| Message ID | 20230422100314.1650-3-thomas@t-8ch.de |
|---|---|
| State | New |
| Headers | show |
| Series | linux-user: Fix mincore() with PROT_NONE | expand |
Le 22/04/2023 à 12:03, Thomas Weißschuh a écrit : > 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 <thomas@t-8ch.de> > --- > 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 69f740ff98c8..5ec848b459f7 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -11897,7 +11897,7 @@ 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; > } Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Le 22/04/2023 à 12:03, Thomas Weißschuh a écrit : > 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 <thomas@t-8ch.de> > --- > 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 69f740ff98c8..5ec848b459f7 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -11897,7 +11897,7 @@ 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; > } Applied to my linux-user-for-8.1 branch. Thanks, Laurent
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 69f740ff98c8..5ec848b459f7 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -11897,7 +11897,7 @@ 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; }
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 <thomas@t-8ch.de> --- linux-user/syscall.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)