From c3b3f52476412a3899f2c65b220075aceb18dd2c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 5 May 2020 12:12:53 +0200 Subject: signal: refactor copy_siginfo_to_user32 Factor out a copy_siginfo_to_external32 helper from copy_siginfo_to_user32 that fills out the compat_siginfo, but does so on a kernel space data structure. With that we can let architectures override copy_siginfo_to_user32 with their own implementations using copy_siginfo_to_external32. That allows moving the x32 SIGCHLD purely to x86 architecture code. As a nice side effect copy_siginfo_to_external32 also comes in handy for avoiding a set_fs() call in the coredump code later on. Contains improvements from Eric W. Biederman and Arnd Bergmann . Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- arch/x86/kernel/signal.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) (limited to 'arch/x86/kernel/signal.c') diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 83b74fb38c8f..f3df262e370b 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -37,6 +37,7 @@ #include #ifdef CONFIG_X86_64 +#include #include #include #endif /* CONFIG_X86_64 */ @@ -511,6 +512,31 @@ Efault: } #endif /* CONFIG_X86_32 */ +#ifdef CONFIG_X86_X32_ABI +static int x32_copy_siginfo_to_user(struct compat_siginfo __user *to, + const struct kernel_siginfo *from) +{ + struct compat_siginfo new; + + copy_siginfo_to_external32(&new, from); + if (from->si_signo == SIGCHLD) { + new._sifields._sigchld_x32._utime = from->si_utime; + new._sifields._sigchld_x32._stime = from->si_stime; + } + if (copy_to_user(to, &new, sizeof(struct compat_siginfo))) + return -EFAULT; + return 0; +} + +int copy_siginfo_to_user32(struct compat_siginfo __user *to, + const struct kernel_siginfo *from) +{ + if (in_x32_syscall()) + return x32_copy_siginfo_to_user(to, from); + return __copy_siginfo_to_user32(to, from); +} +#endif /* CONFIG_X86_X32_ABI */ + static int x32_setup_rt_frame(struct ksignal *ksig, compat_sigset_t *set, struct pt_regs *regs) @@ -543,7 +569,7 @@ static int x32_setup_rt_frame(struct ksignal *ksig, user_access_end(); if (ksig->ka.sa.sa_flags & SA_SIGINFO) { - if (__copy_siginfo_to_user32(&frame->info, &ksig->info, true)) + if (x32_copy_siginfo_to_user(&frame->info, &ksig->info)) return -EFAULT; } -- cgit v1.2.3