanks for your comments.
> What is the benefit of having a separate set of macros for this? I think that
> adds more complexity than it saves in the end.
I was unsure whether the exact return types needed to be respected for syscall
handlers or not. I realise that under the existing behaviour,
system_call_exception performs an indirect call, the return type of which is
interpreted as a long, so the return type should be irrelevant. On inspection
PPC_SYSCALL_DEFINE is readily replacable with COMPAT_SYSCALL_DEFINE as you
have suggested.
Before resubmitting this series, I will try for a patch series which modernises
syscall handlers in arch/powerpc, and inspect where powerpc private versions
are strictly necessary, using __ARCH_WANT_... wherever possible.
Rohan
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCH 2/6] powerpc: Provide syscall wrapper
2022-06-15 1:47 ` Rohan McLure
@ 2022-06-15 10:13 ` Arnd Bergmann
0 siblings, 0 replies; 31+ messages in thread
From: Arnd Bergmann @ 2022-06-15 10:13 UTC (permalink / raw)
To: Rohan McLure
Cc: linuxppc-dev, Andrew Donnellan, Arnd Bergmann, Nicholas Piggin
On Wed, Jun 15, 2022 at 3:47 AM Rohan McLure <rmclure@linux.ibm.com> wrote:
> > On 3 Jun 2022, at 7:04 pm, Arnd Bergmann <arnd@arndb.de> wrote:
> > On Wed, Jun 1, 2022 at 7:48 AM Rohan McLure <rmclure@linux.ibm.com> wrote:
> > What is the benefit of having a separate set of macros for this? I think that
> > adds more complexity than it saves in the end.
>
> I was unsure whether the exact return types needed to be respected for syscall
> handlers or not. I realise that under the existing behaviour,
> system_call_exception performs an indirect call, the return type of which is
> interpreted as a long, so the return type should be irrelevant. On inspection
> PPC_SYSCALL_DEFINE is readily replacable with COMPAT_SYSCALL_DEFINE as you
> have suggested.
>
> Before resubmitting this series, I will try for a patch series which modernises
> syscall handlers in arch/powerpc, and inspect where powerpc private versions
> are strictly necessary, using __ARCH_WANT_... wherever possible.
Ok, great! The parameter ordering is a bit tricky for some of them. I think
in most cases the version used by risc-v now should be the same as what
you need for powerpc (with the appropriate compat_arg_u64_dual()).
If some don't work, I would suggest modifying the common code so it can
handle both riscv and powerpc instead of keeping a private copy.
Arnd
^ permalink raw reply [flat|nested] 31+ messages in thread