From ebc26c8259160193dde5b0baecf7230c8388fd29 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Sat, 20 Sep 2025 21:32:01 -0400 Subject: kern: proc: Add address checking routine Add routine to check if an address is valid within a process's address space. More work will need to be done with this but this introduces a great starting point Signed-off-by: Ian Moffett --- src/sys/include/sys/proc.h | 13 +++++++++++++ src/sys/os/os_proc.c | 23 +++++++++++++++++++++++ 2 files changed, 36 insertions(+) (limited to 'src/sys') diff --git a/src/sys/include/sys/proc.h b/src/sys/include/sys/proc.h index 2ff2876..6a356ef 100644 --- a/src/sys/include/sys/proc.h +++ b/src/sys/include/sys/proc.h @@ -146,6 +146,19 @@ int md_proc_kill(struct proc *procp, int flags); */ int md_set_ip(struct proc *procp, uintptr_t ip); +/* + * Check that a virtual address is within the bounds of + * a process. + * + * @proc: Process the address should be within + * @addr: Virtual address to check + * @len: Length of memory referenced by 'addr' + * + * Returns zero if the address is within the process bounds, + * otherwise a less than zero value on failure. + */ +int proc_check_addr(struct proc *proc, uintptr_t addr, size_t len); + /* * Put the current process into a halt loop * until the next one runs. diff --git a/src/sys/os/os_proc.c b/src/sys/os/os_proc.c index 3a42496..f21fc69 100644 --- a/src/sys/os/os_proc.c +++ b/src/sys/os/os_proc.c @@ -139,3 +139,26 @@ proc_kill(struct proc *procp, int status) proc_clear_ranges(procp); return md_proc_kill(procp, 0); } + + +/* + * Check that an address is within the bounds of a + * process. + */ +int +proc_check_addr(struct proc *proc, uintptr_t addr, size_t len) +{ + uintptr_t stack_base; + uintptr_t stack_end; + + /* Within the bounds of the stack? */ + stack_base = STACK_TOP - STACK_LEN; + if (addr >= stack_base && addr <= STACK_TOP) { + return 0; + } + if ((stack_base + len) < stack_end) { + return 0; + } + + return -EFAULT; +} -- cgit v1.2.3