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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-08-07 13:11:22 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-08-07 13:11:22 +0000 |
| commit | b20732900e4636a467c0183a47f7396700f5f743 (patch) | |
| tree | 42f079ff82e701ebcb76829974b4caca3e5b6798 /arch/riscv/kernel/traps.c | |
| parent | Adding upstream version 6.8.12. (diff) | |
| download | linux-b20732900e4636a467c0183a47f7396700f5f743.tar.xz linux-b20732900e4636a467c0183a47f7396700f5f743.zip | |
Adding upstream version 6.9.7.upstream/6.9.7
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/riscv/kernel/traps.c')
| -rw-r--r-- | arch/riscv/kernel/traps.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 142f5f5168..05a16b1f0a 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -6,6 +6,7 @@ #include <linux/cpu.h> #include <linux/kernel.h> #include <linux/init.h> +#include <linux/randomize_kstack.h> #include <linux/sched.h> #include <linux/sched/debug.h> #include <linux/sched/signal.h> @@ -310,7 +311,8 @@ asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs) } } -asmlinkage __visible __trap_section void do_trap_ecall_u(struct pt_regs *regs) +asmlinkage __visible __trap_section __no_stack_protector +void do_trap_ecall_u(struct pt_regs *regs) { if (user_mode(regs)) { long syscall = regs->a7; @@ -322,10 +324,23 @@ asmlinkage __visible __trap_section void do_trap_ecall_u(struct pt_regs *regs) syscall = syscall_enter_from_user_mode(regs, syscall); + add_random_kstack_offset(); + if (syscall >= 0 && syscall < NR_syscalls) syscall_handler(regs, syscall); else if (syscall != -1) regs->a0 = -ENOSYS; + /* + * Ultimately, this value will get limited by KSTACK_OFFSET_MAX(), + * so the maximum stack offset is 1k bytes (10 bits). + * + * The actual entropy will be further reduced by the compiler when + * applying stack alignment constraints: 16-byte (i.e. 4-bit) aligned + * for RV32I or RV64I. + * + * The resulting 6 bits of entropy is seen in SP[9:4]. + */ + choose_random_kstack_offset(get_random_u16()); syscall_exit_to_user_mode(regs); } else { |