From: Thomas Weißschuh <[email protected]> The kernel does not require PROT_READ for addresses passed to mincore. For example the fincore(1) tool from util-linux uses PROT_NONE and currently does not work under qemu-user.
Example (with fincore(1) from util-linux 2.38): $ fincore /proc/self/exe RES PAGES SIZE FILE 24K 6 22.1K /proc/self/exe $ qemu-x86_64 /usr/bin/fincore /proc/self/exe fincore: failed to do mincore: /proc/self/exe: Cannot allocate memory With this patch: $ ./build/qemu-x86_64 /usr/bin/fincore /proc/self/exe RES PAGES SIZE FILE 24K 6 22.1K /proc/self/exe Signed-off-by: Thomas Weißschuh <[email protected]> Reviewed-by: Laurent Vivier <[email protected]> Message-Id: <[email protected]> Signed-off-by: Laurent Vivier <[email protected]> --- linux-user/syscall.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 95da74ab1234..7170332041ca 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -11981,7 +11981,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1, #ifdef TARGET_NR_mincore case TARGET_NR_mincore: { - void *a = lock_user(VERIFY_READ, arg1, arg2, 0); + void *a = lock_user(VERIFY_NONE, arg1, arg2, 0); if (!a) { return -TARGET_ENOMEM; } -- 2.40.1
