linux-stable/arch/powerpc/include/asm/signal.h
Nicholas Piggin 2896b2dff4 powerpc/signal: Report minimum signal frame size to userspace via AT_MINSIGSTKSZ
Implement the AT_MINSIGSTKSZ AUXV entry, allowing userspace to
dynamically size stack allocations in a manner forward-compatible with
new processor state saved in the signal frame

For now these statically find the maximum signal frame size rather than
doing any runtime testing of features to minimise the size.

glibc 2.34 will take advantage of this, as will applications that use
use _SC_MINSIGSTKSZ and _SC_SIGSTKSZ.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
References: 94b07c1f8c ("arm64: signal: Report signal frame size to userspace via auxv")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220307182734.289289-2-npiggin@gmail.com
2022-05-19 23:11:26 +10:00

17 lines
506 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_SIGNAL_H
#define _ASM_POWERPC_SIGNAL_H
#define __ARCH_HAS_SA_RESTORER
#include <uapi/asm/signal.h>
#include <uapi/asm/ptrace.h>
struct pt_regs;
void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags);
unsigned long get_min_sigframe_size_32(void);
unsigned long get_min_sigframe_size_64(void);
unsigned long get_min_sigframe_size(void);
unsigned long get_min_sigframe_size_compat(void);
#endif /* _ASM_POWERPC_SIGNAL_H */