riscv: signal: fix signal_minsigstksz

BugLink: https://bugs.launchpad.net/bugs/2106703

commit 564fc8e upstream.

The init_rt_signal_env() funciton is called before the alternative patch
is applied, so using the alternative-related API to check the availability
of an extension within this function doesn't have the intended effect.
This patch reorders the init_rt_signal_env() and apply_boot_alternatives()
to get the correct signal_minsigstksz.

Fixes: e92f469 ("riscv: signal: Report signal frame size to userspace via auxv")
Signed-off-by: Yong-Xuan Wang <[email protected]>
Reviewed-by: Zong Li <[email protected]>
Reviewed-by: Andy Chiu <[email protected]>
Reviewed-by: Alexandre Ghiti <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Noah Wager <[email protected]>
Signed-off-by: Mehmet Basaran <[email protected]>

Author: yong-xuan

arch/riscv/kernel/setup.c

@@ -288,8 +288,8 @@ void __init setup_arch(char **cmdline_p)
 
 	riscv_init_cbo_blocksizes();
 	riscv_fill_hwcap();
-	init_rt_signal_env();
 	apply_boot_alternatives();
+	init_rt_signal_env();
 
 	if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) &&
 	    riscv_isa_extension_available(NULL, ZICBOM))